Medullary Pyramids: These are two white matter tracts on the ventral side of the medulla that carry motor fibers from the cerebral cortex to the spinal cord.
Arcuate Nucleus: Located in the medulla, these nuclei are involved in motor control and receive input from the cerebral cortex.
Olivary Body:
A pair of prominent oval structures involved in motor learning and coordination.
Inferior Olivary Nucleus: This nucleus plays a crucial role in motor learning by sending signals to the cerebellum.
Rostral Ventrolateral Medulla: This area helps regulate blood pressure by controlling sympathetic nervous system activity.
Caudal Ventrolateral Medulla: It is involved in cardiovascular regulation and influences blood pressure and heart rate.
Solitary Nucleus (Nucleus of the Solitary Tract): This nucleus processes sensory information from the internal organs and taste.
Respiratory Center-Respiratory Groups:
These groups control the rhythm of breathing.
Dorsal Respiratory Group: Located in the medulla, it primarily controls the inspiratory muscles.
Ventral Respiratory Group (Apneustic Centre):
Controls both inspiratory and expiratory muscles.
Pre-Bötzinger Complex: Critical for generating the rhythm of breathing.
Botzinger Complex: Contributes to the regulation of the breathing rhythm and expiration.
Retrotrapezoid Nucleus: Contains chemoreceptors that respond to changes in blood CO2 levels.
Nucleus Retrofacialis: Influences respiratory rhythms and responses to hypoxia.
Nucleus Retroambiguus: Involved in coordinating respiratory and laryngeal activities.
Nucleus Para-Ambiguus: Modulates respiratory activity and vocalization.
Paramedian Reticular Nucleus: Involved in motor coordination and control of eye movements.
Gigantocellular Reticular Nucleus: Plays a role in regulating motor activity and consciousness.
Parafacial Zone: Contributes to the control of respiration and facial motor functions.
Cuneate Nucleus: Processes sensory information from the upper body.
Gracile Nucleus: Processes sensory information from the lower body.
Perihypoglossal Nuclei:
These nuclei are involved in coordinating eye movements.
Intercalated Nucleus: Integrates sensory and motor signals for eye movement coordination.
Prepositus Nucleus: Contributes to the control of eye movements and gaze holding.
Sublingual Nucleus: Involved in tongue movement and coordination.
Area Postrema: A chemoreceptor trigger zone involved in detecting toxins and inducing vomiting.
Medullary Cranial Nerve Nuclei:
These nuclei contain cell bodies of various cranial nerves and are involved in their functions.
Inferior Salivatory Nucleus: Controls salivation through the glossopharyngeal nerve.
Nucleus Ambiguus: Controls muscles involved in swallowing and vocalization.
Dorsal Nucleus of Vagus Nerve: Regulates autonomic functions of the heart, lungs, and digestive tract.
Hypoglossal Nucleus: Controls tongue movements.
Chemoreceptor Trigger Zone: Detects chemical stimuli in the blood and can trigger vomiting.
Pontine Nuclei: These nuclei relay information from the cerebral cortex to the cerebellum, playing a key role in motor control.
Pontine Cranial Nerve Nuclei:
These nuclei contain cell bodies of cranial nerves and are involved in their functions.
Chief or Pontine Nucleus of the Trigeminal Nerve Sensory Nucleus (V): Processes touch and proprioceptive information from the face.
Motor Nucleus for the Trigeminal Nerve (V): Controls muscles involved in mastication (chewing).
Abducens Nucleus (VI): Controls the lateral rectus muscle, which abducts the eye.
Facial Nerve Nucleus (VII): Controls muscles of facial expression and some aspects of taste and salivation.
Vestibulocochlear Nuclei (VIII): These include the vestibular nuclei, which process balance and spatial orientation, and the cochlear nuclei, which process auditory information.
Superior Salivatory Nucleus: Controls lacrimal (tear) and salivary gland secretions.
Pontine Tegmentum:
This region is involved in various functions including motor control, sensory processing, and arousal.
Pontine Micturition Center (Barrington's Nucleus): Controls bladder function.
Locus Coeruleus: A primary site for the synthesis of norepinephrine, involved in arousal and stress responses.
Pedunculopontine Nucleus: Involved in regulating sleep-wake cycles and locomotion.
Laterodorsal Tegmental Nucleus: Plays a role in arousal and the modulation of wakefulness.
Tegmental Pontine Reticular Nucleus: Involved in the modulation of sensory processing and motor control.
Nucleus Incertus: Influences behavioral arousal and stress responses.
Parabrachial Area:
This area processes sensory information and influences autonomic and emotional responses.
Medial Parabrachial Nucleus: Involved in respiratory control and cardiovascular regulation.
Lateral Parabrachial Nucleus: Processes visceral sensory information.
Subparabrachial Nucleus (Kölliker-Fuse Nucleus): Part of the pontine respiratory group, involved in respiratory rhythm modulation.
Superior Olivary Complex:
Involved in the auditory pathway, contributing to sound localization.
Medial Superior Olive: Processes interaural time differences for sound localization.
Lateral Superior Olive: Processes interaural level differences for sound localization.
Medial Nucleus of the Trapezoid Body: Involved in the localization of high-frequency sounds.
Paramedian Pontine Reticular Formation: Controls horizontal eye movements.
Parvocellular Reticular Nucleus: Involved in coordinating motor functions and processing sensory information.
Caudal Pontine Reticular Nucleus: Plays a role in regulating arousal and motor control.
Cerebellar Peduncles:
These are bundles of fibers that connect the cerebellum to the brainstem, facilitating communication between these structures.
Superior Cerebellar Peduncle: Connects the cerebellum to the midbrain and is involved in motor coordination.
Middle Cerebellar Peduncle: Carries information from the pons to the cerebellum, involved in motor control.
Inferior Cerebellar Peduncle: Connects the cerebellum to the medulla and spinal cord, involved in integrating sensory and motor information.
Fourth Ventricle: This is a fluid-filled cavity located between the pons and the cerebellum. It is part of the ventricular system that contains cerebrospinal fluid (CSF), which cushions the brain and spinal cord.
Cerebellar Vermis: The midline structure of the cerebellum that helps coordinate posture and locomotion.
Cerebellar Hemispheres:
These lateral parts of the cerebellum are involved in the coordination of voluntary movements and motor learning.
Anterior Lobe: Involved in the regulation of muscle tone and coordination of skilled voluntary movement.
Posterior Lobe: Plays a significant role in the fine-tuning of movements and motor planning.
Flocculonodular Lobe: Important for balance and eye movements, receiving input from the vestibular system.
Fastigial Nucleus: Involved in the control of balance and eye movements.
Interposed Nucleus:
A combination of the globose and emboliform nuclei, involved in the coordination of limb movements.
Globose Nucleus: Helps in regulating limb movements and fine motor control.
Emboliform Nucleus: Works with the globose nucleus in coordinating the timing of movements.
Dentate Nucleus: The largest cerebellar nucleus, involved in planning and initiating voluntary movements by sending output to the motor and premotor cortices.
Corpora Quadrigemina:
Consists of four colliculi involved in sensory processing.
Inferior Colliculi: Responsible for auditory processing and reflexes.
Superior Colliculi: Involved in visual processing and control of eye movements.
Pretectum: A region that participates in the pupillary light reflex and other visual reflexes.
Periaqueductal Gray: Plays a crucial role in pain modulation and defensive behaviors.
Rostral Interstitial Nucleus of Medial Longitudinal Fasciculus: Involved in coordinating vertical eye movements.
Midbrain Reticular Formation: Contributes to arousal, motor control, and various reflexes.
Dorsal Raphe Nucleus: Produces serotonin and is involved in mood regulation.
Red Nucleus: Aids in motor coordination, especially in the control of limb movements.
Ventral Tegmental Area (VTA):
Contains dopaminergic neurons involved in reward, motivation, and addiction.
Parabrachial Pigmented Nucleus: Contains dopaminergic neurons involved in motor and reward pathways.
Paranigral Nucleus: Contributes to the reward system and motor functions.
Rostromedial Tegmental Nucleus: Modulates the activity of the VTA and reward-related behaviors.
Caudal Linear Nucleus: Involved in motor control and autonomic functions.
Rostral Linear Nucleus of the Raphe: Contributes to serotonergic modulation of various brain functions.
Interfascicular Nucleus: Involved in motor control and sensory processing.
Substantia Nigra:
Divided into two parts, involved in movement control and reward.
Pars Compacta: Contains dopaminergic neurons that project to the striatum, involved in movement control.
Pars Reticulata: Integrates signals from the basal ganglia and modulates motor output.
Interpeduncular Nucleus: Involved in modulating limbic system functions and aversive stimuli processing.
Crus Cerebri: Contains motor tracts that carry signals from the cerebral cortex to the brainstem and spinal cord.
Oculomotor Nucleus (III): Controls most of the eye's movements and the constriction of the pupil.
Edinger-Westphal Nucleus: Provides parasympathetic input to the eye, controlling pupil constriction and lens shape.
Trochlear Nucleus (IV): Controls the superior oblique muscle of the eye, enabling downward and lateral eye movement.
Mesencephalic Duct: A narrow channel that connects the third and fourth ventricles, allowing the flow of cerebrospinal fluid (CSF).
Pineal Body (Pineal Gland): Produces melatonin, a hormone that regulates sleep-wake cycles and circadian rhythms.
Habenular Nuclei: Involved in the regulation of neurotransmitter systems and plays a role in emotional and reward processing.
Stria Medullaris: A fiber tract that connects the habenular nuclei to the limbic system and other brain regions.
Taenia Thalami: A thin band of tissue along the thalamus involved in linking the epithalamus with other parts of the brain.
Subcommissural Organ: A small glandular structure that may play a role in the regulation of the cerebrospinal fluid (CSF) and the development of the central nervous system.
Circumventricular Organs (also Fourth Ventricle): Specialized structures that lack a blood-brain barrier, allowing them to monitor blood chemistry and regulate homeostasis. Examples include the area postrema (involved in vomiting reflex) and the subfornical organ (involved in osmoregulation).
Anterior Nuclear Group:
Involved in memory and emotion.
Anteroventral Nucleus (a.k.a. Ventral Anterior Nucleus): Plays a role in motor control and planning.
Anterodorsal Nucleus: Involved in spatial learning and memory.
Anteromedial Nucleus: Associated with emotional processing and memory.
Medial Nuclear Group:
Plays roles in emotion, cognition, and autonomic functions.
Medial Dorsal Nucleus: Involved in emotional regulation and executive functions.
Midline Nuclear Group: Connects to limbic structures and participates in arousal and autonomic regulation.
Paratenial Nucleus: Involved in limbic system functions and memory.
Reuniens Nucleus: Integrates information between the hippocampus and prefrontal cortex, important for memory.
Rhomboidal Nucleus: Participates in limbic and autonomic functions.
Intralaminar Nuclear Group: Plays a role in arousal and consciousness.
Centromedian Nucleus: Involved in arousal, attention, and integrating sensory and motor information.
Parafascicular Nucleus: Associated with nociception and attention.
Paracentral Nucleus: Participates in sensory and motor integration.
Central Lateral Nucleus: Involved in the regulation of consciousness and pain.
Lateral Nuclear Group:
Involved in sensory processing and cognitive functions.
Lateral Dorsal Nucleus: Plays a role in visual processing and spatial orientation.
Lateral Posterior Nucleus: Associated with sensory integration and higher cognitive functions.
Pulvinar: Involved in visual processing, attention, and integration of sensory information.
Ventral Nuclear Group:
Important for sensory relay and motor function.
Ventral Anterior Nucleus: Modulates motor activity and planning.
Ventral Lateral Nucleus: Involved in the coordination of movement.
Ventral Posterior Nucleus:
Processes somatosensory information.
Ventral Posterior Lateral Nucleus: Relays sensory information from the body.
Ventral Posterior Medial Nucleus: Relays sensory information from the face.
Metathalamus:
Involved in auditory and visual processing.
Medial Geniculate Body: Processes auditory information.
Lateral Geniculate Body: Processes visual information.
Thalamic Reticular Nucleus: Modulates the activity of other thalamic nuclei and plays a role in attention and arousal.
Anterior
Medial Area
Parts of Preoptic Area
Medial Preoptic Nucleus:
Involved in thermoregulation, reproductive behaviors, and sleep.
INAH 1-4 (Interstitial Nuclei of the Anterior Hypothalamus): These are thought to be involved in sexual behavior and regulation of neuroendocrine functions.
Median Preoptic Nucleus: Plays a role in fluid and electrolyte balance.
Suprachiasmatic Nucleus: The master circadian clock, regulating daily rhythms.
Paraventricular Nucleus: Regulates stress response, metabolism, and autonomic functions.
Supraoptic Nucleus: Mainly involved in the production of vasopressin and oxytocin.
Anterior Hypothalamic Nucleus: Involved in thermoregulation and regulating thirst.
Lateral Area
Parts of Preoptic Area
Lateral Preoptic Nucleus: Involved in sleep regulation and wakefulness.
Anterior Part of Lateral Nucleus: Modulates feeding behavior and arousal.
Part of Supraoptic Nucleus: Contributes to the regulation of water balance and vasopressin secretion.
Other Nuclei of Preoptic Area
Median Preoptic Nucleus: As above, involved in fluid and electrolyte balance.
Periventricular Preoptic Nucleus: Involved in the regulation of hormone release and other autonomic functions.
Tuberal
Medial Area
Dorsomedial Hypothalamic Nucleus: Regulates feeding behavior, energy homeostasis, and circadian rhythms.
Ventromedial Nucleus: Known as the "satiety center," it plays a crucial role in inhibiting hunger.
Arcuate Nucleus: Contains neurons that produce neuropeptides influencing hunger and energy balance.
Lateral Area
Tuberal Part of Lateral Nucleus: Involved in the regulation of food intake and energy homeostasis.
Lateral Tuberal Nuclei: Contribute to feeding behavior and metabolic regulation.
Posterior
Medial Area
Mammillary Nuclei (part of Mammillary Bodies): Involved in memory processing and relay information to the thalamus.
Posterior Nucleus: Plays a role in thermoregulation and arousal.
Lateral Area
Posterior Part of Lateral Nucleus: Involved in modulating wakefulness and arousal.
Surface
Median Eminence: A structure involved in the regulation of hormone secretion from the pituitary gland.
Mammillary Bodies: Important for memory formation and recall.
Pituitary Stalk (Infundibulum): Connects the hypothalamus to the pituitary gland, facilitating hormone transport.
Optic Chiasm: The site where optic nerves partially cross, playing a critical role in visual processing.
Subfornical Organ: A circumventricular organ that detects changes in blood composition and regulates thirst and fluid balance.
Periventricular Nucleus: Involved in the regulation of various autonomic and endocrine functions.
Tuber Cinereum:
A region of the hypothalamus that includes several nuclei involved in endocrine control.
Tuberal Nucleus: Involved in regulating hormonal secretions.
Tuberomammillary Nucleus: The primary source of histamine in the brain, playing a role in wakefulness and arousal.
Subthalamic Nucleus: Involved in the regulation of motor control and part of the basal ganglia circuitry, playing a role in modulating movement.
Zona Incerta: A functionally diverse region involved in motor control, sensory processing, and possibly some aspects of arousal and attention.
Neurohypophysis: The posterior lobe of the pituitary gland that releases hormones produced by the hypothalamus, including oxytocin and vasopressin.
Pars Intermedia (Intermediate Lobe): A thin layer that produces melanocyte-stimulating hormone (MSH) in some animals; its function in humans is less pronounced and largely vestigial.
Adenohypophysis: The anterior lobe of the pituitary gland, which produces and secretes various hormones including growth hormone (GH), prolactin (PRL), adrenocorticotropic hormone (ACTH), and others, playing a crucial role in regulating various physiological processes.
Centrum Semiovale: A large mass of white matter located beneath the cerebral cortex, containing a network of nerve fibers connecting different regions of the brain.
Corona Radiata: A fan-shaped collection of white matter fibers that radiate out from the internal capsule to the cerebral cortex, facilitating communication between the cortex and the brainstem.
Internal Capsule: A major white matter structure that carries information past the basal ganglia, consisting of both ascending and descending axons going to and from the cerebral cortex.
External Capsule: A thin layer of white matter that lies between the putamen and the claustrum, containing association fibers that connect different parts of the cerebral cortex.
