CVS Regulatory Centers & ABP & Its Determinants Flashcards

1
Q

Mention site of CVS centers

A

Medulla oblongata & lower pons (brainstem)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Mention supply and function of VMC

A

Supplies whole heart, blood vessels & adrenal medulla
Origin of noradrergic sympathetic innervation, it is excitatory to heart & responsible for vasomotor tone on arterial system.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Describe function & supply of CIC

A

It supplies atria only (vagal escape) & some blood vessels

It is responsible for parasymoathetic inhibitory vagal tone (supply) to heart

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

The VMC synapses in spinal cord at level of ….

A

Thoracolumbar segments ( T1 to L2 or L3)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Mention parts of CIC

A

Nucleus ambiguous

Dorsal nucleus of vagus nerve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Mention oarts of VMC & their functions

A

Pressor area: in dorsolateral medulla, responsible for continous discharge in sympathetic noradrenergic fibers.
Depressor area: caudal & ventromedial to pressor area, inhibitory to pressor area thus dec discharge in symoathetic niradrenergic fibers.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

The main sensory component of CVS centers is ….

A

Nucleus tractus solitarus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Mention effects of stimulation of pressor area & depressor area

A

Pressor
1. Arteriolar VC
2. Increased heart rate & contractility
3. Inc release of catecholamines from adrenal medulla
4. Reciprocal decrease in activity of depressor area
Depressor is opposite

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Mention the inhibitory afferents and their action

A

Stimulate the depressor center

  1. Baroreceptors (aortic arch & carotid sinus & cardiopulmonary receptor) via NTS
  2. Cerebral cortex : in grief
  3. Severe pain or prolonged visceral pain
  4. Lung inflation, VD & dec ABP, mediated by vagus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Mention the excitatory afferents and their action

A

Stimulate pressor area & inhibit depressor

  1. From chemoreceptors inc PaCO2 or dec PaO2 BY AORTIC & carotid bodies via NTS
  2. Mild to moderate pain from skin
  3. Cerebral cortex in excitement & anger
  4. During muscular exercise
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Cerebral cortex interacts with CVS centers via …..

A

Hypothalamus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

The sensory afferents in muscular exercise interact with CVS centers via

A

Reticular formation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

The VMC is directly stimulated by ….&….

A

High CO2 or low O2 (low)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Describe Cushing’s reflex

A

Increased intracranial pressure stimulated VMC directly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

The main cardiac component affected by CIC

A

SA node

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Mention functions of ABP

A
  1. ABP is the driving force responsible for blood flow through different arteries to all tissue & organs ensure adequate perfusion
  2. ABP is responsible for opening arteries
  3. ABP is responsible fir exhange by filtration across capillary pores
  4. ABP is responsible for GFR for urine formation.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

MAP = …..

A

DBP + (SBP-DBP)/3

18
Q

Decribe effect if gravity on ABP

A

ABP Is measure in brachial artery on level of heart. In vertical position, any artery above above heart level shows dec & any artery below heart shows inc in ABP by factor if 0.77 mmHg for each 1 cm height.

19
Q

Decribe effect if distance from heart on ABP

A

Elasticity dec with inc distance from heart, so SBP & PP are inc while DBP are dec.

20
Q

Mention effect of age & sex

A

Age: in newoborns it is 30-50 mmHg, increased to normal value in adulthood. With progressive age, elasticity dec so SBP inc & DBP dec, inc PP.
Sex: dec in females due to sex hormones, equalize at menopause.

21
Q

Describe nocturnal & diurnal variation

A

At early morning its is least, rises slightly by afternoon, dec again at night at least by 10 mmHg due to parasympathetic activity.

22
Q

Describe effect of exercise & body position

A

SBP is inc in all types of exercise, DBP & MAP is slightly dec in isotonic exercise, but both are inc markedly by isometric exercise.
Sitting/recumbent position is dec by 15 mmHg upon standing

23
Q

Define static component of pressure & its value

A

It is the pressure of blood in the arterial system without pumping force of heart. It is determined by the total volume of blood and the total capacity of CVS when heart is arrested
7-8 mmHg

24
Q

Define dynamic component of pressure & its value

A

Pressure generated by pumping force the heart

About 90 mmHg

25
Q

Mention factors affecting ABP

A
  1. COP
  2. TPR
    ^^^most important
  3. Total blood volume
  4. Capacity if vessels
  5. Elasticity of aorta & large arteries
26
Q

CO represents ….. while TPR represents ……

A

Inlfow of blod into arterial system

Outflow of blood from arterial system

27
Q

Mention determinants of MAP

A

CO & TPR

28
Q

Decsribe effect if increased SV

A

Inc SBP, MAP & PP

29
Q

Describe effect if inc HR

A

Inc DBP & MAP

but dec PP

30
Q

Decsribe effect of inc TPR

A

Inc DBP primarily but SBP & MAP are also inc

31
Q

Mention the componenys of TPR

A
  1. Length of vessel
  2. Viscosity of blood
  3. Diameter of vessel
32
Q

TPR =

A

8 nL/ pi*r^4

33
Q

GR: There is no friction resistance between the vessel wall & first layer of blood

A

Since it doesn’t move at all

34
Q

Viscosity is inc ….&…., dec in ….

A

Polycythemia & inc Igs

Anemia

35
Q

Determinants of PP

A

SV

Elasticity of arterial system

36
Q

What is the most imp mechanism of regulation of ABP

A

Change in diameter of arterioles

37
Q

What is the function of elasticity of arterial system

A

Prevent excessive rise of SBP during rapid ejection phase, and prevent excessive fall of DBP during diastole

38
Q

Determinants of SBP

A

SV

Elasticity of aorta & big arteries

39
Q

Determinants of DBP

A

TPR
Normal elastic recoil of aorta & large arteries
An intact aortic valve

40
Q

Factors that inc PP

A

SV, loss of elasticity of aorta & large arteries & incompetent aortic valve

41
Q

Effects of loss of elasticity

A

Inc SBP, dec DBP, inc PP