Brainscape's Knowledge GenomeTM

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


See full index

Cardiology > Cardiac Pathophysiology > Flashcards

Cardiac Pathophysiology Flashcards

1
Q

Where is the heart located?

A

In the mediastinum between second rib and fifth intercostal space

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

Superficial fibrous pericardium
function?
3

A
  1. Protects,
  2. anchors, and
  3. prevents overfilling
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Layers of the heart wall

3

A
  1. Epicardium—
  2. Myocardium
  3. Endocardium
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the epicardium?

What is the myocardium made of? 2

Endocardium is continuous with what?

A

-visceral layer of the serous pericardium

  • Spiral bundles of cardiac muscle cells
  • Fibrous skeleton of the heart: crisscrossing, interlacing layer of connective tissue

-continuous with endothelial lining of blood vessels

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

Function of the myocardium? 3

A
  1. Anchors cardiac muscle fibers
  2. Supports great vessels and valves
  3. Limits spread of action potentials to specific paths
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

When is pericarditis most likely caused by?

4

A
  1. Post viral
  2. Autoimmune/lupus
  3. Cancer
  4. Idiopathic
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Tampanade does happen (friction rub) what will they describe it as?

What makes it better? 2

A

stabbing, shooting, pain of 7 to 10

Leaning forward
Shallow breathing

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

What encircles the junction of the atria and ventricles?

What is the function of the auricles?

A

Coronary sulcus (atrioventricular groove)

Auricles increase atrial volume

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

What marks the interventricular septum externally? 2

A

Anterior and posterior interventricular sulci mark

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

What lines the wall of the atria?

What vessels enter the right atrium? 3

What vessels enter the let atrium? 2

A

Walls are ridged by pectinate muscles

Vessels entering right atrium

  1. Superior vena cava
  2. Inferior vena cava
  3. Coronary sinus

Vessels entering left atrium
1. Right and 2. left pulmonary veins

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

Ventricles: The Discharging Chambers

  1. What lines the walls of the ventricles?
  2. What kind of muscles project into the ventricular cavities?
  3. What vessel leaves the right ventricle?
  4. What vessel leaves the left ventricle?
A
  1. Walls are ridged by trabeculae carneae
  2. Papillary muscles project into the ventricular cavities
  3. Vessel leaving the right ventricle
    Pulmonary trunk
  4. Vessel leaving the left ventricle
    Aorta
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Pathway of Blood Through the Heart

The heart is two side-by-side pumps

  1. Right side is the pump for the what?
  2. Left side is the pump for the what?
A
  1. Right side is the pump for the pulmonary circuit
    Vessels that carry blood to and from the lungs
  2. Left side is the pump for the systemic circuit
    Vessels that carry the blood to and from all body tissues
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Describe the pathway of blood through the heart?

Including chambers, great vessels and valves

A

Right atrium → tricuspid valve → right ventricle
Right ventricle → pulmonary semilunar valve → pulmonary trunk → pulmonary arteries → lungs

Lungs → pulmonary veins → left atrium
Left atrium → bicuspid valve → left ventricle
Left ventricle → aortic semilunar valve → aorta
Aorta → systemic circulation

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

_______ volumes of blood are pumped to the pulmonary and systemic circuits
Pulmonary circuit is a ____, _____-pressure circulation
Systemic circuit blood encounters _____ resistance in the long pathways

Anatomy of the ventricles reflects these differences

A

Equal

short, low

much

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

What is Coronary Circulation?

______ _______ varies considerably and contains many anastomoses (junctions) among branches

______ routes provide additional routes for blood delivery

A

The functional blood supply to the heart muscle itself

Arterial supply

Collateral

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

What are the arteries in our coronary circulation? 5

What are the veins in our coronary circulation? 3

A

Arteries

  1. Right and
  2. left coronary (in atrioventricular groove),
  3. marginal,
  4. circumflex, and
  5. LAD

Veins

  1. Small cardiac,
  2. anterior cardiac, and
  3. great cardiac veins (join together to make the cardiac sinus and dumps into the right atrium)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

The right coronary artery supplies blood to the ?
4

The left coronary artery supplies blood to the ? 2

A
  1. right ventricle, the
  2. right atrium, and
  3. the SA (sinoatrial) and
  4. AV (atrioventricular) nodes,
  5. left ventricle and
  6. left atrium
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

When does does cornary circlaiton deliver blood to the heart?

