Pulmonary Circulation Flashcards
Pulmonary circulation has _______ pressures than the systemic circulation
LOWER pressures
Pulmonary circulation has _______ resistance than the systemic circulation
LOWER resistance
Pulmonary circulation has _______ compliance than the systemic circulation
HIGHER compliance
Pulmonary circulation has _______ than the systemic circulation
LOWER volume
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?
4-5 seconds
0.75 seconds
Are the diameters of pulmonary arteries and arterioles smaller or larger than systemic arterioles?
LARGER
What are the walls like of pulmonary arteries and arterioles?
They are thin and distensible = they have large compliance
Are pulmonary capillaries more or less distensible than systemic capillaries?
MORE distensible/compliant
Is there a population of pulmonary capillaries that are closed at rest?
Yes
Are pulmonary veins shorter or longer than systemic veins?
SHORTER than systemic veins
Bronchial circulation supplies oxygen and nutrients to the ___________ __________ down to the ________ _______.
- tracheobronchial tree
- terminal bronchioles
Bronchial circulation also goes to the:
- Pulmonary blood vessels
- Visceral pleura
- Nerves
-Hilar lymph nodes
How much bronchial flow is CO of the left ventricle?
About 2%
Blood in the left atrium has a slightly ______ O2 concentration than blood in the ________ _______. WHY?
- LOWER
- PULMONARY CAPILLARIES
- BC some deoxygenated blood from bronchial venins mix with oxygenated blood in pulmonary veins
Where do structures in the respiratory zone receive oxygen directly from?
Diffusion from the alveolar air and receive nutrients from the mixed venous blood in the pulm. circulation
Pulm. Circulation is a ______ pressure and a ______ resistance circuit.
LOW pressure
LOW resistance
Systemic circulation of 120/80 makes MAP = ______ (____)
93 mmHg
Pulmonary circulation of 25/8 makes MAP = _____ (____)
14 mmHg
Pressure continues to ________ as it goes to the pulmonary capillaries and left atrium
DECREASE
Pulmonary blood volume accounts for how much blood volume?
Approx 9% but is highly variable
During inspiration, does the volume of the pulmonary circulation circuit go UP or DOWN?
UP. Because Pip becomes more negative, pulling blood vessels open.
During expiration, does the volume of the pulmonary circulation circuit go UP or DOWN?
DOWN
Does lying down increase or decrease blood volume? WHY?
INCREASES blood volume
- there is less of a gravitational effect
Do diseases like heart failure increase or decrease the volume of the pulmonary circuit?
INCREASE the volume
- Isn’t a good thing
- Can be why there’s increased risk for pulm. edema
Are pulmonary vessels far more distensible?
YES
- can alter their size and adjust to change their pulmonary volumes
Does CO increase or decrease with exercise?
It INCREASES about 4-7 times with heavy exercise. However, only a small increase in pulmonary artery pressure
At rest, are multiple pulmonary capillary networks OPEN or CLOSED?
They are CLOSED but they are capable of opening up if necessary
What will opening more capillaries do to the total resistance?
When you open more capillaries you INCREASE the surface area, and this DECREASES the total resistance
T/F: Pulmonary circulation is NOT as prone to hypertension as the systemic circulation
True
During exercise, cardiac output may increase 7-fold but the MAP of the pulmonary circultion will only increase 1-2 mmHg. HOW?
An INCREASE in blood flow DECREASES the PVR (resistance). This is why there is not much of a change in MAP.
What is the mechanism that allows pulmonary resistance to FALL when flow goes up?
- The RECRUITMENT of pulmonary capillaries
- The DISTENTION of pulmonary capillaries
What happens to the blood vessels when PAO2 (the alveolar concentration of O2) drops to 70 mmHg from 100 mmHg?
The neighboring blood vessels CONSTRICT
What happens to the blood vessels when PAO2 is high?
The blood vessels will dilate. Blood will be delivered to the alveoli where it will be most effective at gas exchange
What would happen throughout the pulmonary circulation at a high altitude where PAO2 is reduced?
Would cause vasoconstriction throughout pulmonary circuit, which would cause pulm. hypertension.
