Pulmonary Blood Flow

Question 1

Why is pulmonary blood flow important?

Answer 1

without the optimal flow through the lungs, ventilation is of no use

Question 2

Characterize pulmonary vessels.

Answer 2

have great dispensability and compliance, more capillaries than alveoli

Question 3

In the pulmonary system, venous blood is in the _____ and arterial blood is in the _____.

Answer 3

arteries, veins

Question 4

in pulmonary circulation, what induces vasoconstriction?

Answer 4

hypoxia

Question 5

Pulmonary artery pressure is ___ of systemic arterial pressure.

Answer 5

1/6th

Question 6

What does bronchiolar circulation supply?

Answer 6

nutritional blood to the tracheobronchial tree up to the terminal bronchiole, hilar lymph nodes, visceral pleura, pulmonary artery and vein, vagus nerve, and esophagus

Question 7

How does the bronchial and pulmonary system communicate?

Answer 7

via a shunt

Question 8

What is difference in pressures in the A-a pressure gradient?

Answer 8

5-10 mmHg

Question 9

Which has higher pressure: bronchial circulation or pulmonary circulation?

Answer 9

bronchial circulation

Question 10

Is resistance higher in pulmonary or systemic circulation?

Answer 10

pulmonary

Question 11

What is the mean pulmonary vascular resistance?

Answer 11

15 mmHg

Question 12

What is Poiseulle’s law for volume flow rate?

Answer 12

P1-P2 = Q (with a dot) x R

Question 13

What is P1 in Poiseulle’s law for volume flow?

Answer 13

pressure at the beginning of the tube in mmHg

Question 14

What is P2 in Poiseulle’s law for volume flow?

Answer 14

pressure at the end of the tube in mmHg

Question 15

What is Q in Poiseulle’s law for volume flow?

Answer 15

flow (mL/minute)

Question 16

What is R in Poiseulle’s law for volume flow?

Answer 16

resistance (mmHg/mL/minute)

Question 17

How do you calculate pulmonary vascular resistance?

Answer 17

PVR = (MPAP-MLAP)/pulmonary blood flow

Question 18

True or False: Pulmonary capillaries cannot stretch with change in resistance

Answer 18

False: they are distensible

Question 19

What happens to the small capillaries when the volume of the lung increases?

Answer 19

the alveoli inflate, and they are pinched

Question 20

When is the PVR the lowest?

Answer 20

when functional residual capacity is met

Question 21

How do you explain a fall in PVR during exercise?

Answer 21

recruitment and distention; they have to decrease resistance to compensate for increased flow to keep change in pressure the same

Question 22

How does more smooth muscle affect pulmonary arterial pressure?

Answer 22

it increases it (hypoxia)

Question 23

What species are highly susceptible to hypoxic vasoconstriction?

Answer 23

cattle and pig

Question 24

How does localized hypoxia affect pulmonary flow?

Answer 24

it redistributes it

Question 25

What is EIPH?

Answer 25

exercise induced pulmonary hemorrhage

Question 26

What causes EIPH?

Answer 26

high vaccuum during excercise that increases the transmural pressure difference, the barrier breaks, and the red blood cells end up in the alveoli

Question 27

In zone 1 of the lung, rank these pressures from highest to lowest(during ventilation); PA, PV, Pa.

Answer 27

PA > Pa> Pv

Question 28

What happens in zone 1 of the lung during ventilation?

Answer 28

there is no blood flow, alveolar pressure is pinching the vessels, not usually seen

Question 29

In zone 2 of the lung, rank these pressures from highest to lowest (during ventilation); PA, PV, Pa.

Answer 29

Pa > PA > Pv

Question 30

What happens in zone 2 during ventilation?

Answer 30

intermittent blood flow

Question 31

In zone 3 of the lung, rank these pressures from highest to lowest (during ventilation); PA, PV, Pa.

Answer 31

Pa > PV > PA

Question 32

What happens in zone 3 during ventilation?

Answer 32

high hydrostatic pressure, distended vessels, high blood flow

Question 33

What is Starling's equation important in determining?

Answer 33

the amount of fluid flowing per minute

Question 34

What causes an increase in Pcap?

Answer 34

exercise

Question 35

When does clinical edema develop?

Answer 35

the lymphatic capacity is exceeded, proteoglycan bridges break, and fluid enters the alveoli and bronchioles

Question 36

Why does pulmonary edema fluid look foamy?

Answer 36

because it is a mixture of edema fluid and surfactant

Question 37

What does decreased plasma oncotic pressure cause?

Answer 37

hypoproteinemia, increased vascular permeability, inflammation, lymphatic obstruction

Question 38

What does lung edema impede on?

Answer 38

ventilation and oxygenation

Question 39

How is pulmonary fluid reabsorbed?

Answer 39

through stomata on the parietal fleura, and then through the lymphatics