Nervous Flashcards
1
Q
sympathetic nerves are very important in control of what
A
circulation and heart function
2
Q
Parasympathetic nervous system plays a role in control of what
A
only the heart - it has a very minor role in circulation
3
Q
arterial and venous system are regulated by part of nervous system
A
sympathetic
4
Q
sympathetic nerves innervate all vessels except:
A
microcirculation: capillaries, precapillary sphincters, and metarterioles
5
Q
when there is sympathetic stimulation blood vessels to what tissues will constrict more than blood vessels to heart or brain
A
kidneys, gut, spleen, skin
6
Q
Arterial pressure =
A
CO x Total peripheral resistance
7
Q
how do sympathetic increase HR
A
stimulate heart to increase heart rate and contractility
constrict arterioles to increase total peripheral resistance
contract large veins to decrease compliance
8
Q
what does sympathetic do to veins
A
decrease compliance (less blood, so increased CO)
9
Q
what do beta receptors block
A
sympathetic control to increase heart rate and contractility directly on the heart
10
Q
what controls regulation of blood/heart
A
vasomotor center
11
Q
what is control fo sympathetic nerves to cardiovasulcar system
A
vasomotor center
12
Q
VMC stands for
A
vasomotor center
13
Q
important areas of VMC
A
Vasoconstrictor region
Cardiac region
Sensory Region
14
Q
vasoconstrictor area transmits signals continously to
A
sympathetic nerve fibers
15
Q
where is VMC located
A
medulla oblongata
16
Q
how often does vsoconstrictor area fire
A
constantly
17
Q
sympathetic tone means there is
A
tonic activity
18
Q
sympathetic nerves are constantly firing at
A
low rate
19
Q
are sympathetic nerves constantly firing?
A
yes
20
Q
sympathetic nerves constantly firing means that blood vessels are always
A
partially contrcited
21
Q
what is vasomotor tone
A
sympathetic nerves constantly firing so blood vessels are always partially constricted
22
Q
what is importance of vasomotor tone
A
causes blood pressure in other parts to be higher to push it through tissues
23
Q
if you fire vasoconstrictor more what happens
A
vessels constrict more
24
Q
if you fire less in vasoconstrictore what happens
A
vessels are more dialted/less constrsicted
25
where is pressure higher due tot he vasomotor tone controlled by vasoconstrictor area
aorta, lung arteries, small arteries, a little arterioles
26
if you give someone spinal anesthesia high enought o bloock the VMC, what do you see
blood pressure drop
27
if you infuse NE into person who has the VMC blocked what happens
blood pressure increases
28
why is there decrease in BP when you block VMC
blood vessels dilate b/c you can't get the firing of VMC to cause the vasomotor tone
29
CA stands for
cardiac accelerator area
30
CA is what
sympathetic nerves to heart
31
What does CA do
transmits signals to regulate sympathetic nerves to heart
32
if CA increases activity what happens
HR increases
33
What does CI stand for
cardioinhibitory area
34
where is CI located
dorsal motor nuclei of vagus nerve - where vagus nerve starts
35
what does CI do
sends parasympathetic impulses to heart through vagus nerve
36
what cardiac center would increase or decrease blood vessel diameter
VC
37
what cardiac center would decrease rate/contractility of heart
CI
38
what cardiac center would increase rate/contracitily of heart
CA
39
what is transmitted via CA
NE
40
what is transmitted via CI
Ach
41
how do we control the cardiac center
there is sensory area located in nucleus tractus solitarius
42
what does NTS stand for
nucleus tractus solitarius
43
NTS controls
what happens in cardiac center
44
how does NTS control cardiac center
baroreceptors that are constantly monitoring blood pressure and it relays it up to NTS and the NTS tells the cardic center what to do
45
what is reflex control of circulatory function
the baroreceptors talk to NTS which talks to cardiac center which respnods
46
reflex is
bodies response to initial problem
47
what are the four negative feedback mechanisms
1. Baroreceptor Reflex
2. Chemoreceptor reflex
3. Atrial and Pulmonary Reflex
4. Central Nervous System Ischemic Response
48
baroreceptors, what are they
stretch receptors
49
where are baroreceptors located
walls of carotid sinus and aortic arch
50
baroreceptors are sensory _____
afferents
51
baroreceptors are ____ afferents
sensory
52
baroreceptors use ____ to know what pressure is
stretch
53
baroreceptors terminate where
NTS
54
vagus nerve is a nerve
trunk
55
vagus nerve as nerve trunk means
it has afferent to brain and efferent to body
56
how do baroreceptors communicate to sensory areas
how many impulses they send up
57
if BP goes from 100 to 160 what do baroreceptors do
the firing rate increases, they send more stimuli to sensory area and that tells brain BP is up
58
if BP goes from 100 to 80 what do baroreceptors do
the firing rate decreases, less impulses to brain, tells brain BP is lower
59
rate of firing of baroreceptors tells ____ what is goign on
NTS
60
ultimately baroreceptors will change what to bring BP to normal
to the cardiac centers, b/c it will talk to NTS which will tell cardiac centers what to do
61
person hit by car and hemorrhaging, decreased blood volume causes drop in BP, what is first thing that happens
baroreceptors sense drop in BP and firing rate decreases
62
person hit by car and hemorrhaging, decreased blood volume causes drop in BP, baroreceptors fire less and then what happens
NTS receives signal, then it will tell cardiac centre to increase sympathetic and decrease parasympathetic
so blood vessels and veins constrict, heart increases firing rate and contractility
63
increaed heart rate, what is medical term
tachycardia
64
reflex tachycardia
SA node firing faster, result of baroreceptors and NTS
65
what happens to blood vessels in kidney in response to hemorrhage
they will constrict
66
what happens to blood vesels in GI tract in response to hemorrhage
constrict
67
what happens to brain in response to hemorrage
no change - want blood flow to brain to stay the same
68
what happens to blood vessels in skeletal muscles in response to hemorrhage
constrict a little
69
what happens to sympathetic nerves is arterial pressure increases
symapthetic nerves decrease
70
if you decrease sympathetic activity what happens to blood vessels
dilate
71
if you decrease sympathetic activity what happens to heart
HR falls, contracts a little less strongly
72
parasympathetic nerves do not innervate
blood vessels
73
the only thing that controls the blood vessels are
sympathetic
74
lying position and jump up quickly, you get dizzy , why?