A

relaxation/diastole

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

DURING WHAT PERIOD OF THE CARDIAC CYCLE DO THE CORONARY ARTERIES RECEIVE PERFUSION?

A

diastole

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

What is angina pectoris?

What does this cause?

A

–Thoracic pain caused by a fleeting deficiency in blood delivery to the myocardium

–Cells are weakened

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Describe Myocardial infarction (heart attack)?

2

A
  • -Prolonged coronary blockage

- -Areas of cell death are repaired with noncontractile scar tissue

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

Infarction is different from ischemia how?

A

sudden and not going away. Killing heart cells until you do an itervention and perfuse again

ischemia can leave and be relieved on its own

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q
  1. Which side of the heart acts as the pulmonary pump?
  2. Which side of the heart acts as the systemic pump?
  3. Which ventricle is larger?
  4. Which system is a high pressure system?
  5. Name two main branches of the RCA?
A
  1. right
  2. left
  3. left
  4. systemic
  5. PDA and marginal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are the different AV heart valves and what is their purpose?

What anchor AV valve cusps to papillary muscles?

When pressure increases and blood fills in what happens to the valves?

A 
Atrioventricular (AV) valves
Prevent backflow into the atria when ventricles contract
Tricuspid valve (right)
Mitral valve (left)

Chordae tendinae

the valves close
Intraventricluar pressure increases and look to shoot out the blood!

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

What are the semilunar valves and what is their function?

A

Prevent backflow into the ventricles when ventricles relax

Aortic semilunar valve
Pulmonary semilunar valve

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

What causes the opening of the AV valves?

What causes them to close?

A

AV valves open; atrial pressure greater than ventricular pressure

AV valves closed; atrial pressure less than ventricular pressure

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

Fibrous insulator exists between atrium and ventricle. Why?

A

provides electrical insulation

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

46

A

46

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

Describe cardiac muscle?

3

A
  1. Gap junctions (for conduction)
  2. Actin and mysoin filaments
  3. low resistance intercalated disks
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q
  1. Depolarization of the heart is ______ and ______?
  2. About __% of cardiac cells have automaticity— (are self-excitable)
  3. What do gap junctions ensure?
  4. Describe the refractory period of the cardiac muscle?
A
  1. rhythmic and spontaneous
  2. 1
  3. the heart contracts as a unit
  4. Long absolute refractory period (250 ms)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Similarities of Cardiac and Skeletal Muscle

  1. WHich are triggered by action potentials that sweep across cell membranes?

1% of cardiac fibers are autorhythmic

  1. The bulk of heart muscle, however, is composed of _______ ______ _____responsible for the heart’s pumping action
  2. In these cells, the sequence of events leading to contraction is similar to that in ________ ______ ____?
A
  1. Both
  2. contractile muscle fibers
  3. skeletal muscle fibers

Cardiac (short and interconnected, one or two nuclei)

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

What happens during systole?

What happens during diastole?

On the EKG what is the:
Pwave?
QRS?
T wave?

A

Systole – ventricular muscle stimulated by action potential and contracting

Diastole – ventricular muscle reestablishing Na+/K+/Ca++ gradient and is relaxing

EKG -
P-atrial wave
QRS - Ventricular wave T - ventricular repolarization

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

Volume overload to fibrosis what do you hear?

Heart failure what do you hear?

A

S4

S3

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

What is the intrinsic cardiac conduction system?

A

A network of noncontractile (autorhythmic) cells that initiate and distribute impulses to coordinate the depolarization and contraction of the heart

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

What are the parts of the cardiac conduction system?

