part 6 Flashcards
(100 cards)
1
Q
What is the resistance like in the venous compartment?
A
it is very small.
2
Q
What is pulse pressure like in the capillaries?
A
No pulse pressure.
3
Q
What is arteriosclerosis?
A
hardening of arteries that leads to a loss of normal elastic dampening, and this leads to passing on the pulse of the waves downstream where it can do damage.
4
Q
What is the average pressure in veins?
A
zero mm Hg
5
Q
Systemic venous blood pressure is aka?
A
Central venous pressure.
6
Q
What is the average central venous blood pressure?
A
zero mm Hg
7
Q
What makes the central venous blood pressure rise above zero?
A
The collective venous pump system.
8
Q
What makes up the venous pump?
A
Valves and skeletal muscle.
9
Q
What are the 2 pumps in the systemic circulatory system?
A
- The left ventricle. 2. The collective venous pump.
10
Q
What is hydrostatic forces?
A
the affect of gravity on blood pressure.
11
Q
With hydrostatic forces what part or level of the body while standing will blood pressure be at 100 mm Hg?
A
At the level of the heart.
12
Q
When standing what will the venous blood pressure in the feet rise to?
A
about 90 mm Hg
13
Q
When walking what will the venous blood pressure in the feet rise to?
A
about 25 mm Hg.
14
Q
What is venous pressure like in the head while standing?
A
negative (well not actually negative, but air can enter here with an accident because there is no pressure).
15
Q
How was blood pressure taken in the old world?
A
By palpating for a pulse and then looking at tissues.
16
Q
What is the modern world name used for how we meausre blood pressure?
A
Sphygmomanometry.
17
Q
What is a formula for blood pressure?
A
cardiac output multiplied by peripheral resistance.
18
Q
What are 3 causes of peripheral resistance?
A
- Blood volume. 2. viscosity of blood. 3. size of vasculature container (r^4).
19
Q
What can affect blood pressure?
A
almost anything.
20
Q
What do we need to do to determine the anti-hypertensive therapies we can use?
A
Determine what is causing the hypertension.
21
Q
What is mean arterial blood pressure?
A
it is cardiac output multiplied by peripheral resistance usually 100mm Hg.
22
Q
Since we said delta-P is stable we took it out of the equation for flow, but what makes delta-P stable or constant?
A
a dozen or more control systems.
23
Q
What would a control that is high gain and low gain mean?
A
High gain would be high power to correct something. Low gain would be low power to correct something.
24
Q
What are the 2 main controls of blood pressure?
A
- Baroreceptors. 2. Renal-blood pressure control.
25
Short term and long term blood pressure controls are best done with what system?
Short term- ANS affecting the heart and vessels. Long term- controlling blood in vascular compartments.
26
What receptors will function as a baroreceptor for controlling blood pressure? Where are they found at?
aortic and carotid baroreceptors. Aortic found on aortic arch. Carotid found in carotid bifurcation
27
What type of sensors are baroreceptors?
Pressure
28
What cranial nerves make up these baroreceptors that help control blood pressure?
aortic- X, Carotid-IX.
29
Where are signals from the baroreceptors sent?
To the cardiovascular center in the brain medulla.
30
How will baroreceptor reflex alter blood pressure?
Through efferent innervation to heart and vasculature.
31
If blood pressure is low how will the baroreceptor reflex help?
The receptors send signals to the brain and then the brain will send an increased sympathetic respons to the heart and increase cardiac output. It will send an increased sypmathetic respons to blood vessels to vasoconstrict.
32
If blood pressure is high how will the baroreceptor reflex help?
The receptors send signals to the brain and then the brain will lessen the sympathetic respons to the heart and decrease cardiac output. It will lessen the sypmathetic respons to blood vessels and will slow vasoconstriction.
33
How sensitive are baroreceptors?
very responsive at normal blood pressures.
34
How fast acting, and effective are baroreceptors at stabalizing blood pressure?
Rapid-acting and high gain.
35
How long will baroreceptor reflex work at stabalizing blood pressure?
about 2-4 days and then it falls off.
36
After 2-4 days when barorecpetors stop working what are they doing?
They are re-adjusting the level at which they will help correct blood pressure levels.
37
What is the suggested usage for the baroreceptor refelx?
For sudden changes in Blood pressure.
38
What is the baroreceptor reflex used for?
Postural changes.
39
What will the mean blood pressure be if the baroreceptor refelx is gone?
It will remain at 100 mm Hg, but it will vary a lot more.
40
What will the arterial chemoreceptor reflex use?
Chemical sensors for oxygen.
41
Where are the chemoreceptors found at?
They are extremely well supplied with blood in small organs called Aortic and carotid bodies.
42
how fast and how effective is the chemoreceptor reflex at regulating blood pressure?
Rapid-acting and high gain.
43
How long will the chemoreceptor reflex last for?
Only a couple hours.
44
What will these chemoreceptors monitor?
Really low levels of Oxygen and high levels of Co2 and H+ .
45
When will the chemoreceptor reflex be used?
When mean arterial blood pressure drops below 80 mm Hg.
46
What will the chemoreceptor reflex help control?
Respiration.
47
What is atrial stretch reflex?
a nervous system control that uses stretch receptors in the walls of the atria to regulate blood pressure.
48
What are the receptors called used in atrial stretch reflex?
Atrail stretch receptors.
49
Which atrium is most notable for the atrial stretch reflex and why?
right atrium because right atrial pressure is so low.
50
The atrail stretch reflex receptors really monitor what?
Blood volume.
51
How fast and efficient is the atrial stretch reflex at regulating blood pressure?
Rapid acting and the gain is unknown.
52
What type of effect will atrial stretch reflex have?
can cause an additional 50% increase in heart rate.
