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2 - Keiser A&P 2 > 0-1 Chapter 20 - blood vessels and circulation > Flashcards

0-1 Chapter 20 - blood vessels and circulation Flashcards

1
Q

arteries

A

carry blood away from heart

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2
Q

veins

A

carry blood back to heart

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3
Q

capillaries

A

connect smallest arteries to veins

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4
Q

tunica interna

A

(tunica intima)
–lines the blood vessel and is exposed to blood
–endothelium –simple squamous epithelium overlying a basement membrane and a sparse layer of loose connective tissue

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5
Q

tunica interna

functions

A

•acts as a selectively permeable barrier
•secrete chemicals that stimulate dilation or constriction of the vessel
•normally repels blood cells and platelets that may adhere to it and form a clot
•when tissue around vessel is inflamed, the endothelial cells produce cell-adhesion molecules that induce leukocytes to adhere to the surface
–causes leukocytes to congregate in tissues where their defensive actions are needed

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6
Q

tunica media

A

–middle layer
–consists of smooth muscle, collagen, and elastic tissue
–strengthens vessel and prevents blood pressure from rupturing them

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7
Q

vasomotion

A

changes in diameter of the blood vessel brought about by smooth muscle

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8
Q

tunica externa

A

(tunica adventitia)
–outermost layer
–consists of loose connective tissue that often merges with that of neighboring blood vessels, nerves, or other organs
–anchors the vessel and provides passage for small nerves, lymphatic vessels

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9
Q

vasa vasorum

A

small vessels that supply blood to at least the outer half of the larger vessels
•blood from the lumen is thought to nourish the inner half of the vessel by diffusion

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10
Q

arteries

A

are sometimes called resistance vessels because they have relatively strong, resilient tissue structure that resists high blood pressure

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11
Q

conducting (elastic or large) arteries

A
  • biggest arteries
  • aorta, common carotid, subclavian, pulmonary trunk, and common iliac arteries
  • have a layer of elastic tissue, internal elastic lamina, at the border between interna and media
  • external elastic lamina at the border between media and externa
  • expand during systole, recoil during diastole which lessens fluctuations in blood pressure
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12
Q

distributing (muscular or medium) arteries

A
  • distributes blood to specific organs
  • brachial, femoral, renal, and splenic arteries
  • smooth muscle layers constitute three-fourths of wall thickness
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13
Q

aneurysm

A

weak point in an artery or the heart wall

–forms a thin-walled, bulging sac that pulsates with each heartbeat and may rupture at any time

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14
Q

dissecting aneurysm

A

blood accumulates between the tunics of the artery and separates them, usually because of degeneration of the tunica media

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15
Q

most common sites

A

abdominal aorta, renal arteries, and arterial circle at the base of the brain

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16
Q

results from

A

congenital weakness of the blood vessels or result of trauma or bacterial infections such as syphilis
•most common cause is atherosclerosis and hypertension

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17
Q

resistance (small) arteries

A

–arterioles –smallest arteries
•control amount of blood to various organs
–thicker tunica media in proportion to their lumen than large arteries and very little tunica externa

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18
Q

metarterioles

A

–short vessels that link arterioles to capillaries
–muscle cells form a precapillary sphincter about entrance to capillary
•constriction of these sphincters reduces or shuts off blood flow through their respective capillaries
•diverts blood to other tissues

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19
Q

Arterial Sense Organs

A

sensory structures in the walls of certain vessels that monitor blood pressure and chemistry
–transmit information to brainstem that serves to regulate heart rate, vasomotion, and respiration

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20
Q

carotid sinuses

A

baroreceptors (pressure sensors)
•in walls of internal carotid artery
•monitors blood pressure –signaling brainstem
–decreased heart rate and vessels dilation in response to high blood pressure

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21
Q

carotid bodies

A

chemoreceptors
•oval bodies near branch of common carotids
•monitor blood chemistry
•mainly transmit signals to the brainstem respiratory centers
•adjust respiratory rate to stabilize pH, CO2, and O2

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22
Q

aortic bodies

A

chemoreceptors
•one to three in walls of aortic arch
•same function as carotid bodies

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23
Q

capillaries

A

site where nutrients, wastes, and hormones pass between the blood and tissue fluid through the walls of the vessels (exchange vessels)
–the ‘business end’ of the cardiovascular system
–composed of endothelium and basal lamina
–absent or scarce in tendons, ligaments, epithelia, cornea and lens of the eye