4

A
  1. SA node
  2. AV node
  3. Bundle of HIS
  4. Bundle branch
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Pathway of the heartbeat:

  1. Begins where?
  2. Then?
  3. Where does the impulse pause?
  4. Then?
  5. Then?
A
  1. Begins in the sinoatrial (S-A) node
  2. Internodal pathway to atrioventricular (A-V) node
  3. Impulse delayed in A-V node and bundle
  4. A-V bundle takes impulse into ventricles
  5. Left and right bundles of Purkinje fibers take impulses to all parts of ventricles
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Why is the impulse delayed in the AV node?

A

(allows atria to contract before ventricles)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q
  1. What kind of cells have unstable resting potentials (pacemaker potentials or prepotenials)?
  2. Why?
  3. When the potenial reaches threshold what happens?
  4. This causes?
  5. What does repolarization result from?
A
  1. Autorhythmic Cells
  2. due to open slow Na+ channels
  3. At threshold, Ca2+ channels open
  4. Explosive Ca2+ influx produces the rising phase of the action potential
  5. Repolarization results from inactivation of Ca2+ channels and opening of voltage-gated K+ channels
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q 
Pacemaker potential:
This slow depolarization is 
due to both opening of \_\_\_
channels and closing of \_\_\_
channels. Notice that the 
membrane potential is 
never a flat line.
A

Na+

K+

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q 
Depolarization The 
action potential begins when 
the pacemaker potential 
\_\_\_\_\_\_ \_\_\_\_\_\_\_. 
Depolarization is due to \_\_\_\_
influx through \_\_\_\_ channels.
A

Reaches threshold

Ca2+
Ca2+

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q 
Repolarization is due to 
\_\_\_ channels inactivating and 
\_\_\_ channels opening. This 
allows \_\_\_ efflux, which brings 
the membrane potential back 
to its most \_\_\_\_\_\_\_ voltage.
A

Ca2+
K+

K+
negative

42
Q
  1. What is the SA node?
  2. What does it act as and why?
  3. When membrane potential reaches -40 mV what happens?
  4. After 100-150 msec _____ channels close and ___ channels open more thus returning membrane potential to -55mV
A
  1. Specialized cardiac muscle connected to atrial muscle
  2. Acts as pacemaker because membrane leaks Na+ and membrane potential is -55 to -60mV
  3. When membrane potential reaches -40 mV, slow Ca++ channels open causing action potential

4.
Ca++
K+

43
Q

What actually causes the depolarization/contraction of the heart?

A

Ca+ channels open

44
Q

Heart Physiology: Sequence of Excitation

First?
Second?
Third?
Fourth?
Fifth?
A
  1. Sinoatrial (SA) node (pacemaker)
  2. Atrioventricular (AV) node
  3. Atrioventricular (AV) bundle (bundle of His)
  4. Right and left bundle branches
  5. Purkinje fibers
45
Q

SA node generates impulses at what rate?

________ faster than any other part of the myocardium

SA is mediated by who?

A

75 times/minute

Depolarizes

Parasympathetic system (otherwise normal would be 100 or over)

46
Q

Describe the structure of the AV node? 2

Delays impulses how much?

Depolarizes how many times per minute without the SA node influence?

A
  1. Smaller diameter fibers;
  2. fewer gap junctions (so the impulses move slower)

Delays impulses approximately 0.1 second

Depolarizes 50 times per minute in absence of SA node input

47
Q

What is the only electrical connection between the atria and the ventricles?

A

Atrioventricular (AV) bundle (bundle of His)

Only electrical connection between the atria and ventricles

48
Q

Whats the purkinje system?

Describe its conduction and why?

A

Fibers lead from A-V node through A-V bundle into Ventricles

Fast conduction; many gap junctions at intercalated disks

49
Q

What are the Right and left bundle branches?

A

Two pathways in the interventricular septum that carry the impulses toward the apex of the heart

50
Q

Purkinje fibers complete the conduction pathway into the _____ and __________ _____?

