Lecture 10 - Pulmonary Blood Flow

Question 1

what is the normal CO for both ventricles

Answer 1

5L/min each

Question 2

what is unique about the pulmonary circulation

Answer 2

the pulmonary artery carries de-oxygenated blood and the vein carries oxygenated blood

Question 3

What is the formula for CO

Answer 3

HR x SV

Question 4

What is the left side of the heart larger

Answer 4

the resistance in systemic circulation is higher

Question 5

What part of the lung features high pressure A

Answer 5

bronchial A

Question 6

compare and contrast alveolar and extra-avleolar caps

Answer 6

Alv

• from right vent
• gas exchange
• millions of alveoli covered in cap sheet

E-alv

• left vent
• deliver gas to lung tissue
• return to heart
  
  • reduces PaO2 increased PaCO2

Question 7

What is the pressure in the RA usually

Answer 7

15/2

Question 8

what is the pressure in teh RV usually

Answer 8

25/0

Question 9

what is the pressure in the LA usually

Answer 9

15/4

Question 10

what is the pressure in the LV usually

Answer 10

120/0

Question 11

What is the mean pressure of the pulmonary circ

Answer 11

15

Question 12

what is the mean pressure of systemic circ

Answer 12

100

Question 13

What is the pressure difference in the pulmonary circ

Answer 13

15 in circ and 5 in LA gives 10 mm Hg

Question 14

What is the pressure difference in systemic circ

Answer 14

100 in circ and 2 in RA gives 98 mm Hg

Question 15

About what is the resistance difference in pulmonary v systemic

Answer 15

1/10

Question 16

Why is resistance lower in pulmonary circ

Answer 16

• high cap content
• less sympathetic innervation
• less SM at arteriole level
• during exercise, even more caps open and less resistance

Question 17

What are the zones of the lung? where are they

Answer 17

apex = zone 1
middle = zone 2
base = zone 3

Question 18

what zone gets the highest airflow? highest blood flow

Answer 18

airflow highest in 1; blood highest in 3

Question 19

what are the general pressure differences in the lung zones

Answer 19

1 P_A>P_a>P_v
2 P_a>P_A>P_v
3 P_a>P_v>P_A

Question 20

What is the effect of NO

Answer 20

made my l-arg; made by eNOS; vasodilator

Question 21

What is endothelin-1

Answer 21

vasoconstrictor; inhibit this to treat pulmonary hypertension

Question 22

What is thromboxane A2 (TXA2)

Answer 22

vasoconstrictor

Question 23

what keeps the lungs dry

Answer 23

starling forces

• hydrostatic pressure
• oncotic pressure

Question 24

what causes fluid to leave the capillaries of the lungs

Answer 24

oncotic pressure out of lungs and hydrostatic pressure out of lungs; fluid goes to lymph

Question 25

Where is ACE (angiotensin converting enzyme) found

Answer 25

lungs

converts angiotensin 1 to 2

Question 26

what creates angiotensin 1

Answer 26

renin in kidneys converts angiotensinogen –> angiotensin 1

Question 27

what is an off target effect of ace inhibitors

Answer 27

bradykinin in lungs is affected; they develop cough; bradykinin is a vasodilator and ACE_i keeps it from getting degraded

Question 28

what is one metabolite removed from the lungs

Answer 28

arachidonic acid metabolites; leukotrienes, prostaglandins E_2 and F_2alpha