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24
Q

three capillary types distinguished by

A

ease with which substances pass through their walls and by structural differences that account for their greater or lesser permeability

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25
Q

continuous capillaries

A

occur in most tissues
–endothelial cells have tight junctions forming a continuous tube with intercellular clefts
•allow passage of solutes such as glucose
–pericytes wrap around the capillaries and contain the same contractile protein as muscle
•contract and regulate blood flow

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26
Q

fenestrated capillaries

A

kidneys, small intestine
–organs that require rapid absorption or filtration
–endothelial cells riddled with holes called filtration pores (fenestrations)
•spanned by very thin glycoprotein layer
•allows passage of only small molecules

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27
Q

sinusoids (discontinuous capillaries)

A

liver, bone marrow, spleen
–irregular blood-filled spaces with large fenestrations
–allow proteins (albumin), clotting factors, and new blood cells to enter the circulation

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28
Q

Capillary Beds

A

capillaries organized into networks called capillary beds

–usually supplied by a single metarteriole

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29
Q

thoroughfare channel

A

metarteriole that continues through capillary bed to venule

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30
Q

precapillary sphincters

A

control which beds are well perfused

•three-fourths of the body’s capillaries are shut down at a given time

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31
Q

when sphincters open

A

•capillaries are well perfused with blood and engage in exchanges with the tissue fluid

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32
Q

when sphincters closed

A

•blood bypasses the capillaries
•flows through thoroughfare channel to venule
(skeletal muscles at rest)

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33
Q

Veins (Capacitance Vessels)

A

greater capacity for blood containment than arteries
•thinner walls, flaccid, less muscular and elastic tissue
•collapse when empty, expand easily
•have steady blood flow
•merge to form larger veins
•subjected to relatively low blood pressure
–remains 10 mm Hg with little fluctuation

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34
Q

postcapillary venules

A

smallest veins
–even more porous than capillaries so also exchange fluid with surrounding tissues
–tunica interna with a few fibroblasts and no muscle fibers
–most leukocytes emigrate from the bloodstream through venule walls

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35
Q

muscular venules

A

up to 1 mm in diameter
–1 or 2 layers of smooth muscle in tunica media
–have a thin tunica externa

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36
Q

medium veins

A

up to 10 mm in diameter
–thin tunica media and thick tunica externa
–tunica interna forms venous valves
–varicose veins result in part from the failure of these valves
–skeletal muscle pump propels venous blood back toward the heart

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37
Q

venous sinuses

A

–veins with especially thin walls, large lumens, and no smooth muscle
–dural venous sinus and coronary sinus of the heart
–not capable of vasomotion

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38
Q

large veins –larger than 10 mm

A

–some smooth muscle in all three tunics
–thin tunica media with moderate amount of smooth muscle
–tunica externa is thickest layer
•contains longitudinal bundles of smooth muscle
–venae cavae, pulmonary veins, internal jugular veins, and renal veins

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39
Q

Varicose Veins

A

blood pools in the lower legs in people who stand for long periods stretching the veins
–cusps of the valves pull apart in enlarged superficial veins further weakening vessels
–blood backflows and further distends the vessels, their walls grow weak and develop into varicose veins

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40
Q

hemorrhoids

A

varicose veins of the anal canal

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41
Q

Circulatory Routes

general

A

simplest and most common route
–heart to arteries to arterioles to capillaries to venules to veins
–passes through only one network of capillaries from the time it leaves the heart until the time it returns

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42
Q

Circulatory Routes

portal system

A

–blood flows through two consecutive capillary networks before returning to heart
•between hypothalamus and anterior pituitary
•in kidneys
•between intestines to liver

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43
Q

anastomosis

A

the point where two blood vessels merge

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44
Q

arteriovenous anastomosis

A

(shunt)

–artery flows directly into vein bypassing capillaries

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45
Q

venous anastomosis

A

–most common
–one vein empties directly into another
–reason vein blockage less serious than an arterial blockage

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46
Q

arterial anastomosis

A

–two arteries merge
–provides collateral (alternative) routes of blood supply to a tissue
–coronary circulation and around joints

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47
Q

Principles of Blood Flow

A

blood supply to a tissue can be expressed in terms of flow and perfusion

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47
Q

at rest, total flow is

A

quite constant, and is equal to the cardiac output (5.25 L/min)
•important for delivery of nutrients and oxygen, and removal of metabolic wastes

