Chapter 20 Flashcards Preview

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Flashcards in Chapter 20 Deck (100):
0

Three parts of the blood vessel wall are?

Tunica interna (endothelium) - inner layer

Tunica media - middle layer

Tunica externa- outer layer

1

This layer lines the inside of the vessel

This layer is simple squamous epithelium overlying a basement membrane

This layer Is a selectively permeable barrier to materials entering or leaving the bloodstream

Tunica interna

2

This layer is made of smooth muscle, collagen and elastic tissue

This layer strengthens the vessel and changes the diameter of the blood vessel

Tunica media

3

This layer is made of loose connective tissue

This layer anchors the vessel and provides passage for small nerves, lymphatic vessels and smaller blood vessels

Small blood vessels called vasa vasorum supply blood to the outer wall of larger vessels

Tunica externa

4

These carry blood away from the heart

Arteries

5

There are three types of arteries, what are they?

Conducting (elastic or large) arteries

Distributing (muscular or medium) arteries

Resistance (small) arteries

6

The aorta, pulmonary trunk, Common iliac, common carotid, and subclavian arteries, are what type of arteries?

Conducting arteries

7

- These arteries are smaller branches that distribute blood to specific organs

- There Tunica media has layers of smooth muscle allowing vasomotion

Distributing arteries

8

- Small arteries, the smallest are arterioles (constriction going on)

Resistance arteries

9

- Short vessels that link arterioles and capillaries

- Each forms a pre-capillary sphincter, which is smooth muscle that encircles the entrance to one capillary and can shut off
blood through the capillary bed

Metarterioles

Meta= between

10

A weak point in an artery or in the heart wall is called a?

Aneurysm

11

These exchange vessels, they are called?

Capillaries

12

There are three types of capillaries, what are they?

Continuous capillaries

Fenestrated capillaries

Sinusoids (discontinuous capillaries)

13

- These capillaries are endothelial cells from a continuous tube

- They're found in most tissues

- Small solutes pass-through, but larger particles are held back

- In the brain blood vessel cells are tightly joined in and form the blood brain barrier

- They have pericytes, which are cells with tendrils that wrap around capillaries and regulate permeability, they contribute to
growth and repair

Continuous capillaries

14

- Cells that have filtration pores

- These pores allow rapid passage of small molecules, but retain larger molecules

- They are found in the kidneys, endocrine glands, small intestine and choroid plexus

Fenestrated capillaries

15

- Irregular blood-filled spaces

- Found in the liver, bone marrow and spleen

- Endothelial cells are separated by wide gaps so blood cells and proteins can pass through

Sinusoids

16

- Capillaries are organized into networks called these?

- 10-100 capillaries supplied by single metarteriole

- metarteriole Continues as a thoroughfare channel and leads to a venule

- Capillaries branch off proximal end and empty into the distal end

- When sphincters are closed, blood bypasses the capillaries and flows through the thoroughfare channel to the venule

Capillary beds

17

- These carry blood back to the heart, what are they?

- expand easily to accommodate increased blood volume

- low blood pressure, about 10 mm Hg

Veins

18

There are five types of veins, what are they?

Postcapillary venules

Muscular Venules

Medium veins

Venous sinuses

Large veins

19

- These are small veins that receive blood from capillaries

- They are porous and also exchange fluid

Postcapillary venules

20

- These receive blood from postcapillary venules

- Contain one or two layers of smooth muscle

Muscular venules

21

- Infolding of their tunica interna form venous valves

- Valves keep the blood from dropping down with the pool of gravity

Medium veins

22

- Veins with thin-walls, large lumen and no smooth muscle

Venous sinuses

23

- They have smooth muscle in all three tunics

- Venae cavae, pulmonary, internal jugular, and renal veins

Large veins

24

The flow of blood back to the heart is achieved by five mechanisms, this process is called?

venous return

25

These Allow blood to flow in only one direction?

Venous valves

26

There is a venous pressure gradient from venules to the heart favoring the flow of blood to the heart, this is called?

Pressure gradient

27

Blood from the head and neck returns to the heart by flowing down through large veins, this is called?

Gravity

28

In the limbs, the veins are surrounded by muscles which squeeze the blood out of the vein when the muscles contract, this is called?

Skeletal muscle pump

29

When you inhale the thoracic cavity pressure drops and the abdominal cavity pressure raises putting pressure on the abdominal inferior vena cava and creating a pressure gradient toward the heart, this is called?

