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Cardio Block - CPR > General, Week 1 Cardio Block2 > Flashcards

General, Week 1 Cardio Block2 Flashcards

1
Q

blood vessels only have direct _____________ innervation. what does this cause?

A

sympathetic, vascoconstriction

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2
Q

aldosterone (adrenal gland) is secreted in response to:

A

angiotensin II or high serum potassium levels

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3
Q

how can velocity of blood vary under constant flow? what is the deciding factor/equation?

A

Q = V x A

if there is a larger cross sectional area (capillaries), the blood will move slower

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4
Q

where are continuous capillaries found?

A

skeletal and cardiac muscle, skin, lung, CT, brain (BBB)

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5
Q

between the endocardium and myocardium lies the _________ ________, which houses what?

A

subendocardial layer

nerves, blood vessels, and Purkinje fibers

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6
Q

opening of the mitral valve _________ opening of the tricuspid valve

opening of the aortic valve ________ opening of the pulmonic

A

precedes (activation of LV occurs first, pressure increases in L ventricle)

follows (less pressure to overcome in the pulmonary arteries)

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7
Q

what does activation of alpha-2 adrenergic receptors do?

A

usually act presynaptically to inhibit NE release
RELAXES GUT

in low dose decreases BP

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8
Q

what are the three ways you can regulate a patient’s contractility as a physician?

A
  1. ANS
  2. HR (independent of ANS)
  3. Cardiac gangliosides
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9
Q

cardiac muscle cells (in myocardium) are started, _______, central nuclei, and have ________ ________

A

branches

intercalated disks

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10
Q

what is the event that causes the closing of the mitral valve?

A

the ventricles are exciting, leading to contraction and a HUGE increase in ventricular pressure. This exceeds aortic pressure, closing the mitral valve

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11
Q

the parasympathetic preganglionics are derived from where?

A

CN 3, 7, 9, 10 and sacral part of spinal cord

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12
Q

when the cardiac muscle cell AP is more positive than the Na/Ca exchanger equilibrium potential, calcium flows (into/out of) cardiac muscle cell

A

into

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13
Q

in smooth muscle, what allows for adaption to a new length? (think uterus)

A

filaments are dynamically repositioning their alignment and changing their number with stretch

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14
Q

List the three transport mechanisms involved in lowering cytosolic calcium:

A
  1. SERCA Ca++ ATPase (back into SR)
  2. PMCA Ca++ ATPase (through plasma membrane)
  3. Na/Ca pump
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15
Q

Conduction velocity is directly related to (2):

Indirectly related to: (2)

A

Directly = cross sectional area of the fiber, rate of rise of action potential

Indirect = resistance (number of gap junctions), and current needed to discharge capacitance (largely ignored)

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16
Q

what are the determinants of cardiac output?

A

HR and SV

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17
Q

epinephrine binds to which adrenergic receptors?

A

alpha1, alpha2, beta1, beta2

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18
Q

what characterizes the absolute refractory period in ventricular cells?

A

the inactivation of VG Na+ channels

they need to get back down to a specific voltage to open (around -65 mV)

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19
Q

where are fenestrated capillaries found?

A

glomerulus, synovium, endocrine glands, intestinal mucosa, choroid plexus

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20
Q

SA node cells:

size?
resistance?
action potentials?

conduction velocity?

A

small, intracellular resistance high (little gap junctions), action potentials small and sloe

SLOW speed of conduction

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21
Q

what factors affect resistance in a vessel? (3)

A
  1. viscosity
  2. length
  3. radius
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22
Q

conduction system cells

size?
resistance?
action potentials?

conduction velocity?

A

very large cells
very low resistance
large/fast APs

VERY large conduction velocity

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23
Q

name the three layers (think histo) of the heart

A
  1. endocardium
  2. myocardium
  3. epocardium (visceral pericardium)
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24
Q

on ejection, radius of a chamber _______ and tension _________

what does this do to chamber pressure?

A

decreases, tension remains constant

it increases chamber pressure (P = 2HT/r)

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25
Q

murmurs are simply _______ blood flow in a vessel

A

turbulent

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26
Q

what mediates a ventricular cell action potential upstroke?

