Lecture - CVS (Rajesh Physiol 7 Control) Flashcards
1
Q
Arterioles
- Aorta and large arteries are ____ ______ ______/conduit
- Aorta and large arteries porvide the ____ _____ that drives ____ through the systemic circuit
- Do large arteries give any resistance?
- What’s the main difference in arterioles and arteries? Why are they resistance vessels?
- Smaller arteries and arteriles: control of these vessels determines what?
- 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?
A
- Arterioles have little elastic but lots of SM so control the resistance with the diameter
2
Q
Vascular tone
- This is the _____ exerted by vascular ____ ______ cells
- What does this regulate?
- What happens when you increase the tone in terms of local blood flow?
- What about the decrease in tone?
- How does Poiseullie come in this?
- Vascular tone regulates arterial blood presure- how?
- Continous adjustment of resistance vessel tone helps to control BP during when?
- Vascular tone is controlled by intrinsic and extrinsic mechanisms - what are the 6 (3 each) and what do they all act on?
- What’s the control hierarchy in terms of vascular regulation
A
- So you change the resistance by changing the radius - four fold relationshiop acording to the law
- Because it controls TPR and that’s in the equation
3
Q
#1 Intrinsic control - myogenic response
- When arterial pressure is altered, blood flow in many vascular beds remains constant - what is this called?
- 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? - What does NO have to do with the myogenic response?
- 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)
- What does this operate by?
- Helps to maintain the blood flow to organs such as what to match what?
- Draw out the flowchart on slide 15 of this thing
#3 Intrinsic control - reactive hyperemia
- What does this occur in response to?
- What happens when you remove the occulusion?
- What does this look like in Laser Doppler?
_________________________________
#4 Intrinsic control - paracrine factors
- You can control the tissue blood flow by endothelial-derived factors….what are some examples of vasoconstrictors and vasodilators that the endothelium produces?
- 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?
A
- O2 is a vasoconstrictor and CO2 is a vasodilator
4
Q
Extrinsic control of BV
- Why do you have extrinsic controls? (2)
- What are the 2 types of extrinsic controls?
- What are by far the most wide spread and important extrinsic control normally?
A
5
Q
3 Extrinsic control: hormornal factors controlling circulation
#1 Extrinsic control: sympathetic vasoconstrictor system
- Whats the course of the sympathetic vasoconstrictor system? What receptors does it work on in the heart, BV?
- What is it controlled by?
- Innervate most _____ and ____ of the body
- Terminate at the edge of ______ ____, in strings of ______ ______
- Varicosities release what, containing what?
- What does noradrenalin (that the sympathetic nerves release) affect on the vascular myocyte?
- What do these receptors cause?
- The fibres are ____ _____ (1 impulse/sec) thereofre a fall in activity or alpha-blockers causes what?
- Reduced sym activity lead to what? (question 8)
- 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
- Found in organs where what?
- What are the two common transmitters released by the parasymp fibres
- Read over slide 35
- What does adrenalin/epinephrine do? (dilator or constrictor?)
- 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? - What are three other hornomal factors controlling circulation and how do they do it?
A
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6
Q
Go read slide 41
A