Thoracic (respiratory) pump

30

During ventricular systole, the atria enlarge creating a slight suction, This is called?

Cardiac suction

31

When blood pools in the lower limbs, stretches the veins, and pulls the venous valves apart until the Valves cannot prevent back flow of blood, wall of vein becomes weak developing into a regular dilations, this is called?

Varicose veins

32

What is the simplest and most common route of blood flow?

Heart- arteries- arterioles - capillaries - venules - veins - heart

33

There's the simple pathway which is the most common circulatory route but there are exceptions, name four of them.

Portal system

Arteriovenous anastomosis

Venous anastomoses

Arterial anastomoses

34

When blood flows through two capillary beds before returning to the heart, this is called?

Portal system

35

When blood flows from artery to vein by bypassing capillaries, this is called?

Arteriovenous anastomosis

36

When veins that interconnect provide alternate routes, this is called?

Venous anastomoses

37

Went to arteries merge an organ to provide alternate route, this is called?

Arterial anastomoses

38

The amount of blood flowing through an organ, tissue, or blood vessel in a given time (mL/min), is called what?

Flow

39

The flow per given volume or mass of tissue (mL/min/g), is called what?

Perfusion

40

The physical principles of bloodflow are based on two things, what are they?

Pressure (causing flow)

Resistance (preventing flow)

41

The force that the blood exerts against a vessel wall is called what?

Blood pressure

42

Blood pressure is measured with this it is connected to an inflatable cuff . The pressure in cuff is greater than the pressure in blood vessel, cuts off blood and then slowly releases, what is this Instrument called?

Sphygmomanometer

43

Where is blood pressure recorded from?

The brachial artery

44

What are the five different pressures that we look at?

Systolic pressure
Diastolic pressure
Arterial blood pressure
Pulse pressure
Mean arterial pressure

45

What is the peak arterial blood pressure occurring during Ventricular contraction (120mmHg)?

Systolic pressure

46

The minimum arterial blood pressure occurring during ventricular relaxation, between heartbeats (75mmHg)?

Diastolic pressure

47

Systolic pressure divided by diastolic pressure (Systolic pressure/Diastolic pressure)

Arterial blood pressure

48

Systolic pressure - Diastolic pressure

(The maximum stress exerted on small arteries by the pressure surges generated from the heart)

Pulse pressure

49

Diastolic pressure + 1/3 Pulse pressure

(Measure of stress on blood vessels)

Mean arterial pressure (MAP)

50

Chronic resting blood pressure higher than 140/90

Hypertension

51

Chronic low resting blood pressure

Hypotension

52

Does the blood flow in the arteries pulsate?

Yes

53

Blood flows in the capillaries and veins at a steady speed (with or without) pulsation?

Without

54

Why does blood pressure rise with age?

Because of arteriosclerosis and atherosclerosis

55

What is blood-pressure determined by?

Cardiac output, blood volume and resistance

56

What is the opposition to flow that the blood encounters in blood vessels?

Peripheral resistance

57

Peripheral resistance hinges on three variables, what are they?

Blood viscosity
Vessel length
vessel radius

58

- Thickness of the blood

- Deficiency of red blood cells or albumin reduces viscosity and speeds up bloodflow (decreases resistance)

- Polycythemia or dehydration increases viscosity and slows down bloodflow (increases resistance)

Blood viscosity

59

- The farther a liquid travels thru a tube, the more cumulative friction it encounters, thus pressure and flow drop with distance (increases resistance)

Vessel length

60

- The only significant way of controlling peripheral resistance from moment to moment is by vasomotion which is adjusting the
radius of the blood vessels.

- vasomotion includes:
-vasoconstriction- Narrowing of a vessel when smooth muscles contract (increases Resistance)

-Vasodilation - Widening of a vessel when smooth muscles relax

.

61


- When the vessel dilates more blood is in the middle of the blood stream and the flow is faster, while when the vessel
constricts, more of the blood is close to the wall and the flow is slower

- Vessel radius markedly affects blood velocity

- From a order to capillary, velocity Diminishes

Vessel radius

62

There are three ways of controlling blood pressure and flow, what are they?

Local control

Neural control

Hormonal control

63

What is the ability of tissues to regulate their own blood supply?

Autoregulation

64

What does hypoxia and accumulation of waste products in tissue do?

