Unit One Flashcards
1
Q
Extrinsic regulation of heart is innervation of the heart via
A
Autonomic nervous system
2
Q
Why does HR at 180 stop increasing CO
A
Not having enough time for diastole, or need ventricles to fill
3
Q
A
SA block
4
Q
Flow (volume per unit time) represented by what
A
Q
5
Q
The purkinje fibers lead from the
A
AV node, through the AV bundle through the left and right bundle branches then throughout the ventricular muscle
6
Q
During diastole, aortic pressure falls due to
A
Elastic recoil of the aorta to 80 mmHg
7
Q
Normal cardiac output is
A
5 L/min
8
Q
Equation for stroke volume
A
End diastolic volume - end systolic volume
9
Q
Carbon dioxide retention causes
A
Acidosis leading to confusion, come, arrhythmia, muscle weakness, GI disturbances
10
Q
3rd degree AV blocks look like what
A
AV node creates own pace, SA node communications with AV node is not happening
11
Q
Semilunar valves close when
A
Aortic/ pulmonic pressure greater than ventricular pressure
12
Q
What are the three places within the systemic circuit that has serial blood supply
A
Liver, kidney and anterior pituitary
13
Q
What is intrinsic regulation of the heart
A
Frank starlings mechanism
14
Q
What can cause left axis deviation
A
Short stock build, obesity, LV hypertrophy and left bundle branch block
15
Q
Relaxation of heart requires what
A
Pumping Ca2+ back into SR and out of the cell
16
Q
Individually leads 1, 2, or 3 should be was QRS voltage
A
.5 - 2 mV
17
Q
Cardiac muscle cells exhibit what two properties
A
Automaticity and rhythmicity
18
Q
Right atrial stretch increase heart rate by
A
10 - 20%
19
Q
AV node located where
A
Posterior right atrium
20
Q
What is stroke volume
A
Amount of blood ventricle ejects after one contraction
21
Q
Equation for ejection fraction
A
Strok volume/ end diastolic volume x 100
22
Q
What occurs during phase 2
A
V gated slow Ca2+ channels open and decrease in K+ permeability also occurs
23
Q
Lead one positive lead goes where
A
Left shoulder/ wrist
24
Q
Aka of incisura
A
Dicrotic notch
25
Decreased voltage of QRS is caused by
Damaged heart muscle
26
What is S1 heart sound
First heart sound, closure of AV valves, “lib”, beginning of systole
27
Biphasic is what type of quantity
Vector
28
How is there a greater force of contraction on a cellular level in heart
Cardiac muscles sarcomeres are short and resist stretch, increase in length increases number of functional cross bridges between actin and myosin therefore creating greater force of contraction
29
What is einthoven’s triangle
Group of leads that form a triangle
30
1st AV block
31
Is the systemic circuit parallel or series
Parallel
32
V3 goes where
Between V2 and V4
33
What are the standard bipolar limb leads
Lead 1,2,3
34
What is a blood conditioner organ
Any organ that changes the composition of the blood for the benefit of the rest of the body
35
Tachycardia caused by
Fever, certain toxins, SNS activity
36
What can cause LV hypertrophy
Hypertension, aortic valve stenosis, aortic valve regurgitation
37
What occurs during phase 3
V gated Ca2+ channels close and V gated K+ channels open
38
QRS complex represents
Ventricular depolarization
39
What are some organs that are important but not blood conditioners
Brain, muscle and heart
40
Contractility is a modification of
Strength independent of loading changes
41
What is Monophasic
Only show amplitude of voltage changes as recorded at a point in a cell
42
2nd degree AV block looks like
Dropped beat, ventricles don’t have electrical activity, skipped beats
43
What are the three components of the aortic pressure curve
During systole, incisura, and during diastole
44
Why can you have multiple negative electrodes but have one positive
Positive electrode gives direction it is heading toward
45
V1 goes where
4 ICS to the right of sternum
46
Positive lead of aVL
Left wrist
47
The systemic circuit goes from where to where
Left ventricle, body, right atrium
48
Function of systemic circuit
Supplies many organs, trunk, head and limbs in parallel circulation
49
Can demands be met by just diffusion from the outside of the body
No, diffusion is too slow over large distances
50
Parasympathetic does what to heart
Decreases heart rate, weakly decreases force of contraction
51
Sinus arrhythmia can occur when heart rate increases with
Deep inspiration
52
Negative lead for aVL
Right wrist and right ankle
53
Current injury is what
Acute damaged heart muscle (MI) does not repolarize normally and therefore becomes a source of current
54
V2 goes where
4 ICS to the left of sternum
55
Are there any measuring forces in EKG
No just electricity
56
What is end diastolic volume
Amount of blood volume in ventricle at end of diastole
57
How many phases of the heart
Phase 0 through 4
