L8 Role of Airways conducting clean air to lungs

Question 1

describe the upper airway epithelium

Answer 1

pseudo stratified columnar epithelium + cilia + goblet cells + basal cells + brush cells

Question 2

can the upper airway epithelium regenerate

Answer 2

yes, due to basal cells that can differentiate

Question 3

which cells of the URT epithelium are innervated and by which nerve

Answer 3

brush cells forming the thick microvilli. Sensory receptors receive information which is transmitted along trigeminal nerve

Question 4

How can we differentiate between respiratory and olfactory mucosa

Answer 4

respiratory has glands, olfactory doesn’t.

olfactory cells have large processes into lumen

Question 5

describe the cell population of olfactory mucosa

Answer 5

olfactory cell (w/ projections & olfactory cell processes) + sustenacular support cell + basal cell

Question 6

What is the role of the sustenacular cells

Answer 6

metabolic support to olfactory cells

Question 7

Describe the epithelium of the lower respiratory tract

Answer 7

columnar to cuboidal epithelium. Fewer goblet cells. thin lamina propria, cartilage rings of trachea, and plates in bronchi, SMC in bronchi (absent in alveoli), club cells @ bronchioles

Question 8

what are club cells

Answer 8

dome shaped cells in bronchioles & respiratory bronchioles that secret glysoaminoglycans, club cell secretory protein (CCSP) .
stem cell function for repair
engulf toxins and break down

Question 9

does the bronchus or the trachea have more mucus glands

Answer 9

trachea

Question 10

which areas of the respiratory tract have pseudostratified columnar epithelium

Answer 10

trachea, bronchus, segmental bronchi

Question 11

what is the epithelium of the bronchiole and the respiratory bronchioles

Answer 11

bronchiole= cuboidal/ columnar

respiratory bronchiole= cuboidal

Question 12

is cartilage present in the segmental bonchi

Answer 12

yes

Question 13

what controls the calibre of bronchioles, considering there is no cartilage

Answer 13

SMC tonus to keep rigid & open and elastic fibres of alveolar attachments

Question 14

Name some defence mechanisms of the respiratory tract

Answer 14

nasal hairs 
cough sneeze mechanisms 
lymphoid organs 
luminal epithelium (SA, barrier, cytokines) 
MCC
club cells

Question 15

Describe the sneeze reflex

Answer 15

irritation in NASAL PASSAGES –> AP along trigeminal nerve (CNV) -> medulla –> soft palate depressed so air is directed through nose -> deep inspiration and glottis closure to force air

Question 16

Describe the cough reflex

Answer 16

irritation in larynx and trachea (/ parhynx/ bronchi) -> message send via glossopharyngeal and vagus nerve -> inspiration, glottis closes, forced air