Brainscape's Knowledge GenomeTM

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


See full index

DPT732: MAP II > MAPIISG1 - Nervous Regulation of Circulation > Flashcards

MAPIISG1 - Nervous Regulation of Circulation Flashcards

1
Q

How does nervous regulation have more of a global effect on circulation (3)?

A
  1. Redistributes blood to different areas of body prn
  2. Affects heart rate
  3. Can rapidly change arterial blood pressure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What role doe the SNS play in circulation?

A

primary nervous system influence in regulating circulation

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

What role does the PSNS play in circulation?

A

Assists in regulation of heart function

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

The SNS innervates all vessels except (3)?

A
  1. Capillaries
  2. Precapillary Sphincters
  3. Metarterioles
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

The SNS allows stimulation to vasoconstrict, what is the result on arteriole system?

A

small artieries and arterioles vasoconstrict which increases TPR and BP.

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

The SNS allows stimulation to vasoconstric, what is the result on the venous system?

A

large vessels, especially veins decreases storage and increase venous return which increases stroke volume and blood pressure.

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

Describe the path of sympathetic motor nerve fibers

A

leave spinal cord thru T1-L1/2 spinal nerves –> sympathetic chain –> spinal nerves, sympathetic nerves

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

What is the response of the body with blood loss, trauma, etc?

A

Reflexes elicited from aortic bodies and carotid sinus that pick up change in pressure, stimulate sympathetic nervous impuses to the veins. Result is almost normal circulation can be maintained w/ 20% blood loss.

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

Define circulatory shock

A

condition in which blood vessels are inadequately filled and blood can’t circulate normally

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

Define hypovolemic shock

A

low blood volume can be from burns

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

Define vascular shock

A

excessive vasodialation due to anaphylactic shock (histamine release), septic shock (infection using vasodialation)

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

Define cardiogenic shoc

A

heart stops working, pump failure (cardiac muscle - MI)

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

Sympathetic nerves carry ___ vasoconstrictor fibers and ___ vasodialater fibers.

A

Sympathetic nerves carry MANY vasoconstrictor fibers and FEW vasodialater fibers.

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

Where are vasoconstricter fibers distributed?

A

all segments of circulation

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

Where is the largest distribution of vasoconstrictor fibers, why?

A

kidneys, intestines, spleen, skin as these are resevoirs for blood and can be shunted

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

Where are the least distrubuted vasoconstrictor fibers, why?

A

skeletal muscle and brain as always need blood here and want to be able to run from bear

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

Where is the vasomotor center located

A

Located bilaterally in reticular substance of medulla, lower pons

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

How does the vasomotor center transmit parasympathetic impulses?

A

vagus nerve to heart

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

How does the vasomotor center transmit sympathetic impulses?

A

via spinal cord, peripheral nerves to arteries, arterioles, veins

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

What are the three areas of the vaasomotor center?

A
  1. Vasoconstrictor
  2. Vasodilator
  3. Sensory Areas
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the purpose of the vasoconstrictor area?

A

continuous impulses from vasoconstrictor nerve fibers maintain partial state of contraction of blood vessels = vasomotor tone

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

What role does vasomotor tone provide?

A

contributes to maintenance of BP

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

What do neurons in the vasoconstrictor area secrete

A

norepinephrine (NE)

24
Q

What effect does norepinephrine have when released?

A

acts on adrenergic receptors of vascular smooth muscle causing vasoconstrictor

25
Q

What is the purpose of the vasodialator area?

A

fibers project up, to inhibit vasoconstrictor area

26
Q

What is the purpose of the sensory area?

A

receives sensory impulses from circulatory system via vagus, glossopharyngeal nerves –> helps regulate vasoconstrictor and vasodilator areas

27
Q

What is the role of the Adrenal Medulla?

A

receives SNS stimulation simultaneous with blood vessels and secretres NE and epinephrine into blood stream causing vasoconstriction

28
Q

T/F: Epinephrine occasionally causes vasodilation in some tissues.

