Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

physiology (Woods) > test 2 > Flashcards

test 2 Flashcards

1
Q

what is slow conduction in the heart mainly caused by

A

diminished numbers of gap junctions along pathway resulting in an increase in the resistance to conduction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is the threshold for the SA node

A

-40 mV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is the parasympathetic system mostly distributed to in the heart

A

SA and AV nodes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is the sympathetic system mostly innervation in the heart

A

distributed to all parts of the heart, but mainly the ventricles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is depolarization represented by in an ECG

A

P and QRS waves:
P=atrial depolarization
QRS= ventricular depolarization

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is depolarization represented by in ECG

A

T wave (ventricular repolarization)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what does an ECG measure

A

extracellular potential

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what are the normal time durations for the P-Q (P-R) interval and the Q-T interval

A

P-Q = 0.16 sec

Q-T: 0.35 sec

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what does the limb lead 1 connect

A

neg terminal end connected to right arm
positive term end is connected to left arm
*looks at the heart from left to right

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what does the limb lead 2 connect

A

neg term is connected to right arm
pos term connected to left leg
*looks at heart from upper right to lower left

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what does the limb lead 2 connect

A

neg term connected to left arm
positive term connected to left leg
*looks at heart from upper left to lower left

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is eithoven’s law

A

if the electrical potentials of any 2 of the 3 bipolar limb ECG leads are known at any given instant, the 3rd can be determined by summing the first 2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

how does current typically flow in the ventricles (ECG)

A

negative to positive primarily in the direction from the base of the heart toward the apex for most of the heart cycle until the very end

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

define vector

A

arrow that points in the direction of the electrical potential generated by the current flow, with the arrowhead in the positive direction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is the direct of the lead for lead 1-3

A

1: 0
2: 60
3: 120

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is the degree for the QRS vector in relation to the zero reference point

A

+59 degrees

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

where does atrial depolarization begin

A

Sinus node

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what is the first part to become depolarized in the atrial T-wave

A

sinus node area

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what are the main leads used for ECG

A

3 conventional bipolar limb leads
six standard leads (V1-V6)
Three augmented leads (aVR, aVL, aVF)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what are some abnormal ventricular conditions that cause axis deviation

A 
change in position of heart in the chest
hypertrophy of one ventricle
bundle branch block
fluid in pericardium
pulmonary emphysema
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what is the most common cause of increased voltage in the standard bipolar leads

A

hypertrophy of the ventricle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what is decreased voltage of the QRS complex typically caused by

A

cardiac myopathies

conditions around the heart

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what are abnormalities that cause current of injury

A

mechanical trauma
infectious processes
ischemia (most common cause)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what is the effect of current of injury on QRS complex

A

abnormal negative current flows from infarcted area and spreads toward the rest of the ventricles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

what is the J point

A

reference point for analyzing current of injury

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

define tachycardia

A

fast heart rate (>100 beats/min)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

what are the causes of tachycardia

A

increased body temperature
stimulation of the heart by sympathetic nerves
toxic conditions of the heart

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

what occurs during endogenously mediated tachycardia (i.e. exercise)

A

heart rate increases, cardiac output increases, filling time is reduced by SV does not fall

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

what occurs during pathologically mediated tachycardia

A

heart rate increases
cardiac output decreases
occurs because atrial pressure decreases and activates the sympathetic nervous system, which occurs after the fact and is unable to compensate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

define bradycardia

A

slow heart rate (

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

what are the causes of bradycardia

A

athletic heart
vagal stimulate
extremely sensitive carotid baroreceptors in carotid sinus syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

what does spillover signals do (respiratory type of sinus arrhythmia)

A

alternately increase and decrease number of impulses transmitted through sympathetic and vagus nerves to the heart

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

what are characteristics of sinoatrial block

A

sudden cessation of P waves
resultant standstill of atria
ventricles pick up a new rhythm, usually originating in the AV node
Rate of QRS is slowed but not otherwise altered

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

what conditions cause atrioventricular block

A

ischemia of AV node or AV bundle fibers through coronary insufficiency
compression of AV bundle by scar tissue or calcified portions of the heart
inflammation of the AV node or bundle
Extreme stimulation of the heart by the vagus nerves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

when does a first degree incomplete atrioventricular block occur

A

when the P-R interval increases to greater than 0.20 sec, the P-R interval is prolonged

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

when does a 2nd degree incomplete atrioventricular block occur

A

P-R time interval increases to 0.25 to 0.45 sec
atria P wave is present by QRS-T wave may be missing, resulting in dropped beats of the ventricle,
2:1 rhythm or other variations may develop

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

what usually occurs as a result from a complete atrioventricular block

A

person will faint due to lack of blood to the brain until the ventricles escape
typically these fainting spells are referred to as Stokes-Adams syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

define partial intraventricular block

A

referred to as electrical alternans

refers to an alternation in the amplitude of P waves, QRS complexes, or T waves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

what do most premature contraction result from

A

ectopic foci: local ischemic areas, calcified plaques, irritation of the conduction system or nodes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

what occurs during paroxysmal tachycardia

A

heart becomes rapid in paroxysms:
paroxysm begins suddenly and lasts for a few seconds, minutes or longer
paroxysm ends suddenly
pacemaker of the heart instantly shifts back to the sinus node

