Blood Flow $\left(Q\right)=\frac{\mathrm{\Delta }P}{R}\left(\frac{Liters}{min}\right)$$\left(\ Q \ \right) = \frac{\Delta P}{R}\ \left(\ \frac{Liters}{min} \ \right)$

Resistance $\left(R\right)\propto \frac{1}{{\text{radius}}^4}$$\left(\ R \ \right) \propto \frac{1}{\text{radius}^4}$

$MAP=\text{Diastolic}+\frac{\text{Systolic}-\text{Diastolic}}{3}$$MAP = \text{Diastolic} + \frac{\text{Systolic} - \text{Diastolic}}{3}$

$CO=SV\ast HR$$CO = SV * HR$

$TPR\approx \frac{MAP}{CO}$$TPR \approx \frac{MAP}{CO}$

Starling Equation :

• positive = efflux = filtration out of capillary into intersitium

• negative = influx = absorption from interstitium into capillary

Cardiac Myocyte ECG Waveform :

• P = atria contract

• QRS = ventricles contract

• ST = semilunar valves open

• T = ventricles close

• Filling

Cardio Myocyte Action Potential Waveform :

1. Depolarization due to sodium entering

2. Temporary Plateau as combination of Calcium entering and Potassium leaving

   • calcium enters , potassium leaves

3. Repolarization due to calcium channels closing , and potassium channels remaining open

4. NA-K-ATPase pumps re-establish resting membrane potential

Sympathetic Nervous System Control :

• Baro Reflex = $\downarrow$$\downarrow$ MAP ➡️ Baro/Stretch Receptors ➡️ CNS 9 & 10 ➡️ $\uparrow$$\uparrow$ Sympathetic & $\downarrow$$\downarrow$ Parasympathetic ➡️ $\uparrow$$\uparrow$ Cardiac Output

• Chemoreflex = carotid bodies detect high $CO2$$CO2$ ➡️ CNS 9 & 10 ➡️ $\uparrow$$\uparrow$ Sympathetic & $\downarrow$$\downarrow$ Parasympathetic ➡️ $\uparrow$$\uparrow$ Cardiac Output

Vasoconstrictors :

• Angiotensin 2

• Prostaglandins

• Thromboxane

Vasodialators :

• Nitric Oxide

• Bradykinin

Maximize Diffusion of Oxygen in Alveoli = large surface area , low tension / thickness , strong pressure gradient , warm and moist air

Anatomic Dead Space = trachea

Functional Dead Space = collapsed bronchioles / alveoli

Respiratory System Cells :

• Type 1 Pneumocytes = gas diffusion

• Type 2 Pneumocytes = surfactant production

• Ciliated Epithelial = debris removal

• Goblet Cells = mucus production

Slow , Deep Breaths = more efficient

• larger total tidal volume than fast , short breaths

• you have to subtract some to dead space every breath , so you might as well make each as large as possible

${\dot{V}}_A$$\dot{V}_A$ = alveolar minute ventilation

$\dot{Q}$$\dot{Q}$ = perfusion / blood flow through the capillaries

Restrictive vs Obstructive Pulmonary Diseases :

• Restrictive :

  • reduction in compliance

  • fibrosis , embolism

  • difficulty inhaling

  • reduced lung volumes ( all )

  • high $V/Q$$V/Q$ = dead space = no perfusion

• Obstructive :

  • inflammation

  • asthma , COPD , emphysema

  • difficulty exhaling

  • incomplete emptying of air from the lungs

  • increases reserve volume

  • low $V/Q$$V/Q$ = shunted = no ventilation

Hemoglobin is needed because $O_2$$O_2$ is poorly dissolvable in the blood plasma

Left Shift = high affinity for $O_2$$O_2$ , alkalosis , low temperature , low 2,3-BPG

• Haldane Effect = hemoglobin binds $C{O}_2$$CO_2$ easier

• fetal hemoglobin so they can have preference over the mom's hemoglobin

Right Shift = low affinity for $O_2$$O_2$ , acidosis , high temperature , high 2,3-BPG

• Bohr Effect = Hb binds $O_2$$O_2$ easier

3 Ways $C{O}_2$$CO_2$ is Transported :

1. Dissolved in blood plasma

2. Bound to hemoglobin

3. In bicarbonate ion form

Negative Pressure Pump :

• diaphragm contraction increases thoracic volume creating sub-atomospheric pressure in the lungs to draw air in

Hypoxic Pulmonary Vasoconstriction ( HPV ) = redirects bloodflow , leading to emphysema , leading to embolism , leading to pressure increases , leading to right heart failure

Control of Breathing :

• pre-Botzinger = inhalation rhythm

• Botzinger = exhalation rhythm

Parasympathetic = dilates , reduces mucus

Sympathetic = constricts , increases mucus

Muscle activity reduces venous pressure

Venous system has majority of capacitance

Circulatory System :

• nutrient transport , waste removal , fluid balance , temperature regulation , chemical signaling , immune response

Capillaries = single cell layer

• no elastin , no collagen , no smooth muscle

Arterioles = major determinant of TPR

Convection is in upper respiratory tract and in systemic circulation

Diffusion is in pulmonary alveoli and into mitochondria

Hypoxia :

• systemic arteries = dilates arteries to increase perfusion

• pulmonary arteries = constrict to try and shunt blood flow

Hering-Breuer Reflex = if overstretched , send signal to slow/stop breathing

Diving Reflex = cold water ➡️ vasoconstriction to prevent stuff from entering the lungs

LH :

• Leydig Cells = LH ➡️ cAMP ➡️ PKA ➡️ Cholesterol ➡️ Pregnenolone ➡️ Testosterone

• Theca Cells = LH ➡️ cAMP ➡️ PKA ➡️ Cholesterol ➡️ Pregnenolone ➡️ Androgens

FSH :

• Sertoli Cells = FSH ➡️ cAMP ➡️ PKA ➡️ Gene Transcription ➡️ Androgen-Binding Protein ( ABP )

• Granulosa Cells = FSH ➡️ cAMP ➡️ PKA ➡️ Gene Transcription ➡️ Aromatase ➡️ Androgens ➡️ Estrogens

Embryo :

• zygote = fertilized egg , single diploid cell

• blastocyst :

  • inner cell mass = forms baby / gastrulation

  • gastrulation @ 3rd week :

    • endoderm = GI tract

    • mesoderm = muscles

    • ectoderm = CNS , skin , nails

• Fetus = @ 10 weeks

3 Sources of Progesterone :

• Corpus Luteum , hCG , Placenta

3 Positive Feedforward Loops :

• LH Surge , Oxytocin in contractions , Oxytocin in lactation