Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

CardioRenal II > Phys- Regulation of Blood Pressure > Flashcards

Phys- Regulation of Blood Pressure Flashcards

1
Q

Describe baroreceptor stretch receptors

A

highly branched, enmeshed within the elastin matrix of the vessel wall

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

Name some things that infulence MAP

A

1.) Cardiac 2.) Systemic Nervous System 3.) Humoral 4.) Renal Fluid Volume control 5.) Local control

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

Reflex arc

A

feedback loops in which a stimulus is transmitted via afferent pathways to the central nervous system wher it gets processed and integrated to generate an appropriate output signal that is sent to the periphery via efferent pathway to an effector organ

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

Pressor Center Response to increased pressure

A

In response to increased pressure the pressor center causes a decrease in sympathetic output and passive vasodilation

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

Rate of baroreceptor firing is greatest during (systole/diastole) and decreases during (systole/diastole)

A

Greatest during systole (get burst of activity) and decreases during diastole

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

Medulla Oblongata

A

contains a number of important information receiving and integrating celnters for both the cardiovascular and respiratory systems. Stimulation results in specific effects

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

Which baroreceptors are tonically active (what does this mean)

A

Carotid baroreceptors (always firing)

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

relationship between arterial pressure and firing frequency in carotid baroreceptors

A

increased pressure causes distention and increased firing freqency (decreased pressure causes decreased fring frequency )

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

Cerebral cortex and regulation

A

1.) Emotional stimuli (extreme fear, anxiety, embarassment) can alter efferent output 2.) Painful stimuli can evoke powerful sympathetic stimulation that originates in the spinal cord

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what is the driving force for tissue perfusion

A

arterial blood pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

increased sympathetic activity to arterioles causes

A

ACTIVE vasoconstriction

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

Cardioinhibitory center

A

tonically active. Controls PARASYMPATHETIC (vagal output)

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

CO equation

A

CO= HR x SV

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

Pressor Center

A

TONICALLY ACTIVE. Controls peripheral resistance by controling sympathetic output. In face of increased pressure it causes a decrease in sympathetic output and passive vasodilation

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

Baroreflex negative feedback system

A

in response to DECREASED ARTERIAL PRESSURE the reflex acts to increase sympathetic activity - increase in caradiac output and causes peripheral vasoconstriction to raise pressure. In response to INCREASED ARTERIAL PRESSURE the reflex decreases sympathetic activity and increases sympathetic activity to decrease blood pressure

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

Why is the baroreflex considered superior to the other mechanisms that influence blood pressure

A

barorelflex mechanism responds most rapidly (within 15-20 seconds) and with a greater gain that other mechanisms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what is the pimary mechanism involved in regulating moment to moment changes in arterial blood pressure

A

Barorelflex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

which “center” is not tonically active

A

Depressor center

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Components of the baroreflex arc

A

1.) Baroreceptors in the carotid sinus, aortic arch, and other large thoracic arteries 2.) Afferent pathways in cranial nerves IX and X 3.) Medullary centers 4.) Efferent autonomic (sympathetic and parasympathetic) pathways 5.) Effector organs (heart, arterioles, and venules/veins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what is “effective circulating blood volume”

A

pressure in the system (blood pressure) that drives perfusion to the tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Response of hypothalamus to decreased arterial pressure

A

sends inhibitory signals to the nucleus ambiguous (cardioinhibitory center) and decreases vagal output

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Aortic baroreceptor afferents

A

carried in the aortic nerve via the vagus nerve (CN X)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

cardiostimulatory center

A

tonically active. Controls the sympathetic output of the heart (SA and AV nodes and ventricular myocardium)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

define regultaion

A

maintanance at a CONSTANT level - the ability of the body to keep arterial pressure constant in the face of stress (eg: changes in body position or exertion)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Example of regulation and control

A

under normal circumstances mean arterial pressure is REGULATED at aprox 95 mmhg through reflexes that CONTROL cardiac output and peripheral resistance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

tonic component of baroreceptor firing

A

depending on the magnitude of mean arterial pressure (average number of spikes over time) Static component

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

reflex

A

harwired involuntary response to a stimulus

28
Q

what factors does the pressor center adjust to change MAP

A

Adjusts Total peripheral resistance (TPR) and Venous Capacitance

29
Q

Response of capacitance vessels to baroreflex

A

change in effective circulating blood volume

30
Q

Respone of the Resistance vessels to baroreflex

A

change peripheral vascular resistance through control of arteriole size (vascular resistance) - primarily under sympathetic control

31
Q

response of cardiostimulatory center to increased pressure

A

decrease sympathetic outflow leading to decreased heart rate, contractility, and conduction velocity