when you are lying flat BP pretty level in body, when you jump up BP in upper part of body falls, so you get dizzy, less blood flow to brain
75
when you change body posture what are very important
baroreceptors
76
lying to standing decreases arterial pressure where
head and upper part of body
77
what is baroreceptor response when person goes from lying to standing position
falling pressure sensed by baroreceptors and increased sympathetic discharge maintains presure
78
look at graph on pg 17
17
79
what keeps BP constant during posture chagne
baroreceptors
80
why do we need to keep BP constant
so tissues get the blood they need
| so you don't pass out/get dizzy
81
flow =
change in pressure/resistance
82
role of baroreceptors in long term regulation of arterial presure?
doesn't change the average BP
| they don't control long term pressure
83
long term arterial pressure is determined by
kidneys
84
kidensy determien what blood pressure is, and what keeps it that way
baroreceptors
85
chemoreceptors where are they located
around arotic baroreceptors and carotid bodies
86
chemoreceptors monitor changes in
blood levels of things like oxygen, CO2, and hydrogen ions in blood
87
how do chemoreceptors send sensory afferents
same as baroreceptors - to VMC which then changes sympathetic activity
88
chemoreceptors only sense what
decrease in pressure
89
chemoreceptors are not stimulated unless pressure is below
80 mmHg
90
chemoreceptors are more important in what than in monitoring pressure
respiratory control
91
what change in O2 will chemoreceptors ense
decrease
92
what change in CO2 will chemoreceptors sense
increase
93
what change in pH will chemoreceptors sense
decrease
94
baroreceptors are ___ pressure sensors
high
95
what reflex activate the kidney
atrial reflex
96
if blood volume increases and you stretch the atria, what happens to kidney
sympathetic nerves to kidney, increase in sodium and water excretion to try to lower blood volume
97
CNS ischemic response is what kind of response
emergency pressure control system
98
CNS ischemic response is
last ditch effort to kee psomeone alive -
99
CNS ischemic response is not active untless BP is
below 60 mmHg
100
CNS Ischemic Response is not from body it is
brain response
101
CNS Ischemic Response response is activated in response to
creebral ischemia
102
at some point decrease in blood flow to brain does hat to CO2
causes CO2 to increase in brain
103
CO2 increase in brain does what
increases talk to vasomotor center, increases sympathetic activity, increase arterial pressure
104
what is ultimate response of CNS Ischemic Response
sympathetic nerves firing so fast they are closed, so any blood going through heart is going to brain, blood vessels in kidney are closed, blodo vessels in gut are clsoed, you are just getting blood to heart and brain
105
cushing reaction is what
special type of CNS Ischemic Response
106
if you increase cerenospinal fluid pressure what will it do
causes arterial pressure to increase to try to open up vessels to get blodo flow there
107
if you decrease CSF pressure, what happens to arterial pressure
it goes back down
108
anytime there is atrial stretch, the atrial refelx will increase heart rate by stretchign SA node by stretching atria, and also:
Bainbridge Reflex
109
what is Bainbridge Reflex
stretchign atria sends afferent to vasomotor center and it only activates heart, doesn't activate blood vessels
110
Bainbridge Reflex only activates
heart
111
Bainbridge Reflex is
stretch of atria causes increase in HR and contractility without affecting blood vessels
112
why does person who gets shocking news faint?
Vasovagal Syncope reflex gone bad
113
Vasovagal Syncope (reflex) what is it
emotional stress causes person to faint
114
list pathway for Vasovagal Syncope
cortex to hypothalamus to medulla, medulla says decrease sympathetic output and increase vagal output ,this decreases total peripheral resistance and decrease venous returna nd cardiac output, thsi decreases arterial pressure and that decreases cerebral blood flow and person loses consciousness
115
arterial pressure is controlled independently of
local blood flow control & cardiac output control
116
atrial reflex is what kind of reflex
volume
117
what are low pressure receptors in atria and pulmonary arteries
atrial reflexes
118
blood volume changes and what reflex
atrial reflex
119
increase in blood volume stretch atria and activate low pressure receptors that lower pressure by
working at kidney
120
activation of atrial reflex does what to kidney
enhances sodium and water excretion