A

True

29
Q

What does the cardiac center adjust?

A

heart rate and force of contraction

30
Q

How does the cardioacceleratory center of the Cardiac Center work?

A

SNS–> increase HR and Force of Contration

31
Q

How does the cardioinhibitory center work?

A

PSNS–> decrease HR

32
Q

What is the cardiovasular center?

A

Cardiac Center and Vasomotor center

33
Q

Under normal circumstances, stimulation of vasomotor center also stimulates

A

cardiac centers, therefore control heart function and vascular function simultaneously.

34
Q

Due to simultaneous control of centers, if you increase HR you get ___

A

increased vasoconstriction (SNS)

35
Q

Due to simultaneous control of centers, if you decrease HR you get ___

A

vasodilation (PSNS)

36
Q

Describe the speed of the nervous system control of blood pressue

A

most rapid of responses

-can increase BP within seconds, 2-fold increase within 5-10 seconds, decrease to 1/2 normal can occur in 10-40 seconds

37
Q

What systems does the nervous system use to rapidly increase BP?

A

simultaneous stimulation of vasoconstrictor and cardioaccelerator – reciprocal inhibition of PSNS vagal signals to heart

38
Q

What are the three major changes to increase BP?

A
  1. Most arterioles constrict
  2. Veins and other large vessels constrict
  3. SNS stimulation of heart
39
Q

What are the two reflex mechanisms to maintain normal arterial pressure?

A
  1. Baroreceptor Reflex

2. Cehmoreceptor Reflex

40
Q

What are baroreceptors and where are they located?

A

neural receptors in the carotid sinus, aortic arch, and walls of nearly every large artery in neck and thorax

41
Q

What are Baroreceptors sensitive to?

A

pressure sensitive: respond to stretch of lack of stretch in vessel walls.

42
Q

What happens when Baroreceptors are triggered?

A

Stretch sends rapid impusles to the vasomotor center and cardiac center

43
Q

What effect would a decrease in MAP have on Baroreceptors

A

detect lack of stretch, initiates reflex vasoconstriction and increases CO - BP rises

44
Q

How do Baroreceptors act as a “pressure buffer system”

A

protect circulation from acute changes in BP via Carotid Sinus Reflex and Aortic Reflex, decreases variation in BP.

45
Q

How can Baroreceptors become ineffective with prolonged pressure changes?

A

they adapt by resetting at a higher point with hypertension which limits their long term response to perceived higher pressure.

46
Q

What do Chemoreceptors respond to?

A

changes in O2 (lack), CO2, and H+ excess in arterial blood

47
Q

Where are Chemoreceptors located?

A

carotid bodies and aortic bodies

48
Q

What do Chemoreceptors stimulate?

A

nerve fibers traveling to the vasomotor centers to increase arterial pressure

49
Q

When are Chemoreceptors important?

A

only at low arterial pressures

50
Q

Describe the action mechanism of Chemoreceptors.

A

In contact with arterial blood, senses low O2 or high levels of CO2 or H+ that results with a drop in arterial pressure, initations reflexive vaso/venoconstriction

51
Q

What are Atrial reflexes - low-pressure receptors?

A

receptors are stretch receptors in walls of atria which minimize arterial pressure changes in response to change in blood volume

52
Q

What are Atrial reflexes - bainbridge reflex?

A

stretch receptors that with increase in arterial pressure, will get increase in HR and strength of constriction to prevent blood from “backing up” into system

53
Q

What is CNS Ischemic Response?

A

occurs when blood flow to vasomotor center severely decreased - comproises nutritional access = cerebral ischmia

54
Q

What happens with a CNS Ischemic Response?

A

get strong reaction of vasoconstrictor and cardioaccelerator centers, large rise in systemic arterial pressure

55
Q

What effect can CNS Ischemic Response have on MAP?

A

increase MAP ~250mmHG for up to 10 minutes, most powerful activator of SNS vasoconstrictor system.

DPT732: MAP II (14 decks)

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