Lecture 10 - Pulmonary Blood Flow Flashcards
what is the normal CO for both ventricles
5L/min each
what is unique about the pulmonary circulation
the pulmonary artery carries de-oxygenated blood and the vein carries oxygenated blood
What is the formula for CO
HR x SV
What is the left side of the heart larger
the resistance in systemic circulation is higher
What part of the lung features high pressure A
bronchial A
compare and contrast alveolar and extra-avleolar caps
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
What is the pressure in the RA usually
15/2
what is the pressure in teh RV usually
25/0
what is the pressure in the LA usually
15/4
what is the pressure in the LV usually
120/0
What is the mean pressure of the pulmonary circ
15
what is the mean pressure of systemic circ
100
What is the pressure difference in the pulmonary circ
15 in circ and 5 in LA gives 10 mm Hg
What is the pressure difference in systemic circ
100 in circ and 2 in RA gives 98 mm Hg
About what is the resistance difference in pulmonary v systemic
1/10
Why is resistance lower in pulmonary circ
- high cap content
- less sympathetic innervation
- less SM at arteriole level
- during exercise, even more caps open and less resistance
What are the zones of the lung? where are they
apex = zone 1 middle = zone 2 base = zone 3
what zone gets the highest airflow? highest blood flow
airflow highest in 1; blood highest in 3
what are the general pressure differences in the lung zones
1 P_A>P_a>P_v
2 P_a>P_A>P_v
3 P_a>P_v>P_A
What is the effect of NO
made my l-arg; made by eNOS; vasodilator
What is endothelin-1
vasoconstrictor; inhibit this to treat pulmonary hypertension
What is thromboxane A2 (TXA2)
vasoconstrictor
what keeps the lungs dry
starling forces
- hydrostatic pressure
- oncotic pressure
what causes fluid to leave the capillaries of the lungs
oncotic pressure out of lungs and hydrostatic pressure out of lungs; fluid goes to lymph
Where is ACE (angiotensin converting enzyme) found
lungs
converts angiotensin 1 to 2
what creates angiotensin 1
renin in kidneys converts angiotensinogen –> angiotensin 1
what is an off target effect of ace inhibitors
bradykinin in lungs is affected; they develop cough; bradykinin is a vasodilator and ACE_i keeps it from getting degraded
what is one metabolite removed from the lungs
arachidonic acid metabolites; leukotrienes, prostaglandins E_2 and F_2alpha