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48
Q

hemodynamics

A

physical principles of blood flow based on pressure and resistance
•F is proportional to P/R, (F = flow, P = difference in pressure, R = resistance to flow)
•the greater the pressure difference between two points, the greater the flow; the greater the resistance the less the flow

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49
Q

blood pressure

A

(bp) –the force that blood exerts against a vessel wall

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50
Q

measured at

A

brachial artery of arm using sphygmomanometer

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51
Q

two pressures are recorded

A

systolic pressure

diastolic pressure

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52
Q

systolic pressure

A

peak arterial BP taken during ventricular contraction (ventricular systole)

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53
Q

diastolic pressure

A

minimum arterial BP taken during ventricular relaxation (diastole) between heart beats

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54
Q

normal value, young adult:

A

120/75 mm Hg

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55
Q

pulse pressure

A

difference between systolic and diastolic pressure

–important measure of stress exerted on small arteries by pressure surges generated by the heart

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56
Q

mean arterial pressure (MAP

A

the mean pressure one would obtain by taking measurements at several intervals throughout the cardiac cycle
–diastolic pressure + (1/3 of pulse pressure)
–average blood pressure that most influences risk level for edema, fainting (syncope), atherosclerosis, kidney failure, and aneurysm

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57
Q

hypertension

A

high blood pressure
–chronic is resting BP > 140/90
–consequences
•can weaken small arteries and cause aneurysms

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58
Q

hypotension

A

chronic low resting BP

–caused by blood loss, dehydration, anemia

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59
Q

Blood Pressure

A

one of the body’s chief mechanisms in preventing excessive blood pressure is the ability of the arteries to stretch and recoil during the cardiac cycle

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60
Q

importance of arterial elasticity

A

–expansion and recoil maintains steady flow of blood throughout cardiac cycle, smoothes out pressure fluctuations and decreases stress on small arteries
•BP rises with age
–arteries less distensible and absorb less systolic force

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61
Q

BP determined by

A

cardiac output, blood volume and peripheral resistance

–resistance hinges on blood viscosity, vessel length, and vessel radius

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62
Q

peripheral resistance

A

the opposition to flow that blood encounters in vessels away from the heart

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63
Q

resistance hinges on three variables

A

blood viscosity “thickness”

vessel length

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64
Q

blood viscosity “thickness”

A
  • RBC count and albumin concentration elevate viscosity the most
  • decreased viscosity with anemia and hypoproteinemia speed flow
  • increased viscosity with polycythemia and dehydration slow flow
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65
Q

vessel length

A

the farther liquid travels through a tube, the more cumulative friction it encounters
•pressure and flow decline with distance

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66
Q

vessel radius

A

most powerful influence over flow

•only significant way of controlling peripheral resistance.

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67
Q

vasomotion

A

change in vessel radius
–vasoconstriction-by muscular effort that results in smooth muscle contraction
–vasodilation -by relaxation of the smooth muscle

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68
Q

laminar flow

A

flows in layers, faster in center

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69
Q

arterioles can constrict to

A

1/3 of fully relaxed radius

–an increase of three times in the radius of a vessel results in eighty one times the flow

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70
Q

from aorta to capillaries, blood velocity (speed) decreases:

A

–farther from heart, the number of vessels and their total cross-sectional area becomes greater and greater

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71
Q

from capillaries to vena cava, flow increases again

A

–large amount of blood forced into smaller channels

–never regains velocity of large arteries

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72
Q

arterioles

A

are most significant point of control over peripheral resistance and flow
–on proximal side of capillary beds and best positioned to regulate flow into the capillaries
–outnumber any other type of artery, providing the most numerous control points
–more muscular in proportion to their diameter
•highly capable of vasomotion

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73
Q

arterioles produce

A

half of the total peripheral resistance

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74
Q

Regulation of BP and Flow

A

vasomotion is a quick and powerful way of altering blood pressure and flow

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75
Q

three ways of controlling vasomotion:

A

–local control
–neural control
–hormonal control

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76
Q

Local Control of BP and Flow

4 ways

A

autoregulation
vasoactive chemicals
reactive hyperemia
angiogenesis

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77
Q

autoregulation

A

the ability of tissues to regulate their own blood supply
–metabolic theory of autoregulation –if tissue is inadequately perfused,wastes accumulate stimulating vasodilation which increases perfusion
–bloodstream delivers oxygen and remove metabolites
–when wastes are removed, vessels constrict