A

increase in Na+ permeability

VG Na+ channel

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27
Q

volume of blood that leaves the L ventricle per minute =

A

cardiac output

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28
Q

store operated calcium channels in smooth muscle are activated when ________________________. They induce what two events?

A

SR Ca++ levels are depleted

  1. restore SR calcium levels
  2. activates contraction
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29
Q

the sympathetic preganglionic fibers are derived from what areas?

A

from thoracic and lumbar divisions of spinal cord

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30
Q

the lacrimal glands are only innervated by the __________ NS

A

parasympathetic

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31
Q

how does NE increase contractility?

(think signal transduction and 2 main things it phosphorylates)

what do they phosphorylations do ultimately in the cell?

A

NE –> beta-1 –> Gs –> cAMP –> PKA

phosphorylates VG Ca channel to let more in
phosphorylates phospholamban (to increase SERCA activity)

enhances Ca++ influx and results in increased loading of Ca into SR (INCREASES AVAILABILITY CA)

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32
Q

what comprises the L margin of the heart?

A

arch of the aorta
pulmonary trunk
L atrium
L ventricle

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33
Q

what do cardiac gangliosides do cellularly?

what does this mean for cardiac contraction

A

inhibits Na/K ATPase… changing Na+ gradient

now, Na/Ca exchanger has calcium INFLUX almost ALL of systole

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34
Q

MLCK usually binds to Ca-CM… but this affinity is decreased when what happens?

what happens to tension?

A

when MLCK is phosphorylated (by PKA)

tension decreases

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35
Q

a decrease in MAP decreases renal arterial pressure, converting _______ to _______. This then converts _____________ (from the liver) to __________. Via ACE, this converts ____________ to __________.

A

prorenin –> renin
angiotensinogen –> angiotensin 1
angiotensin 1 –> angiotensin 2

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36
Q

name the valve between the R atrium and R ventricle

A

right AV valve (tricuspid)

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37
Q

preload definition

A

pressure of the L ventricle prior to contraction (closely related to volume of blood in L ventricle prior to contraction)

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38
Q

_______________ is compromised in diastolic heart failure due to the inability to accommodate larger volumes of blood (think pressure volume curves)

A

heterometric reserve

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39
Q

what is the muscle called of the R ventricle wall?

A

trabecular carnae

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40
Q

under resting conditions the _________ NS plays the largest role in the heart

A

parasympathetic

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41
Q

what is the purpose (very general - main goal) for extrinsic control of arteriolar diameter?

intrinsic control?

A

regulating MAP

matching organ blood flow to metabolic needs of that specific organ

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42
Q

what factors can cause edema? think about pressures.

A

Increase in hydrostatic pressure (arteriolar vasodilation, long term standing/sitting)

Decrease in oncotic pressure of capillaries (liver failure, malnutrition, late term pregnancy)

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43
Q

transcapillary SOLUTE exchange depends on what three things? which the most?

A
  1. solute permeability
  2. SA of exchange
  3. concentration difference (capillary - intersitium)

3 is most important

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44
Q

name the 5 factors that enhance venous return:

A

1) cardiac contraction (suction)
2) sympathetically induced venous vasoconstriction
3) skeletal muscle activity
4) venous valves
5) respiratory activity

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45
Q

define a long QT syndrome

A

increased time between ventricular activation and re-polarization

delayed ventricular repolarization

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46
Q

the adrenal gland (on top of kidneys) is stimulated by the ______ nervous system to release ________

A

sympathetic, epineprhine

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47
Q

how can you increase the active pressure curve on a pressure/volume diagram of the heart? (i.e., make it so that you have higher possible pressures generated at any given volume)

A

increase contractility (Ca++ availability or sensitivity)

increase sarcomeres (hypertrophy)

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48
Q

decreased arterial compliance can lead to increased _________ ____________ and therefore ___________

A

systolic pressure

hypertension

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49
Q

the key EXTRINSIC factor of arteriolar tone is the ______________.

_____ receptors cause vasoconstriction
_____ receptors cause vasodilation

A

sympathetic NS

alpha-1
beta-2

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50
Q

the SA node is located at the junction of the _________ and the _________

the AV node is located where?