58
what is the S3 heart sound
Due to filling of ventricles in mid diastole
59
Purpose of hexaxial reference system
Used to determine the vector of depolarization through the heart
60
The cardiac cycle components relating to pressure changes are recorded from the
Left atrium and ventricle
61
Premature contractions can occur in what part of heart
Atrial and ventricular
62
What is extreme axis
-90 to -180 degrees
63
The SA node connects to the
Atrial muscle and internodal fibers
64
V5 should go where
5 ICS, left anterior axillary line
65
What are the two forms of work the heart does
External work and kinetic energy of blood flow
66
Conduction system coordinates what
Timing of atrial and ventricular contractions
67
Can you hear S4
No, only recorded using phonocardiograms
68
Frank starlings law of heart says venous return equals what
Cardiac output
69
Lead two negative lead goes where
Right shoulder/ wrist
70
How long for O2 to diffuse 1 cm
14 hours
71
AV valves open when
Atrial pressure greater than ventricular pressure
72
Conduction blocks can be due to
Some part of heart sustained damage
73
Advantage of parallel circuit
If something is blocked then there are other ways around to have area receive blood, simultaneous blood supply
74
How does the venous system work with pressure and bringing blood to heart
Pressure still builds up but not greater than arterial pressure and veins contain valves
75
QRS usually last for how long
.04 to .11 sec
76
How much of the blood in the atria moves to the ventricles before atrial systole
80%
77
What occurs to ventricle during late systole
Reduced ejection
78
What occurs to ventricle during middle diastole
Diastasis, reduced inflow
79
What occurs during S4 heart sound
Due to atrial systole
80
What causes right axis deviation
Tall, long waist, lean build, RV hypertrophy, right bundle branch block
81
What occurs to ventricle during late diastole
Last 20% of blood comes in, atrial systole
82
The pulmonary circuit goes from where to where
Right ventricle, lungs to left atrium
83
AVR should show what type of deflection
Negative due to going from left to right
84
What are the parts of the left heart
Left atrium, bicuspid/ mitral valve, left ventricle and aortic valve, pulmonary veins
85
Sympathetic does what to heart
Increases heart rate, increases force of contraction
86
What is the equation for resistance
8Ln/(pi)r^4
87
Semilunar valves open when
Ventricular pressure greater than aortic/ pulmonic pressure
88
Equation for cardiac output
Stroke volume x heart rate
89
Location of SA node
Superior posterolateral right atrium
90
During exercise, how to increase cardiac output
Increase heart rate or increase stroke volume or both
91
What is the negative electrode in the precordial chest leads
Machine is used as reference point
92
Increased voltage of QRS is caused by what
Hypertrophy
93
Ventricle diastole has how many phases
Three, early, middle and late
94
What is ejection fraction
Amount of blood percent squeezed out at end of contraction
95
What occurs during isovolumic relaxation
Pressure in ventricle decreases, valve can now close, diastole
96
P R interval goes from what to what
SA node to AV node
97
When do AV valve close
Ventricular pressure greater than atrial pressure
98
Lead one negative lead goes where
Right shoulder/ wrist
99
Phase 2 aka
Plateau
100
What are not propagated through the fibrous septum
Action potentials
101
What is S2 heart sound
Closure of the semilunar valve, “dub”, transition into diastole
102
What is the main determinant of resistance
Blood vessel radius especially in arteriole
103
What are the characteristics of brain, muscle and heart not being blood conditioners
Blood flow is regulated to be at or just above metabolic need, loss of blood flow to these organs has more dramatic effect
104
Phase 3 aka
Repolarization
105
Main purpose of the cardiovascular system
Provide a sufficiently fast mechanism of delivery and removal of gasses, nutrients, and wastes by blood flow
106
Is sinus arrhythmia a normal variant
Yes
107
What explains why the T wave is positive (lead 2)
Due to the pattern starting at apex then goes to base
108
Contractility is what type of state
Ionotropic state
109
Function of internodal tract
Spread AP to AV node, spread AP into both atria, help to spread AP throughout cells
110
atrial fibrillation
111
What is einthovens law
2 = 1 + 3, in regards to the amplitude of the R wave
112
Function of left heart
Receives blood from lungs and pumps blood to body
113
What must the heart do in order for flow to occur
Arterial pressure greater than venous pressure
114
V6 should go where
5 ICS, left mid axillary line
115
What is the external work the heart does
Move blood from veins to arteries (most of the work done)
116
Why is the blood vessel radius in arterioles the most important
Radius is regulated the most here
117
Contractility includes effects of
autonomic nervous system and hormones
118
What is an electrode
Physical wired from machine to skin
119
EKG notices what
Deflection from zero lines due to depolarizations and repolarizations
120
Amount of actin and myosin in the conduction system
Very little and contracts very weakly
121
P wave initiated by
SA node
122
Since atrial repolarization is not seen on EKG, the wave is actually called
atrial T
123
What occurs during phase 1
V gated Na+ channels inactive
124
What does the signal move slowly through AV node
Allow for ventricle to fill with blood
125
The chambers of the heart alternate between periods of
Systole and diastole
126
What are electrical alternans
Alternating strength signals, not effective repolarization causing weak signal
127
P wave precedes
Atrial systole
128
Incomplete intraventricular block
129
Biphasic is
Records both amplitude and direction of waves of voltage changes through heart muscle
130
What is rhythmicity
Action potentials repeat at regular intervals
131
What causes RV hypertrophy
Pulmonary valve stenosis/ regurgitation, interventricular septal defect, tetralogy fallot
132
Flow (Q) is also called
Cardiac output
133
Lead three negative lead goes where
Left shoulder/ wrist
134
Aka of premature contractions
Extrasystole and ectopic beat
135
Is a stimulus needed for cardiac cells to have an AP
No
136
Does end systole in ventricle completely empty all blood
No
137
QT interval shows
Electrical events in ventricle
138
What is phase 0 aka
Depolarization
139
The duration of cardiac contraction is about equal to
Duration of the cardiac action potential
140
Bradycardia
141
Communication between the atria and ventricles is done through
Bundle of His
142
Tachycardia
143
The 12 lead EKG has what three lead groups
3 standard bipolar limb leads, 3 augmented unipolar limb leads, 6 precordial chest leads
144
Definition of cardiac cycle
All events occurring in the heart from the beginning of one heart beat to the beginning of the next
145
If you have 10 electrodes how many leads
12
146
What connects the adjacent cells in the cardiac muscle
Gap junctions
147
Systole aka
Contraction
148
What organs are blood conditioner organs
Lungs, kidneys, GI tract and skin
149
Describe cardiac cells
Single centrally located nucleus, branched fibers, striated, intercalated discs
150
What is frank starlings mechanism
Greater the heart muscle is stretched during filing, greater the force of contraction and the greater the quantity of blood pumped into the aorta
151
Heart sounds can be recorded using a
Phonocardiogram
152
QRS axis can be estimated by comparing what
The size of the QRS complexes of all six limb leads
153
The S wave represents
Left left ventricular activation
154
What is the supply and demand concept of the heart
Cells demand O2 and nutrients, the CV system supply blood to cells
155
PR interval is how long
.16 sec
156
Aka of hyperpolarization
Undershoot
157
What is left axis deviation
QRS axis of 0 to -90 degrees
158
Positive lead of aVR
Right wrist
159
What occurs in ventricle during early systole
Rapid ejection
160
What are the requirements for effective heart function
Synchronized contraction of heart muscle, valves open fully, no leaky valves, contractions adequately strong, ventricles fill adequately
161
What is the mean vector
Average of all vectors
162
The R wave return represents
Left ventricular activation
163
Premature contraction
164
Constriction in vessels cause
Diversion to another place
165
How does temperature influence heart function
Fever causes and increase in heart rate
166
Lead three positive lead goes where
Left ankle
167
Internodal fibers receives action potential from
SA node
168
What occurs during phase 0
Opening of fast V gated Na+ channels
169
T wave represents
Ventricular repolarization
170
Cardiac cells greatly depend on what for initiation and strength of contraction
Extracellular Ca2+ for initiation and strength of contraction
171
Ventricular Fibrillation
172
V4 goes where
5 ICS, Left mid clavicular line
173
What are the primer pumps
Atria
174
The right cardiac cycle looks essentially the same, except the pressures are about what compared to the left
1/6
175
Action potential recordings are Monophasic or biphasic
Monophasic
176
Purpose of diastole
Release pressure so that the heart chamber can fill with blood
177
Internodal fibers connects to what node
AV node
178
SA node connects with conduction system and what to control the rate of the whole heart
Intercalated discs
179
What are the three other influences on heart function
Potassium ions, calcium ions and temperature
180
