Blood Vessels

Front 1

3 major types of blood vessels

Back 1

1) Arteries

2) Veins

3) Capillaries

Front 2

Define blood vessels

Back 2

Delivery system of dynamic structures that begins and ends at the heart

Front 3

Arteries carry blood ____ the heart

Back 3

away from

Front 4

Arteries carry ____ blood is the systemic system and _____ blood in the pulmonary system and umbilical vessels of fetus

Back 4

1) oxygenated

2) Oxygen poor

Front 5

Veins carry blood ____ the heart

Back 5

towards

Front 6

Only ____ have intimate contact with tissue cells and directly serve cellular needs

Back 6

capillaries

Front 7

Exchange between blood and tissue cells occurs through ___

Back 7

gossamer-thin capillary walls

Front 8

Three layers of blood vessels walls

Back 8

1) Tunica intima

2) Tunica media

3) Tunica externa

Front 9

Define lumen

Back 9

central blood-containing space

Front 10

The ____ has intimate contact with the blood lumen

Back 10

Tunica Intima

Front 11

Tunica intima contains ___ that lines the ___ of all vessels

Back 11

1) endothelium

2) lumen

Front 12

Purpose of the endothelium of tunica intima

Back 12

Creates a slick surface that minimizes friction as blood moves through lumen

Front 13

Tunica Media is mostly ___ and ___

Back 13

1) Smooth muscle

2) sheets of elastin

Front 14

The activity of smooth muscle cell in ___ is regulated by ____ of the autonomic nervous system. This controls _____ and _____ of vessels.

Back 14

1) tunica media

2) vasomotor nerve fibers

3) Vasconstriction

4) Vasodilation

Front 15

Tunica externa is also called ___

Back 15

tunica adventitia

Front 16

Tunica externa is composed largely of ___ that ___ and ___ the vessel.

Back 16

1) collagen fibers

2) protect

3) anchor

Front 17

In larger vessels, the tunica externa contains ____ which _____

Back 17

1) Vasa vasorum

2) nourish the more external tissues of the blood vessel wall

Front 18

3 types of arteries

Back 18

1) Elastic

2) Muscular

3) Arterioles

Front 19

Define elastic arteries

Back 19

Large, thick-walled arteries with elastin in all three tunics

Front 20

Arteries that are elastic arteries

Back 20

aorta and its major branches

Front 21

___ arteries are the largest in diameter

Back 21

Elastic

Front 22

Large ___ of elastic arteries offers ___

Back 22

1) Lumen

2) low resistance

Front 23

____ act as pressure reservoirs that ____ and ___ as the heart ejects blood

Back 23

1) Elastic arteries

2) expand

3) recoil

Front 24

_____ are relatively inactive in vasoconstriction

Back 24

Elastic arteries

Front 25

Elastic arteries allow blood to

Back 25

flow fairly continuously rather than starting and stopping with the pulse of the heartbeat

Front 26

Elastic arteries are also called

Back 26

conducting arteries

Front 27

Muscular arteries are also called

Back 27

distributing arteries

Front 28

Define muscular arteries

Back 28

Distal to the elastic arteries and deliver blood to body organs

Front 29

____ arteries account for most of the named arteries

Back 29

Muscular

Front 30

___ have the thickest tunica media which contains more ____ and less ____

Back 30

1) Muscular

2) smooth muscle

3) elastin

Front 31

____ arteries are more active in vasoconstriction/vasodilation

Back 31

Muscular

Front 32

Define arterioles

Back 32

Smallest arteries

Front 33

Large arterioles have _____

Back 33

all three tunics

Front 34

Small arterioles lead _____ and are little more than ____

Back 34

1) into capillary beds

2) a single layer of smooth muscle around endothelial lining

Front 35

Arterioles controls flow into ____ via ____ and ___

Back 35

1) capillary beds

2) vasoconstriction

3) vasodilation

Front 36

Define capillaries

Back 36

Smallest blood vessels in the body

Front 37

Walls of capillaries consist of

Back 37

just a thin tunica intima

Front 38

The size of the capillary allow

Back 38

RBCs to pass one at a time

Front 39

Capillaries exist in all tissues except

Back 39

1) Cartilage

2) Epithelia

3) Cornea and lens of eye

Front 40

Function of capillaries

Back 40

Exchange of materials such as gases, nutrients, hormones, and wastes

Front 41

Three structural types of capillaries

Back 41

1) Continous

2) Fenestrated

3) Sinusoidal (sinusoids)

Front 42

____ capillaries are most common and exist in the skin and muscles

Back 42

Continous

Front 43

_____ are connected by tight junctions to create uninterrupted lining in continuous capillaries

Back 43

Endothelial cells

Front 44

Define Intercellular clefts

Back 44

Gaps of unjoined membrane in tight junctions of continuous capillaries that allow passage of fluid and solutes.

