Exam review Flashcards
(153 cards)
1
Q
collaterals
A
multiple arteries that contribute to 1 capillary bed
2
Q
arterial anastomosis
A
fusion of 2 collateral arteries
3
Q
arterial anastomosis function
A
allows capillary circulation to continue if an artery is blocked
4
Q
arteriovenous anastomoses
A
direct connections between arteries and venules to bypass the capillary bed and flow directly into venous circulaion
5
Q
3 factors the affect circulation
A
pressure, resistance, and venous return
6
Q
amount of blood in veins & venules at rest
A
60-65%
7
Q
amount of blood in arteries and arterioles at rest
A
13%
8
Q
capillary blood flow in peripheral tissues and organs maintained by
A
ΔP (pressure gradient) = the difference between pressure of left side (at heart), and pressure returning to right side (at peripheral capillary beds)
9
Q
capillary blood flow equals
A
cardiac output
10
Q
capillary blood flow determined by
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pressure and resistance (ΔP/R = force/flow)
11
Q
how are pressure and resistance related to flow
A
pressure= directly related
resistance= inversely related (R increase, flow decrease)
12
Q
laminar flow
A
13
Q
turbulent flow
A
14
Q
abnormal turbulence caused by
A
15
Q
4 factors associated with blood pressure
A
systolic pressure
diastolic pressure
16
Q
systolic pressure
A
17
Q
diastolic pressure
A
18
Q
pulse pressure
A
19
Q
pulse pressure formula
A
20
Q
mean arterial pressure (MAP)
A
21
Q
MAP formula
A
CO x TPR
22
Q
factors that affect MAP
A
23
Q
3 regulatory mechanisms
A
autoregulation, neural mechanisms, and endocrine mechanisms
24
Q
regulatory mechanism purpose
A
control CO & BP to restore adequate blood flow
25
autoregulation is
the ability to make changes as needed by demand for O2 and waste removal
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autoregulation is adjusted by
peripheral resistance while CO stays the same
27
local vasodilators dilate precapillary sphincters
to accelerate blood flow at tissue level in response to physical changes
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local vasodilator examples
low O2 or high CO2 levels
low pH
histamines
warmer temp
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local vasoconstrictors released by
damaged tissues
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local vasoconstrictor examples
prostaglandins and thromboxanes
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neural mechanisms
autoregulation, neural mechanisms, and endocrine mechanisms
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cv centers adjust
CO & peripheral resistance
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each cardiac center has
cardioacceleratory center (increase CO thru SNS)
cardioinhibitory center (decrease CO thru PNS)
34
sympathetic nervous system
increase HR & contractility
fight or flight
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parasympathetic nervous system
decreases HR
rest or digest
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vasomotor center controls
the activity of sympathetic motor neurons (vasodilation & vasoconstriction)
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vasoconstriction
controlled by adrenergic nerves (NE)
stimulates smooth muscle contraction
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vasodilation
controlled by cholinergic nerves (NO)
relaxes smooth muscle
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vasomotor tone
produced by constant action of sympathetic vasoconstriction nerves
keeps arterioles partially constricted
40
hormonal regulation
has short and long term effects on CV regulation
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types of hormones
anti diuretic (ADH)
angiotensin II
erythropoietin (EPO)
atrial natriuretic peptide (ANP)
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anti diuretic (ADH)
released by posterior lobe of pituitary to elevate BP & reduce water loss at kidneys
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anti diuretic (ADH) responds to
low blood volume
high plasma osmotic concentration
circulating
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angiotensin II
appears in blood when decrease in BP or decreased blood flow to kidneys
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release of renin results in
formation of angiotensin II and aldosterone
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angiotensin II important functions
aldosterone production
secretion of ADH
stimulates thirst
stimulates CO & triggers constriction of arterioles
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aldosterone
H2O & Na+ reabsorption
increase total blood volume
48
erythropoietin (EPO)
is released at kidneys to stimulate RBC production
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erythropoietin (EPO) responds to
low BP
low O2 content
50
atrial natriuretic peptide (ANP)
is produces by cells in right atrium to lower blood volume and pressure
reduces stress on heart
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atrial natriuretic peptide (ANP) responds to
excessive diastolic stretching
52
shock
failure of CV system to deliver enough O2 & nutrients
53
what happens in shock
inadequate perfusion
cells forced to switch to anaerobic respiration