AV bundle and Purkinje fibers depolarize only __ times per minute in absence of AV node input

A

apex and ventricular walls

30

51
Q

Describe Homeostatic Imbalances?

A

Defects in the intrinsic conduction system

52
Q

Defects in the intrinsic conduction system may result in what?
3

A
  1. Arrhythmias: irregular heart rhythms
  2. Uncoordinated atrial and ventricular contractions
  3. Fibrillation: rapid, irregular contractions; useless for pumping blood
53
Q

Defective SA node may result in
what?
2

A
  1. Ectopic focus: abnormal pacemaker takes over

2. If AV node takes over, there will be a junctional rhythm (40–60 bpm)

54
Q

Defective AV node may result in what?

2

A
  1. Partial or total heart block

2. Few or no impulses from SA node reach the ventricles

55
Q

Heartbeat is modified by what system?

A

autonomic nerve system

56
Q

Where are the cardiac nerve centers located?

A

medulla oblingata

57
Q

Cardioacceleratory center innervates what? 3

Cardioinhibitory center inhibits what and through what system?

A

Cardioacceleratory center innervates

  1. SA and AV nodes,
  2. heart muscle, and
  3. coronary arteries through sympathetic neurons

Cardioinhibitory center inhibits
1. SA and AV nodes through parasympathetic fibers in the vagus nerves

58
Q

What nerve decreases heart rate?

What nerve increases heart rate?

A
  1. The vagus nerve
    (parasympathetic)
    decreases heart rate.
  2. Sympathetic cardiac
    nerves increase heart rate
    and force of contraction.
59
Q

What is an EKG?

What are the three waves and describe them?

A

a composite of all the action potentials generated by nodal and contractile cells at a given time

P wave: depolarization of SA node
QRS complex: ventricular depolarization
T wave: ventricular repolarization

60
Q

Why doesnt the p wave repolarization show up?

A

hidden in the QRS

61
Q

What happens in a junctional rhythm?

A

The SA node is nonfunctional, P waves are absent, and heart is paced by the AV node at 40 - 60 beats/min.

62
Q

What is a Second-degree heart block?

A

Some P waves are not conducted through the AV node; hence more P than QRS waves are seen. In this tracing, the ratio of P waves to QRS waves is mostly 2:1.

63
Q

What is ventricular fibrillation?

A

These chaotic, grossly irregular ECG deflections are seen in acute heart attack and electrical shock.

64
Q

What is the Lubb heart sound?

When does it occur?

A

first heart sound (S1)
A-V valves closing
occurs during ventricular systole

65
Q

What happens if you have a long QT what can happen?

A

go into torsades

66
Q

What is the Dubb heart sound?

When does it occur?

A

second heart sound (S2)
pulmonary and aortic semilunar valves closing
occurs during ventricular diastole

67
Q

First heart sound occurs when what happens and signifies what?

Second heart sound occurs when what happens and signifies what?

A

First sound occurs as AV (Tricuspid and Mitral) valves close and signifies beginning of systole

Second sound occurs when SL (Aortic and Pulmonic) valves close at the beginning of ventricular diastole

68
Q

What are heart murmurs?

A

Heart murmurs: abnormal heart sounds most often indicative of valve problems

69
Q
  1. Aortic valve is heard where?
  2. Pulmonary valve is heard where?
  3. Mitral valve is heard where?
  4. Tricuspid valve is heard where?
A
  1. Aortic valve sounds heard
    in 2nd intercostal space at
    right sternal margin
  2. Pulmonary valve
    sounds heard in 2nd
    intercostal space at left
    sternal margin
3. Mitral valve sounds
heard over heart apex
(in 5th intercostal space)
in line with middle of
clavicle
  1. Tricuspid valve sounds typically
    heard in right sternal margin of
    5th intercostal space
70
Q

What is the definition of the cardiac cycle?

What is systole?
What is diastole?