Front 45

Brain capillary tight junctions are ___ and create the ___

Back 45

1) complete

2) blood brain barrier

Front 46

Fenestrated capillaries contain ___ in their endothelial cells

Back 46

fenestrations (oval pores)

Front 47

____ capillaries are more permeable to fluids and solutes

Back 47

Fenestrated

Front 48

Function of fenestrated capillaries and are found in ___

Back 48

1)Function in absorption or filtrate formation

2) Kidneys, endocrine organs, and small intestines

Front 49

Define Sinusoids

Back 49

Highly modified, leaky capillaries found in the liver, adrenal medulla, bone marrow, and spleen.

Front 50

_____ have large, irregular lumens and are usually ___

Back 50

1) Sinusoids

2) fenestrated

Front 51

Endothelial cells of ___ have fewer ____, larger ___ and larger ____

Back 51

1) Sinusoids

2) tight junctions

3) lumens

4) intercellular clefts

Front 52

Sinusoids allow ___

Back 52

large molecules and blood cels to pass between blood and surrounding tissue

Front 53

Define capillary beds

Back 53

Interwoven networks of capillaries form the microcirculation between arterioles and venules

Front 54

Veins are called ____ and ___ because they can hold up to ____ of the body's blood supply at any time

Back 54

1) Capacitance vessels

2) blood reservoirs

3) 65%

Front 55

Define blood pressure

Back 55

Force per unit area exerted on the wall of a blod vessel by the blood

Front 56

Blood pressure is expressed in

Back 56

mmHg

Front 57

The ___ provides the driving force that keeps ____

Back 57

1) pressure gradient

2) blood moving from higher to lower pressure areas

Front 58

Define resistance in terms of blood pressure

Back 58

Opposition to flow and is a measure of the amount of friction blood encounters as it passes through vessels

Front 59

Resistance is called ____ because ____

Back 59

1) peripheral resistance

2) most friction is encountered in the systemic (peripheral) circulation

Front 60

Three sources of resistance

Back 60

1) Blood viscosity (remains relatively constant)

2) Total blood vessel length (remains relatively constant)

3) Blood vessel diameter

Front 61

Define blood viscosity

Back 61

The stickiness of blood due to formed elements and plasma proteins

Front 62

Relationship between blood vessel length and resistance

Back 62

The longer the vessel the more resistance

Front 63

Resistance varies inversely with the ___

Back 63

fourth power of vessel radius

Front 64

If the radius of a vessel doubles the resistance drops to ___ of its original value

Back 64

1/16th

Front 65

____ are the major determinants of peripheral resistance

Back 65

Small-diameter arterioles

Front 66

____ is directly proportional to the blood pressure gradient

Back 66

Blood flow

Front 67

If blood pressure increases, blood flow ___

Back 67

speeds up

Front 68

Blood flow is inversely proportional to ____

Back 68

peripheral resistance

Front 69

If peripheral resistance increases, blood flow ___

Back 69

decreases

Front 70

Peripheral resistance is more important in ____ because it is _____

Back 70

1) influencing blood flow

2) because it is easily changed by altering blood vessel diameter

Front 71

As ___ decreases, velocity increases

Back 71

cross sectional area

Front 72

____ of blood flow is fastest in the ____ and slowest in ___

Back 72

1) Velocity

2) large arteries

3) capillaries

Front 73

Systemic pressure if highest in the ____ and declines throughout the pathway to finally reach ___

Back 73

1) aorta

2) 0 mm hg in the right atrium

Front 74

The steepest drop in systemic pressure occurs in the ___ which offer the ___

Back 74

1) arterioles

2) greatest resistance to blood flow

Front 75

Arterial blood pressure reflects two factors ___ and ____

Back 75

1) How much the elastic arteries close to the heart can stretch (compliance or distensibility)

2) Volume of blood forced into them at any time

Front 76

Blood pressure is ____ near the heart

Back 76

Pulsatile - it rises and falls

Front 77

Defie Systolic pressure

Back 77

pressure exerted during the ventricular contraction

Front 78

Define Diastolic pressure

Back 78

lowest level of arterial pressure

Front 79

Define Pulse pressure

Back 79

The difference between systolic and diastolic pressure

Front 80

Capillary blood pressure ranges from ___ to ___

Back 80

15 to 35

Front 81

Venous Blood Pressure has a ___ pressure gradient

Back 81

small, about 15 mm Hg

Front 82

The low pressure of the venous system reflects the ____

Back 82

cumulative effects of peripheral resistance

Front 83

Three factors important for venous return

Back 83

1) Muscular pump

2) Respiratory Pump

3) Sympathetic venoconstriction

Front 84

Define Respiratory pump

Back 84

The pressure changes created during breathing that move blood toward the heart by squeezing abdominal veins as thoracic veins expand

Front 85

Define muscular pump

Back 85

Contraction of skeletal muscles "milk" blood toward the heart and valves prevent backflow

Front 86

Define Sympathetic venoconstriction

Back 86

As the layer of smoother muscle around the veins contricts under sympathetic control, venous volume is reduced and blood is pushed toward the heart