lactic acid builds up
cells & tissues become damaged and die
54
hypovolemic shock
due to loss of blood or body fluids (hemorrhage, sweating, diarrhea)
venous return to heart declines, output decreases
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cardiogenic shock
caused by damage to pumping action of the heart (ischemia, valve problems, arrhythmias)
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vascular shock
causing drop inappropriate vasodilation
head trauma
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obstructive shock
caused by blockage of circulation
pulmonary embolism
58
homeostatic responses to shock
activation of renin-angiotensin-aldosterone
secretion of ADH
activation of SNS
release of local vasodilators
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CV response to light exercise
extensive vasodilation
venous return increases
CO rises
60
CV response to heavy exercise
CV centers activate the SNS
CO increases
blood flow to most tissues is diminished
skin perfusion increases because temp increases
61
diffusion
substances move down concentration gradient to pass freely thru lipid bilayer, fenestrations, or channels
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blood brain barrier
does not allow diffusion of water soluble materials
63
water, ions, small molecules diffusion route
between adjacent endothelial cells
fenestrated capillaries
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Na+ K+ Ca2+ Cl- diffusion route
channels in cell membrane
65
large water soluble compound diffusion route
fenestrated capillaries
66
lipids, O2, CO2 diffusion route
thru endothelial cell membranes
67
plasma protein diffusion route
endothelial lining in sinusoids
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filtration
is the removal of large solutes thru porous membrane
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filtration driven by
hydrostatic pressure
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filtration leaves
larger solutes in the blood stream by forcing water and small solutes thru capillary wall
71
reabsorption
is the result of osmosis
72
osmotic pressure
pressure required to prevent osmosis
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blood colloid osmotic pressure (BCOP)
created by suspended blood proteins that are too large to cross capillary walls
74
hydrostatic pressure forces
water out of a solutions
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osmotic pressure forces
water into a solution
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net filtration pressure (NFP)
the difference between
net hydrostatic pressure
net osmotic pressure
77
NFP formula
(CHP + ICOP) - (IFHS + BCOP)
(filtration factors - reabsorption factors)
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net outward pressure on arterial end
10 mm Hg
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net inward pressure at venous end
9 mm Hg
80
net hydrostatic pressure
the difference between
capillary hydrostatic pressure (CHP)
interstitial fluid hydrostatic pressure (IHP)
pushes water & solutes out of capillaries, into IF
81
net colloid osmotic pressure
the difference between
blood colloid osmotic pressure (BCOP)
interstitial fluid colloid osmotic pressure (ICOP)
pulls water & solutes into capillary from IF
82
edema
an abnormal increase in IF if filtration exceeds reabsorption
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edema result of excess filtration
increase in BP
increase permeability of capillaries allows plasma proteins to escape
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edema result of inadequate reabsorption
decrease concentration of plasma proteins lowers BCOP
85
affects of aging general changes
decreased compliance of aorta
cardiac muscle fiber size reduce
reduced CO & max HR
increase systolic pressure
86
blood pressure measures
arterial pressure
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capillary hydrostatic pressure (CHP) measures
pressure w/in capillary beds
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venous pressure measures
pressure in venous system
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90
circulatory pressure must overcome
total peripheral resistance (the resistance of entire CV system)
91
vascular resistance
R of blood vessels due to friction between blood & vessel walls
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R depends on
avg blood vessel radius
blood viscosity
total blood vessel length
93
smaller vessels offer
more R to blood flow
cause fluctuations in P
94
blood viscosity (thickness) is
the ratio of RBCs to plasma volume
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increase in viscosity =
increase in R = decrease in flow
dehydration or polycythemia (elevated RBC count)
96
the longer vessels =
greater R to flow
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every pound of fat =
200 miles of vessels
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R formula
R= (8ln)/(pi r^4)
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greatest influence on R
vessel radius
r increase, R decrease
vary r the most by vasoconstriction & vasodilation
100
velocity
speed of blood flow is inversely related to cross sectional area