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78
Q

vasoactive chemicals

A

substances secreted by platelets, endothelial cells, and perivascular tissue stimulate vasomotion
–histamine, bradykinin, and prostaglandins stimulate vasodilation
–endothelial cells secrete prostacyclin and nitric oxide (vasodilators) and endothelins (vasoconstrictor)

79
Q

reactive hyperemia

A

if blood supply cut off then restored, flow increases above normal

80
Q

angiogenesis

A

growth of new blood vessels
–occurs in regrowth of uterine lining, around coronary artery obstructions, in exercised muscle, and malignant tumors
–controlled by growth factors

81
Q

Neural Control of Blood Vessels

A

vessels under remote control by the central and autonomic nervous systems

82
Q

vasomotor center of medulla oblongata exerts

A

sympathetic control over blood vessels throughout the body

–stimulates most vessels to constrict, but dilates vessels in skeletal and cardiac muscle to meet demands of exercise

83
Q

precapillary sphincters respond only to

A

to local and hormonal control due to lack of innervation

84
Q

vasomotor center is the integrating center for three autonomic reflexes

A

baroreflexes
•chemoreflexes
•medullary ischemic reflex

85
Q

baroreflex

A

an automatic, negative feedback response to changes in blood pressure
–increases in BP detected by carotid sinuses
–signals sent to brainstem by way of glossopharyngeal nerve

86
Q

baroreflexes important in

A

short-term regulation of BP but not in cases of chronic hypertension
–adjustments for rapid changes in posture

87
Q

chemoreflex

A

an automatic response to changes in blood chemistry

–especially pH, and concentrations of O2 and CO2

88
Q

chemoreceptors

A

called aortic bodies and carotid bodies

–located in aortic arch, subclavian arteries, external carotid arteries

89
Q

chemoreceptors called

A

aortic bodies and carotid bodies

–located in aortic arch, subclavian arteries, external carotid arteries

90
Q

primary role:

A

adjust respiration to changes in blood chemistry

91
Q

secondary role

A

vasomotion
–hypoxemia, hypercapnia, and acidosis stimulate chemoreceptors, acting through vasomotor center to cause widespread vasoconstriction, increasing BP, increasing lung perfusion and gas exchange
–also stimulate breathing

92
Q

medullary ischemic reflex

A

automatic response to a drop in perfusion of the brain
–medulla oblongata monitors its own blood supply
–activates corrective reflexes when it senses ischemia (insufficient perfusion)

93
Q

cardiac and vasomotor centers send sympathetic signals to

A

heart and blood vessels
–increases heart rate and contraction force
–causes widespread vasoconstriction
–raises BP and restores normal perfusion to the brain

94
Q

Hormonal Control

A

hormones influence blood pressure
–some through their vasoactive effects
–some by regulating water balance

95
Q

angiotensin II

A

potent vasoconstrictor

–raises blood pressure

96
Q

aldosterone

A

–promotes Na+ and water retention by kidneys

–increases blood volume and pressure

97
Q

atrial natriuretic peptide

A

increases urinary sodium excretion
–reduces blood volume and promotes vasodilation
–lowers blood pressure

98
Q

ADH

A

promotes water retention and raises BP

–pathologically high concentrations -vasoconstrictor

99
Q

epinephrine and norepinephrine

A

effects
–most blood vessels
•binds to B-adrenergic receptors -vasoconstriction
–skeletal and cardiac muscle blood vessels
•binds to B-adrenergic receptors -vasodilation

100
Q

Two Purposes of Vasomotion

A
  • general method of raising or lowering BP throughout the whole body
  • method of rerouting blood from one region to another for perfusion of individual organs
101
Q

localized vasoconstriction

A

–if a specific artery constricts, the pressure downstream drops, pressure upstream rises
–enables routing blood to different organs as needed

102
Q

Blood Flow in Response to Needs

A

arterioles shift blood flow with changing priorities

103
Q

Capillary Exchange

A

two way movement of fluid across capillary walls

–water, oxygen, glucose, amino acids, lipids, minerals, antibodies, hormones, wastes, carbon dioxide, ammonia

104
Q

Capillary Exchange

importance

A
  • the most important blood in the body is in the capillaries

* only through capillary walls are exchanges made between the blood and surrounding tissues