A

superior vena cava, R atrium

between R atrium and R ventricle

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51
Q

most arteries and arterioles are innervated only by __________ nerves that release NE. NE binds to ___________ receptors in the vascular smooth muscle. What does opening of this receptor do?

A

sympathetic
alpha-1 receptors

PKC –> IP3 –> Ca release from SR

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52
Q

repolarization of the nodal cell action potential is caused by what?

A

opening of delayed-rectifier K+ channels.

K+ efflux

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53
Q

describe the histology of a heart valve

A

a core of connective tissue lined on both sides by endocardium

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54
Q

On diastolic filling, radius of a chamber _________ and tension _________

what does this do to chamber pressure?

A

increases, increases (think rubber band)

keeps chamber pressure pretty constant

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55
Q

list the 4 phases of the cardiac cycle:

what valves are open at each one?

A
  1. Filling phase (mitral and tricuspid valves open)
  2. Isovolumetric contraction phase (both valves closed)
  3. Ejection phase (aortic and pulmonic valves open)
  4. Isovolumetric relaxation phase (both valves closed)
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56
Q

parasympathetics innervate the heart (at what locations) via the _______ nerve. What does this do to the heart?

A

SA/AV node, vagus nerve, decreases HR

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57
Q

what is the role of aldosterone?

A

sodium retention and potassium secretion by the kidneys

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58
Q

the Na/Ca exchanger in cardiac muscle cells usually mediates calcium _______, but transiently mediates calcium ______ during what phase of the cardiac cycle?

A

efflux, influx

early systole (rapid depolarization)

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59
Q

what characterizes the supranormal period in ventricular cells?

A

when the membrane potential is close to the resting membrane potential, there are enough Na+ channels available that if you give a stimulus, it would actually fire and create a normal action potential

even though the stimulus is less than what you usually need.

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60
Q

The more depolarized the rmp of a smooth muscle cell, the more _________ the cells are, the more hyperpolarized the rmp the more __________ the cells are

A

contracted, relaxed

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61
Q

At steady state HR, calcium ________ equals calcium _______ each beat. With an increase in HR… what happens?

A

influx, efflux

influx > efflux, increased Ca in SR… new steady state
more Ca for CICR, larger contractility

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62
Q

where are nicotinic cholinergic receptors located??

A
  • all autonomic sympathetic and parasympathetic ganglia neurons (including adrenal medulla)
  • NMJ
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63
Q

epicardium is the same as __________ _________

A

visceral pericardium

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64
Q

the left coronary artery branches into the ________ _______ and ______________ right away

A

circumflex branch, anterior interventricular artery

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65
Q

parasympathetics –> ______ —> SA/AV nodes.

Heart rate slows by what two mechanisms?

A

Ach

  1. ACh-gated K+ channels open
  2. muscarinic receptors activated –> reduces cAMP and decreases effects of sympathetic activation
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66
Q

what is the principle determinant for how much volume ends up inside your ventricle?

A

the filling pressure (preload), the pressure required to establish the EDV

more preload pressure -> more filling

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67
Q

Ach, through muscarinic receptors, triggers _____ production, which diffuses into SM where it is __________

A

NO

vasodilatory

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68
Q

what is the equation for the resistance of a vessel?

what is the main deciding factor?

A

R = 8viscositylength/pi*r^4

the radius is the largest player

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69
Q

__________ muscle generates force over a much larger range of lengths than _________ muscle

A

smooth, skeletal

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70
Q

Afterload:

A

pressure the L ventricle has to overcome for the blood to be ejected

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71
Q

what does angiotensin 2 do? (5)

A
  1. stimulates the adrenal gland to produce ALDOSTERONE
  2. arteriolar vasoconstriction (increase TPR)
  3. Increases Na+ reabsorption and K+ secretion in kidneys
  4. activates sympathetics
  5. increase ADH secretion

OVERALL - INCREASES MAP

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72
Q

what is net driving force?

oncotic pressure moves fluid _____ the capillaries. this is called _________ and has a net driving force of (> or

A

NDF=(Pc –Pi)–σ(πc –πi)

into, reabsorption, < 0

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73
Q

how do muscarinic cholinergic receptors decrease HR?

A

their activation opens K+ channels, hyper-polarizing cell for longer

also decrease PKA activity, halting all of those phosphorylation channel effects from the sympathetics

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74
Q

how can you modulate stroke volume?

A

increase venous return (EDV) and ventricular contractility (sympathetics)

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75
Q

describe the fibrous skeleton of the heart:

A

4 dense CT rings that support the 4 valves

cardiac muscle cells attach

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76
Q

in a tube with a _________ radius, there is less resistance and ________ blood flow (mL/min)

A

smaller

increased

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77
Q

what structural part of the heart has the highest conduction velocity? lowest?

A

highest: Purkinje system, His, BB
lowest: AV node, then SA node

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78
Q

on isovolumetric contraction, radius of a chamber ___________ and tension __________

what does this do to chamber pressure?

A

remains constant, tension increases

this increases chamber pressure (P = 2HT/r)

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79
Q

what is the valve connecting the left atrium and left ventricle?

A

the left AV valve or MITRAL VALVE

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80
Q

the passive tension curve on the pressure/volume plot of the heart represents what?

A

the work being done on the heart by increasing blood filling at increasing volumes. pressure generated by filling the heart to a certain volume (no active work)

81
Q

where are the locations of the baroreceptors?

what CNs do they travel with?

A

carotid sinus - glossopharyngeal (CN 9)

aortic arch - vagus n. (CN 10)

82
Q

why does edema occur? (general)

what factors can cause this?

A

the net filtration exceeds the ability of lymphatic drainage - excess of fluid in interstitial space

83
Q

the cells of a ventricle and atria have a ten fold higher resting membrane permeability to ______ than do skeletal muscle or nerve cells due to the large number of ______ channels.

what is the result?

A

Potassium, Kir

stabilizes resting membrane potentials, decreasing likelihood of arrhythmias (need a large stimulus to stimulate cells)

84
Q

what two things determine contractility of the heart? (2)

A
  1. Availability of calcium

2. Sensitivity to calcium

85
Q

what is the basis behind valves opening?

A

pressure differences across compartments

86
Q

when the cardiac muscle cell AP is more negative then the Na/Ca exchanger equilibrium potential, calcium flows (into/out of) the cell

A

out of

87
Q

what are the ways cytosol calcium can be increased in a smooth muscle cell via intracellular mechanisms? (2)

A
  1. CICR from SR (VG Ca++ opening causes this, but that is extracellular)
  2. IP3 mediated calcium release from SR
88
Q

smooth muscle cells have a low permeability to:

A

potassium

89
Q

what is the most predictable effect of alpha-1 adrenergic activation?

A

vasoconstriction of arteries and veins

increase TPR, increase venous return

–> increase BP

90
Q

ejection fraction:

A

percentage that leaves the L ventricle

91
Q

what is a ventricular cell resting membrane potential?

A

-80 to -85 mV

high resting K+ efflux, high ATPase level contributes

92
Q

on isovolumetric relaxation, the radius of a chamber ___________ and tension _________

what does this do to chamber pressure?

A

radius remains constant, decreases

it decreases chamber pressure (P = 2HT/r)

93
Q

Low K permeability in SMCs means other permeability pathways more easily do what?. Consequently, the resting membrane potential of smooth muscle cells is typically around _______.

A

draw the membrane potential away from EK

-45 mV

94
Q

most of the blood volume is found in the _______ and _______ at any point in time. they have a large ________, which allows them to expand volume at a given pressure

A

veins and venues

compliance

95
Q

sweat glands are mediated by the __________ NS but have ________ receptor activation

A

sympathetic, cholinergic

96
Q

the blood pressure does not decrease from the arteries to veins in a linear manner. the largest drop of blood pressure is in the ____________. Here, blood flow to the various organs is controlled.

A

arterioles

97
Q

the smooth surface that accompanies the vena cava and continues into a portion of the atrium is derived from what embryological feature?

A

sinus venosus

98
Q

what are the determinants of FORCE in the heart (2)? (since all cells fire together)

A
  1. length-tension

2. Contractility (modulate Ca++ availability)

99
Q

the _________ muscles attach to the flaps of the tricuspid valve via _____________. What are the purpose of these muscles?

A

papillary, via the chordae tendinae

to keep the valve from prolapsing back into the atria during contraciton

100
Q

what do indirect cholinergic stimulating drugs do?

