Chapter 19 Flashcards
to allow me to kick ass on the quiz/midterm
1
Q
what are the main factor influencing BP
A
- Cardiac output (CO = SV + HR)
- Peripheral resistence
- Blood Volume and Blood Viscosity
2
Q
what is the vasomotor center
A
- cluster of sympathic neurons in the medulla that oversea changes in blood vessel diameter
- receives input from baroreceptors, chemoreceptors and higher brain centers
3
Q
what does the baroreceptor reflex do
A
increased blood pressure stimulates baroreceptors to the vasomotor centre, which intern causes vasodilation (negative feedback loop)
4
Q
What are the chemoreceptors
A
monitor CO2, pH, and O2 levels and send messages to VCC and cardioacceleratory centre (CAC) for vasoconstriction
5
Q
T/F - vasoconstriction increases BP
A
true
6
Q
T/F - vasodilation decreases BP
A
true
7
Q
what do the short term chemical controls to BP do
A
cause vasodilation or vasoconstriction
8
Q
what is the artery found on only the right side of the body
A
brachiocephalic
9
Q
endocrine gland that produces ADH
A
posterior pituitary
10
Q
shortage of blood flow to tissues
A
ischemia
11
Q
vessels which regulate blood flow into the capillaries
A
arterioles
12
Q
only veins that carry highly oxygenated blood
A
Pulmonary veins
13
Q
capillary with pores in the wall
A
fenestrated
14
Q
vessels with the lowest blood pressure
A
large veins (vena ceva)
15
Q
hormone produced in heart in response to high BP
A
ANP - atrial natriuretic peptide hormone
16
Q
effect of NO (nitric oxide) on blood vessels
A
vasodilation
17
Q
distributing artery
A
muscular arteries
18
Q
the characteristic of blood that increases resistance to flow
A
viscosity
19
Q
heart attack
A
myocardial infarction
20
Q
the aorta is the largest of this type of artery
A
elastic
21
Q
difference between systolic and diastolic pressure
A
pulse pressure
22
Q
activated by renin, causes a rise in BP
A
angiotensin II
23
Q
opposition to flow
A
resistance
24
Q
layer of blood vessel wall that contains smooth muscle
A
tunica media
25
commonest type of circulatory shock
hypovolemic (haemorrhage)
26
if the blood vessel in constricted to the radius size, what is the effect on the pressure
increases pressure by 16 times
27
vessel which carries blood through two capillary beds before returning to the heart
portal (ie.hepatic portal vein)
28
function of tunica media
friction free surface for blood flow
29
function of tunica media
controls diameter of vessel (vasoconstriction and vasodilation)
30
function of tunica externa
anchors and reinforces vessel
31
what is a vascular shunt and arteriovenous shunt
way of bypassing capillay beds and direct blood to where its needed.
vascular shunt - thoroughfare channel
arteriovenous shunts - bypass capillary beds
32
describe the 3 types of capillaries
1. continuous - tight junctions w/o gaps in-between cells
2. fenestrated - contains pores, absorb/filtrate formation, some intercellular clefts
3. Sinusoidal - fewer tight junctions, many intercellular cleft, allow blood cells and large molecules to pass
33
what do pre capillary sphincters do
regulate blood flow into the capillaries
34
what do veins have that arteries don't
venous valves to prevent backflow
35
what is a vascular anastomoses
interconnections of blood vessels that provide alternate pathways to a given body region
36
what is peripheral resistance
opposition to flow (resistance)
| measures the amount of friction encountered by blood
37
what are the three important sources of resistence
1. blood viscosity - increase V = increased resistance
2. total blood vessel length - increase length = increased resistance
3. blood vessel diameter - decreased diameter = increased resistance (to the 4th power. 16x)
38
what is pulse pressure
systolic pressure minus the diastolic pressure
39
what is mean arterial pressure (MAP)
diastolic pressure + (1/3 of systolic P - diastolic P)
40
list some things that can increase Blood pressure
```
increased blood volume
increased heart rate
increased stroke volume
increased blood viscosity
increased peripheral resistance
```
41
which tunic of an artery contains endothelium
tunica intima
42
which tunic of an artery contains the most elastin
tunica media
43
which tunic of an artery has vaso vasorum
tunica externa
44
function of capillaries
exchanges with tissue cells
45
what is the relationship between blood flow, blood pressure, and resistance
blood flow is "directly proportional" to pressure gradient - if the pressure gradient increases, blood flow speeds up.
