Pulmonary Circulation Flashcards Preview

Physiology III > Pulmonary Circulation > Flashcards

Flashcards in Pulmonary Circulation Deck (17):
1

How much blood is within the pulmonary circulation?

450mL
9% of total blood volume
70mL is in pulmonary capillaries

2

What results in the pulmonary circulation as a result of failure of left side of the heart?

blood volume increases as much as 100%
increase in blood pressure

3

What is a physiologic shunt?

This is the 2% of blood that has evaded the oxygenation process in the lungs.

4

How many zones are there in the lungs and what do they designate?

There are 3 lung zones. These zones are made because they receive different amounts of blood flow. The blood flow in bottom of lungs are 5x more than blood flow in upper lungs.

5

What type of blood flow is seen in zone 3?

continuous blood flow

6

What type of blood flow is seen in zone 2?

There is only blood flow during systole

7

What type of blood flow is seen in zone 1?

no blood flow, local alveolar capillary pressure never rises higher than alveolar air pressure

8

True or False.
Pulmonary veins are very distensible making them an important blood reservoir.

true

9

What are agents that can constrict pulmonary arterioles?

norepinephrine
epinephrine
angiotensin II
some prostaglandins

10

What are 3 agents that constrict pulmonary venules?

serotonin
histamine
E.coli endotoxin

11

What are 2 agents that dilate pulmonary arterioles?

isoproterenol
acetylcholine

12

What effect do sympathetic vasoconstrictors have on the circulation?

decreases pulmonary blood flow by as much as 30%, mobilizes blood from pulmonary reserve.

13

What effect does exercise have on blood flow through the lungs?

-increase number of open capillaries up to 3x
-distends all capillaries and increases flow rate up to 2x
-increase pulmonary arterial pressure

14

What are 4 causes of pleural effusion?

-blockage of lymphatic drainage from pleural cavity
-cardiac failure
- reduced plasma colloid osmotic pressure
-infection/inflammation

15

What is the most common cause of hypoxia?

bronchial obstruction

16

What are 4 causes of bronchial obstruction?

-low alveolar PO2 effect on the vessels
- drop in pH due to accumulation of CO2
-decline in pH produces vasoconstriction in pulmonary vessels
- decline in pH produces vasodilation in other tissues.

17

What is the pulmonary arterial pressure?

24/9mmHg