Lecture - CVS (Rajesh Physiol 7 Control)

Question 1

Arterioles

1. Aorta and large arteries are ____ ______ ______/conduit
2. Aorta and large arteries porvide the ____ _____ that drives ____ through the systemic circuit
3. Do large arteries give any resistance?
4. What’s the main difference in arterioles and arteries? Why are they resistance vessels?
5. Smaller arteries and arteriles: control of these vessels determines what?
6. So on slide 5, what is:
   - the pressure reservoir
   - the variable-resistance outflow rubes
   - flow to ‘organs’
   - aka the arterioles control the flow to organs by doing what?

Answer 1

4. Arterioles have little elastic but lots of SM so control the resistance with the diameter

Question 2

Vascular tone

1. This is the _____ exerted by vascular ____ ______ cells
2. What does this regulate?
3. What happens when you increase the tone in terms of local blood flow?
4. What about the decrease in tone?
5. How does Poiseullie come in this?
6. Vascular tone regulates arterial blood presure- how?
7. Continous adjustment of resistance vessel tone helps to control BP during when?
8. Vascular tone is controlled by intrinsic and extrinsic mechanisms - what are the 6 (3 each) and what do they all act on?
9. What’s the control hierarchy in terms of vascular regulation

Answer 2

5. So you change the resistance by changing the radius - four fold relationshiop acording to the law
6. Because it controls TPR and that’s in the equation

Question 3

#1 Intrinsic control - myogenic response

1. When arterial pressure is altered, blood flow in many vascular beds remains constant - what is this called?
2. Myogenic response (flow autoregulation) - resistance vessels respond ______ to a change in ______ by ______ or ______
   - what is the flow diagram on slide 13? Bring O2 and CO2 into this
   - what does the myogenic response have todo with activation of L-type Ca2+ channels?
3. What does NO have to do with the myogenic response?
4. So the myogenic response protects against organ perfusion against minute-minute fluctuation in arterial blood pressure. What is it well-developed in? (3)

#2 Intrinsic control - metabolic regulation (active hyperemia)

1. What does this operate by?
2. Helps to maintain the blood flow to organs such as what to match what?
3. Draw out the flowchart on slide 15 of this thing

#3 Intrinsic control - reactive hyperemia

1. What does this occur in response to?
2. What happens when you remove the occulusion?
3. What does this look like in Laser Doppler?

_________________________________

#4 Intrinsic control - paracrine factors

1. You can control the tissue blood flow by endothelial-derived factors….what are some examples of vasoconstrictors and vasodilators that the endothelium produces?
2. NO:
   - 60-80% of NO production is from what?
   - circulating _____ and _____ can activate NO production to a lesser extent
   - does flow increase NO production?
   - what’s the half life of NO?
   - how does this relate to the myogeic response?
   - what are some factors affecting NO production? (3)
   - how does this relate to cardiac angina?

Answer 3

2. O2 is a vasoconstrictor and CO2 is a vasodilator

Question 4

Extrinsic control of BV

1. Why do you have extrinsic controls? (2)
2. What are the 2 types of extrinsic controls?
3. What are by far the most wide spread and important extrinsic control normally?

Question 5

3 Extrinsic control: hormornal factors controlling circulation

#1 Extrinsic control: sympathetic vasoconstrictor system

1. Whats the course of the sympathetic vasoconstrictor system? What receptors does it work on in the heart, BV?
2. What is it controlled by?
3. Innervate most _____ and ____ of the body
4. Terminate at the edge of ______ ____, in strings of ______ ______
5. Varicosities release what, containing what?
6. What does noradrenalin (that the sympathetic nerves release) affect on the vascular myocyte?
7. What do these receptors cause?
8. The fibres are ____ _____ (1 impulse/sec) thereofre a fall in activity or alpha-blockers causes what?
9. Reduced sym activity lead to what? (question 8)
10. Increased sympatehtic activity leads to vasoconstriciotn:
    - in terms of tissue blood flow reduced, what happens?
    - tissue blood volume reduced, what happens?
    - cap pressure reduced, what happens?

#2 Extrinsic control: vasodilator nerves

1. Found in organs where what?
2. What are the two common transmitters released by the parasymp fibres
3. Read over slide 35

1. What does adrenalin/epinephrine do? (dilator or constrictor?)
2. In terms of epinephrine (adrenalin) and norepinephrine (NA)
   - what releases each?
   - increase the hormone in what compartment?
   - what receptors do each affect
   - why does the epinephrine mostly produce vasoconstriction though?
3. What are three other hornomal factors controlling circulation and how do they do it?

Answer 5

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Question 6

Go read slide 41