32
Q

Depressor Center

A

NOT TONICALLY ACTIVE. Inhibits pressor center

33
Q

what is responsible for short term blood pressure (seconds, minutes, hours)

A

Cardiovascular system

34
Q

Role of Hypothalamus in regulation of blood pressure

A

1.) recieves input from low pressure baroreceptors in the right artrium and pulmonary artery. Hypothalamus sends signals to the the cardiostimulayory and cardioinhibitory centers to alter sympathetc and parasympathetic activity 2.) Thermoregulation

35
Q

Baroreceptor adaptation

A

afferent output resets in the face of chronic change in pressure. EX: in the face of chronically elevated pressure (early stages of hypertension) the baroreceptors will have a lower sensitivity at a given blood pressure. Sensitivity curve shifts to the right so that NOW the baroreceptor is most sensitive at the NEW mean. Adaptation occurs over hours to days

36
Q

Aortic baroreceptor threshold

A

100-110 mmhg (not as sensitive as carotid baroreceptors)

37
Q

define sensitivity in terms of baroreceptors

A

number of impulses per mmHg

38
Q

decreased sympathetic activity to arterioles causes

A

PASSIVE vasoconstriction

39
Q

which “center” acts through parasympathetic output

A

cardioinhibitory center

40
Q

what is responsible for long term regulation of arterial blood pressure

A

Kidney

41
Q

Thermoregulation and arterial pressure

A

changes in core body temperature can alter the regional distribution of blood flow which can compromise regulation of arterial pressure

42
Q

define control

A

change in the activity level of a given system (ex: changing cardiac output, peripheral vascular resistance)

43
Q

what are the five components of the reflex arc

A

1.) Receptor 2.) Afferent Pathway 3.) Central integrator 4.) Efferent pathway 5.) Effector organ

44
Q

Carotid Sinus barorecptors threshold

A

50-60 mmhg (most sensitive and effective baroreceptors)

45
Q

Response of medulla to baroreflex

A

release of epinephrine

46
Q

Where is the sensitivity of baroreceptors the greatest? What is the significance of this?

A

90-100 mmHg (the normal mean arterial pressure) Allows Baroreceptors to be very responsive to small changes in arterial pressure

47
Q

what modulates the activity of the pressor center

A

Depressor center (inhibits the pressor center)

48
Q

How does changing Vascular capacitance help to maintain blood pressure

A

constriction of smooth musle in large capacitance veins and an increase in the “effective” circulating blood volume that can help maintain blood pressure

49
Q

response of cardioinhibitory center to decreased pressure

A

decreased pressure results in decreased vagal output and increased heart rate

50
Q

response of cardiostimulatory center to decreased pressure

A

increase sympathetic outflow to increase heart rate, contractility and conduction velocity

51
Q

which “centers” act to change peripheral resistance

A

1.) Pressor center 2.) Depressor center

52
Q

Carotid baroreceptor afferents

A

carried in the carotid sinus nerve via CN IX (glossipharyngeal)

53
Q

Response of the heart to baroreflex

A

changes in cardiac output via changes in heart rate and contractility (which influences stroke volume)

54
Q

Baroreflex receptor type

A

stretch receptors - changes in transmural pressure elicits an action potential (stretch determines firing frequency)

55
Q

components involed in maintaining short term blood pressure

A

Integration of: 1.) Cardiac output 2.) Peripheral vascular resistance 3.) effective circulating blood volume

56
Q

Location of baroreceptors

A

1.) Carotid Sinus (bilaterally) 2.) Aortic arch and other large vessels of the throrax

57
Q

response of cardioinhibitory center to increased pressure

A

increaed pressure results in increased vagal output leading to decreased heart rate, decreased afferent input

58
Q

examples of effector organs in the reflex arc

A

Heart, vessels, respiratory muscle, kidney, GI mucosa, sweat glands

59
Q

Phasic component of baroreceptor firing

A

reflects the rate of change of pressure (burst pattern) Dynamic component

60
Q

Depressor response to increased arterial pressure

A

Increaed inhibition of th pressor center to cause decreased sympathetic outflow resulting in passive vasodilation

61
Q

Baroreceptor sensitivity zone

A

50-200 mmHg

62
Q

Mean Arterial pressure equation

A

MAP = CO X TPR

63
Q

Nucleus tractus solitarius

A

caudal medulla that receives afferent information and relays it to the four control centers.

64
Q

Afferents from baroreceptors travel where?

A

to the nucleus tractus solitarius of the medulla

65
Q

which “centers” act to change cardiac output

A

1.) Cardiostimulatory center 2.) Cardioinhibitory center

CardioRenal II (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions