lecture 5

Question 1

Where is the bronchial circulation supplied via

Answer 1

via the bronchial arteries arising from systemic circulation

Question 2

where is the pulmonary circulation supplied from

Answer 2

supplied from the left and right pulmonary arteries originating from the right ventricle

Question 3

the pulmonary circulation returns oxygenated blood to the left atrium via what vessel

Answer 3

the pulmonary vein

Question 4

the rate of diffusion across the membrane is directly or indirectly proportional to the partial pressure gradient

Answer 4

directly

Question 5

the rate of diffusion across the membrane is directly or indirectly proportional to gas solubility

Answer 5

direcctly

Question 6

the rate of diffusion across the membrane is directly or indirectly proportional to the available surface area

Answer 6

directly

Question 7

the rate of diffusion across the membrane is directly or inversely proportional to the thickness of the membrane

Answer 7

inversely

Question 8

what cells are responsible for gas exchange in the alveoli

Answer 8

type 1 cells

Question 9

what is the function of alveolar macrophages

Answer 9

ingest foreign material that reaches the alveoli

Question 10

What does emphysema do

Answer 10

in emphysema the inner walls of the alveoli eventually weaken resulting in rupture, creating one large air sac instead of many small ones and this reduces the surface area for gas exchange.

Question 11

what is fibrotic lung disease

Answer 11

Scar formation, the accumulation of excess fibrous connective tissue (the process called fibrosis), leads to thickening of the walls, and causes reduced oxygen supply in the blood. As a consequence patients suffer from perpetual shortness of breath.

Question 12

pulmonary edema is fluid in the interstitial space, this increase diffusion distance however arterial co2 may still be normal, why?

Answer 12

due to higher co2 solubility in water

Question 13

where is blood flow highest at the base of the lungs or the apex

Answer 13

base

Question 14

why is blood flow low at the apex of the lungs

Answer 14

arterial pressure is less than alveolar pressure. This compresses the arterioles and vascular resistance is increased.

Question 15

define what a shunt is

Answer 15

when the alveoli of the lungs are perfused with blood as normal, but ventilation fails to supply the perfused region.

Question 16

decreased levels of oxygen and increased levels of carbon dioxide caused the arterioles to do what?

Answer 16

constrict diverting blood to better ventilated alveoli

Question 17

shunt is the opposite to what?

Answer 17

alveolar dead space

Question 18

define alveolar dead space

Answer 18

alveoli that are ventilated but not perfused