Exsc 224

Front 1

blood vessels

Back 1

-where the blood goes and returns to the heart from
-form a closed system (really semi closed)

Front 2

3 major types of blood vessels

Back 2

1. artery
2. capillary
3. vein

Front 3

artery

Back 3

carries blood away form the heart

Front 4

what is the largest example of an artery

Back 4

aorta

Front 5

capillary

Back 5

where we deliver and exchange nutrients and waste

Front 6

vein

Back 6

carries blood TOWARDS the heart

Front 7

vessels are made up of 3 tunics (not all blood vessels have all 3)

Back 7

1. tunica intima
2. tunica media
3. tunica externa

Front 8

tunica intima

Back 8

(lines lumen wall)
-principally simple squamous epithelial layer
-vessels > 1mm diameter
-potent blood vessel dilator

Front 9

principally simple squamous epithelial layer of tunica intima

Back 9

forms smooth layer (decrease friction-purpose)

Front 10

vessels > 1mm diameter of tunica intima

Back 10

subendothelial layer- basement membrane

Front 11

potent blood vessel dilator of tunica intima

Back 11

secrete nitric oxide

Front 12

tunica media

Back 12

(thickest layer)
-smooth muscle and elastin connective tissue
-vasoconstrict of vasodilate
-how we control the tone of the blood vessel

Front 13

smooth muscle and elastin connective tissue of tunica media

Back 13

connective tissue rich in elastin (allows to stretch then return back to original shape)

Front 14

vasoconstric of vasodilate of tunica media

Back 14

regulated by vasomotor nerve from ANS (sympathetic portion)

Front 15

how we control the tone of the blood vessel of tunica media

Back 15

constrict or dilated

Front 16

tunica externa

Back 16

(outermost layer)
-principally connective tissue that surrounds the vessel and holds it together
-loose collagen connective tissue
-nerves and lymph vessels
-vasa vasorum- vessels of the vessels

Front 17

vasa vasorum

Back 17

vessels branch off and provide with oxygen and nutrients

Front 18

vascular components

Back 18

-anastomosis
-alternative pathways (collateral channels)

Front 19

anastomosis

Back 19

-shunt
-connection from the atrial side to venus side without passing through a capillary
-a network of streams that both branch out and reconnect

Front 20

alternative pathways (collateral channels)

Back 20

-primary locations thought to occur is in the heart itself which has its own set of blood vessels
-form collateral channels around vessels that have constriction
-this is another way to get blood to the same place

Front 21

what are examples of ateriovenous anastomoses

Back 21

thorough fare channels

Front 22

thorough fare channels are examples of ateriovenous anastomoses

Back 22

allows blood to bypass the capillaries proper and go from the atrial to venus side

Front 23

where is most of your blood when at rest

Back 23

the venous system

Front 24

capacitance vessel

Back 24

having the ability to stretch and accept blood

Front 25

what percent of blood is found in the systemic veins

Back 25

60%

Front 26

what percent of blood is in the systemic arteries and arterioles

Back 26

15%

Front 27

what percent of blood is found in the heart

Back 27

8%

Front 28

what percent of blood is found in the capillaries

Back 28

5%

Front 29

circulating blood in the body

Back 29

most of your blood is not actively circulating, most is pooling in venous system

Front 30

elastic (conducting) arteries

Back 30

-thick-walled arteries near the heart, the aorta and branches
-large lumen-low resistance to flow

Front 31

large lumen-low resistance to flow (elastic arteries)

Back 31

contain elastin in all 3 tunics
-smooth out large blood pressure fluctuations
-serve as pressure reservoirs

Front 32

one cause of systolic hypertension (elastic arteries)

Back 32

aorta becomes stiff as we get older, less elastic, therefore higher peak pressures

Front 33

muscular arteries

Back 33

distal to elastic arteries; deliver blood to body organs

Front 34

characteristics of muscular arteries

Back 34

-have thick tunica media with more smooth muscle
-active in vasoconstriction
-have high pressures
-have all 3 tunics

Front 35

arterioles

Back 35

smallest arteries; lead to capillary beds

Front 36

properties of arterioles

Back 36

-control flow into capillary beds (resistance vessels)
-have lumen of 1mm or less
-very small and very abundant
-contain all 3 tunics
-responsible for creating most of the total peripheral resistance seen in afterload