53
The atrial stretch reflex is known as what?
Bainbridge reflex
54
When atrial stretch reflex increases heart rate this will increase cardiac output which stimulates arterial baroreceptors and this creats competition between these 2 reflexes when will each of them dominate?
Bainbridge reflex- dominated when blood volume rises. Baroreceptors dominate when blood volume diminishes.
55
What is the purpose of the bainbridge reflex aka the atrial stretch reflex?
to minimize venous damming of blood.
56
What is the hormonal effect that comes from atrial stretch reflex?
atrial myocytes will release atrial natriuretic factor (ANF) when the atrial pressure/stretch occurs.
57
What will atrial natriuretic factor do?
The effect is seen on the kidneys and it will decrease the blood volume and decrease blood pressure.
58
What causes the CNS ischemic response to blood pressure?
a cerebral ischemia.
59
When we have a cerebral ischemia what will the cns ischemic response do?
Neurons in the cardiovascular control center become hyperactive.
60
What are the neurons in the cardiovacular center that become hyperactive?
Neurons of the medullary pressor area.
61
How fast and how effective is the CNS ischemic response?
Very fast and high gain.
62
How long will CNS ischemic response work for and why?
only a hour or so because the brain realisitcally cant be in ischemia for longer than this.
63
Why will a cerebral ischemia cause the hyperactive neurons?
It is due to very slow moving blood failing to remove the CO2 from the cardiovascular center.
64
When will the CNS ischemic response be seen?
In rare situations that involve life threatening hemorrhage it is like a last ditch attempt to increase blood pressure in emergency.
65
Where is the cardiovascular center found at?
ill defined neuronal groups found in the lower 1/3 of pons and the medulla.
66
What are the 2 regions of the cardiovascular center?
1. Pressor region. 2. Depressor region.
67
What will the pressor region of the cardiovascular center do?
evokes vasoconstriction, cardiac acceleration, myocardial contractility. This is also responsible for vasomotor tone.
68
What will the depressor region of the cardiovascular center do?
Evokes inhibition of the Pressor area: So it will decrease sympathetic outflow and increase parasymphathetic activity. This leads to vasodilation.
69
Mental states can influence blood pressure by how?
Through cardiovascular center.
70
What will depression and fright/shock do to blood pressure?
Decrease it.
71
What will excitement anxiety and mild pain do to blood pressure?
Increase it.
72
How will the Epinephrine system help regulate blood pressure?
It sends hormones through the humeral control system from adrenal medulla.
73
How will the hormones from the Epinephrine system act?
As sympathetic neurotransmitters.
74
What are the 2 hormones released by the Epinephrine system?
1. Epinephrine (80%). 2. Norepinephrine (20%).
75
what will the hormones released by the epinephrine system land on and what will this do?
They land on alpha and beta receptors and cause peripheral vasoconstriction and increase cardiac output.
76
How fast and how effective is the epineprine system at regulating blood pressure?
Very fast and gain is unknown.
77
How long will the epinephrine system help regulate blood pressure?
rather long lasting.
78
What is the stress-relaxation behavior that helps regulate blood pressure?
a property of the arterial system that after increased or decreased constant pressure will result in a new contractile state. A re-sizing of the vascular compartment.
79
How fast and effective is the stress-relaxation behavior at regulating blood pressure?
Slow with a low gain.
80
What is the capillary fluid shift that helps regulate blood pressure?
a redistribution of blood to and from the vascular compartment (sending blood out to tissues or bringing it back in).
81
How fast and how effective is the capillary fluid shift at regulating blood pressure?
slow and has a low gain.
82
Capillary fluid shift can cause what type of pathology?
peripheral edema.
83
What will the renin-angiotensin system use to regulate blood pressure?
the humoral control system by sending hormones from the kidneys and blood.
84
What hormones will the renin-angiotensin system use?
renin and angiotenin II.
85
How fast and how effective is the Renin-angiotensin system at regulating blood pressure?
slow acting and has a low gain.
86
The renin-angiotensin system will increase and decrease blood pressure where?
at afferent arterioles.
87
The renin-angiotensin system will increase and decrease sympathetic stimulation to what?
The Kidneys.
88
What will renin do?
Convert angiotensinogen into angiotensin I
89
Angiotensin I will be converted to angiotensin II by an enzyme and what will angiotensin II do?
Increase vasoconstriction of peripheral vasculature. It also increases aldosterone which increases NA2+ and h2o absorption which increaes blood volume.
90
What happens to renin production if blood pressure is increased?
It will slow down and then it wont convert angiotensinogen into angiotensisn II.
91
What is an ACE inhibitor?
a drug that blocks angiotensin converting enzyme (ACE) so no angiotensin II can be made and this will help keep blood pressure from rising due to renin.
92
What is the aldosternoe system for regulating blood pressure?
aldosterone is released from the adrenal cortex.
93
What will alodsterone do?
It works closely with the renin-angiotensin system. It increases and decreases angiotensin II levels which increases and decreases K+ levels
94
How fast and effective is the aldosterone system at regulating blood pressure?
slow and low gain.
95
How will the vasopressin system regulate blood pressure?
it uses osmoticaly sensitive neurons in hypothalamus to make a hormone that is released from the posterior pituitary gland called vasopressin.
96
What is another name for vasopressin?
anti-diuretic hormone (ADH)
97
Why will vasopressin have 2 names?
Because it has 2 functions.
98
What are the 2 functions of vasopressin aka anti-diuretic hormone.
1. cardiovascular pressor agent. 2. renal fluid retention agent.
99
Vasopressin will cause vasoconstriction on smooth muscles with what receptors?
v1
100
How fast and how effective is vasopressin system at regulating blood pressure?
slow and gain is unknown.
