Respiration: Gas Exchange

Question 1

What is the order of air flow into the lungs (start -> finish)

Answer 1

Trachea -> Bronchi -> Bronchioles -> Alveoli

Question 2

How many types of epithelial cells are alveoli composed of and what is the function of each?

Answer 2

Type 1: Occupy 97% surface, PRIMARY site of gas exchange

Type 2: Occupy 3%, produce pulmonary surfactant which reduces surface tension

Question 3

How many blood supplies do the lungs have?

Answer 3

2
Pulmonary circulation

Bronchial circulation: supplies lungs with oxygen

Question 4

What are the 2 circuits called in which gas exchange occurs throughout the body?

Answer 4

Pulmonary Circuit: O2 enters blood, CO2 leaves

Systemic Circuit: O2 leaves blood, CO2 enters

Question 5

What are the average gas concentration gradients found in pulmonary capillaries and systemic capillaries

Answer 5

Pulmonary Capillary:
(Alveolar Air)  (Venous Blood)
PO2 100 --> 40
PCO2 40  (Arterial Blood)
PO2 <40 46 --> 40

Question 6

Gases move [up/down] pressure gradients?

Answer 6

Down