Extreme Capsule: The most lateral layer of white matter, situated between the claustrum and the insular cortex, involved in connecting the insula to other cortical areas.
Dentate Gyrus: Part of the hippocampal formation, involved in the formation of new episodic memories and spatial memory.
Cornu Ammonis (CA Fields):
Subdivided into four regions (CA1-CA4), involved in different aspects of hippocampal function.
Cornu Ammonis Area 1 (CA1): Plays a key role in the consolidation of long-term memories.
Cornu Ammonis Area 2 (CA2): Involved in social memory and recognition.
Cornu Ammonis Area 3 (CA3): Critical for pattern completion during memory retrieval.
Cornu Ammonis Area 4 (CA4): Acts as a transition zone between the dentate gyrus and CA3, involved in memory processes.
Central Nucleus: Regulates the autonomic nervous system and emotional responses.
Medial Nucleus: Processes information from the accessory olfactory system.
Cortical and Basomedial Nuclei: Involved in processing olfactory information.
Lateral and Basolateral Nuclei: Connect with the frontotemporal cortex and are involved in emotional processing and memory.
Stria Terminalis:
A major output pathway of the amygdala, involved in stress and anxiety responses.
Bed Nucleus of the Stria Terminalis: Regulates autonomic and behavioral responses to stress.
Claustrum: A thin layer of gray matter involved in coordinating different cortical areas and possibly in consciousness.
Striatum:
Involved in motor control, reward, and cognitive functions.
Dorsal Striatum (Neostriatum):
Includes the putamen and caudate nucleus.
Putamen: Involved in motor skills and learning.
Caudate Nucleus: Involved in motor processes, learning, and memory.
Ventral Striatum:
Includes the nucleus accumbens and olfactory tubercle.
Nucleus Accumbens: Central to the reward system and involved in motivation and pleasure.
Olfactory Tubercle: Involved in the processing of olfactory information and reward.
Globus Pallidus:
Regulates voluntary movement and forms part of the lentiform nucleus with the putamen.
Ventral Pallidum: Involved in motivation and reward processing.
Subthalamic Nucleus: Involved in regulating movements and part of the basal ganglia circuitry.
Anterior Perforated Substance: Contains perforating blood vessels and is involved in olfactory processing.
Substantia Innominata: Contains the nucleus basalis and is involved in arousal, learning, and memory.
nucleus basalis / nucleus basalis of Meynert / nucleus basalis magnocellularis
Nucleus Basalis: Produces acetylcholine and is involved in learning and attention.
Diagonal Band of Broca: Involved in the regulation of the limbic system and olfactory processing.
Septal Nuclei:
Involved in reward and reinforcement.
Medial Septal Nuclei: Involved in the modulation of hippocampal activity.
Lamina Terminalis:
A thin layer of tissue involved in regulating thirst and hormone release.
Vascular Organ of Lamina Terminalis: Involved in osmoregulation and thirst.
Olfactory Bulb: Processes smell information from the nose.
Olfactory Tract: Carries olfactory information from the olfactory bulb to the brain.
Anterior Olfactory Nucleus: Involved in processing olfactory information.
Piriform Cortex: Primary olfactory cortex involved in the perception of smells.
Anterior Commissure: Connects the two hemispheres of the brain, involved in olfactory and limbic functions.
Uncus: Part of the parahippocampal gyrus, involved in olfactory processing.
Periamygdaloid Cortex: Involved in processing olfactory information and emotion.
Cortex
Primary Motor Cortex (Precentral Gyrus, M1): Controls voluntary movements.
Premotor Cortex: Involved in the planning of movements.
Supplementary Motor Cortex: Participates in the coordination of complex movements.
Prefrontal Cortex:
Critical for complex cognitive behavior, decision making, and moderating social behavior.
Orbitofrontal Cortex: Involved in decision making and emotional processing.
Dorsolateral Prefrontal Cortex: Associated with executive functions, such as working memory and cognitive flexibility.
Ventrolateral Prefrontal Cortex: Involved in processing risk and fear.
Dorsomedial Prefrontal Cortex: Plays a role in self-referential thought and emotional regulation.
Ventromedial Prefrontal Cortex: Involved in the processing of risk and fear, as well as decision making.
Gyri
Superior Frontal Gyrus: Involved in self-awareness and executive functions.
Middle Frontal Gyrus: Associated with complex cognitive processes.
Inferior Frontal Gyrus: Contains Broca’s area, which is involved in speech production.
Brodmann Areas: 4 (primary motor cortex), 6 (premotor and supplementary motor areas), 8 (frontal eye fields), 9, 10, 11, 12 (prefrontal cortex), 24, 25, 32, 33, 44, 45, 46, 47 (various prefrontal functions).
Cortex
Primary Somatosensory Cortex (S1): Processes tactile information from the body.
Secondary Somatosensory Cortex (S2): Further processes sensory information.
Posterior Parietal Cortex: Involved in integrating sensory information and spatial reasoning.
Gyri
Postcentral Gyrus (Primary Somesthetic Area): Main sensory receptive area for the sense of touch.
Other
Precuneus: Involved in visuospatial processing, episodic memory, and aspects of consciousness.
Brodmann Areas: 1, 2, 3 (primary somesthetic area), 5, 7, 23, 26, 29, 31, 39, 40 (involved in various sensory and associative functions).
Cortex
Primary Visual Cortex (V1): Processes visual information from the eyes.
V2, V3, V4: Further stages of visual processing, involved in color and form recognition.
Gyri
Lateral Occipital Gyrus: Involved in the visual processing of objects.
Other
Cuneus: Part of the visual cortex that processes visual information from the lower visual field.
Brodmann Areas: 17 (primary visual cortex, V1), 18, 19 (secondary visual processing areas).
Cortex
Primary Auditory Cortex (A1): Processes auditory information.
Secondary Auditory Cortex (A2): Further processes auditory information.
Inferior Temporal Cortex: Involved in visual object recognition.
V5/MT: Processes motion in the visual field.
Posterior Inferior Temporal Cortex: Involved in visual processing.
Gyri
Superior Temporal Gyrus: Contains the primary auditory cortex and Wernicke’s area (important for language comprehension).
Middle Temporal Gyrus: Involved in the processing of sensory inputs.
Inferior Temporal Gyrus: Involved in visual object recognition.
Entorhinal Cortex: Plays a role in memory and navigation.
Perirhinal Cortex: Involved in visual perception and memory.
Parahippocampal Gyrus: Important for memory encoding and retrieval.
Fusiform Gyrus: Involved in facial recognition and processing.
Brodmann Areas: 20, 21, 22, 27, 34, 35, 36, 37, 38, 41, 42 (associated with auditory and visual processing, memory).
Other
Medial Superior Temporal Area (MST): Involved in the perception of motion.
Insular Cortex: Involved in consciousness, emotion, and the regulation of homeostasis.
Anterior Cingulate: Involved in decision making, emotion, and autonomic functions.
Posterior Cingulate: Plays a role in memory and spatial orientation.
Retrosplenial Cortex: Involved in memory formation and navigation.
Indusium Griseum: A thin layer of gray matter involved in limbic functions.
Subgenual Area 25: Involved in mood regulation.
Brodmann Areas: 23, 24 (anterior and posterior cingulate cortex); 26, 29, 30 (retrosplenial areas); 31, 32 (involved in various cognitive and emotional functions).
Superior Longitudinal Fasciculus:
A major bundle of nerve fibers that connect the frontal, parietal, occipital, and temporal lobes, involved in integrating sensory and motor functions.
Arcuate Fasciculus: A part of the superior longitudinal fasciculus that specifically connects Broca's area and Wernicke's area, playing a crucial role in language processing.
Uncinate Fasciculus: A white matter tract that connects the anterior temporal lobe with the orbitofrontal cortex, involved in emotional regulation and memory.
Perforant Pathway: Connects the entorhinal cortex to the hippocampus, playing a key role in the formation and retrieval of memories.
Thalamocortical Radiations: These pathways connect the thalamus with various regions of the cerebral cortex, facilitating sensory and motor information relay.
Corpus Callosum: The largest white matter structure in the brain, connecting the left and right cerebral hemispheres and allowing for interhemispheric communication.
Anterior Commissure: A bundle of nerve fibers that connects the two temporal lobes, involved in olfactory and possibly some pain perception functions.
