Respiratory I

Question 1

describe the lamina propria of the olfactory mucosa

Answer 1

• lamina propria
  
  • continuous with the periosteum
  • highly vascularized
  • abundant nerve ending
  • olfactory (Bowman’s) glands
    
    • serous secretory units that drain to surface
    • contain lipofucin granules which contributes to yellow color of olfactory region

Question 2

describe the respiratory region of the nasal cavity

Answer 2

• mostly lined by respiratory mucosa
  
  • blood vessels lined parallel to air to warm the air
  • large venous plexus (leads to congestion)

Question 3

describe the larynx

Answer 3

• tubular region between the oropharynx and trachea

Question 4

contrast the vestibular (ventricular) folds and the vocal folds (true vocal cords)

Answer 4

• vestibular
  
  • loose CT containing glands and lymphoid aggregations
  • covered by respiratory epithelium
• vocal folds
  
  • vocalis muscle
  • vocal ligament
  • lined by stratified squamous non-keratinized epithelium

Question 5

describe the picture

Question 6

describe the mucosa of the trachea

Answer 6

• consists of epithelium + lamina propria
• respiratory epithelium
  
  • lines most of the conducting part of the resp. system
• ciliated columnar cells:
  
  • most numerous and run the full thickness of the epi.
  • each cell has about 250 cilia at the apical surface attached to basal bodies
  • aggregated basal bodies give the appearance of a dark line at the apical surface

Question 7

describe the small granule cells in the mucosa

Answer 7

• aka enteroendocrine cells
• contain many small granules concentrated in their basal cytoplasm
• synthesize different polypeptide hormones:
  
  • calcitonin
  • serotonin
  • catecholamine

Question 8

describe the lamina propria in the trachea

Answer 8

• loose CT with well developed lymphatic tissue
• contains elastic fibers arranged in longitudinal bands at the mucosa/submucosa boundary

Question 9

describe the submucosa of the trachea

Answer 9

• loose CT character similar in appearance to the LP
• seromucous glands (mucous acini w/ serous demilunes) which secrete glycoprotein

Question 10

describe the cartilaginous layer of the trachea

Answer 10

• the skeleton of the trachea is formed by 16-20 C shaped rings of hyaline cartilage
  
  • guarantees patency but permits flexibility
• the gap in the ring is completed by a fibroelastic membrane which contains the trachealis muscle (smooth)
• outside the cartilage layer is the adventitia
  
  • CT which binds trachea and trachealis muscle to other structures in the neck and mediastinum
  • contains large bv, nerves and lymphatics

Question 11

describe the intrapulmonary bronchi

Answer 11

• mucosa:
  
  • respiratory epi.
• muscularis:
  
  • layer of spirally oriented SM deep to mucosa; regulates airway diameter
• submucosa:
  
  • loose CT with glands
• cartilage layer
  
  • discontinuous cartilage plates arranged in a linear pattern around the bronchus
• adventitia

Question 12

describe the bronchial tree

Answer 12

• trachea
• main bronchus
• lobar bronchus
• segmental bronchus
• terminal bronchus
• respiratory bronchus
• alveolar duct
• alveolar sacs
• alveoli

Question 13

describe clara cells

Answer 13

• cuboidal cells with domed or club shaped apical surface
• well develped basal rER, sER, Golgi and secretory granules
• secretes:
  
  • surface active agent
    
    • prevents bronchiole collapse
  • clara cell protein (CC16)

Question 14

describe a terminal bronchiole

Answer 14

• lined by simple cuboidal epithelium with cilia and clara cells
• sparse loose CT under epi
• circumferential SM
• widespread constriction of SM in the bronchioles decreases diameter
  
  • ribboned shape ring

Question 15

describe a respiratory bronchiole

Answer 15

• transition airways involved in both conduction and resp.
• first site where gaseous exchange occurs
• simple cuboidal epi. with ciliated and Clara cells
• discontinous walls interrupted by alveoli
• these narrow tubes are supported by a small amount of SM and lung tissue

Question 16

describe alveolar ducts

Answer 16

• respiratory bronchioles transition into alveolar ducts as the number of alveolar out pouchings increase
• AD are lined by numerous alveoli
• bundles of SM cells found between knob-like alveolar out-pocketing (interalveolar septum)

Question 17

contrast type I and II pneumocyte cells

Answer 17

• type I
  
  • most common
  • squamous cells
  • not capable of mitosis
• type II
  
  • cuboidal cells: secrete surfactant
  • regenerate both types of pneumocytes
  • apical cytoplasm contains lamellar bodies

Question 18

describe the different surfactant proteins

Answer 18

• SP-A regulates synthesis and secretion of surfactant and modulates immune response
  
  • SP-A and SP-D regulates the allergic response to airborne antigens
• SP-B and SP-C: surfactant organizing protein regulates spreading of surfactant on the alveolar surface
• SP-D binds to microorganisms and lymphocytes; SP-D is involved in the local inflammatory response to acute lung injury

Question 19

describe the interalveolar septum

Answer 19

• thin layer of CT found between adjacent alveoli
• contains collagen fibrils and elastic fibers
• the elastic fibers contributes to the pulmonary recoil needed for expiration
• abundant capillary network
• site of the air-blood barrier
  
  • structures through which gasses must diffuse between alveoli and capillaries

Question 20

describe the alveolar pores (of Kohn)

Answer 20

• pores of Kohn interruption in the interalveolar septa which allow circulation of air between alveoli
  
  • permits collateral flow in instances of obstruction of a lobular bronchiole but may also facilitate spread of infection from one lobule to another