Pulmonary Circulation

Question 1

Pulmonary circulation has _______ pressures than the systemic circulation

Answer 1

LOWER pressures

Question 2

Pulmonary circulation has _______ resistance than the systemic circulation

Answer 2

LOWER resistance

Question 3

Pulmonary circulation has _______ compliance than the systemic circulation

Answer 3

HIGHER compliance

Question 4

Pulmonary circulation has _______ than the systemic circulation

Answer 4

LOWER volume

Question 5

It takes about ___-___ seconds for a RBC to travel through the pulmonary circulation at resting CO. How much time is spent in the pulmonary capillaries?

Answer 5

4-5 seconds
0.75 seconds

Question 6

Are the diameters of pulmonary arteries and arterioles smaller or larger than systemic arterioles?

Answer 6

LARGER

Question 7

What are the walls like of pulmonary arteries and arterioles?

Answer 7

They are thin and distensible = they have large compliance

Question 8

Are pulmonary capillaries more or less distensible than systemic capillaries?

Answer 8

MORE distensible/compliant

Question 9

Is there a population of pulmonary capillaries that are closed at rest?

Answer 9

Yes

Question 10

Are pulmonary veins shorter or longer than systemic veins?

Answer 10

SHORTER than systemic veins

Question 11

Bronchial circulation supplies oxygen and nutrients to the ___________ __________ down to the ________ _______.

Answer 11

• tracheobronchial tree
• terminal bronchioles

Question 12

Bronchial circulation also goes to the:

Answer 12

• Pulmonary blood vessels
• Visceral pleura
• Nerves
  -Hilar lymph nodes

Question 13

How much bronchial flow is CO of the left ventricle?

Answer 13

About 2%

Question 14

Blood in the left atrium has a slightly ______ O2 concentration than blood in the ________ _______. WHY?

Answer 14

• LOWER
• PULMONARY CAPILLARIES
• BC some deoxygenated blood from bronchial venins mix with oxygenated blood in pulmonary veins

Question 15

Where do structures in the respiratory zone receive oxygen directly from?

Answer 15

Diffusion from the alveolar air and receive nutrients from the mixed venous blood in the pulm. circulation

Question 16

Pulm. Circulation is a ______ pressure and a ______ resistance circuit.

Answer 16

LOW pressure
LOW resistance

Question 17

Systemic circulation of 120/80 makes MAP = ______ (____)

Answer 17

93 mmHg

Question 18

Pulmonary circulation of 25/8 makes MAP = _____ (____)

Answer 18

14 mmHg

Question 19

Pressure continues to ________ as it goes to the pulmonary capillaries and left atrium

Answer 19

DECREASE

Question 20

Pulmonary blood volume accounts for how much blood volume?

Answer 20

Approx 9% but is highly variable

Question 21

During inspiration, does the volume of the pulmonary circulation circuit go UP or DOWN?

Answer 21

UP. Because Pip becomes more negative, pulling blood vessels open.

Question 22

During expiration, does the volume of the pulmonary circulation circuit go UP or DOWN?

Answer 22

DOWN

Question 23

Does lying down increase or decrease blood volume? WHY?

Answer 23

INCREASES blood volume
- there is less of a gravitational effect

Question 24

Do diseases like heart failure increase or decrease the volume of the pulmonary circuit?

Answer 24

INCREASE the volume
- Isn’t a good thing
- Can be why there’s increased risk for pulm. edema

Question 25

Are pulmonary vessels far more distensible?

Answer 25

YES - can alter their size and adjust to change their pulmonary volumes

Question 26

Does CO increase or decrease with exercise?

Answer 26

It INCREASES about 4-7 times with heavy exercise. However, only a small increase in pulmonary artery pressure

Question 27

At rest, are multiple pulmonary capillary networks OPEN or CLOSED?

Answer 27

They are CLOSED but they are capable of opening up if necessary

Question 28

What will opening more capillaries do to the total resistance?

Answer 28

When you open more capillaries you INCREASE the surface area, and this DECREASES the total resistance

Question 29

T/F: Pulmonary circulation is NOT as prone to hypertension as the systemic circulation

Answer 29

True

Question 30

During exercise, cardiac output may increase 7-fold but the MAP of the pulmonary circultion will only increase 1-2 mmHg. HOW?

Answer 30

An INCREASE in blood flow DECREASES the PVR (resistance). This is why there is not much of a change in MAP.

Question 31

What is the mechanism that allows pulmonary resistance to FALL when flow goes up?

Answer 31

1. The RECRUITMENT of pulmonary capillaries 2. The DISTENTION of pulmonary capillaries

Question 32

What happens to the blood vessels when PAO2 (the alveolar concentration of O2) drops to 70 mmHg from 100 mmHg?

Answer 32

The neighboring blood vessels CONSTRICT

Question 33

What happens to the blood vessels when PAO2 is high?

Answer 33

The blood vessels will dilate. Blood will be delivered to the alveoli where it will be most effective at gas exchange

Question 34

What would happen throughout the pulmonary circulation at a high altitude where PAO2 is reduced?

Answer 34

Would cause vasoconstriction throughout pulmonary circuit, which would cause pulm. hypertension.