Gas Exchange

Question 1

describe the pathway of the respiratory tree starting at the trachea

Answer 1

trachea - bronchi - non respiratory bronchioles - respiratory bronchioles - alveolar ducts

Question 2

conducting airways

Answer 2

do not participate in gas exchange and are anatomically dead space
consist of the trachea, bronchi and non-respiratory bronchioles

Question 3

respiratory unit

Answer 3

gas exchanging unit

consists of respiratory bronchioles, alveolar ducts and alveoli

Question 4

alveoli

Answer 4

have very thin walls and a large surface area therefore perfect for gas exchange
no cartilage surrounding them therefore they can expand

Question 5

what type of cells are alveoli composed of

Answer 5

type 1 and type 2 epithelial cells
type 1 - occupy 97%, dite of gas exchange
type 2 - also known as septal cells, produce pulmonary surfactant

Question 6

pulmonary surfactant

Answer 6

produced by type 2 epithelial cells, reduces tension between airs/ liquids in lungs allowing them to expand and have elastic properties

Question 7

what surrounds alveoli

Answer 7

capillaries

Question 8

pulmonary circuit

Answer 8

carries blood from right ventricle to alveolar-capillary network to be oxygenated. Large volumes of blood at low pressure

Question 9

bronchial circuit

Answer 9

brings oxygenated blood to lung parenchyma

Question 10

how is partial pressure calculated

Answer 10

fraction of gas in mixture
x
barometric pressure

Question 11

what happens to the partial pressure of air as it moves from the mouth to the alveoli

Answer 11

it decreases due to humidification and O2 passing into capillary system