blood flow is "inversely proportional" to resistance - if resistance increases, blood flow decreases
46
describe direct renal mechanisms
increased BP and bloood volume causes kidneys to eliminate more urine = decreases blood volume = decreases BP
(decreased BP causes the reverse)
47
describe the indirect (renin-angiotensin) mechanism
decreased BP, releases renin by kidney
| Renin produces angiotensin II, causes generalized constriction, increases peripheral resistance, increases BP
48
what are the three types of hypotension
1. orthostatic - temporary low pressure because sympathetic nervous system cannot respond to change in body position
2. chronic - caused by poor nutrition, hormonal problems
3. Acute - sign of circulatory shock
49
90% of hypertension is this type
primary (essential) hypertension - heredity, obesity, age, stress, diet, smoking
other 10% is secondary (kidney disease, hormone disorders)
50
describe autoregulation
1. organs regulate their own blood flow
2. dilating or constricting arterioles = increase/decrease of blood flow
3. there are two types: metabolic and myogenic
51
describe the metabolic controls to autoregulation
vasoldilation of the arterioles and relaxation of pre capillary sphincters occur in response to declining oxygen
- relaxes the vascular smooth muscle
- NO (nitric oxide) release for endothelial cells, leads to vasodilation, increases blood flow to that area
52
describe the myogenic controls to autoregulation
1. vascular smooth muscle responds directly to pressure and volume changes
2. changes in the degree of stretch of muscle cells
3. increased stretch, triggers vasoconstriction = decreases blood flow.
reduced stretch, triggers vasodilation = increases blood flow
53
The circulatory route that runs from the digestive tract to the liver is called this
Hepatic portal circulation
54
One process provides a long-term response to changes in blood pressure
Renal regulation
55
What chemicals help regulate blood pressure
Angiotensin II
ADH
Atrial Natriuretic peptide
56
What is the other name for the distributing arteries
Muscular arteries
57
What is the significance of peripheral resistance and it's influence on blood vessel diameter
It's inversely proportional to the fourth power of the vessel radius
58
Modified pillories are lined with phagocytes called this
sinusoids
59
What are the three main factors influencing blood pressure
Peripheral resistance
Blood volume
Cardiac output
60
What reflects the balance, or imbalance, between the direction and amount of fluid that flows across the capillary walls
hydrostatic and osmotic pressure
61
T/F - veins are called capacitance vessels or blood reservoirs
true
62
A thrombus (blood clot) in the first branch of the arch of the aorta would affect the flow of blood to this
Right side of the head and neck and right upper arm
63
what is a pre-capilary sphincter
a cuff of smooth muscle that regulates the flow of blood into the capillaries
64
thick-walled arteries close to the heart are called this
elastic arteries
65
T/F - arterial pressure in the pulmonary circulation is much higher than in the systemic circulation because of it's proximity to the heart
False
66
T/F - vasodilation is a widening of the lumen do you use smooth muscle contraction
False (should be smooth muscle relaxation)
67
T/F - an increase in blood viscosity will cause an increase in peripheral resistance
true
68
list the types of circulatory shock
1. Hypovolemic - large loss of blood (haemorrhage)
2. vascular shock - extreme vasodilation (anaphylactic reaction)
3. Septic - severe bacterial infection (toxins that cause dilation)
4. Cardiogenic - insufficient heart cannot sustain adequate circulation
5. Transient vascular shock - cutaneous vessels dilate (after prolonged sunbathing)
69
what is Net Filtration Pressure (NFP)
all the forces acting on a capillary bed
- the arterial end, the hydrostatic forces dominate and fluid moves out of a Capillary into the tissues.
- the Venuos end, osmotic forces dominate and most fluid move back into Capillary out of the tissues