A

all events associated with blood flow through the heart during one complete heartbeat

Systole—contraction
Diastole—relaxation

71
Q
  1. What is the first phase of the cardiac cycle?
  2. When does it take place?
  3. What valves are open?
  4. What percent of the blood passively flows into the ventricles?
  5. What delivers the remaining percentage?
  6. What is end diastolic volume?
A
  1. Ventricular filling—
  2. takes place in mid-to-late diastole
  3. AV (tricuspid and mitral) valves are open
  4. 80% of blood passively flows into ventricles
  5. Atrial systole occurs, delivering the remaining 20%
  6. End diastolic volume (EDV): volume of blood in each ventricle at the end of ventricular diastole
72
Q
  1. What is the second phase of the cardiac cycle?
  2. What do the atria do here?
    Ventricles?
  3. What causes the closing of the AV valves?
  4. What contraction phase is this?
  5. What happens in the ejection phase?
  6. What is end systolic volume?
A
  1. Ventricular systole
  2. Atria relax and ventricles begin to contract
  3. Rising ventricular pressure results in closing of AV valves
  4. Isovolumetric contraction phase (all valves are closed)
  5. In ejection phase, ventricular pressure exceeds pressure in the large arteries, forcing the SL valves open
  6. End systolic volume (ESV): volume of blood remaining in each ventricle
73
Q
  1. What is the third phase of the cardiac cycle?
  2. What do the ventricles do?
  3. What closes the SL valves and what does this cause?
A
  1. Isovolumetric relaxation occurs in early diastole
  2. Ventricles relax
  3. Backflow of blood in aorta and pulmonary trunk closes SL valves and causes dicrotic notch (brief rise in aortic pressure)
74
Q

SV =

CArdiac output =

A

EDV - ESV

SV(stroke volume) X HR

75
Q
  1. The second heart sound is associated with the closing of which heart valves?
  2. If the MV were insufficient, would you expect to hear the murmur during ventricular systole or diastole?
  3. During the cardiac cycle, there are two periods when all four valves are closed. Name these two periods.
A
  1. SL valves closing
  2. systole (AV valve should we closed during systole)
    • -Isovolumetric contraction phase- beginning of systole (ventricle depolarization) and
    • -Isovolumetric relaxation -beginning of diastole (ventricle repolarization)
76
Q

What is cardiac output?

A

Volume of blood pumped by each ventricle in one minute

77
Q

What is stroke volume?

A

volume of blood pumped out by a ventricle with each beat

78
Q
  1. At rest what is our normal cardiac output?
  2. Maximal CO is ____ times resting CO in nonathletic people
  3. Maximal CO may reach ___ L/min in trained athletes
  4. What is the Cardiac reserve?
A
  1. CO (ml/min) = HR (75 beats/min) × SV (70 ml/beat) = 5.25 L/min
  2. 4–5
  3. 35
  4. difference between resting and maximal CO
79
Q

Three main factors affect SV?

A

Preload (EDV)
Contractility (ESV)
Afterload (ESV)

80
Q
  1. Ejection fraction is what?
  2. Whats normal?
  3. How can we determine this? 2
A
  1. measurement of ventricular systolic function
  2. normal is 60%
    • echocardiogram
    • cardiac catheterization
81
Q

What is the definition of preload?

A

Preload: degree of stretch of cardiac muscle cells before they contract (Frank-Starling law of the heart)

82
Q
  1. What kind of relationship does cardiac muscle exhibit?
  2. What length are cardiac cells at rest?
  3. What increases venous return?
  4. What does increased venous return do?2
A
  1. Cardiac muscle exhibits a length-tension relationship
  2. At rest, cardiac muscle cells are shorter than optimal length
  3. Slow heartbeat and exercise increase venous return
  4. Increased venous return
    - -distends (stretches) the ventricles and
    - -increases contraction force
83
Q
  1. Pressure-volume relationships are critical for understanding the pathophysiologic mechanisms of diseases that affect the entire ventricular chamber function, such as ______ _______ and_______ abnormalities.
  2. Increase pre-load ______ SV
  3. Increase after-load _______ SV
  4. Increasing contractile state shifts the isovolemic pressure-volume relationship ______ (_______ ESV) _______ SV
A
  1. heart failure
    valvular
  2. increases
  3. decreases
  4. leftward
    decreasing
    increasing
84
Q

What is contractility?