A

inhibit destruction of ACh by the enzyme acetylcholinesterase, increasing concentration of ACh.

101
Q

what is the equation for cardiac efficiency?

A

Cardiac Efficiency = SW / QO2

102
Q

what structural feature of smooth muscle cells accommodates the broad range of lengths over which smooth muscle cells can function?

A

loose organization of actin and myosin filaments (myosin light chains aren’t even anchored)

what it interacts with depends on what actin filament is nearest!!

103
Q

vascular smooth muscle has ____ and ____ adrenergic receptors. the first ____________ and the second __________

A

alpha-1, beta-2

vasoconstricts
vasodilates

104
Q

an increase in venous tone, peripheral vascular pressure _________ and venous return _________

A

increases, increases

105
Q

the blood flow (mL/min) in a vessel is directly proportional to the ___________ and inversely proportional to the __________

A

pressure gradient

resistance

106
Q

what is usually the cause of a long QT interval?

A

mutations in genes comprising the delayed-rectifier K channels causing delayed activation and making repolarization occur later

107
Q

where are discontinuous capillaries found?

A

liver, bone marrow, spleen

108
Q

volume of blood that leaves the L ventricle per beat

A

stroke volume

109
Q

a low blood pressure would affect the baroreceptors, _________ their firing rate. This would activate the ____________________. What is the ultimate result?

A

decreasing
sympathetic NS
increase sympathetics to cardiac - HR and contractility, vasoconstrict (DIRECT - from activation of sympathetics - this is unlike the parasympathetics)

110
Q

____________ increase CO by increasing BOTH heart rate AND stroke volume

A

parasympathetics

111
Q

the muscle of the right atrium is called the _________ muscle. the muscle and smooth surface of the atrium are separated by the ____________ internally

A

pectinate muscle

crista terminales

112
Q

nerves going to the heart (both sympathetic and parasympathetic) enter the _______ ________. The parasympathetics come from the _______ nerve and are preganglionic.

A

cardiac plexus

vagus

113
Q

Nodal cell AP: I funny channels are activated by ____________ and are ___________ ___________ channels that let in ______, __________ the cell

A

hyperpolarization
non-specific cation channels
Na+
depolarizing

114
Q

Stretch-activated channels in smooth channel: non-selective cation channels – tend to _________ m.p. causing ___________

A

depolarize, causing contraction

115
Q

adrenergic receptors (sympathetics):

alpha receptors are generally _________ except in _____

beta receptors are generally _________ except in _______

A

excitatory, gut

inhibitory, heart

116
Q

what are the ways cytosol calcium can be increased in a smooth muscle cell via extracellular mechanisms? (4)

A
  1. VG Ca++ opening (L-type Ca channel)
  2. Store-activated Ca++ channel (activated when SR calcium stores are low)
  3. Non-selective cation channels - let in Na+ and Ca2+
    (stretch or ligand)
117
Q

what does activation of beta-2 adrenergic receptors do?

A

vasodilator (especially in skeletal muscles) –> decrease TPR –> drop BP

bronchodilator

118
Q

a more compliant vessel can hold more _________ at a certain __________

state the equation for compliance

A

volume, pressure

C = delta V/ delta P

119
Q

what causes the plateau phase of the ventricular action potential?

A
  1. an increase in Ca++ permeability (l-type calcium channels)
  2. Magnesium blocking of Kir channels, decrease in K+ efflux.

The hyperpolarizing and depolarizing effects cancel out, leaving mp at 0 mV for an extended period of time

120
Q

NE binds to which adrenergic receptors?

A

alpha1, alpha2, beta1

121
Q

unitary smooth muscle has ______ gap junctions

what are it’s 3 properties?

give examples of locations of unitary smooth muscle

A
  1. syncytial behavior
  2. respond to stretch with increased activity
  3. low to moderate innervation density

hollow organs, blood vessels, uterus, gut

122
Q

homeometric regulation of contractility is governed by:

heterometric regulation of contractility is governed by:

A

homeometric - change in contractility (independent of changes in length)
heterometric: length-tension (changes in sarcomere length)

123
Q

sympathetic fibers release ____ and bind to _____ adrenergic receptors on the ventricles, activating _ _ _.

What does this do to the ventricular AP?

