BP Control + Hemostasis Flashcards
What is vascular resistance?
Force that opposes blood flow in a blood vessel
Name 3 factors that affect vascular resistance.
- Vessel diameter (narrower, higher resistance)
- Blood viscosity (thicker, more resistance)
- Vessel length (longer, more resistance)
What is meant by “Blood flow”?
Blood flow refers to the volume of blood moving through a particular vessel/organ/tissue in the circulatory system.
Name 2 factors that affect blood flow.
- Pressure difference (greater difference, higher blood flow)
- Resistance (higher resistance, lower blood flow)
What is meant by “Total Peripheral Resistance” (TPR)?
The overall resistance to blood flow in the body’s entire circulatory system.
TPR is essentially the sum of all the vascular resistances of all systemic blood vessels in the body.
True/False
The body regulates blood flow to different organs based on their metabolic needs.
True
What is “Cardiac Output” (CO)?
The total volume of blood pumped by the heart (left ventricle) into the systemic circulation per minute.
What are the 2 ways of regulating blood pressure?
- Short-term regulation (e.g. baroreceptor reflex)
- Long-term regulation (e.g. RAAS system)
What is pulse pressure?
It is the difference between systolic and diastolic blood pressure.
Name the 2 local factors that influence constriction/dilation of arterioles.
- Metabolic
- Myogenic
What affects velocity of blood flow?
- Blood flow, Q
- Cross-sectional area, A
V = Q/A
Name the 2 external factors that influence constriction/dilation of arterioles.
- Autonomic Nervous System
- Hormones
True/False
Diastolic blood pressure is the pressure remained in the blood vessel when the heart is relaxed.
True
True/False
Total cross-sectional area is largest at the capillary.
True
What is the function of high-pressure baroreceptor?
To detect changes in blood pressure
Where are high-pressure baroreceptors located?
- The wall of aortic arch
- The carotid sinus
Define Thrombosis.
The formation of stationary blood clot (thrombus) in a blood vessel.
Define Embolism.
The blockage of blood vessel by an embolus.
(embolus can be blood clot /air bubble /..)
Why you don’t faint when you stand up?
Baroreceptor Reflex.
Detect low blood pressure - fewer signals to brain - activate parasympathetic activity: increase heart rate - decrease sympathetic activity: increase TPR
What is the function of low-pressure baroreceptors?
To detect changes in blood volume.