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

define fibrillation

A

twitching (usually slow) of individual muscle fibers in the atria or ventricles and also in recently denervated skeletal muscle fibers
occurs as a result of circus movements

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

what are 3 different conditions that cause circus movement

A

pathway around the circle is too long’
length of the pathway remains constant but the velocity of the conduction slows down
refractory period of the muscle might become greatly shortened

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

what causes the length of the pathway to remain normal. but the conduction velocity of the impulse to slow down (circus movement)

A

because of blockage of the purkinje system, ischemia or high potassium levels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

what causes the refractory period of the muscle to shorten (circus movement)

A

may occur in response to drugs such as epinephrine

may occur after repetitive electrical stimulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

how are the atrial muscle fibers separated from the ventricular muscle fibers

A

cardiac fibrous skeleton

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

what are causes of atrial fibrillation

A

enlargement of atria

inadequate emptying of the ventricles causing blood to back up into the atria

47
Q

what are the values for arterial pressure

A

120 mm Hg (systolic)

80 mm Hg (diastolic)

48
Q

what is the arterial pressure at the vena cava

A

0 mm Hg

49
Q

what is the systolic pulmonary artery pressure value

A

25 mm Hg

50
Q

what is the pulmonary diastolic pressure value

A

8 mm Hg

51
Q

what are the functional parts of circulation

A

arteries (transport under high pressure)
arterioles (control conduits)
capillaries (exchange between blood and extra cell fluid)
venules (collect blood from the capillaries and gradually coalesce into progressively larger veins)
veins (function as conduits for transport of blood from the venules back to the heart & serve as a major reservoir of extra blood )

52
Q

what is the distribution of blood (percentages)

A

84% in systemic circulation (64% in veins, 13% in arteries, 7% in systemic arterioles and capillaries)
16% in heart and lungs

53
Q

what is the equation for velocity of blood flow

A

V=F/A (F=volume of blood flow)

54
Q

what are the 3 functional principles of the circulatory system

A
  • rate of blood flow to each tissue of the body is almost always precisely controlled in relation to the tissue need
  • cardiac output is controlled mainly by the sum of all the local tissue flows
  • arterial pressure regulation is generally independent of either local blood flow control or cardiac output control
55
Q

what monitors tissue needs in each tissue

A

microvessels

56
Q

what happens if arterial pressure falls below 100 mm Hg, nervous reflexes:

A
  • increase force of heart pumping
  • constrict large venous reservoirs
  • generally constrict most of the arterioles throughout the body (increases arterial pressure)
  • kidneys may later play important role in pressure control
57
Q

define pressure gradient

A

pressure difference between the 2 ends of a vessel

58
Q

define resistance

A

impediment to blood flow through the vessels

59
Q

define poiseuille equation

A

F= (P1-P2)/R

60
Q

what are the typical units for blood flow

A

ml/min or liters/min

61
Q

what are characteristics of laminar blood flow

A
  • streamline flow
  • blood flows at a steady rate
  • blood vessel is long and smooth
  • blood flows in streamlines (layers)
  • each layer maintains same distance from vessel wall
  • central-most portion of the blood stays in the center
  • each layer slips easily past surrounding layers
  • velocity of fluid flowing in center is greater than that of fluid flowing towards the outer edges
62
Q

what are characteristics of turbulent flow

A

*nonlayered flow
creases murmurs
produces more resistance than laminar flow
occurs when: flow is too great, blood passes an obstruction within the vessel, blood has to make a sharp turn, blood passes over a rough surface
*blood flows with greater resistance when eddy currents flow

63
Q

when does the tendency for turbulent flow increases

A
  • in direct proportion to velocity of blood flow
  • in direct proportion to the diameter of the vessel
  • in direct proportion to the density of the blood
  • inversely to the viscosity of the blood
64
Q

what is laminar flow directly proportional and inversely proportional with

A
  • directly: mean velocity of blood flow in cm/sec, vessel diameter in cm, density
  • indirectly: viscosity (in poise)
65
Q

define blood pressure

A

force exerted by the blood against any unit area of the vessel wall

66
Q

how is pressure measured

A

with a mercury manometer or with electronic transducers

67
Q

what is the impediment to blood flow in a vessel

A

resistance

68
Q

how is resistance calculated

A

it must be indirectly calculated from measurements of blood flow and pressure

69
Q

what are the 3 main variables that determine resistance

A

vessel radius
blood viscosity
vessel length

70
Q

what is resistance proportional to and inversely proportional to

A

proportional: blood viscosity and vessel length
inversely: radius (radius of blood vessel is to the fourth power)

71
Q

what is the lowest arterial pressure

A

diastolic

72
Q

what is the rate of blood flow through the entire circulatory system

A

=cardiac output

=100ml/sec

73
Q

what is the pressure difference from systemic arteries to systemic veins

A

100 mmHg

74
Q

resistance of entire systemic circulation

A

100/100=1 PRU

75
Q

what is the mean pulmonary arterial pressure

A

avg 16 mm Hg

76
Q

Mean left arterial pressure

A

avg 2 mm Hg

77
Q

what is the total pulmonary vascular resistance when cardiac output is normal at 100 ml/sec

A

14/100=0.14 PRU

78
Q

define conductance

A

measure of blood flow through a vessel for a given pressure difference (usually expressed in ml/sec per ml Hg

79
Q

how are arterioles, capillaries, venues, and veins arranged?