Front 37

capillaries

Back 37

the smallest blood vessels

Front 38

properties of capillaries

Back 38

-walls-thin tunica interna, one cell thick
-allow only a single RBC to pass at a time
-perictyes on outer surface stabilize capillary walls
-do not dilate do not constrict

Front 39

what are the 3 structural types of capillaries

Back 39

1. continuous
2. fenestrated
3. sinusoids

Front 40

where are continuous capillaries most abundant

Back 40

the skin and muscles

Front 41

endothelial cells of continuous capillaries

Back 41

endothelial cells provide uninterrupted lining

Front 42

adjacent cells of continuous capillaries

Back 42

adjacent cells are connected with tight junctions

Front 43

what allows passage of fluids in continuous capillaries

Back 43

intercellular clefts allows the passage of fluids

Front 44

size of continuous capillaries

Back 44

so small RBC have to squeeze through them, alter their shape

Front 45

continuous capillaries of the brain

Back 45

-have tight junctions completely around the endothelium
-thick basal lamina
-constitute the blood-brain barrier
-prevent things you do not want in your blood from getting to the brain
-no cleft

Front 46

fenestrated capillaries

Back 46

-found wherever active capillary absorption or filtrate formation occurs (e.g. small intestines, endocrine glands, and kidneys)
-allows larger particles to pass through than continuous capillaries

Front 47

fenestrated capillaries are characterized by

Back 47

-an endothelium riddled with pores (fenestration)
-greater permeability than other capillaries

Front 48

sinusoids capillaries

Back 48

-highly modified, leaky, fenestrated capillaries with large lumens
-found in liver, bone marrow, lymphoid tissue, and in some endocrine organs
-allows large molecules (proteins and blood cells) to pass between the blood and surrounding tissues

Front 49

capillary beds

Back 49

network of capillaries (what we are really talking about)

Front 50

how do capillaries exist

Back 50

in networks, all of the same type of capillary

Front 51

where to capillaries originate

Back 51

off of a terminal arterial (resistance vessels)

Front 52

branching of arterials

Back 52

branching of arterials is thoroughfare channel then capillary network

Front 53

what does the capillary network allow

Back 53

allows us to increase the surface area of nutrient exchange
-deliver more oxygen to more cells and pick up more waste products from more cells

Front 54

sphincters

Back 54

essentially muscles that act as valves

Front 55

what is the point of sphincters

Back 55

point to regulate the amount of blood with fresh O2 in it in these capillaries

Front 56

when do sphincters need to regulate delivery of O2

Back 56

because it is toxic when in excess

Front 57

what happens when there is enough O2

Back 57

sphincters close and force blood thoroughfare channels when enough O2 already there

Front 58

what can regulate blood flow as through aterial

Back 58

capillary beds

Front 59

venus system

Back 59

-venules
-veins

Front 60

blood is carried toward the heart in the ___________

Back 60

venous system

Front 61

how are venus capillaries formed?

Back 61

formed when capillary beds unite

Front 62

venus capillaries

Back 62

-porous
-fluids and WBC's pass through wall form interstitial space

Front 63

postcapillary venules

Back 63

smallest venules, composed of endothelium and a few pericytes
-tunica intima
-tunica externa

Front 64

large venules

Back 64

have one or two layers of smooth muscle (tunica media)
-dont find much in the way of externa

Front 65

how are veins formed

Back 65

when venules converge

Front 66

veins are composed of

Back 66

all 3 tunicas: tunica intima, thin tunica media, thick tunica externa (collagen fibers and elastic networks)

Front 67

capacitance vessels

Back 67

(blood reservoirs) contain 65% of the blood supply

Front 68

veins compared to arteries

Back 68

tend to be more floppy less rigid than arteries allowing them to stress and accommodate all this blood at rest

Front 69

valves of veins

Back 69

veins have 1-way valves

Front 70

what is the point of 1-way valves of veins

Back 70

point of veins is to allow blood flow back to the heart

Front 71

how do 1-way valves of veins help

Back 71

help venus return by taking to load off the heart

Front 72

diminish hydrostatic pressure

Back 72

downward pressure

Front 73

what is the only reason we have 1-way valves in veins

Back 73

only have to open the valve lifting a small amount of blood

Front 74

varicose vein

Back 74

failure of these valves

Front 75

properties of varicose veins

Back 75

-extremely painful
-increases blood clot formation
-makes more difficult for blood to return back
-loss function of these veins