105
Q

chemicals pass through the capillary wall by three routes

A

–through endothelial cell cytoplasm
–intercellular clefts between endothelial cells
–filtration pores (fenestrations) of the fenestrated capillaries

106
Q

mechanisms involved

A

diffusion, transcytosis, filtration, and reabsorption

107
Q

diffusion

A

is the most important form of capillary exchange
–glucose and oxygen being more concentrated in blood diffuse out of the blood
–carbon dioxide and other waste being more concentrated in tissue fluid diffuse into the blood

108
Q

capillary diffusion can only occur if:

A

–the solute can permeate the plasma membranes of the endothelial cell, or
–find passages large enough to pass through
•filtration pores and intercellular clefts

109
Q

lipid soluble substances

A

–steroid hormones, O2and CO2diffuse easily through plasma membranes

110
Q

water soluble substances

A

–glucose and electrolytes must pass through filtration pores and intercellular clefts

111
Q

Transcytosis

A
  • endothelial cells pick up material on one side of the plasma membrane by pinocytosis or receptor-mediated endocytosis, transport vesicles across cell, and discharge material on other side by exocytosis
  • important for fatty acids, albumin and some hormones (insulin)
112
Q

Filtration

A

fluid filters out of the arterial end of the capillary and osmotically reenters at the venous end
–delivers materials to the cell and removes metabolic wastes

113
Q

opposing forces

A

–blood hydrostatic pressure drives fluid out of capillary
•high on arterial end of capillary, low on venous end
–colloid osmotic pressure (COP) draws fluid into capillary
•results from plasma proteins (albumin)-more in blood
•oncotic pressure = net COP (blood COP -tissue COP)

114
Q

Reabsorption

A
  • capillaries reabsorb about 85% of the fluid they filter

* other 15% is absorbed by the lymphatic system and returned to the blood

115
Q

hydrostatic pressure

A

physical force exerted against a surface by a liquid

•blood pressure is an example

116
Q

Capillary Filtration

can happen at

A
  • capillary filtration at arterial end

* capillary reabsorption at venous end

117
Q

capillaries usually reabsorb most of the fluid they filter –exception:

A

–kidney capillaries in glomeruli do not reabsorb

–alveolar capillaries in lung absorb completely to keep fluid out of air spaces

118
Q

edema

A

the accumulation of excess fluid in a tissue

–occurs when fluid filters into a tissue faster than it is absorbed

119
Q

three primary causes

A

–increased capillary filtration
•kidney failure, histamine release, old age, poor venous return
–reduced capillary absorption
•hypoproteinemia, liver disease, dietary protein deficiency
–obstructed lymphatic drainage
•surgical removal of lymph nodes

120
Q

Consequences of Edema

A

tissue necrosis
pulmonary edema
cerebral edema
severe edema or circulatory shock

121
Q

tissue necrosis

A

–oxygen delivery and waste removal impaired

122
Q

pulmonary edema

A

–suffocation threat

123
Q

cerebral edema

A

–headaches, nausea, seizures, and coma

124
Q

severe edema or circulatory shock

A

–excess fluid in tissue spaces causes low blood volume and low blood pressure

125
Q

venous return

A

the flow of blood back to the heart

126
Q

Mechanisms of Venous Return

A 
pressure gradient
gravity
skeletal muscle pump in the limbs
thoracic (respiratory) pump
cardiac suction
127
Q

pressure gradient

A
  • blood pressure is the most important force in venous return
  • 7-13 mm Hg venous pressure towards heart
  • venules (12-18 mm Hg) to central venous pressure –point where the venae cavae enter the heart (~5 mm Hg)
128
Q

gravity

A

gravity drains blood from head and neck

129
Q

skeletal muscle pump in the limbs

A

contracting muscle squeezed out of the compressed part of the vein

130
Q

thoracic (respiratory) pump

A

•inhalation -thoracic cavity expands and thoracic pressure decreases, abdominal pressure increases forcing blood upward
–central venous pressure fluctuates
•2mm Hg-inhalation, 6mm Hg-exhalation
•blood flows faster with inhalation

131
Q

cardiac suction

A

of expanding atrial space

132
Q

exercise increases venous return in many ways:

A

–heart beats faster, harder increasing CO and BP
–vessels of skeletal muscles,lungs,and heart dilate and increase flow
–increased respiratory rate, increased action of thoracic pump
–increased skeletal muscle pump