A

in series

80
Q

what are some circulations arranged in parallel

A

brain, kidney, muscle, GI, skin, coronary circulation

81
Q

what can occur if there is amputation of a limb or kidney that removes a parallel circuit

A
  • reduces total vascular conductance
  • reduces total blood flow
  • increases total peripheral vascular resistance
82
Q

what is viscosity

A

measure of the fluid’s internal resistance

83
Q

how does the viscosity of normal blood compare to that of water

A

viscosity of normal blood is about 3X as great as that of water

84
Q

what occurs to viscosity in anemia and polycythemia

A

anemia: decreases viscosity
polycythemia: increases viscosity

85
Q

define vascular distensibility

A

increase in volume/ (increase in pressure X original volume)

86
Q

are arteries or veins more distensible

A

veins

87
Q

define vascular compliance

A

increase in volume/increase in pressure

88
Q

what does vascular compliance tell us

A

tells us the total quantity of blood that can be stored in a given portion of the circulation for each mm Hg rise in pressure

89
Q

how is capacitance related to elastance

A

inversely proportional

90
Q

what happens to the elastance as the amount of elastic tissue increases in a blood vessel

A

elastance increases

compliance decreases

91
Q

define compliance

A

measure of the ease with which a hollow viscus may be distended: volume change resulting from the application of a unit pressure differential between the inside and outside of the viscus

92
Q

define vascular compliance

A

total quantity of blood that can be stored in a given portion of the circulatory system

93
Q

define elastance

A

measure of the tendency of a hollow viscus to recoil toward its original dimensions upon removal of a distending or collapsing force

94
Q

what are the 2 major factors that effect pulse pressure

A

stroke volume output of the heart

compliance of the arterial tree

95
Q

what is the most important determinant of pulse pressure

A

stroke volume output of the heart

96
Q

what happens to the diastolic pressure during ventricular systole

A

it remains unchanged

97
Q

what happens during aortic valve stenosis

A

diameter of the aortic valve opening is reduced significantly, and the aortic pressure pulse is decreased significantly
blood flow through the aortic valve is diminished

98
Q

what happens during patent ductus arteriosus

A

half or more of the cardiac output flows back into the pulmonary artery and lung blood vessels
diastolic pressure falls very low before next heartbeat

99
Q

what happens during aortic regurgitation

A

the aortic valve is absent or will not close properly

aortic pressure may fall all the way to zero between heartbeats

100
Q

what is the progressive reductio of the pulsations in the periphery

A

damping of the pressure pulses

101
Q

what is the calculation for mean arterial pressure

A

diastolic pressure + (1/3) pulse pressure

102
Q

what are factors that regulate right atrial pressure

A

ability of the heart to pump blood out of the right atrium/ventricle
tendency of blood to flow into the right atrium

103
Q

what are factors that increase venous return

A

increased blood volume
increased peripheral venous pressures due to increased large vessel tone
dilation of arterioles

104
Q

describe arterioles

A

small arteries that control blood flow to each tissue
local conditions in tissues control diameter of arterioles
arterioles are highly muscular

105
Q

describe capillaries

A

smooth muscle fiber encircles capillary at point where it originates from a met arteriole (referred to as pre capillary sphincter)

106
Q

what do slit pores do

A

located in capillaries

allow for rapid diffusion of water, water-soluble ions, and small solutes

107
Q

what do plasmalemmal vesicles do

A

formed from cave-ins

play a role in endocytosis and transcytosis

108
Q

what is the most important factor regulating vasomotion

A

concentration of oxygen in the tissues

109
Q

what type of substances can diffuse readily through the capillary cell membranes

A

lipid soluble substances such as oxygen and CO2

110
Q

why is the passage of substances through the interstitial mostly via diffusion rather than flow

A

because of the large number of proteoglycan filaments found in the interstitial
rivulets that allow fluid flow through the interstitial do sometimes form

111
Q

what are the outward starling forces

A

capillary pressure and interstitial fluid colloid pressure

112
Q

what are the inward starling forces

A

interstitial fluid pressure and capillary plasma colloid osmotic pressure

113
Q

what are some factors that increase lymph flow

A

elevated capillary hydrostatic pressure
decreased plasma colloid osmotic pressure
increased interstitial fluid colloid pressure
increased permeability of capillaries

114
Q

what is the equation for determining rate of lymph flow

A

interstitial fluid pressure and activity of lymphatic pump

physiology (Woods) (18 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions