Chapter 21 Flashcards
1
Q
5 general classes of blood vessels
A
- arteries
- arterioles
- capillaries
- venules
- veins
2
Q
arteries
A
carry blood aways from heart
3
Q
arterioles
A
smaller branches of arteries found in tissues
4
Q
venules
A
smaller veins
5
Q
veins
A
larger vessels that carry blood toward heart
6
Q
where is all the blood located in the body?
- answer
- total blood volume in venous system
A
- blood is unevenly distributed among blood vessel
- ~70%
7
Q
systemic venous system
-3 things
A
- venules and medium-sized veins (25%)
- large venous networks (liver, bone marrow, skin) (21%)
- large veins (18%)
8
Q
pulmonary circuit
- total percent
- 3 things
A
- 9%
- pulmonary arteries (3%)
- pulmonary capillaries (2%)
- pulmonary veins (4%)
- pulmonary arteries (3%)
9
Q
Heart
-percentage of blood
A
-7%
10
Q
systematic arterial system
- percent
- 4 things
A
- 13%
- aorta (2%)
- elastic arteries (4%)
- muscular arteries (5%)
- arterioles (2%)
- aorta (2%)
11
Q
systematic capillaries
-percent
A
7%
12
Q
3 types of veins
A
- large vein
- medium sized vein
- venule
13
Q
2 types of capillary
A
- fenestrated
2. continuous
14
Q
large vein
A
superior and inferior vena cava
15
Q
venule
A
collect blood from capillary
16
Q
fenestrated capillary
A
pores penetrate endothelium
17
Q
continuous capillary
A
endothelium is complete
18
Q
3 types of arteries
A
- elastic artery
- muscular artery
- arterioles
19
Q
elastic arteries
- known as
- function
A
- conducting arteries
- transport large volumes of blood away from heart
20
Q
muscular artery
A
distribution arteries
21
Q
capillaries
- definition
- what do they function as
- high tissue demand for O2
- low tissue demand for O2
A
- only blood vessels that permit exchange between blood and surrounding
- an interconnected network - capillary bed
- precapillary sphincter opens
- precapillary sphincter closes
22
Q
precapillary sphincter opens
-what does this allow
A
allows more blood flow through capillary bed
23
Q
precapillary sphincter closes
-what does this allow
A
less blood flow through capillary bed
24
Q
what is at the entrance to the capillary
A
band of smooth muscle
25
structure of blood vessels
| -3 distinct layers
1. tunica intima
2. tunica media
3. tunica externa
26
tunica intima
- layer
- type of tissue
- innermost layer
- squamous epithelium = endothelium
- layer of connective tissue (areolar and elastic)
27
tunica media
- layer
- 2 features
- middle layer
- layers of smooth muscle -allows vessel diameter to change
- supplied by ANS
28
Tunica externa
| -2 features
- outer most layer
| - connective tissue
29
vessel: artery
- endothelium (tunica intima)
- areolar/elastic tissue (tunica intima)
- tunica media
- tunica externa
- yes
- yes
- yes (large and thick)
- yes
30
vessel: arteriole
- endothelium (tunica intima)
- areolar/elastic tissue (tunica intima)
- tunica media
- tunica externa
- yes
- yes
- yes (less elastic tissue, more smooth muscle)
- yes
31
vessel: capillary
- endothelium (tunica intima)
- areolar/elastic tissue (tunica intima)
- tunica media
- tunica externa
- yes
- no
- no
- no
- no
32
vessel: venule
- endothelium (tunica intima)
- areolar/elastic tissue (tunica intima)
- tunica media
- tunica externa
- yes
- no
- no
- yes
33
vessel: vein
- endothelium (tunica intima)
- areolar/elastic tissue (tunica intima)
- tunica media
- tunica externa
- type of vessels located in tunica media
- yes
- yes
- yes (less smooth muscle compared to arteries)
- Capacitance vessels - able to easily expand
34
special feature of veins
valves
35
valves
- function
- what are they?
- permit blood flow in only 1 direction and are required to overcome the force of gravity
- extensions of the tunica interna
36
valves closed
prevents back flow of blood
37
valves opened
contraction of skeletal muscle helps to squeeze blood toward heart
38
Blood flow
- definition
- total blood flow =
- why does blood flow
- volume of blood flowing through a vessel or group of vessels
- cardiac output
- due to pressure gradients (moves from high to low)
39
what creates the pressure in blood
the heart
40
2 factors affecting blood flow
1. F a P
| 2. F a 1/R
41
F a P
- definition
- ex
flow is directly proportional to the pressure gradient
| - increase Pressure = increase Flow
42
F a 1/R
- definition
- ex 1
- ex 2
- flow is inversely proportional to resistance
- increase resistance = decrease flow
- decrease flow = increase resistance
43
resistance
radius of vessel and viscosity of blood
44
blood pressure
force of blood exerted against the vessel wall
45
arterial blood pressure
- definition
- how is it reported
pressure of blood in arteries
| - reported as mmHg
46
venous blood pressure
- definition
- low or high pressure
- pressure within the venous system
| - very low
47
measuring arterial blood pressure : heart contracts
- where is the blood ejecting
- pressure
- type of pressure
- into aorta and arteries
- pressure in arteries is increasing to 120 mmHg
- systolic pressure
48
systolic pressure
- definition
- highest or lowest pressure in aorta
pressure in arteries due to ventricular systole
| -highest pressure in aorta
49
measuring arterial blood pressure: heart relaxes
- blood is ejected where
- blood flows up or down pressure gradient
- pressure
- type of pressure
- blood is not ejected into arteries
- down
- decreases to 80 mmHg
- diastolic pressure
50
diastolic pressure
- definition
- highest or lowest pressure in aorta
pressure in arteries during ventricular diastole
51
how do you measure
| -what is the norm
systolic/diastolic
| -120/80
52
3 things combine to form fluctuation and creates pulse
1. aorta
2. elastic arteries
3. muscular arteries
