respiratory anatomy

Question 1

conducting zone of the lung are composed of what on histology?

Answer 1

cartilage and goblet cells extend to the end of the bronchi; pseudostratified ciliated columnar cells (clear mucus from lungs) extend to the begnning of terminal bronchioles, then transition to cuboidal cells; airway smooth muscle cells extend to end of terminal bronchilies (sparse beyond this point)

Question 2

respiratory zone of the lung

Answer 2

consists of respiratory bronchiloes, alveolar ducts, and alveoli; these are the parts that contribute to gas exchange; mostly cuboidal cells in respiratory bronchioles then simple squamous cells up to alveoli; cilia terminate in respiratory bronchioles; alveolar macrophages clear debris and participate in the immune response

Question 3

what are the three types of pneumocytes?

Answer 3

type I, type II, and club(clara) cells

Question 4

type I pneumocytes

Answer 4

97% of alveolar surfaces; line the alveoli; squamous, thin for optimal gas diffusion

Question 5

type II pneumocytes

Answer 5

secrete surfactant; cuboidal and clustere; also serve as precursors to type I cells and other type II cells; type II cells proliferate during lung damage

Question 6

club (clara) cells

Answer 6

nonciliated; low-columnar/cuboidal with secretory granules; secrete component of surfactant, degrade toxins, act as reserve cells

Question 7

alveoli collpase when?

Answer 7

they have an increased tendency to collapse on expiration as the radius decreases (Law of Laplace)

Question 8

surfactant

Answer 8

synthesis begins around week 26 of gestation but mature levels are not achieved until around week 35; lecithin to sphingomyelin ratio greater than 2.0 in amniotic fluid indicates fetal lung maturity.

Question 9

right versus left lung lbes

Answer 9

the right rung as three lobes, the left has less lobes (2) and lingula

Question 10

why is the right lung more common site for inhaled foreign body?

Answer 10

right main stem bronchus is wider and more vertical than the left

Question 11

horizontal versus oblique fissure

Answer 11

horizontal is the top one (separates upper lobe from middle lobe) and oblique is the lower one (separates middle from upper)

Question 12

Relation of pulmonary artery to the bronchus at each lung hilum

Answer 12

RALS; right anterior, left superior

Question 13

Structures perforating the diaphragm

Answer 13

T8: IVC, T10: esophagus, vagus, T12: aorta, thoracic duct, azygous vein (red, white and blue); I ate 10 eggs at 12

Question 14

diaphragm innervation

Answer 14

C3, C4, C5 (phrenic nerve); pain from the diaphragm irritation can be referred to shoulder (C5) and trapezius ridge (C3, C4)

Question 15

the common carotid bifurcates where

Answer 15

C4

Question 16

the trachea bifurcates where?

Answer 16

T4

Question 17

the abdominal aorta bifurcates where?

Answer 17

L4