Front 76

blood flow

Back 76

volume of blood flowing through a vessel

Front 77

blood pressure

Back 77

force exerted per unit area on a vessel wall (mmHg)

Front 78

arterial pressure

Back 78

pressure differences (or gradient)

Front 79

resistance

Back 79

opposition to flow (peripheral resistance) viscosity, vessel length and vessel radius

Front 80

what is one of the most important factors regulating resistance

Back 80

vessel radius

Front 81

viscosity

Back 81

measure of the resistance of a fluid (fluidity of a liquid)

Front 82

blood vessel radius

Back 82

1/2 the diameter

Front 83

blood flow, blood pressure, and resistance

Back 83

flow through a tube is proportional to the change in P and inversely related to R

Front 84

poiseuille's law

Back 84

Q= (delta P x r^4 x pi)/ (viscosity x L x 8) = delta P / R
where R(resistance) = (viscosity x L)/ r^4 = 1/r^4

Front 85

flow in poiseuille's law

Back 85

flow is = to the resistance of pressure over the resistance to flow

Front 86

flow through a tube is proportional to what

Back 86

the difference in pressure (delta p)

Front 87

flow through a tube is inversely related to what

Back 87

to resistance

Front 88

what happens when pressure differences goes up

Back 88

flow moves faster, when resistance goes up flow through the tube decreases

Front 89

decrease resistance does what

Back 89

increases in flow

Front 90

increase radius causes

Back 90

decrease resistance to flow and increase flow in the tube

Front 91

blood vessel dilate blood vessels in order to

Back 91

increase blood flow to the working muscles

Front 92

doubling the radius causes

Back 92

a 16 fold increase

Front 93

what do small changes in radius result in

Back 93

large changes in flow

Front 94

systemic blood pressure

Back 94

atrial blood pressure

Front 95

systolic blood pressure

Back 95

pressure exerted by the blood the blood vessel walls during ventricular contraction (i.e. peak blood pressure in the aorta)

Front 96

diastolic blood pressure

Back 96

pressure exerted by the blood on the blood vessel walls during ventricular relaxation (i.e. the pressure necessary to open the aortic valve)
-lowest pressure in aorta

Front 97

delta P = Q x R, delta P is a function of

Back 97

delta P is a function of blood flow times resistance

Front 98

delta P = Q x R, increase flow _______ pressure

Back 98

increase flow increase pressure

Front 99

delta P = Q xR, increase resistance ________ pressure

Back 99

increase

Front 100

delta P = Q x R, as increase cardiac output diastolic blood pressure _______

Back 100

doesn't change

Front 101

delta P = Q x R, during exercise as you increase cardiac output what happens to blood flow and pressure in the aorta

Back 101

increase blood flow, pressure in the aorta is going to increase (systolic pressure)

Front 102

can you feel the pulse in venus system

Back 102

no

Front 103

why can you calculate the mean arterial pressure (MAP)

Back 103

because of this huge range
-the amount of blood forced into them at any given time (Q)
-their elasticity (compliance or distensibility)

Front 104

what is the driving force for blood flow

Back 104

atrial blood pressure

Front 105

pulse pressure

Back 105

the difference between systolic and diastolic pressure
-pulse pressure = SBP - DBP = delta P

Front 106

mean arterial pressure (MAP)

Back 106

pressure that propels blood to the tissues
-MAP = diastolic pressure + 1/3 pulse pressure
-MAP = diastolic pressure + 1/3 (SBP - DBP)
-proportional to the work performed by the heart

Front 107

factors aiding venus return

Back 107

-pushes through, does so by creating a pressure gradient
-veins have valves, 1 way, help with venus return
-dynamic muscle contraction (contraction relaxation) helps return blood to heart
-the abdomino-thoracic pump (respiratory pump)

Front 108

abdomino-thoracic pump

Back 108

-inhale, lower pressure inside your chest, aid venus return (blood returning to right atrium)
-exhale, increase pressure in your chest, this results in a temp reduction of venus return
-the alternating of these aids in venus return

