1/28 Cardiac Performance Randall

Front 1

heart job in blood pressure

Back 1

has to have short term regulation and long term regulation

neural and hormonal is extrinsic

built in is intrinsic

Front 2

positive feedback cycle has an ___ number of inverse relationships

___ of cycles increases stability of the regulated variable but can also ______ .

the linking assures dysfunction of an organ system ultimately ___

Back 2

even

nesting. the redundancy helps

hide dysfunction (so terrible CO can be fixed for BP)

impacts other systems like cog transmitting power

Front 3

example of neural and non-neural BP mechanisms

Back 3

intrinsic/non-neural is the tubular Na/H20 excretion in urine where high BP leads to urine excretion. This is when it's just going, not with hormonal inputs

Extrinsic/neural has the baroreflex which if high, have sympathetics to arterioles go down so vasomotor tone goes down for lower PVR

Front 4

overall view of blood pressure done by neural control

Back 4

plexus in heart: intracardiac nerve network for the heart brain.

afferent and efferent coming in/out in vagus to brainstem and to lungs

sympathetic nerves in and out of spine so cardio-cardiac reflexes

baroreceptors in aorta to brain

hypothalamus

emotions

Front 5

main cycles of regulating plasma volume

Back 5

ADH/renal water absorption

RAAS

Renal arteriole constriction decides filtration rate and sal and water

systemic vascular ressistance changed for capillary hydrostatic pressure for interstitial regulation

Front 6

long-term regulation of BP is combination of

Back 6

pressure diuresis

volume regulation

Front 7

heart cannot serve as a ___ or ___ of blood for more than a few ___. So ___ is closely related to ___.

___ is obviously important to maintenance and regulation of arterial BP. So ___ is also important in regulation of BP.

Back 7

sink or source of blood for more than few beats

CO related to Venous return VR

CO so VR also important

Front 8

at what point does CO turn into VR?

how does this work?

Back 8

mean circulatory filling pressure which is about 7

so like if there were no heart pump then there would be 7 left.

arterials are way higher but veins have the majority of the blood volume

Front 9

the vascular function curve

apply Ohn's law into what equation

Back 9

flow = gradient/resistance

Venous Return = k(Pmc - Pra)

k is conductance which is 1/Resistance

Pmc is mean circulator filling pressure

this is charted as venous return against RA pressure

Front 10

there's only so much you can increase VR. why?

Back 10

there has to be transmural pressure for the vena cava to be patent.

The higher the RA pressure the higher the venous return.

Front 11

how can you shift the vascular function curve?

what hacks are available for the vascular function curve as far as equivalents

what other curve uses these variables

Back 11

shift to right with venoconstriction or higher blood volume

VR = CO so either can be on axis

during diastole, Pra equals Prv which are both preload

RV and LV functions have to be equal

Starlings Law. EDV vs CO

Front 12

when you plot starling's law of the heart and vascular function curve, where do they intersect?

Back 12

steady-state operating point

Front 13

what would increase VR?

Back 13

venomotor tone

not increase in P(RA) since the equation is k(Pmc-Pra).. the CO goes down as Pra increases.

Front 14

Arterial BP is normall quite stable. Anything that overcomes the reflexes for it are called ___. If you suck at reflexes you'll have ___ or ___ ___

in htn the tx act primarily upon the ___

Back 14

perturbations

syncope

orthostatic intolerance

effector organs- not the actual cause of htn

Front 15

when you put a healthy pt on a tilt table how does pt react to compensate?

in diabetic with definite neuropathy?

Back 15

higher HR and increase in BP

BP drops, HR increases only a little

the increase in HR and MAP is called the gain

Front 16

5 elements for a regulation thing

Back 16

-sensor to see current value

--afferent path from sensor to controller- the controller/integrator compares current value with desired value

-efferent path carry instructions to effectors

-effectors which are ogans/tissues effect a change in BP

Front 17

arterial baroreflex is ___term regulation based on what equation

Back 17

short-term

BP = CO x TPR

CO = HR x SV

so BP = TPR x HR x SV

Front 18

how do the sensors for the aorta work?

what walls are they on?

Back 18

they're just straight up stretch receptors that progressively activate as arterial BP increases- the higher the BP the more frequently the sensor cells fire for live feed to brain

there is one in the arch of the aorta and two carotid sinus ones (bilateral)

Front 19

between smooth muscle contraction and resistance, what is the calculation done for that and what is its name?

Back 19

Poiseuille's law

resistance is 1/r^4

Front 20

there's one important exception about autonomic control with vagus nerve?

Back 20

the parasympathetic going in with ACh and muscarinic- will decrease HR and BP

the sympathetic going in with NE on Beta1

Front 21

what would happen if baroreflex was destroyed?

Back 21

the average mean arterial pressure stays steady around 100 in normal

in destroyed the pressure varies greatly but the avg trends towards 100 still like before

so short term extrinsic is gone, but long term intrinsic still operating

Front 22

where do baroreceptor afferent fibers go to

what comes out and what is the effect?

Back 22

nucleus tractus solitarius in brainstem

Caudal VLM which inverts going to Rostralventral lateral medulla send out sympathetics to up chrono drono inotropism and contract vasculature

nucleus ambiguus sends out through vagus nerve to SA and AV node and can stop heart if it wanted

Front 23

what happens when you go from supine to upright posture?

Back 23

gravity pools blood in lower body which "starves" heart for blood, so lower VR means lower CO and lower arterial BP and lower cerebral flow, so feel faint

the low carotid sinus pressure activates baroreflex so then SNA is up, PNA down equals tachycardia and higher SV

Front 24

how does higher nerve control come into the BP reflexes?

Back 24

the tone and rats- the tone was interpreted way before SNA or anything could be used.

"open-loop controls" can reset BP to higher level.

Front 25

what receptor does sympathetics going to vasculature to constrict it use?

Back 25

alpha1