Front 87

Maintaining blood pressure requires

Back 87

1) Cooperation of the heart, blood vessels, and kidneys

2) Supervision by the brain

Front 88

Main factors influencing blood pressure

Back 88

1) Cardiac Output

2) Peripheral resistance

3) Blood volume

Front 89

____ controls alter both CO and PR

Back 89

Neural controls

Front 90

Blood pressure is maintained in the short-term by ____ which counteract fluctuations by ____

Back 90

1) neural and hormone controls

2) altering peripheral resistance

Front 91

Blood pressure is maintained in the long-term by ____ which counteract fluctuations by ____

Back 91

1) renal regulation

2) altering blood volume

Front 92

Neural controls of peripheral resistance are directed at two main goals:

Back 92

1) Maintain MAP by altering the blood vessel diameter

2) Alter blood distribution in response to specific demands

Front 93

Neural controls operate via reflex arcs that involve

Back 93

Baroreceptors

Vasomotor centers and fibers

Vascular smooth muscle

Front 94

Define vasomotor center

Back 94

A cluster of sympathetic neurons in the medulla that oversee changes in the blood vessel diameter

Front 95

Baroreceptors are located in (3)

Back 95

1) Carotid sinuses to protect the brain

2) Aortic arch

3) Walls of large arteries of the neck and thorax

Front 96

Norepinephrine and epinephrine cause

Back 96

generalized vasocontriction and increase cardiac output

Front 97

_____, generated by kidney release of renin, causes vasocontriction

Back 97

Angiotensin

Front 98

_____ causes blood volume and blood pressure to decline, which causes __

Back 98

1) Atrial Natriurectic peptide

2) generalized vasodilation

Front 99

___ causes intense vasocontriction in cases of extremely low BP

Back 99

ADH

Front 100

____ quickly adapt to chronic high or low BP

Back 100

Baroreceptors

Front 101

Long-term mechanisms step in to control BP by altering ___

Back 101

blood volume

Front 102

Kidneys act directly and indirectly to regulate ___

Back 102

arterial blood pressure

Front 103

How direct renal mechanism works

Back 103

alters blood volume independently of hormones

Front 104

Increased BP or blood volume causes the kidneys to ___, thus reducing BP

Back 104

eliminate more urine

Front 105

Decreased BP causes the kidneys to ____, thus BP rises

Back 105

conserve more water

Front 106

Kidneys regulate blood pressure indirectly through the ____

Back 106

renin-angiotensin-aldosterone mechanism

Front 107

When ___ declines, certain cells in the kidneys release the enzyme ___ in the blood. This produces ___ which causes ____. This causes renal absorption of ____ which ___ urine formation.

Back 107

1) arterial blood pressure

2) renin

3) Angotensin II

4) aldosterone secretion

5) Na

6) decreases

Front 108

Hormones that can affect BP

Back 108

1) Renin

2) ANP

3) Angiotensin

4) Nitric oxide

5) Aldosterone

Front 109

____ capillaries in the small intestine receive nutrients from digested food.

Back 109

Fenestrated

Front 110

____ capillaries in the endocrine organs allow hormones rapid entry into the blood

Back 110

Fenestrated

Front 111

_____ capillaries with perpetually open pores occur in the kidneys where rapid filtration of blood plasma is essential.

Back 111

Fenestrated

Front 112

Blood flows sluggishly through the _____, allowing time for it to be _____

Back 112

1) Sinusoids

2) modified in various ways.

Front 113

Define microcirculation

Back 113

The flow of blood from an arteriole to a venule

Front 114

Capillary bed consists of two types of vessels

Back 114

1) Vascular shunt

2) True capillaries

Front 115

Define vascular shunt

Back 115

A short vessel that directly connects the arteriole and venule at opposite ends of the bed

Front 116

Define True capillaries

Back 116

the exchange vessels

Front 117

Factors that affect blood flow to capillary

Back 117

1) Local chemical conditions

2) Arteriolar vasomotor nerve fibers

Front 118

___ carry blood from capillary beds toward the heart

Back 118

Veins

Front 119

Define Venules

Back 119

Capillaries unite to form these

Front 120

____ join to form veins

Back 120

Venules

Front 121

____ usually have three distinct tunics, but their walls are always ____ and their lumens are ___ than corresponding arteries.

Back 121

1) Veins

2) thinner

3) larger

Front 122

Tunica media of ____ is poorly developed and tends to be thin even in larger ones.

Back 122

Veins

Front 123

Because of their ____ and ____ veins can accommodate a fairly large blood volume

Back 123

1) large lumens

2) thin walls

Front 124

The walls of veins can be much thinner than arterial walls without the danger of bursting because ____

Back 124

the blood pressure is low

Front 125

Two adaptions of veins that ensure veins return blood to the heart at the same rate it is pumped into circulation.

Back 125

1) Large lumens that offer little resistance to blood flow

2) valves that prevent blood from flowing backward