Chapter 21 Flashcards Preview

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Flashcards in Chapter 21 Deck (52):
1

5 general classes of blood vessels

1. arteries
2. arterioles
3. capillaries
4. venules
5. veins

2

arteries

carry blood aways from heart

3

arterioles

smaller branches of arteries found in tissues

4

venules

smaller veins

5

veins

larger vessels that carry blood toward heart

6

where is all the blood located in the body?
-answer
-total blood volume in venous system

-blood is unevenly distributed among blood vessel
- ~70%

7

systemic venous system
-3 things

1. venules and medium-sized veins (25%)
2. large venous networks (liver, bone marrow, skin) (21%)
3. large veins (18%)

8

pulmonary circuit
-total percent
-3 things

-9%
-1. pulmonary arteries (3%)
2. pulmonary capillaries (2%)
3. pulmonary veins (4%)

9

Heart
-percentage of blood

-7%

10

systematic arterial system
-percent
-4 things

-13%
-1. aorta (2%)
2. elastic arteries (4%)
3. muscular arteries (5%)
4. arterioles (2%)

11

systematic capillaries
-percent

7%

12

3 types of veins

1. large vein
2. medium sized vein
3. venule

13

2 types of capillary

1. fenestrated
2. continuous

14

large vein

superior and inferior vena cava

15

venule

collect blood from capillary

16

fenestrated capillary

pores penetrate endothelium

17

continuous capillary

endothelium is complete

18

3 types of arteries

1. elastic artery
2. muscular artery
3. arterioles

19

elastic arteries
-known as
-function

-conducting arteries
-transport large volumes of blood away from heart

20

muscular artery

distribution arteries

21

capillaries
-definition
-what do they function as
-high tissue demand for O2
-low tissue demand for O2

-only blood vessels that permit exchange between blood and surrounding
-an interconnected network - capillary bed
-precapillary sphincter opens
-precapillary sphincter closes

22

precapillary sphincter opens
-what does this allow

allows more blood flow through capillary bed

23

precapillary sphincter closes
-what does this allow

less blood flow through capillary bed

24

what is at the entrance to the capillary

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