A

NE, beta, PKA

phosphorylates calcium channels, slow and fast delayed-rectifier K+ channels

shorten AP duration

124
Q

purkinje fibers of the heart are derived from:

what do they look like in histo?

A

cardiac myocytes

wide-diameter, “puffy”, few sarcomeres, connected by gap junctions electric)

125
Q

long term regulation of MAP through blood volume is done through the:

A

renin-angiotensin-aldosterone system

126
Q

the upstroke of the nodal action potential is caused by what?

A

increase in Ca++ permeability (L-type VG)

127
Q

why are smooth muscle cells sensitive to small changes in membrane permeabilities?

A

The overall low permeability of smooth muscle cells to ions, but K in particular. Easier to pull membrane potential farther from Ek

our rmp is really so close to the Ca-L channel activation threshold - small permeability changes really signficicanly change contraction

128
Q

the right and left bundle branches off the bundle of His are composed of ______ _________ in the __________ _________

A

purkinje fibers

subendocardial space

129
Q

sympathetics innervate what part of the heart?

what does it cause?

A

the SA/AV nodes, L ventricle

increase in HR AND contractility

130
Q

when thinking about transcapillary FLUID exchange, oncotic pressure tends to favor movement _______ the capillaries while hydrostatic pressure tends to favor movement ______

A

into

out

131
Q

in pharmacomechanical coupling for smooth muscle activation cytosolic Ca2+ is controlled by:

  1. ___________- induced Ca2+ release from ___________ (change in membrane potential not necessary)
  2. and/or _____________________________
A
  1. second messenger- induced Ca2+ release from internal stores
  2. change in sensitivity of filaments to Ca2+ via phosphorylation
132
Q

The range of volumes over which an increase in volume results in increased active pressure due to optimization of thick-thin filament overlap in sarcomeres

A

heterometric reserve

133
Q

what event on the Wiggers diagram marks the end of ventricular diastole and start of ventricular systole? (L heart for example)

A

Closure of mitral valve (go into isovolumetric contraction phase)

134
Q

when the cardiac muscle cell AP is more negative then the Na/Ca exchanger equilibrium potential, calcium flows (into/out of) the cell

A

out of

135
Q

the openings for the coronary arteries are in the:

A

sinuses of the aortic valves

136
Q

the right marginal artery comes from the ________ __________ _________

A

right coronary artery

137
Q

epinephrine ________ ventricular action potential by increasing opening probability of _______ and ______ channels and increasing permeability

A

shortens

delated-rectifier K+ channels (fast and slow)
L-type Ca++ channels

138
Q

ACE stands for what and does what?

A

angiotensin converting enzyme

angiotensin 1 –> angiotensin 2

139
Q

EMBRYOLOGY HERE

A

m

140
Q

what is the equation for how much pressure a chamber can develop?

A

P = 2HT/r

H = thickness
T = tension
r = radius of chamber
141
Q

what phases of the cardiac cycle are considered diastole?

A
  1. isovolumetric relaxation phase

2. filling phase

142
Q

__________ - determines volume and therefore sarcomere length; can change suddenly
___________ - determines how much work the heart must do to successfully eject blood

A

preload

afterloas

143
Q

what activates myosin light chain kinase? (MLCK) in smooth muscle

A

`its binding to Ca-CM (calcium calmodulin)

144
Q

what does activation of beta-1 adrenergic receptors do?

A

Increase HR
Increase contractility
Increase lipolysis
Increase renin secretion

145
Q

____________ is a measure of distensibility of a vessel

A

compliance

146
Q

the difference between diastolic and systolic pressures is called:

A

pulse pressure

147
Q

what is the equation for the total energy needed by the heart in systole?

A

Qo2 = Stroke Work (SW) * Tension heat

148
Q

in multiunit smooth muscle, there are ____ gap junctions
coordinated movements are usually _______ mediated and there is an ________ of neural connections.

examples of multiunit smooth muscle in the body

A

no gap junctions

neurally
abundance of neural connections

pilomotor cells for body hair, iris, ciliary body

149
Q

what phases of the cardiac cycle are considered systole?

A
  1. isovolumetric contraction phase

2. ejection phase

150
Q

what does NE do to the ventricular action potential in terms of membrane proteins? in terms of length of AP?