Amygdalofugal Pathway: Connects the amygdala to various brain regions, including the hypothalamus and thalamus, playing a role in emotional processing and autonomic responses.
Interthalamic Adhesion: A small, midline structure that connects the two thalami, facilitating communication between them.
Posterior Commissure: A bundle of nerve fibers that connects the two sides of the midbrain, involved in the coordination of eye movements and the pupillary light reflex.
Habenular Commissure: Connects the habenulae of both hemispheres, involved in the regulation of monoamine release and aversion processing.
Fornix: A C-shaped bundle of nerve fibers that connects the hippocampus to the mammillary bodies and septal nuclei, playing a crucial role in memory processing.
Mammillotegmental Fasciculus: Connects the mammillary bodies to the tegmentum, involved in autonomic functions and the regulation of wakefulness.
Incertohypothalamic Pathway: Connects the zona incerta to the hypothalamus, involved in motor control and possibly some endocrine functions.
Cerebral Peduncle: Contains large bundles of nerve fibers (crus cerebri) that convey motor signals from the cerebral cortex to the brainstem and spinal cord.
Medial Forebrain Bundle: A collection of fibers that connect the brainstem with various forebrain structures, involved in reward, motivation, and autonomic regulation.
Medial Longitudinal Fasciculus: A bundle of nerve fibers that coordinate eye movements and head movements by connecting the cranial nerve nuclei and vestibular system.
Myoclonic Triangle (Triangle of Guillain-Mollaret): Involves connections between the red nucleus, inferior olive, and dentate nucleus, implicated in motor control and coordination.
Solitary Tract: A pathway that conveys visceral sensory information to the solitary nucleus, involved in autonomic reflexes and visceral sensation.
Mesocortical Pathway: Connects the ventral tegmental area (VTA) to the prefrontal cortex, involved in cognitive control, motivation, and emotion.
Mesolimbic Pathway: Connects the VTA to the nucleus accumbens, central to the reward system and implicated in addiction.
Nigrostriatal Pathway: Connects the substantia nigra to the dorsal striatum, crucial for motor control and implicated in Parkinson's disease.
Tuberoinfundibular Pathway: Connects the hypothalamus to the pituitary gland, involved in the regulation of prolactin secretion.
Raphe Nuclei: Clusters of serotonergic neurons that project throughout the brain, involved in mood regulation, sleep, and arousal.
Locus Coeruleus and Other Noradrenergic Cell Groups: These pathways spread norepinephrine throughout the brain, involved in arousal, attention, and stress responses.
Epinephrine Pathways: These pathways distribute epinephrine (adrenaline) to various parts of the brain, involved in stress and autonomic regulation.
Glutamate Pathways: Involved in excitatory neurotransmission and critical for synaptic plasticity, learning, and memory.
Acetylcholine Pathways: Involved in arousal, attention, learning, and memory, originating from the mesopontine tegmentum.
Extrapyramidal System: A network of neurons involved in the coordination of movement and motor control, primarily influencing involuntary movements and reflexes. It includes structures such as the basal ganglia, cerebellum, and various brainstem nuclei.
Pyramidal Tract:
Comprises the corticospinal and corticobulbar tracts, responsible for voluntary motor control.
Corticospinal Tract (Cerebrospinal Fibers):
Carries motor signals from the cerebral cortex to the spinal cord to control voluntary movements.
Lateral Corticospinal Tract: Controls fine motor movements of the limbs.
Anterior Corticospinal Tract: Controls movements of the trunk and proximal limbs.
Corticopontine Fibers:
Connect the cerebral cortex to the pons.
Frontopontine Fibers: Originate from the frontal lobe and terminate in the pons.
Temporopontine Fibers: Originate from the temporal lobe and terminate in the pons.
Corticobulbar Tract: Carries motor signals from the cerebral cortex to the brainstem to control the muscles of the face, head, and neck.
Corticomesencephalic Tract: Involved in controlling eye movements by connecting the cerebral cortex to the midbrain.
Tectospinal Tract: Involved in coordinating head and eye movements in response to visual and auditory stimuli, originating from the superior colliculus in the midbrain.
Interstitiospinal Tract: Involved in controlling head movements and posture, originating from the interstitial nucleus of Cajal in the midbrain.
Rubrospinal Tract: Involved in motor control, particularly of the distal muscles of the limbs, originating from the red nucleus in the midbrain.
Rubro-olivary Tract: Connects the red nucleus to the inferior olivary nucleus, involved in the coordination of movement.
Olivocerebellar Tract: Carries signals from the inferior olivary nucleus to the cerebellum, playing a crucial role in motor learning and coordination.
Olivospinal Tract: A less prominent tract that may influence motor functions by connecting the olivary nucleus to the spinal cord.
Vestibulospinal Tract:
Helps maintain posture and balance by transmitting signals from the vestibular nuclei to the spinal cord.
Lateral Vestibulospinal Tract: Controls muscle tone and posture adjustments in response to head movements.
Medial Vestibulospinal Tract: Involved in stabilizing the head and coordinating head and eye movements.
Reticulospinal Tract: Involved in maintaining posture and modulating muscle tone by transmitting signals from the reticular formation to the spinal cord.
Lateral Raphespinal Tract: Modulates pain and motor control by transmitting serotonergic signals from the raphe nuclei to the spinal cord.
Alpha System: Refers to the alpha motor neurons in the spinal cord that directly innervate skeletal muscles, responsible for voluntary muscle contractions.
Gamma System: Refers to the gamma motor neurons that innervate muscle spindles, regulating muscle tone and reflexes.
Gracile Fasciculus: Carries sensory information from the lower body and legs to the brain.
Cuneate Fasciculus: Transmits sensory information from the upper body and arms to the brain.
Medial Lemniscus: The major sensory pathway that conveys information about touch, vibration, and proprioception from the dorsal column nuclei to the thalamus.
Lateral Spinothalamic Tract: Transmits pain and temperature sensations from the body to the thalamus.
Anterior Spinothalamic Tract: Conveys crude touch and pressure sensations to the thalamus.
Spinomesencephalic Tract: Carries pain and temperature information to the midbrain, involved in pain modulation.
Spinocerebellar Tract: Transmits proprioceptive information from the spinal cord to the cerebellum, aiding in coordination and balance.
Spino-Olivary Tract: Conveys proprioceptive information to the olivary nuclei, which then relay it to the cerebellum, contributing to motor learning and coordination.
Spinoreticular Tract: Transmits pain and temperature information to the reticular formation, involved in the autonomic responses to pain.
Optic Tract: Carries visual information from the optic chiasm to the lateral geniculate nucleus (LGN) of the thalamus and other brain regions.
Optic Radiation: A bundle of axons that carry visual information from the LGN to the primary visual cortex (V1) in the occipital lobe.
Retinohypothalamic Tract: Connects the retina to the hypothalamus, involved in regulating circadian rhythms and the pupillary light reflex.
Medullary Striae of Fourth Ventricle: Pathways that carry auditory information from the cochlear nuclei to other brainstem nuclei.
Trapezoid Body: Part of the auditory pathway that decussates (crosses over) in the brainstem, involved in sound localization.
Lateral Lemniscus: A major auditory pathway that carries information from the cochlear nuclei to the inferior colliculus in the midbrain.
Terminal (0): A lesser-known nerve, believed to be involved in pheromone detection and possibly influencing reproductive behavior.
Olfactory (I): Responsible for the sense of smell, transmitting olfactory information from the nasal cavity to the brain.
Optic (II): Carries visual information from the retina to the brain, crucial for vision.
Oculomotor (III): Controls most of the eye's movements, including the constriction of the pupil and maintaining an open eyelid.
Trochlear (IV): Innervates the superior oblique muscle, enabling downward and lateral eye movement.
Trigeminal (V): Responsible for facial sensations and motor functions such as biting and chewing. It has three major branches: ophthalmic, maxillary, and mandibular.
Abducens (VI): Controls the lateral rectus muscle, which abducts the eye.
Facial (VII): Controls the muscles of facial expression, conveys taste sensations from the anterior two-thirds of the tongue, and supplies glands such as the salivary and lacrimal glands.
Vestibulocochlear (VIII): Transmits sound and equilibrium (balance) information from the inner ear to the brain.
Glossopharyngeal (IX): Involved in taste sensation from the posterior one-third of the tongue, swallowing, and the secretion of saliva.