What is it independant of? 2

A

contractile strength at a given muscle length,

independent of muscle stretch and EDV

85
Q

Positive inotropic agents _______contractility. How? 2

Negative inotropic agents _______ contractility
When would this occur? 3

A

Increase
1. Increased Ca2+ influx due to
sympathetic stimulation
2. Hormones (thyroxine, glucagon, and epinephrine)

decrease

  1. Acidosis
  2. Increased extracellular K+
  3. Calcium channel blockers
86
Q

Decreased contractility affects volume and pressure how?

Increased contractiility affects volume and pressure how?

A

Increases them

Decreases them

87
Q

Positive chronotropic factors ______ heart rate

Negative chronotropic factors ______ heart rate

A

increase

decrease

88
Q

Sympathetic nervous system is activated by emotional or physical stressors:
Norepinephrine causes the pacemaker to fire more______ (and at the same time_______ contractility)

A

rapidly

increases

89
Q

Sympathetic Effects on Heart rate

4

A
  1. Releases norepinephrine at sympathetic ending
  2. Causes increased sinus node discharge
  3. Increases rate of conduction of impulse
  4. Increases force of contraction in atria and ventricles
90
Q

Sympathetic activation increases pacemaker rate by

decreasing ___ perm and increasing slow inward___ and ___?

A

K+

Ca++
Na+

91
Q

Does parasympathetic affect contractility?

A

no

92
Q

Parasympathetic nervous system opposes sympathetic effects. How?

The heart at rest exhibits vagal tone. Why?

A

Acetylcholine hyperpolarizes pacemaker cells by opening K+ channels

parasympathetic response

93
Q

Parasympathetic (vagal) nerves, which release ______ at their endings, innervate what? 2

What does this cause and why?

A

acetylcholine

  1. S-A node and
  2. A-V junctional fibers proximal to A-V node.

Causes hyperpolarization because of increased K+ permeability in response to acetylcholine.

94
Q

Hyperpolarization due to increased K+ permeability in response to acetylcholine causes what?

Which leads to what??

A

decreased transmission of impulses maybe temporarily stopping heart rate.

Ventricular escape occurs

95
Q
  1. What is the atrial (brain bridge) reflex?
  2. What stimulates the SA node?
  3. What does this also stimulate?
A
  1. a sympathetic reflex initiated by increased venous return
  2. Stretch of the atrial walls stimulates the SA node
  3. Also stimulates atrial stretch receptors activating sympathetic reflexes
96
Q

Sympathetic stimulation causes an increase in what two things?

Parasympathetic does the opposite

We can tachycardia decrease cardiac output?

A

HR+ contractility
with HR = 180-200 and C.O. = 15-20 L/min.

because there is not enough time for heart to fill during diastole.

97
Q

Epinehphrine from where enhances what two things?

Thyroxine increases what?
And enchances what?

A

Epinephrine from adrenal medulla enhances heart rate and contractility

Thyroxine increases heart rate and enhances the effects of norepinephrine and epinephrine

98
Q

What is the common sign of low contractility?

A

leg edema

CCB

99
Q

Other Factors that Influence Heart Rate

4

A

Age
Gender (females have faster HR)
Exercise
Body temperature

100
Q

Bradycardia: heart rate slower than 60 bpm. What could this result in?

A

May result in grossly inadequate blood circulation

101
Q

HOw do we Assess Perfusion at the Bedside?

3

A
  1. Cold extremities indicate reduced perfusion so feel the feet
  2. Poor Urine Output also indicates poor tissue perfusion

You now have 2 ways to determine if the patient is adequately perfusing or to see if the heart is doing its job or mission.

  1. Don’t forget the Blood pressure

Cardiology (19 decks)

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