A

PKA –> phosphorylates L-type Ca++ channel (opening them sooner and increasing flow –> Ca induced inactivation)

phosphorylates fast and slow Kv channels –> increase probability of opening (and thus repolarization)

decrease ventricular AP

151
Q

sympathetic (NE) input to nodal cells causes _________ in rate of AP. How does it do this (think 3 channels)?

A

Increase

Enhances activity of I funny channels (increase opening probability, faster depolarization)

Increases permeability in delayed-rectifier Ca++ channels (quickens re-polarization)

Increases permeability of L-type Ca++ channels (brings depolarization up faster and stronger but also turns off faster)

152
Q

an increase in __________ increases the end diastolic volume

an increase in _________ decreases the end systolic volume

an increase in _________ increases the end systolic volume

A

preload

contractility

afterload

153
Q

what is the equation for pressure in a compartment?

A

P = 2HT/r

154
Q

where are muscarinic cholinergic receptors located?

A
  • postganglionic parasympathetic effector cells

- other effector cells (blood vessels - not connected to cholingeric innervation)

155
Q

the ___________ ________ is a branch off the trabecular carnae and is important for the conduction system into the ventricles

A

moderator band

156
Q

what is the equation for stroke work?

definition?

A

stroke work (SW) = work done on the blood by the heart

SW = Pafterload * SV + 1/2mv2

157
Q

the __________ must be phosphorylated before it can interact with actin in smooth muscle to form cross bridges

what phosphorylates it?

A

myosin light chain

Ca-CM-MLCK

158
Q

when MLC is dephosphorylated while in the attached state, there is:

A

tension maintenance at low energy exposure

159
Q

the predominant chamber viewed on an anterior view is the:

A

R ventricle

160
Q

the resting permeability of cells in the ventricles, atria, and ventricular conducting system are determined by what?

A

potassium permeability mediated by Kir channels

161
Q

Sustained increase in preload is met with sustained increase in SV principally through increased _____________

A

contractility (ANS)

162
Q

KIR-type channels in smooth muscle tend to ______________ m.p. causing ____________

A

hyperpolarize, causing relaxation

163
Q

MAP is closer to the _______ pressure than the _______ pressure… why?

A

diastolic, systolic

more time is spent in diastole

164
Q

in active muscle and heart, the constrictive effects of adrenergic stimulation are overwhelmed by _______ effects of ___________

A

dilated

metabolites (released by the working muscle)

165
Q

when more volume comes into a chamber, this _________ the sarcomeres, increasing _________ of pressure to be generated

more volume = _______ pressure (potentially)

A

lengthens, ABILITY

more volume = more potential pressure (active pressure curve)

166
Q

the T wave comprises the time between __________ of epicardium and ___________ of endocardium

A

repolarization

167
Q

why does smooth muscle have a baseline “tone”, or a steady level of contractile tension.

A

the membrane potential lies near the Ca-L channel activation threshold (-40-45 mV), some Ca++ is coming in, baseline tone

168
Q

Blood pressure is regulated by controlling _________, ______________,
and ________________

A

cardiac output

total peripheral resistance

blood volume

169
Q

explain the cardiac suction of the heart

A

During ventricular contraction, the AV valves are drawn downwards, enlarging the atrial cavities. Thus the atrial pressure drops below 0 mm Hg

larger pressure difference

170
Q

what channels are the players in the pacemaker potential phase of nodal action potentials? (5)

A
  1. Delated-rectifier K+ channels close
  2. If - I funny channels opens
  3. Na/Ca exchanger
  4. T-type Ca++ channels open
  5. L-type Ca++ channels open
171
Q

P-wave:
QRS-complex:
T-wave:

A

atrial depolarization
ventricular depolarization
ventricular repolarization

172
Q

Receptor operated channels in smooth muscle (electromechanical stimulation of SMCs): usually non-selective cation channels – tend to _________, causing __________

A

depolarize, causing contraction

173
Q

a high blood pressure with activate the __________, increasing their firing rate. This would activate the ____________________ and inhibit the ________________. What is the ultimate result?