Vagus (X): Extends beyond the head and neck to the thorax and abdomen, controlling parasympathetic functions such as heart rate, gastrointestinal motility, and speech.
Accessory (XI): Controls the sternocleidomastoid and trapezius muscles, facilitating head movement and shoulder elevation.
Hypoglossal (XII): Controls the muscles of the tongue, crucial for speech and swallowing.
Middle Cerebral Artery: Supplies blood to the lateral surfaces of the frontal, temporal, and parietal lobes, and is critical for motor and sensory functions as well as language.
Posterior Cerebral Artery: Provides blood to the occipital lobe, the inferior part of the temporal lobe, and various deep structures including the thalamus, playing a key role in vision.
Anterior Cerebral Artery: Supplies blood to the medial portions of the frontal lobes and superior medial parietal lobes, important for motor control and cognitive functions.
Vertebral Artery: Supplies blood to the spinal cord, brainstem, cerebellum, and posterior part of the brain.
Basilar Artery: Formed by the merging of the vertebral arteries, it supplies blood to the brainstem, cerebellum, and posterior part of the brain.
Circle of Willis: A circular network of arteries at the base of the brain that provides collateral blood flow between the anterior and posterior cerebral circulations, ensuring continuous blood supply.
Blood–Brain Barrier: A selective permeability barrier that protects the brain from harmful substances in the bloodstream while allowing essential nutrients to pass through.
Glymphatic System: A waste clearance system that uses cerebrospinal fluid to flush out metabolic waste products from the brain.
Venous Systems: Comprises the dural venous sinuses and cerebral veins that drain deoxygenated blood and waste products from the brain back to the heart.
Circumventricular Organs: Brain structures located around the ventricles that lack a blood-brain barrier, allowing them to sense and respond to changes in the blood composition.
Noradrenaline System: Involves neurons that release noradrenaline (norepinephrine), playing a role in arousal, attention, and the stress response. Major sources include the locus coeruleus.
Dopamine System: Involves neurons that release dopamine, crucial for reward, motivation, and motor control. Includes pathways such as the mesocortical, mesolimbic, nigrostriatal, and tuberoinfundibular pathways.
Serotonin System: Involves neurons that release serotonin, regulating mood, appetite, and sleep. Major sources include the raphe nuclei.
Cholinergic System: Involves neurons that release acetylcholine, important for arousal, attention, memory, and learning. Major sources include the basal forebrain and brainstem nuclei.
GABA (Gamma-Aminobutyric Acid): The primary inhibitory neurotransmitter in the brain, involved in reducing neuronal excitability and regulating muscle tone.
Neuropeptides:
Small protein-like molecules used by neurons to communicate, often modulating the activity of other neurotransmitters.
Opioid Peptides:
Involved in pain modulation and reward.
Endorphins: Natural pain relievers that promote a sense of well-being.
Enkephalins: Play a role in regulating pain and reward.
Dynorphins: Modulate pain response and stress.
Oxytocin: Involved in social bonding, reproduction, and childbirth.
Substance P: Involved in the transmission of pain signals and the regulation of mood.
Cerebrospinal Fluid (CSF): A clear, colorless fluid that cushions the brain and spinal cord, removes waste, and provides a stable chemical environment.
Brain-Cerebrospinal Fluid Barrier: A selective barrier that regulates the exchange of substances between the blood and the cerebrospinal fluid, maintaining the brain's microenvironment.
Dura Mater: The outermost, tough layer of the meninges that protects the brain and spinal cord.
Arachnoid Mater: The middle layer of the meninges, which is web-like and helps cushion the brain.
Pia Mater: The innermost, delicate layer of the meninges that closely adheres to the surface of the brain and spinal cord.
Epidural Space: The space between the dura mater and the vertebral wall, containing fat and small blood vessels.
Subdural Space: The potential space between the dura mater and the arachnoid mater, which can fill with blood in cases of hemorrhage.
Subarachnoid Space:
The space between the arachnoid mater and the pia mater, filled with cerebrospinal fluid and containing blood vessels.
Arachnoid Septum: Delicate strands of tissue that cross the subarachnoid space, providing structural support.
Superior Cistern: A large subarachnoid space located above the cerebellum.
Cistern of Lamina Terminalis: Located near the lamina terminalis, part of the brain's ventricular system.
Chiasmatic Cistern: Located near the optic chiasm, involved in the circulation of cerebrospinal fluid.
Interpeduncular Cistern: Located between the cerebral peduncles of the midbrain.
Pontine Cistern: Located around the pons, containing cerebrospinal fluid.
Cisterna Magna: The largest subarachnoid cistern, located between the cerebellum and the medulla oblongata.
Spinal Subarachnoid Space: Extends around the spinal cord, filled with cerebrospinal fluid.
Lateral Ventricles:
Large, paired cavities within each cerebral hemisphere, producing and containing cerebrospinal fluid.
Angular Bundle: White matter fibers connecting different parts of the brain.
Anterior Horn: The front part of the lateral ventricle, extending into the frontal lobe.
Body of Lateral Ventricle: The central part of the lateral ventricle.
Inferior Horn: The part of the lateral ventricle that extends into the temporal lobe.
Posterior Horn:
The part of the lateral ventricle that extends into the occipital lobe.
Calcar Avis: An elevation in the posterior horn of the lateral ventricle, caused by the calcarine sulcus.
Subventricular Zone: A region in the lateral ventricles where neural stem cells reside and contribute to neurogenesis.
Third Ventricle: A narrow, midline cavity that connects the lateral ventricles to the fourth ventricle.
Fourth Ventricle: Located between the brainstem and cerebellum, it communicates with the subarachnoid space and contains cerebrospinal fluid.
Interventricular Foramina (Foramina of Monro): Channels that connect the lateral ventricles to the third ventricle.
Cerebral Aqueduct (Aqueduct of Sylvius): A narrow channel that connects the third ventricle to the fourth ventricle.
Foramina of Luschka: Openings that allow cerebrospinal fluid to flow from the fourth ventricle into the subarachnoid space.
Foramen of Magendie: An opening that allows cerebrospinal fluid to flow from the fourth ventricle into the cisterna magna.
The limbic system, also known as the paleomammalian cortex, is a set of brain structures located on both sides of the thalamus, beneath the medial temporal lobe of the cerebrum. It plays a key role in emotional processes and memory formation.
Limbic Lobe: Includes structures such as the cingulate gyrus and parahippocampal gyrus, involved in emotional processing and memory.
Orbitofrontal Cortex: Located in the frontal lobe, involved in decision-making and reward processing.
Piriform Cortex: Part of the olfactory system, involved in processing smells.
Entorhinal Cortex: Key in memory and associative functions, serving as a major input to the hippocampus.
Hippocampus: Central to the formation and consolidation of new memories.
Fornix: A white matter structure connecting the hippocampus with other brain structures, including the mammillary bodies and septal nuclei.
Septal Nuclei: Located in front of the lamina terminalis, associated with reward and pleasure.
Amygdala: Deep within the temporal lobes, crucial for processing emotions such as fear and pleasure.
Nucleus Accumbens: Plays a significant role in reward, pleasure, and addiction.
Hypothalamus: A central node of the limbic system, regulating autonomic processes and connecting with various brain regions including the frontal lobes, septal nuclei, brainstem reticular formation, hippocampus, and thalamus.
Mammillary Bodies: Part of the hypothalamus, receiving signals from the hippocampus and projecting them to the thalamus, involved in memory.
Anterior Nuclei of Thalamus: Receive input from the mammillary bodies and are involved in memory processing.
Stria Medullaris: A fiber tract that connects various limbic structures.
Central Gray: Involved in pain modulation and defensive behavior.
Dorsal and Ventral Nuclei of Gudden: Involved in the limbic system, though their specific functions are less clearly defined.
Superior Longitudinal Fasciculus:
A major bundle of nerve fibers that connect the frontal, parietal, occipital, and temporal lobes, involved in integrating sensory and motor functions.
Arcuate Fasciculus: A part of the superior longitudinal fasciculus that specifically connects Broca's area and Wernicke's area, playing a crucial role in language processing.
Uncinate Fasciculus: A white matter tract that connects the anterior temporal lobe with the orbitofrontal cortex, involved in emotional regulation and memory.
Perforant Pathway: Connects the entorhinal cortex to the hippocampus, playing a key role in the formation and retrieval of memories.
Thalamocortical Radiations: These pathways connect the thalamus with various regions of the cerebral cortex, facilitating sensory and motor information relay.
Corpus Callosum: The largest white matter structure in the brain, connecting the left and right cerebral hemispheres and allowing for interhemispheric communication.
Anterior Commissure: A bundle of nerve fibers that connects the two temporal lobes, involved in olfactory and possibly some pain perception functions.
Amygdalofugal Pathway: Connects the amygdala to various brain regions, including the hypothalamus and thalamus, playing a role in emotional processing and autonomic responses.
Interthalamic Adhesion: A small, midline structure that connects the two thalami, facilitating communication between them.
Posterior Commissure: A bundle of nerve fibers that connects the two sides of the midbrain, involved in the coordination of eye movements and the pupillary light reflex.
Habenular Commissure: Connects the habenulae of both hemispheres, involved in the regulation of monoamine release and aversion processing.
Fornix: A C-shaped bundle of nerve fibers that connects the hippocampus to the mammillary bodies and septal nuclei, playing a crucial role in memory processing.
Mammillotegmental Fasciculus: Connects the mammillary bodies to the tegmentum, involved in autonomic functions and the regulation of wakefulness.
Incertohypothalamic Pathway: Connects the zona incerta to the hypothalamus, involved in motor control and possibly some endocrine functions.
Cerebral Peduncle: Contains large bundles of nerve fibers (crus cerebri) that convey motor signals from the cerebral cortex to the brainstem and spinal cord.
Medial Forebrain Bundle: A collection of fibers that connect the brainstem with various forebrain structures, involved in reward, motivation, and autonomic regulation.
Medial Longitudinal Fasciculus: A bundle of nerve fibers that coordinate eye movements and head movements by connecting the cranial nerve nuclei and vestibular system.
Myoclonic Triangle (Triangle of Guillain-Mollaret): Involves connections between the red nucleus, inferior olive, and dentate nucleus, implicated in motor control and coordination.
Solitary Tract: A pathway that conveys visceral sensory information to the solitary nucleus, involved in autonomic reflexes and visceral sensation.
Mesocortical Pathway: Connects the ventral tegmental area (VTA) to the prefrontal cortex, involved in cognitive control, motivation, and emotion.
Mesolimbic Pathway: Connects the VTA to the nucleus accumbens, central to the reward system and implicated in addiction.
Nigrostriatal Pathway: Connects the substantia nigra to the dorsal striatum, crucial for motor control and implicated in Parkinson's disease.
Tuberoinfundibular Pathway: Connects the hypothalamus to the pituitary gland, involved in the regulation of prolactin secretion.
Raphe Nuclei: Clusters of serotonergic neurons that project throughout the brain, involved in mood regulation, sleep, and arousal.
Locus Coeruleus and Other Noradrenergic Cell Groups: These pathways spread norepinephrine throughout the brain, involved in arousal, attention, and stress responses.
Epinephrine Pathways: These pathways distribute epinephrine (adrenaline) to various parts of the brain, involved in stress and autonomic regulation.
Glutamate Pathways: Involved in excitatory neurotransmission and critical for synaptic plasticity, learning, and memory.
Acetylcholine Pathways: Involved in arousal, attention, learning, and memory, originating from the mesopontine tegmentum.
Extrapyramidal System: A network of neurons involved in the coordination of movement and motor control, primarily influencing involuntary movements and reflexes. It includes structures such as the basal ganglia, cerebellum, and various brainstem nuclei.
Pyramidal Tract:
Comprises the corticospinal and corticobulbar tracts, responsible for voluntary motor control.
Corticospinal Tract (Cerebrospinal Fibers):
Carries motor signals from the cerebral cortex to the spinal cord to control voluntary movements.
Lateral Corticospinal Tract: Controls fine motor movements of the limbs.
Anterior Corticospinal Tract: Controls movements of the trunk and proximal limbs.
Corticopontine Fibers:
Connect the cerebral cortex to the pons.
Frontopontine Fibers: Originate from the frontal lobe and terminate in the pons.
Temporopontine Fibers: Originate from the temporal lobe and terminate in the pons.
Corticobulbar Tract: Carries motor signals from the cerebral cortex to the brainstem to control the muscles of the face, head, and neck.
Corticomesencephalic Tract: Involved in controlling eye movements by connecting the cerebral cortex to the midbrain.
Tectospinal Tract: Involved in coordinating head and eye movements in response to visual and auditory stimuli, originating from the superior colliculus in the midbrain.
Interstitiospinal Tract: Involved in controlling head movements and posture, originating from the interstitial nucleus of Cajal in the midbrain.
Rubrospinal Tract: Involved in motor control, particularly of the distal muscles of the limbs, originating from the red nucleus in the midbrain.
Rubro-olivary Tract: Connects the red nucleus to the inferior olivary nucleus, involved in the coordination of movement.
Olivocerebellar Tract: Carries signals from the inferior olivary nucleus to the cerebellum, playing a crucial role in motor learning and coordination.
Olivospinal Tract: A less prominent tract that may influence motor functions by connecting the olivary nucleus to the spinal cord.
Vestibulospinal Tract:
Helps maintain posture and balance by transmitting signals from the vestibular nuclei to the spinal cord.
Lateral Vestibulospinal Tract: Controls muscle tone and posture adjustments in response to head movements.
Medial Vestibulospinal Tract: Involved in stabilizing the head and coordinating head and eye movements.
Reticulospinal Tract: Involved in maintaining posture and modulating muscle tone by transmitting signals from the reticular formation to the spinal cord.
Lateral Raphespinal Tract: Modulates pain and motor control by transmitting serotonergic signals from the raphe nuclei to the spinal cord.
Alpha System: Refers to the alpha motor neurons in the spinal cord that directly innervate skeletal muscles, responsible for voluntary muscle contractions.
Gamma System: Refers to the gamma motor neurons that innervate muscle spindles, regulating muscle tone and reflexes.
Gracile Fasciculus: Carries sensory information from the lower body and legs to the brain.
Cuneate Fasciculus: Transmits sensory information from the upper body and arms to the brain.
Medial Lemniscus: The major sensory pathway that conveys information about touch, vibration, and proprioception from the dorsal column nuclei to the thalamus.
Lateral Spinothalamic Tract: Transmits pain and temperature sensations from the body to the thalamus.
Anterior Spinothalamic Tract: Conveys crude touch and pressure sensations to the thalamus.
Spinomesencephalic Tract: Carries pain and temperature information to the midbrain, involved in pain modulation.
Spinocerebellar Tract: Transmits proprioceptive information from the spinal cord to the cerebellum, aiding in coordination and balance.
Spino-Olivary Tract: Conveys proprioceptive information to the olivary nuclei, which then relay it to the cerebellum, contributing to motor learning and coordination.
Spinoreticular Tract: Transmits pain and temperature information to the reticular formation, involved in the autonomic responses to pain.
Optic Tract: Carries visual information from the optic chiasm to the lateral geniculate nucleus (LGN) of the thalamus and other brain regions.
Optic Radiation: A bundle of axons that carry visual information from the LGN to the primary visual cortex (V1) in the occipital lobe.
Retinohypothalamic Tract: Connects the retina to the hypothalamus, involved in regulating circadian rhythms and the pupillary light reflex.
Medullary Striae of Fourth Ventricle: Pathways that carry auditory information from the cochlear nuclei to other brainstem nuclei.
Trapezoid Body: Part of the auditory pathway that decussates (crosses over) in the brainstem, involved in sound localization.
Lateral Lemniscus: A major auditory pathway that carries information from the cochlear nuclei to the inferior colliculus in the midbrain.
Terminal (0): A lesser-known nerve, believed to be involved in pheromone detection and possibly influencing reproductive behavior.
Olfactory (I): Responsible for the sense of smell, transmitting olfactory information from the nasal cavity to the brain.
Optic (II): Carries visual information from the retina to the brain, crucial for vision.
Oculomotor (III): Controls most of the eye's movements, including the constriction of the pupil and maintaining an open eyelid.
Trochlear (IV): Innervates the superior oblique muscle, enabling downward and lateral eye movement.
Trigeminal (V): Responsible for facial sensations and motor functions such as biting and chewing. It has three major branches: ophthalmic, maxillary, and mandibular.
Abducens (VI): Controls the lateral rectus muscle, which abducts the eye.
Facial (VII): Controls the muscles of facial expression, conveys taste sensations from the anterior two-thirds of the tongue, and supplies glands such as the salivary and lacrimal glands.
Vestibulocochlear (VIII): Transmits sound and equilibrium (balance) information from the inner ear to the brain.
Glossopharyngeal (IX): Involved in taste sensation from the posterior one-third of the tongue, swallowing, and the secretion of saliva.
Vagus (X): Extends beyond the head and neck to the thorax and abdomen, controlling parasympathetic functions such as heart rate, gastrointestinal motility, and speech.
Accessory (XI): Controls the sternocleidomastoid and trapezius muscles, facilitating head movement and shoulder elevation.
Hypoglossal (XII): Controls the muscles of the tongue, crucial for speech and swallowing.
Middle Cerebral Artery: Supplies blood to the lateral surfaces of the frontal, temporal, and parietal lobes, and is critical for motor and sensory functions as well as language.
Posterior Cerebral Artery: Provides blood to the occipital lobe, the inferior part of the temporal lobe, and various deep structures including the thalamus, playing a key role in vision.
Anterior Cerebral Artery: Supplies blood to the medial portions of the frontal lobes and superior medial parietal lobes, important for motor control and cognitive functions.
Vertebral Artery: Supplies blood to the spinal cord, brainstem, cerebellum, and posterior part of the brain.
Basilar Artery: Formed by the merging of the vertebral arteries, it supplies blood to the brainstem, cerebellum, and posterior part of the brain.
Circle of Willis: A circular network of arteries at the base of the brain that provides collateral blood flow between the anterior and posterior cerebral circulations, ensuring continuous blood supply.
Blood–Brain Barrier: A selective permeability barrier that protects the brain from harmful substances in the bloodstream while allowing essential nutrients to pass through.
Glymphatic System: A waste clearance system that uses cerebrospinal fluid to flush out metabolic waste products from the brain.
Venous Systems: Comprises the dural venous sinuses and cerebral veins that drain deoxygenated blood and waste products from the brain back to the heart.
Circumventricular Organs: Brain structures located around the ventricles that lack a blood-brain barrier, allowing them to sense and respond to changes in the blood composition.
Noradrenaline System: Involves neurons that release noradrenaline (norepinephrine), playing a role in arousal, attention, and the stress response. Major sources include the locus coeruleus.
Dopamine System: Involves neurons that release dopamine, crucial for reward, motivation, and motor control. Includes pathways such as the mesocortical, mesolimbic, nigrostriatal, and tuberoinfundibular pathways.
Serotonin System: Involves neurons that release serotonin, regulating mood, appetite, and sleep. Major sources include the raphe nuclei.
Cholinergic System: Involves neurons that release acetylcholine, important for arousal, attention, memory, and learning. Major sources include the basal forebrain and brainstem nuclei.
GABA (Gamma-Aminobutyric Acid): The primary inhibitory neurotransmitter in the brain, involved in reducing neuronal excitability and regulating muscle tone.
Neuropeptides:
Small protein-like molecules used by neurons to communicate, often modulating the activity of other neurotransmitters.
Opioid Peptides:
Involved in pain modulation and reward.
Endorphins: Natural pain relievers that promote a sense of well-being.
Enkephalins: Play a role in regulating pain and reward.
Dynorphins: Modulate pain response and stress.
Oxytocin: Involved in social bonding, reproduction, and childbirth.
Substance P: Involved in the transmission of pain signals and the regulation of mood.
Cerebrospinal Fluid (CSF): A clear, colorless fluid that cushions the brain and spinal cord, removes waste, and provides a stable chemical environment.
Brain-Cerebrospinal Fluid Barrier: A selective barrier that regulates the exchange of substances between the blood and the cerebrospinal fluid, maintaining the brain's microenvironment.
Dura Mater: The outermost, tough layer of the meninges that protects the brain and spinal cord.
Arachnoid Mater: The middle layer of the meninges, which is web-like and helps cushion the brain.
Pia Mater: The innermost, delicate layer of the meninges that closely adheres to the surface of the brain and spinal cord.
Epidural Space: The space between the dura mater and the vertebral wall, containing fat and small blood vessels.
Subdural Space: The potential space between the dura mater and the arachnoid mater, which can fill with blood in cases of hemorrhage.
Subarachnoid Space:
The space between the arachnoid mater and the pia mater, filled with cerebrospinal fluid and containing blood vessels.
Arachnoid Septum: Delicate strands of tissue that cross the subarachnoid space, providing structural support.
Superior Cistern: A large subarachnoid space located above the cerebellum.
Cistern of Lamina Terminalis: Located near the lamina terminalis, part of the brain's ventricular system.
Chiasmatic Cistern: Located near the optic chiasm, involved in the circulation of cerebrospinal fluid.
Interpeduncular Cistern: Located between the cerebral peduncles of the midbrain.
Pontine Cistern: Located around the pons, containing cerebrospinal fluid.
Cisterna Magna: The largest subarachnoid cistern, located between the cerebellum and the medulla oblongata.
Spinal Subarachnoid Space: Extends around the spinal cord, filled with cerebrospinal fluid.
Lateral Ventricles:
Large, paired cavities within each cerebral hemisphere, producing and containing cerebrospinal fluid.
Angular Bundle: White matter fibers connecting different parts of the brain.
Anterior Horn: The front part of the lateral ventricle, extending into the frontal lobe.
Body of Lateral Ventricle: The central part of the lateral ventricle.
Inferior Horn: The part of the lateral ventricle that extends into the temporal lobe.
Posterior Horn:
The part of the lateral ventricle that extends into the occipital lobe.
Calcar Avis: An elevation in the posterior horn of the lateral ventricle, caused by the calcarine sulcus.
Subventricular Zone: A region in the lateral ventricles where neural stem cells reside and contribute to neurogenesis.
Third Ventricle: A narrow, midline cavity that connects the lateral ventricles to the fourth ventricle.
Fourth Ventricle: Located between the brainstem and cerebellum, it communicates with the subarachnoid space and contains cerebrospinal fluid.
Interventricular Foramina (Foramina of Monro): Channels that connect the lateral ventricles to the third ventricle.
Cerebral Aqueduct (Aqueduct of Sylvius): A narrow channel that connects the third ventricle to the fourth ventricle.
Foramina of Luschka: Openings that allow cerebrospinal fluid to flow from the fourth ventricle into the subarachnoid space.
Foramen of Magendie: An opening that allows cerebrospinal fluid to flow from the fourth ventricle into the cisterna magna.
The limbic system, also known as the paleomammalian cortex, is a set of brain structures located on both sides of the thalamus, beneath the medial temporal lobe of the cerebrum. It plays a key role in emotional processes and memory formation.
Limbic Lobe: Includes structures such as the cingulate gyrus and parahippocampal gyrus, involved in emotional processing and memory.
Orbitofrontal Cortex: Located in the frontal lobe, involved in decision-making and reward processing.
Piriform Cortex: Part of the olfactory system, involved in processing smells.
Entorhinal Cortex: Key in memory and associative functions, serving as a major input to the hippocampus.
Hippocampus: Central to the formation and consolidation of new memories.
Fornix: A white matter structure connecting the hippocampus with other brain structures, including the mammillary bodies and septal nuclei.
Septal Nuclei: Located in front of the lamina terminalis, associated with reward and pleasure.
Amygdala: Deep within the temporal lobes, crucial for processing emotions such as fear and pleasure.
Nucleus Accumbens: Plays a significant role in reward, pleasure, and addiction.
Hypothalamus: A central node of the limbic system, regulating autonomic processes and connecting with various brain regions including the frontal lobes, septal nuclei, brainstem reticular formation, hippocampus, and thalamus.
Mammillary Bodies: Part of the hypothalamus, receiving signals from the hippocampus and projecting them to the thalamus, involved in memory.
Anterior Nuclei of Thalamus: Receive input from the mammillary bodies and are involved in memory processing.
Stria Medullaris: A fiber tract that connects various limbic structures.
Central Gray: Involved in pain modulation and defensive behavior.
Dorsal and Ventral Nuclei of Gudden: Involved in the limbic system, though their specific functions are less clearly defined.
Below is a massive supplement—structured in a style similar to your original outline—listing many less-cited, microanatomical, or specialized pathways that can appear in advanced neuroanatomy references. While no list can claim to be perfectly exhaustive, these pathways commonly get mentioned outside the standard "big three" (corticospinal, spinothalamic, dorsal column–medial lemniscus) and major association bundles already covered.
Mammillothalamic Tract (Vicq d’Azyr’s Tract):
Connects the Mammillary Bodies to the Anterior Nuclei of the Thalamus.
Cingulum (Cingulum Bundle):
A major association pathway running beneath the Cingulate Gyrus and continuing into the Parahippocampal Gyrus, carrying information between limbic cortical areas.
Alvear Pathway (Hippocampal Input):
Secondary route from the Entorhinal Cortex to Hippocampus, running over the alveus into CA1 regions.
Presubiculum → Parasubiculum → Subiculum Connections:
Transitional hippocampal areas projecting to and from Entorhinal Cortex and the CA fields, crucial for spatial memory processing.
Hippocampal Commissure (Dorsal Hippocampal Commissure):
Interconnects the left and right hippocampi (specifically connecting the Fornices across midline).
Medial Septal Nucleus → Hippocampus:
Cholinergic and GABAergic projections regulating hippocampal theta rhythms.
Diagonal Band of Broca Fibers (Septal Pathways):
Connect septal nuclei to the Amygdala, Hypothalamus, and Hippocampus.
Stria Terminalis (already listed) but includes small collateral branches:
Bed Nucleus of the Stria Terminalis (BNST) loops to hypothalamus and brainstem autonomic centers.
Ventral Amygdalofugal Pathway (already mentioned as Amygdalofugal Pathway), but in detail:
Includes direct connections from the Amygdala to the Nucleus Accumbens, Mediodorsal Thalamus, and Hypothalamus.
Habenular Commissure (sometimes listed):
Interconnects the left and right Habenular Nuclei.
Commissure of the Lateral Lemniscus:
Small commissural fibers within the Auditory Pathway at the level of the pons/midbrain.
Extreme Capsule → Claustrum Connections:
Additional short association fibers linking the Insula, Claustrum, and Lateral Temporal/Frontal Regions.
Inferior Longitudinal Fasciculus (ILF):
Connects occipital and temporal lobes, important for visual object recognition and visual memory.
Fronto-occipital Fasciculus (Inferior Fronto-occipital Fasciculus, IFOF):
Connects the frontal lobe with occipital and temporo-basal regions, implicated in visuospatial processing and attention.
Central Tegmental Tract (CTT):
Carries Rubro-olivary Fibers (descending) and Taste Pathways (ascending) from the Solitary Nucleus to the VPM of the Thalamus.
Dorsal Longitudinal Fasciculus (DLF):
Connects the Hypothalamus to parasympathetic nuclei in the brainstem and upper spinal cord, central for autonomic reflexes.
Dorsal Trigeminothalamic Tract (DTTT):
Conveys discriminative touch from the face (chief sensory trigeminal nucleus) to the Ventroposterior Medial (VPM) Nucleus of the Thalamus.
Ventral Trigeminothalamic Tract (VTTT):
Carries pain, temperature, crude touch from the face (spinal trigeminal nucleus) to the VPM.
Gustatory Pathway (Taste Pathway):
Solitary Nucleus → (via the Central Tegmental Tract) → VPM → Insular and Frontal Opercular Cortex.
Vestibulothalamic Tract:
From Vestibular Nuclei to the Thalamus (VPL or VPI), contributing to conscious perception of balance.
Olivocochlear Bundle (Efferent Auditory Pathway):
Arises from the Superior Olivary Complex and projects to the Organ of Corti to modulate hair cell activity.
Cuneocerebellar Tract:
Proprioceptive information from the upper limbs via the Accessory Cuneate Nucleus to the Cerebellum (ipsilateral).
Rostral Spinocerebellar Tract:
Proprioceptive and interneuron-driven signals from the cervical cord to the Cerebellum.
Ventral (Anterior) Spinocerebellar Tract (already in spinocerebellar group, but sometimes spelled out separately):
Proprioceptive/interneuron signals from lower body crossing at the spinal cord, then recrossing in the cerebellum.
Corticorubral Tract:
Motor cortex to the Red Nucleus, influences rubrospinal output.
Corticoreticular Tract:
Widespread cortical areas to the Reticular Formation, modulating posture and muscle tone via reticulospinal outputs.
Corticoolivary Fibers:
Cortex to the Inferior Olivary Nucleus, crucial for cerebellar learning loops.
(Often referred to as “circuits” rather than single pathways, but each loop includes definable fiber tracts.)
Corticostriatal Fibers:
Projections from entire cerebral cortex to Caudate/Putamen (Striatum).
Striatopallidal Fibers:
Inhibitory pathways from the striatum to the External (GPe) or Internal (GPi) segments of the Globus Pallidus.
Pallidothalamic Fibers (in two bundles):
Ansa Lenticularis and Lenticular Fasciculus carrying signals from GPi to the Thalamus (VA/VL nuclei).
Thalamocortical Fibers:
From VA/VL → back to Motor and Premotor Cortex.
Hypothalamic–Hypophyseal Tract (Supraopticohypophyseal):
Supraoptic and Paraventricular Nuclei → Posterior Pituitary (neurohypophysis), releasing ADH (vasopressin) & Oxytocin.
Tuberoinfundibular Tract:
Arcuate Nucleus → Median Eminence → Portal circulation to Anterior Pituitary (regulating prolactin, growth hormone, etc.).
Tectoreticulospinal Pathway:
Integrates superior colliculus output with reticulospinal systems to coordinate reflexive head-eye-body orientation.
Nigrothalamic / Nigrotectal Fibers:
From Substantia Nigra (Reticulata) to Thalamus (VA/VL) or Superior Colliculus, modulating movement and gaze.
Retinotectal Pathway:
Retina → Superior Colliculus, crucial for reflexive saccades and orientation of gaze.
Retinopulvinar / Extrastriate Projections:
Retina → Pulvinar of the thalamus, then to Parietotemporal Associative Visual Areas (important for attentional modulation).
Accessory Optic System (AOS):
Minor pathways from retina to Nuclei of the Accessory Optic System (e.g., MTN – medial terminal nucleus), influencing optokinetic reflexes.
Spinobulbar Tracts:
Catch-all term for spinal cord → various brainstem nuclei (e.g., gracile, cuneate, trigeminal).
Spinohypothalamic Tract:
Conveys noxious (pain, temperature) and possibly visceral information to the Hypothalamus, influencing autonomic/endocrine responses.
Interstitiospinal Pathway (some references separate from medial longitudinal fasciculus):
From Interstitial Nucleus of Cajal to cervical spinal cord for head/neck posture.
Retino–Suprachiasmatic Pathway (already conceptually in Retinohypothalamic, but sometimes singled out):
Critical for circadian rhythm entrainment.
Cerebellorubral Tract:
Dentate (and Interposed) Nuclei → Red Nucleus (part of feedback loops).
Rubrothalamic Tract:
Red Nucleus → VL Thalamus, then to motor cortex (less dominant in humans, but recognized).
Pontoreticular-Cerebellar Loops:
Connections from pontine reticular formation → cerebellum (and reciprocally), refining posture and muscle tone.
Intrinsic Cortical Circuits (e.g., radial vs. tangential connections, local inhibitory microcircuits) are beyond the scope of macroanatomical pathway lists but often appear in detailed neuroscience texts.
Local Brainstem Reflex Circuits (e.g., gag reflex arcs, blink reflex arcs, baroreceptor reflex arcs) also represent “pathways,” though typically described in neurophysiology rather than structural anatomy sections.
Efferent Projections from Raphe Nuclei (serotonergic) or Locus Coeruleus (noradrenergic) can be subdivided far more granularly than the standard “Serotonergic” or “Noradrenergic” headings.
Descending Autonomic Pathways from the hypothalamus to spinal cord IML (intermediolateral cell column) also can be subdivided (e.g., Hypothalamospinal Tract), relevant for controlling sympathetic outflow.
Micro-Subcortical Loops (e.g., nucleus accumbens → ventral pallidum → mediodorsal thalamus → prefrontal cortex, repeated for addictive or motivated behavior circuits) might not appear as separate “tracts” in standard texts, but functionally they are recognized loops.