Pressure gradients, blood flow and peripheral resistance Flashcards
What are arteries and what do they serve as?
- Low resistance vessels conducting blood to the various organs with little loss in pressure
- Act as pressure resevoirs for maintaining blood flow between ventricular contractions
What are arterioles and what do they serve as?
- Major sites of resistance to blood flow
- Responsible for the pattern of blood flow distribution
- Participate in the regulation of arterial blood pressure
What is the term for site of exchange between blood and tissues?
Capillaries
What are veins and what do they serve as?
- Low resistance vessels for blood to flow back to the heart
- Their capacity for blood is adjusted to facilitate flow
What are th elayers of the lumen called?
Adventitial layer- connective tissue
Medial layer- smooth muscle cells
Intimal layer- endothelial cells
In the vascular system, blood flow goes from what region of concentration?
Region of higher pressure to one of lower pressure
What is the term for the pressure exerted by a fluid
Hydrostatic pressure
What are the units of pressure difference?
mmHg
to know the flow rate, what do you need to have?
the pressure difference between two points (P) and also the resistance (R) to flow
What is resistance described as for blood flow?
A measure of friction impeding flow
Blood flows through tubes and the driving force is the pressure generated by contractions of the heart. What is the equation?
F=P/R
What can parabolic distribution be described as?
In an arrow like form
What are the 3 factors that resistance to blood flow depend on?
1) Viscosity of the blood
2) Vessel length
3) Vessel radius
What does a two-fold change in radius produce for change in flow?
16-fold
Arterial pressure fluctuates in relation to ventricular systole and diastole. What is the equation for mean arterial pressure?
Mean arterial pressure=diastolic pressure + 1/3 pulse pressure