133
Q

venous pooling occurs with

A

–venous pressure not enough to force blood upward
–with prolonged standing, CO may be low enough to cause dizziness
•prevented by tensing leg muscles, activate skeletal muscle pump
–jet pilots wear pressure suits

134
Q

circulatory shock

A

any state in which cardiac output is insufficient to meet the body’s metabolic needs

135
Q

cardiogenic shock

A

inadequate pumping of heart (MI)

136
Q

low venous return (LVR)

A

cardiac output is low because too little blood is returning to the heart

137
Q

hypovolemic shock

A

most common

-loss of blood volume: trauma, burns, dehydration

138
Q

obstructed venous return shock

A

-tumor or aneurysm compresses a vein

139
Q

venous pooling (vascular) shock

A

long periods of standing, sitting or widespread vasodilation

140
Q

neurogenic shock

A

loss of vasomotor tone, vasodilation

–causes from emotional shock or brainstem injury

141
Q

septic shock

A

–bacterial toxins trigger vasodilation and increased capillary permeability

142
Q

anaphylactic shock

A

severe immune reaction to antigen, histamine release, generalized vasodilation, increased capillary permeability

143
Q

Responses to Circulatory Shock

A
  • compensated shock

* decompensated shock

144
Q

compensated shock

A

several homeostatic mechanisms bring about spontaneous recovery
•decreased BP triggers baroreflex and production of angiotensin II, both counteract shock by stimulating vasoconstriction
•if person faints and falls to horizontal position, gravity restores blood flow to brain
–quicker if feet are raised

145
Q

Decompensated shock

A

if compensating mechanisms inadequate, several life-threatening positive feedback loops occur

146
Q

poor cardiac output results in

A

myocardial ischemia and infarction

•further weakens the heart and reduces output

147
Q

slow circulation can lead to

A

disseminated intravascular coagulation
•vessels become congested with clotted blood
•venous return grows worse

148
Q

ischemia and acidosis of brainstem

A

depresses vasomotor and cardiac centers

•loss of vasomotor tone, further dilation, and further drop in BP and cardiac output

149
Q

damage to cardiac and brain tissue

A

may be too great to survive

150
Q

Special Circulatory Routes-Brain

A

•total blood flow to the brain fluctuates less than that of any other organ (700 mL/min)
–seconds of deprivation causes loss of consciousness
–4-5 minutes causes irreversible brain damage
–blood flow can be shifted from one active brain region to another

151
Q

brain regulates its own

A

blood flow to match changes in BP and chemistry
–cerebral arteries dilate as systemic BP drops, constrict as BP rises
–main chemical stimulus: pH

152
Q

hypercapnia

A

CO2 levels increase in brain, pH decreases, triggers vasodilation

153
Q

hypocapnia

A

raises pH, stimulates vasoconstriction

–occurs with hyperventilation, may lead to ischemia, dizziness ,and sometimes syncope

154
Q

transient ischemic attacks

A

(TIAs ) –brief episodes of cerebral ischemia
–caused by spasms of diseased cerebral arteries
–dizziness, loss of vision, weakness, paralysis, headache or aphasia
–lasts from a moment to a few hours
–often early warning of impending stroke

155
Q

stroke

A

cerebral vascular accident (CVA)
–sudden death of brain tissue caused by ischemia
•atherosclerosis, thrombosis, ruptured aneurysm
–effects range from unnoticeable to fatal
•blindness, paralysis, loss of sensation, loss of speech common
–recovery depends on surrounding neurons, collateral circulation

156
Q

Special Circulatory Routes Skeletal Muscle

A

•highly variable flow depending on state of exertion

157
Q

at rest:

A

–arterioles constrict
–most capillary beds shut down
–total flow about 1L/min

158
Q

during exercise

A

–arterioles dilate in response to epinephrine and sympathetic nerves
–precapillary sphincters dilate due to muscle metabolites like lactic acid, CO2
–blood flow can increase 20 fold
•muscular contraction impedes flow
–isometric contraction causes fatigue faster than intermittent isotonic contractions

159
Q

Special Circulatory Routes Lungs

A

low pulmonary blood pressure (25/10 mm Hg)
–flow slower, more time for gas exchange
–engaged in capillary fluid absorption
•oncotic pressure overrides hydrostatic pressure
•prevents fluid accumulation in alveolar walls and lumens