They stimulate vasodilation which increases perfusion

65

What do platelets, endothelial cells and perivascular tissue do that stimulate vasomotion?

They secrete vasoactive chemicals

66

Over time hypoxic tissue can increase it's own perfusion by what?

Angiogenesis

67

In addition to local control, the blood vessels are under remote control by what?

by the central and autonomic nervous system's (neural control)

68

The vasomotor center is an integrating center for three autonomic reflexes, what are they?

Baroreflex

Chemoreflex

Medullary ischemic reflex

69

Exerts SNS control

The SNS stimulates most blood vessels to constrict which increases blood pressure

The SNS dilates blood vessels of skeletal and cardiac muscles

Vasomotor center of medulla oblongata

70

This is the autonomic nervous system's response to changes in blood pressure

When blood-pressure rises, increasing nerve signals inhibit the vasomotor center and stimulate the cardio inhibitory neurons, this decreases Heart rate, cardiac output, and blood pressure

When blood pressure drops the reverse occurs and blood-pressure rises back to normal

Baroreflex

71

This is The autonomic nervous system response to changes in blood pH, O2, and CO2

Hypoxemia, Hypercapnia (high CO2), and acidosis (high hydrogen) stimulate chemoreceptors and act through the vasomotor center to induce vasoconstriction

Increases overall blood pressure, increasing perfusion of lungs and rate of gas exchange

Chemoreflex

72

The autonomic nervous system's response to a drop in perfusion of brain

Drop in perfusion stimulates the cardiac and vasomotor centers to increase heart rate and widespread vasoconstriction

These actions raise the blood pressure and blood perfusion through the brain

Medullary ischemic reflex

73

There are five hormones under hormone control that influence blood pressure, what are they?

Angiotensin II

Aldosterone

Natriuretic peptides

Antidiuretic hormone

Epinephrine and norepinephrine

74

A potent vasoconstrictor that raises blood pressure

Angiotensin II

75

Promotes sodium retention by the kidneys and water follows

It increases the blood volume and blood pressure

Aldosterone

76

Secreted by the heart and brain to antagonize aldosterone

These increase sodium excretion by the kidneys

These Reduce blood volume and blood pressure

They are used to lower high blood pressure

Natriuretic peptides

77

Promotes water retention

Pathologic, at high concentrations it is a vasoconstrictor

Antidiuretic hormone (Vasopressin)

78

The stimulate vasoconstriction and raise blood pressure in most blood vessels, in cardiac and skeletal muscle blood vessels, they stimulate vasodilation to increase bloodflow (fight or flight)

Epinephrine or norepinephrine

79

A two-way movement of fluid is called what?

Capillary exchange

80

Movement because molecules are more concentrated in blood and tissue fluid or the reverse, is called?

Diffusion

81

Diffusion, filtration and reabsorption are three types of what?

Capillary exchange

82

Filtration and reabsorption

Pushes fluid out

Draws fluid out

Draws fluid in

Draws fluid out

Blood hydrostatic pressure

Interstitial hydrostatic pressure

Blood colloid osmotic pressure

Tissue fluid colloid osmotic pressure

83

Prevailing force is outward ( filtration)?

Arterial end

84

Prevailing force is inward (reabsorption)?

Venous end

85

More is filtered out then reabsorbed?

Net

86

Accumulation of excess fluid in tissue

Edema

87

Kidney failure, hypertension, histamines

Increased capillary filtration

88

Hypoproteinemia from liver disease, dietary protein deficiency, severe burns

Reduced capillary reabsorption

89

Surgical removal of nodes

Obstructed lymphatic drainage

90

Cardiac output is insufficient to meet the bodies needs?

Circulatory shock

91

Inadequate pumping of the heart?

Cardiogenic shock

92

Loss of blood volume as a result of hemorrhage, trauma, bleeding ulcers, burns or dehydration?

Hypovolemic shock

93

Tumor, etc. compresses a vein and impedes it's bloodflow?

Obstructed venous return shock

94

Too much blood accumulates in the lower body?

Venous pooling shock

95

Sudden loss of vasomotor tone?

Neurogenic shock

96

Bacterial toxins trigger vasodilation and increased capillary permeability?

Septic shock

97

Ag-Ab Complexes trigger release of histamine

Anaphylactic shock

98

Brief episodes of cerebral ischemia which may result from spasms of diseased cerebral arteries?

TIA (transient ischemic attack)

99

Sudden-death of brain tissue caused by ischemia?

Stroke