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arterial wall elastic rebound feature
helps absorb pressure waves that come with each heartbeat
102
hypertension
abnormally high blood pressure
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hypotension
abnormally low blood pressure
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venous return
volume of blood flowing back to the heart from the systemic veins
105
skeletal muscle pump
contractions of skeletal muscles near vein compress it helping to push blood towards the heart and valves ensure it only flows in one direction
106
respiratory pump
as you exhale the thoracic cavity decreases in size, pressure rises and air is forced out of lungs and pushes venous blood into right atrium
107
syncope
fainting or a sudden temporary loss of consciousness not due to trauma because BP isnt sufficient enough to move blood
108
vasodepressor syncope
sudden emotional stress
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situational syncope
pressure stress of coughing, defecation, or urination
110
drug induced syncope
antihypertensives, diuretics, vasodilators, tranquilizers
111
orthostatic hypotension
decrease in BP upon standing
112
tissue perfusion affected by
CO
peripheral R
BP
113
proprioceptors
input during physical activity
114
chemoreceptors
monitors concentration of chemicals in the blood
H CO2 O2
115
baroreceptors
changes in pressure w/in blood vessels
stretch receptors
116
lymph capillaries
start as pockets rather than tubes
larger diameters
thinner walls
flat/irreg in section
117
lacteals
specialized lymph capillaries in small intestine that transports lipids from digestive tract
118
lymph capillary structure
endothelial cells loosely bound together with overlap to act as one way valve
119
lymph vessels
travel with veins
superficial & deep lymphatics join to form large lymphatic trunks
120
lymphatic trunks empty into
thoracic duct
right lymphatic duct
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thoracic duct
expands into cisterna chyli to recieve lymph from right & left lumbar trunks and intestinal trunks
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inferior thoracic duct
collects lymph from left bronchiomediastinal trunk, left subclavian trunk, left jugular trunk
123
thoracic duct empties into
left subclavian vein
124
right lymphatic duct
collects lymph from right jugular trunk, right subclavian trunk, right bronchiomediastinal trunk
125
right lymphatic duct empties into
right subclavian vein
126
cytotoxic t cells
attack cells infected by viruses
produce cell mediated immunity
127
helper t cells
stimulate functions of t & b cells
128
suppressor t cells
inhibit function of t & b cells
keep balance in immune system
129
memory t cells
remembers foreign antigen
130
b cells
differentiate into plasma cells with exposure to interleukin 7
131
nk cells
immunological surveillance
attack foreign cells, virus infected cells, cancer cells
132
flow of lymph thru lymph node
subcapsular sinus- macrophages
outer cortex- b cells
deep cortex- t cells
medulla- b & plasma cells
hilus & efferent lymphatics
133
thymus gland function
to mature t cells
lymphocytes divide in cortex, t cells migrate to medulla, mature t cells leave by medullary blood vessels
134
spleen function
remove abnormal blood cells & blood components
store recycled iron from RBC
initiate immune response by b & t cells
135
white pulp
specific immune response
t cells directly attack & destroy antigens
b cells develop into antibodies
macrophages destroy antigens
136
red pulp
clean up
137
lymph composition
similar to plasma
doesnt have plasma proteins
138
artery wall layers
tunica interna usually rippled, elastic membrane
tunica media thick, smooth muscle & elastic fibers
tunica externa collagen & elastic fibers
139
vein wall layers
tunica interna smooth
tunica media thin, smooth muscle cells & collagen fibers
tunica externa collagen & elastic fibers, smooth muscle cells
140
elastic arteries
largest diameter
help propel blood onward despite ventricular relaxation (stretch & recoil)
141
muscular arteries
more muscle than elastic
capable of vasoconstriction and vasodilation to adjust rate of flow
142
arterioles
deliver blood to capillaries
tunic media contain few layers of muscle
143
metarterioles
form branches into capillary bed
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capillary
connect arterioles to venules for exchange of nutrients & wastes between blood and tissue fluid
145
continuous capillary
intercellular clefts are gaps between neighboring cells
CT
lungs
skeletal & smooth muscle
146
sinusoids
very large fenestrations
liver
bone marrow
spleen
147
capillary bed
connect one arteriole and one venule
148
capillary sphincter
guards entrance to each capillary
opens and closes causing capillary blood to flow in pulses (vasomotion)
149
thoroughfare channels
direct capillary connections between arterioles and venules
150
151
varicose veins
twisted dilated superficial veins caused by leaky venous valves that allow backflow & pooling of blood
152
vasa vasorum
vessels of vessels
walls of large vessels contain small arteries and veins that supply the smooth muscle cells and fibroblasts of the tunica media and tunica externa
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