Ventilation-Perfusion Relationships

Question 1

Describe Hypoxic Vasoconstriction

Answer 1

1) Myogenic Mechanism that allows blood flow to redirect to areas of greater ventilation

Question 2

Describe the Mechanism of Hypoxic Vasoconstriction

Answer 2

1) Reduces Redox states
2) Decreased K+ leak channels
3) Depolarization
4) Opening of L-Type Calcium Channels
5) Smooth muscle contraction
6) Vasoconstriction

Question 3

Alveolar Capillaries recieve blood from the ___ ventricle

Answer 3

Right

Question 4

What is the pressure of the right ventricle

Answer 4

25/0

Question 5

What is the pressure of the pulmonary artery

Answer 5

25/15

Question 6

What is the PaCO2 of Alveolar Capillaries? Why?

Answer 6

45mmHg; Blood is recieved from the systemic side.

Question 7

PaO2 in the alveolar capillaries

Answer 7

40 mmHg

Question 8

Extar-alveolar Capillary PaO2

Answer 8

95-100mmHg

Question 9

Function Extra-alveolar Capillary

Answer 9

Deliver O2/remove CO2 from bronchi

Question 10

Function of Alveolar Capillary

Answer 10

Exchange (arterialize)

Question 11

How does Extra-alveolar Capillary return blood back to the blood.

Answer 11

Azygous/Pulm V.

Question 12

Which has a higher resistance: pulmonary or system?

Answer 12

Systemic

Question 13

What happens to pulmonary vascular resistance during exercise

Answer 13

Decreases to compensate for the increase in CO

Question 14

List the Factors of Pulmonary Vascular Resistance (4x)

Answer 14

1) Numbers of Capillaries
2) Number of open capillaries
3) Much less sympathetic tone/vasocontriction forces
4) Lung volume

Question 15

Why at low or very high lumg volumes is the Pulm. resistance increased?

Answer 15

Due to the stretch of the tissue compresses the capillares

Question 16

Describe Pulmonary Vascular Resistance in COPD and why.

Answer 16

1) Increased
2) Decreased SA leads to decreased alveoli and alveolar capillaries
3) Increased Hypoxic Vasoconstriction

Question 17

At the apex of the lungs, The blood pressure is ___. Why?

Answer 17

1) Reduced
2) Slightly above the heart

Question 18

Compare the pressures in the apex: PA; Pa; Pv

Answer 18

PA > Pa > Pv

Question 19

Describe the blood flow in the Apex

Answer 19

Little Blood Flow

Question 20

Describe the Blood flow of the

Answer 20

Normal Blood Flow

Question 21

Describe the blood flow in the base of the lung

Answer 21

High bloog flow

Question 22

Describe how NO influences pulmonary blood flow

Answer 22

1) Increases
2) Vasodilation

Question 23

What stimulates the NO release

Answer 23

Parasympathics

Question 24

Tissue oncotic favors motion of water into ___

Answer 24

Alveolus

Question 25

what are lymphatics crucial for keeping alveoli dry?

Answer 25

Remove filtered fluid from the alveolus

Question 26

What enzyme converts to angiotensin 1 to angiotensin 2

Answer 26

ACE

Question 27

ACE converts angiotensin 1 to angiotensin 2 it also breaks down ____

Answer 27

Bradykinin

Question 28

Leukotrines and PGF2a and PGe are removed via what

Answer 28

Lungs