160
Q

unique response to hypoxia

A

–pulmonary arteries constrict in diseased area

–redirects flow to better ventilated region

161
Q

Pulmonary Circulation

A

•pulmonary trunk to pulmonary arteries to lungs
–lobar branches for each lobe (3 right, 2 left)
•pulmonary veins return to left atrium
–increased O2 and reduced CO2 levels

162
Q

Pulmonary Capillaries Near Alveoli

A
  • basketlike capillary beds surround alveoli

* exchange of gases with air and blood at alveoli

163
Q

Major Systemic Arteries

A

•supplies oxygen and nutrients to all organs

164
Q

Major Branches of Aorta

A

ascending aorta
aortic arch
descending aorta

165
Q

ascending aorta

A

–right and left coronary arteries supply heart

166
Q

aortic arch

A

–brachiocephalic
–left common carotid
–left subclavian

167
Q

brachiocephalic

A
  • right common carotid supplying right side of head

* right subclavian supplying right shoulder and upper limb

168
Q

left common carotid

A

supplying left side of head

169
Q

left subclavian

A

supplying shoulder and upper limb

170
Q

descending aorta

A

–thoracic aorta above diaphragm

–abdominal aorta below diaphragm

171
Q

Arteries of the Head and Neck

A

common carotid divides into internal and external carotids

–external carotid supplies most external head structures

172
Q

Arterial Supply of Brain

A

paired vertebral arteries combine to form basilar artery on pons

173
Q

Circle of Willis

A

on base of brain formed from anastomosis of basilar and internal carotid arteries
•supplies brain, internal ear and orbital structures
–anterior, middle and posterior cerebral
–superior, anterior and posterior cerebellar

174
Q

Major Systemic Veins

A

deep veins run parallel to arteries while superficial veins have many anastomoses

175
Q

Deep Veins of Head and Neck

A
  • large, thin-walled dural sinuses form in between layers of dura mater
  • drain blood from brain to internal jugular vein
176
Q

Superficial Veins of Head and Neck

A

internal jugular vein
external jugular vein
subclavian vein

177
Q

internal jugular vein

A

receives most of the blood from the brain

178
Q

external jugular vein

A

branches of external jugular vein drain the external structures of the head

179
Q

subclavian vein

A

upper limb is drained by subclavian vein

180
Q

Arteries of the Thorax

A

•internal thoracic, anterior intercostal, and pericardiophrenic arise from subclavian artery

181
Q

thoracic aorta supplies

A

viscera and body wall
–bronchial, esophageal, and mediastinal branches
–posterior intercostal and phrenic arteries

182
Q

Major Branches of Abdominal Aorta

A

See diagram

183
Q

Celiac Trunk Branches

A

branches of celiac trunk supply upper abdominal viscera -stomach, spleen, liver, and pancreas

184
Q

Mesenteric Arteries

A

See diagram

185
Q

Inferior Vena Cava and Branches

A

See diagram

186
Q

Veins of Hepatic Portal System

A

drains nutrient rich blood from viscera (stomach, spleen and intestines) to liver so that blood sugar levels are maintained

187
Q

Arteries of the Upper Limb

A

subclavian passes between clavicle and 1st rib
•vessel changes names as passes to different regions
–subclavian to axillary to brachial to radial and ulnar
–brachial used for BP and radialartery for pulse

188
Q

Superficial and Deep Veins of Upper Limb

A

See diagram

189
Q

Arteries of the Lower Limb

A

branches to the lower limb arise from external iliac branch of the common iliac artery

190
Q

Superficial and Deep Veins of Lower Limb

A

See diagram

191
Q

Arterial Pressure Points

A

some major arteries close to surface which allows for palpation for pulse and serve as pressure points to reduce arterial bleeding

192
Q

hypertension

A

most common cardiovascular disease affecting about 30% of Americans over 50

193
Q

•“the silent killer”

A

–major cause of heart failure, stroke, and kidney failure
•damages heart by increasing afterload
–myocardium enlarges until overstretched and inefficient
•renal arterioles thicken in response to stress
–drop in renal BP leads to salt retention (aldosterone) and worsens the overall hypertension

194
Q

primary hypertension

A

–obesity, sedentary behavior, diet, nicotine

195
Q

secondary hypertension

A

secondary to other disease

–kidney disease, hyperthyroidism

2 - Keiser A&P 2 (15 decks)

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