Front 109

what are the main factors influencing blood pressure

Back 109

-cardiac output (Q)
-peripheral resistance (R)
-blood volume
-kidneys do this
-lie horizontally, increase venus return (passing out)
-blood pressure varies directly with Q, R, and blood volume
-Q = MAP/R
-MAP = Q x R where R = 1/r^4
-maintenance or modulation of blood pressure
-1. vasotone
-2. plasma volume

Front 110

controls of blood pressure

Back 110

1. short-term controls (immediate responses)
-counteract moment-to-moment fluctuations
2. long-term controls (typically in terms of days)

Front 111

controls of blood pressure, types

Back 111

1. neural
2. hormonal
3. humeral

Front 112

short-term control for neural controls of blood pressure

Back 112

vasomotor control

Front 113

vasomotor controls

Back 113

-sympathetic (SNS)
-receptors alpha 1 and beta 2
-baroreceptors
-chemorecptors (CO2 and H+ sensitive)
-higher brain centers (hypothalamus)

Front 114

beta 2 receptors

Back 114

causes relaxation of blood vessels, causing the radius to increase

Front 115

where are beta 2 receptors found

Back 115

coronary arteries of heart

Front 116

alpha 1 receptors

Back 116

causes smooth muscles to contract-decreases radius, decrease blood flow through tubes

Front 117

where are alpha 1 receptors found

Back 117

find in systemic (periphery) blood vessels (arms, legs, feed liver and kidneys, etc)

Front 118

baroreceptors

Back 118

(pressure-sensative)
-control blood pressure: aute
-stress receptors or mechanical receptors
-sensitive to blood pressure
-think about receptors in carotid arteries
-these pressure receptors operate in a unique way, when active these pressure receptors cause reduction in sympathetic activity (slows heart rate down)

Front 119

what are baroreceptors effects on beta 1

Back 119

decreases sympathetic activation of beta 1

Front 120

hormonal short-term controls of blood pressure

Back 120

-catecholamines (circulating)
-ang II
-endothelium-derived factors
-ADH, ANP-blood volume

Front 121

catecholamines

Back 121

circulating is epinephrine and its control is by sympathetic nervous system

Front 122

ang II

Back 122

potent vasoconstrictor

Front 123

endothelium-derived factors

Back 123

derived growth factor (PDGF) are both vasoconstrictors, associated with inflammatory response

Front 124

ADH, ANP- blood volume

Back 124

produced by heart, if heart receives large venus return, stretching heart will tell kidneys to secrete more waters to decrease blood vessels

Front 125

whats the relation ship between ADH and ANP

Back 125

they are opposites

Front 126

humeral short-term controls of blood pressure

Back 126

-nitric oxide (NO) (EDRF)
-inflammatory chemicals

Front 127

nitric oxide (NO) (EDRF)

Back 127

produced in blood vessels by epithelial cells and is a potent vasodilator

Front 128

inflammatory chemicals

Back 128

histamine, prostacyclin, and kinins

Front 129

humeral long-term controls of blood pressure

Back 129

control blood pressure by altering blood volume

Front 130

what 3 hormones play a role in water retention, control of blood pressure by altering blood volume, humeral control

Back 130

-ang II
-aldosterone
-ADH

Front 131

what does ang II cause

Back 131

causes secretion of aldosterone and ADH

Front 132

how does ang II, aldosterone, and ADH interact

Back 132

3 hormones work together to restore blood volume and by restoring blood volume we can restore blood pressure

Front 133

pressure is maintained by what

Back 133

cardiac output and resistance

Front 134

do anything to expand plasma (blood volume) does what to venus return

Back 134

increases venus return

Front 135

increase venus return results in what to stroke volume and EDV

Back 135

increase venus return increase stroke volume (increased EDV)

Front 136

increase stroke volume does what to cardiac output

Back 136

increases

Front 137

what is your bodies response when you stand up

Back 137

stand up, mean arterial pressure decrease and makes you feel light headed, no longer sending as much pressure up to the brain

Front 138

control of arteriolar smooth, increase CO2 does what to pH

Back 138

decreases

Front 139

control of arteriolar smooth, local vs federal control

Back 139

local control supersedes federal control

Front 140

what controls blood flow in the control of arteriolar smooth

Back 140

only active muscle controls blood flow

Front 141

what determines whether or not it will get more blood flow in control of arteriolar smooth

Back 141

the active muscle determines whether or not it will get more blood flow or not