A

baroreceptors

parasympathetic NS
sympathetic NS

decrease HR (direct), reduce contractility and vasodilate (indirect, via inhibiting sympathetics)

174
Q

the active pressure curve on a pressure/volume plot of the heart represents what?

A

the maximum pressure the heart my produce actively at a give volume (optimizing sarcomere length here)

175
Q

what is net driving force?

hydrostatic pressure pushes fluid _____ of the capillaries. this is called ______ and has a net driving force of ___ (< or >) than 0

A

NDF=(Pc –Pi)–σ(πc –πi)

out, filtration, > 0

176
Q

what are the structures in the R margin of the heart?

A

the superior vena cava
R atrium
inferior vena cava

177
Q

what causes repolarization in ventricular cell action potentials?

A
  1. opening of delayed-rectifier K+ channels
    (can be rapid or slow)
  2. Ca++ channels (L-type) inactivate
  3. Mg2+ block on Kir channels leaves after sufficient re-polarization (K+ efflux, hyperpolarization)
178
Q

the pericardium, or pericardial sac includes the ______ pericardium, which is actually the outer layer of the heart. And the _____ pericardium, which attaches to the thoracic wall

A

visceral, parietal

179
Q

the bases of heart valves are connected to rings of the _______ _________ that surround the valve opening

A

fibrous skeleton

180
Q

dephosphorylation of MLC (myosin light chain) in smooth muscle is mediated by what?

what does this cause?
what is this regulated by?

A

MLC phosphatase

inability of myosin to form cross bridges with actin –> relaxation of smooth muscle

cGMP

181
Q

what is the adjustable factor that is the prime determinant of resistance?

A

arteriolar radius

182
Q

________ is the major determinant of the total energy requirements of the heart!

A

tension (heat)

183
Q

why are manifestations of a long QT interval triggered by physical exercise?

A

Increased HR –> but patient has failure to shorten the ventricular action potential –> decreases filling –> reduced cardiac output when demand is high

184
Q

the valve for the coronary sinus is seen in the _____ _______ (what chamber)

A

right atrium

185
Q

The refractory periods ensure a _________ nature of the heart and the ability to ______

A

pulsatile, fill

186
Q

MAP = _____ x ______

A

CO x TPR

187
Q

on nodal cell pacemaker potential…. VG T-type calcium channels are activated. As Ca+ enters cell, triggers the ___________ to get rid of the Ca++, bring in __ ______, contributing to _________.

A

Na/Ca Exchanger, 3 Na+ into the cell

depolarization

188
Q

what event on the Wiggers diagram marks the end of ventricular systole and start of ventricular diastole? (L heart for example)

A

closure of the aortic valve (go into isovolumetric relaxation phase)

189
Q

the moment to moment control of the MAP is achieved through the ________ reflex - which changes ____ and ____ to change MAP

A

baroreceptor

CO and TPR

190
Q

equation for cardiac output = _____ x _____

A

HR x SV

191
Q

what is the characteristic feature of the ventricular action potential (a phase)?

A

the plateau phase

192
Q

tension in smooth muscle _______ when cGMP activates ___________

tension in smooth muscle _______ when cAMP activates _______ to phosphorylate MLCK

A

decreases, MLC-phosphotase

decreases, PKA

193
Q

inotropy:

A

force of contraction

194
Q

in what cell action potential is there no period in time that the membrane potential is constant?

A

in nodal cell action potentials

195
Q

actin and myosin are _______ organized in smooth muscle, the thin filaments (actin) are organized into bundles and anchored to ________ ________

A

loosely

dense bodies

196
Q

function of the lymphatics (4);

A
  1. return excess interstitial fluid to venous system
  2. immune defense
  3. transport of absorbed fat
  4. return of filtered protein to vasculature
197
Q

complete the flow chart:

sympathetics –> NE –> B1 in nodal cells –> increase _____ –> activate ____ —> increase activity of ________ channels –> ultimately _______ HR

A

increase cAMP

activate PKA

increase I funny channel activity

decrease HR

198
Q

what are the 4 benefits to the parallel circuitry of the peripheral circulation?

A
  1. overall resistance reduced, less afterload
  2. All organs receive same oxygenated blood, no “leftovers”
  3. common perfusion pressure - can all regulate their own
  4. protects against injury upstream

Cardio Block - CPR (6 decks)

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