Introduction

• Functions of the respiratory system :
  • the major function of the respiratory system is to supply ?
  • to achieve this , the respiratory system works closely with the ?
• Organization of the Respiratory System :
  • consists of the nose , pharynx ( throat ) , larynx ( voice box ) , trachea ( windpipe ) , bronchi , and lungs
  • divided into upper and lower respiratory systems
    • the upper respiratory system consists of the ? , ? , and ?
    • the lower respiratory system consists of the ? , ? , ? , and ?

Nose

• Functions :
  • ?
  • moistens , warms , and filters the air
  • contains olfactory receptors
    • Cranial Nerve 1 ➡️ cribiform plate of sphenoid bone
• The nose consists of the external nose and the nasal cavity
  • External Nose :
    • composed of ? and bone
  • Nasal Cavity :
    • roof is formed by the ethmoid and sphenoid bones
    • floor is formed by the ?
    • the nasal cavity is divided by the ?
    • the external openings of the nasal cavity are the nares ( nostrils )
    • internally , the nasal cavity opens into the nasopharynx ( by way of the ? )
    • protruding medially from each lateral wall of the nasal cavity are the ?
      • the nasal conchae ?
    • the nasal cavity is lined with :
      • stratified squamous epithelium
      • pseudostratified ciliated columnar epithelium

Pharynx

• divided into three regions : nasopharynx , oropharynx , and laryngopharynx
• nasopharynx :
  • border = ? to ?
  • located posterior to the ?
  • when we swallow , the ? and ? close off the nasopharynx
  • contains the openings of the ?
    • auditory tubes equalize pressure between the middle ear and nasopharynx
  • the posterior surface of the nasopharynx contains the pharyngeal tonsil
  • nasopharynx is lined with pseudostratified ciliated columnar epithelium
• oropharynx :
  • border = ? to ?
  • located posterior to the ?
  • continuous with the oral cavity by way of the ?
    • the ? and ? tonsils are located near the fauces
  • the oropharynx is lined with stratified squamous epithelium
• laryngopharynx :
  • border = ? to ?
  • located posterior to the epiglottis and ?
  • continuous with the ?
  • lined with stratified squamous epithelium

Larynx

• major structures of the larynx include : thyroid cartilage , cricoid cartilage , epiglottis , false vocal cords , and true vocal cords
• Thyroid Cartilage :
  • located superior to the ?
  • composed of ?
  • functions in maintaining an open passageway for air movement
    • keeps larynx open
  • often called the ? because it is larger in men
• Cricoid Cartilage :
  • located inferior to the thyroid cartilage
  • composed of ?
  • like the thyroid cartilage , it functions in maintaining an open passageway for air movement
• Epiglottis :
  • composed of ?
  • functions in closing off the opening of the larynx ( glottis ) when we swallow
• False Vocal Cords ( folds ) :
  • located above true vocal cords
  • keep food out of the larynx
    • last resort , backup
  • no role in sound production
• True Vocal Cords :
  • involved with ?

Trachea

• the ? , tubular passageway for air located anterior to the esophagus
• consists of C-shaped rings of ? and the trachealis muscle
  • maintains open airway
• lined with pseudostratified ciliated columnar epithelium
  • smoking can cause the epithelium to change to stratified squamous epithelium
• the trachea divides at the ? to form the right primary bronchus ( enters right lung ) and the left primary bronchus ( enters left lung )
  • the right primary bronchus is wider , shorter , and more vertical than the left
    • therefore , objects are ?
• the primary bronchi further divide into secondary bronchi , tertiary bronchi , conducting bronchioles , and terminal bronchioles
• as the bronchi get smaller , the amount of cartilage ? and the amount of smooth muscle ?
• all of the bronchi , bronchioles , and terminal bronchioles are lined with some type of ciliated epithelium
  • ( either pseudostratified , columnar , or cuboidal )
• terminal bronchioles divide to form ?
  • ( which give rise to alveoli by way of alveolar ducts )
• alveoli are the microscopic air sacs in the lungs where gas exchange occurs
  • ( $O_2$ and $CO_2$ are exchanged between capillaries and alveoli )

Pleura

• consists of the parietal pleura and visceral pleura
• parietal pleura :
  • lines ? of thoracic wall , lateral surface of pericardium , and superior surface of diaphragm
• visceral pleura :
  • lines ? of the lungs
• pleural cavity :
  • cavity located between the parietal and visceral layer of the pleura
    • ( contains ? )

Blood Vessels Associated with the Lungs

• venous blood that needs to be oxygenated is delivered to the lungs by the pulmonary arteries
• within the lungs the pulmonary arteries branch into smaller and smaller blood vessels , eventually forming the ? that surround the ?
  • $O_2$ and $CO_2$ are exchanged between the capillaries and alveoli
• the freshly oxygenated blood is delivered to the heart by the ?
• oxygenated blood is supplied to the lung tissue by the ? ( branch off of the aorta )
• deoxygenated blood from the lung tissue is returned to the heart by the ?

Misc

• Type 1 Pneumocytes = ? , really thin cells
• Type 2 Pneumocytes = ? ( reduces surface tension )
• What two layers form the respiratory membrane ?
  • wall of ? + wall of ?

• Alveolar Macrophage = phagocytes that clears anything that makes it to the alveoli

• Muscles of Inspiration :

  • diaphragm ( contracts and moves inferiorly )
    • innervated by phrenic nerve
  • pectoralis minor ( elevates the ribcage )
  • external intercostals ( elevates the ribcage )

• Muscles of Expiration :

  • diaphragm ( relaxes and moves superiorly )
  • abdominal muscles ( depress the ribcage )
  • internal intercostals ( depress the ribcage )

• What type of tissue lines the walls of the alveolus and why?

  • simple squamous epithelium
    • because we need as thin of a wall as possible for gas exchange