Regulation of Blood Flow and Pressure Flashcards
The arteriolar tone of which organ is the only affected by parasympathetic nervous system?
Penis
Why can dobutamine cause both, increase in contractility and hypotension?
- activation of B1 receptor: ⬆️ contractility
- activation of B2 receptor: hypotension
Why could happen if pulmonary circuit doesn’t distend and recruit when ⬆️ cardiac output?
Very high pulmonary artery pressure
The hemorrhage normally ⬇️ pulmonary artery pressure, what is the response that try to rise that pressure?
- Recoil of pulmonary vessels
- derecruitment of pulmonary capillaries
Which is the main factor that regulates cerebral blood flow?
Arterial carbon dioxide
What mediates the auto regulation of blood flow and which organs do it?
- vasodilatory metabolites: CO2, K, H, adenosine; myogenic mechanism (contract vessel in response to stretch)
- cerebral circulation, coronary circulation, skeletal muscle in exercise, kidney
Effect of polycythemia on cardiac output
Decreased cardiac output
*⬆️ CaO2 ▶️ increased denominator of fick formula
Effect of severe stenosis in turbulence. Based on Reynolds number, Why does it happen?
- increased turbulence
- ⬆️⬆️ velocity (despite ⬇️ diameter)
The unique tissue where the hypoxemia leads arteriolar vasoconstriction
Lungs
*hypoxic vasoconstriction - put blood flow to ventilated regions
Effect of polycythemia on cardiac output
Decreased cardiac output
*⬆️ CaO2 ▶️ increased denominator of fick formula
Effect of severe stenosis in turbulence. Based on Reynolds number, Why does it happen?
- increased turbulence
- ⬆️⬆️ velocity (despite ⬇️ diameter)
The unique tissue where the hypoxemia leads arteriolar vasoconstriction
Lungs
*hypoxic vasoconstriction - put blood flow to ventilated regions