The left ventricle has an average pressure of what
100 mmHg
181
Contractility occurs where
Cellular level
182
What happens if the atria fail to function
Lower cardiac output, clot formation
183
What occurs during the A curve
Increase in pressure due to contraction (atrial systole)
184
Does the purkinje system have a very fast or slow conduction velocity
Fast
185
What indirectly increases contractility
Heart rate
186
2nd AV block
187
What is tetralogy fallot
Interventricular septal defect, over riding aorta, pulmonary stenosis, right ventricular hypertrophy
188
What is the average QRS axis
59 degrees
189
What is end systolic volume
Amount of blood volume in ventricle at end of systole
190
Conduction system is made of
Specialized cardiac muscle cells
191
What is a lead
Set of electrodes used to make a recording
192
Describe T tubules of cardiac cells
5x bigger in diameter
193
Why do our cells need optimal temperature
Function at a narrow temperature range
194
How does potassium ion influence heart function
Hyperkalemia causes weak contractions, slows heart rate, abnormal rhythms and potentially death
195
Ejection fraction should be around what percent
60%
196
EKG recordings are Monophasic or biphasic
Biphasic
197
Aka of phase 1
Initial spike
198
QRS complex precedes
Ventricular systole
199
Sinus arrhythmia is due to
Respiratory center in medulla exciting nearby vasomotor center
200
What is normal axis
0 to 90 degrees
201
Atrial and ventricular syncytia are separated by what
Fibrous septum
202
Because blood flows along the path of least resistance, organs with ???? Resistance receives the ???? Flow.
Low, most
203
Why is the cardiac contraction equal to duration of AP
Want the contraction long enough to empty atrium or ventricle, helps to not spend extra energy
204
When atria contract what relaxes
Ventricles
205
What are the two electrodes to record voltage
Negative (reference) and positive (recording)
206
The fibrous septum surrounds what
Openings of the two AV valves.
207
Incomplete intraventricular block has what
Electrical alternans
208
What occurs during phase 4
Active transport of Na+, K+ and Ca2+
209
It takes how long for O2 to diffuse 100 micrometers
5 seconds
210
What are the conduction blocks
SA block and AV blocks
211
SA node embedded where
Wall of RA
212
Why does AV node delay action potential
Low number of gap junctions, give atria time to contract before ventricles contract
213
What are the precordial leads
V1 - V6
214
What two things do all blood conditioner organs have in common
Blood flow in excess of their basic metabolic needs, can tolerate substantial drops in blood flow for a short period of time
215
What is afterload
Forces against which cardiac muscle must overcome (arterial pressure, resistance to flow)
216
Atrial flutter
217
A signal is detected by the oscilloscope when there is an
Electrical difference between the two electrodes
218
How does resistance of blood flow occur
Frictions,
219
If prolonged QRS time occurs, it is due to
Bundle branch block or hypertrophy
220
What is isovolumic contraction
Pressure in ventricle not greater than pressure on other side of valve
221
Increase heart rate does what to Ca2+
Accumulate faster than it is removed
222
What is automaticity
Cells generate their own action potentials without external stimuli from nerves or chemicals
223
What are the leads in the augmented unipolar limb leads
AVR, aVL, aVF
224
Aka of phase 4
Resting membrane potential
225
What causes U wave
Delayed replarization of purkinje fibers, prolonged repolarization of mid-myocardial M cells, after potentials resulting from mechanical forces in ventricular wall, repolarization of the papillary muscle
226
What occurs to ventricle during early diastole
Blood enters ventricle, rapid inflow
227
The Q wave represents
Septal activation
228
What is bradycardia
Resting heart rate slower than 60 bpm
229
The systemic and pulmonary circuit are parallel or series
Series
230
What is tachycardia
Resting heart rate faster than 110 bpm
231
How does calcium ions influences heart function
Hypercalcemia causes spastic contractions
232
During systole, the aortic pressure rises with
Ventricular contraction, 120 mmHg
233
How many heart sounds are there
4, S1-S4
234
P wave represents
Atrial depolarization
235
The R peak (most significant) represents
Apical activation
236
What is the U wave
Wave on ECG that is sometimes seen
237
Negative lead of aVR
Left wrist and left ankle
238
What is right axis deviation
QRS axis of 90 to 180 degrees
239
What are the three components of the EKG
P wave, QRS complex, T wave
240
What is an interventricular septal defect
Still has hole from embryonic development, blood enters from left to right ventricle
241
Electrodes detect what
Waves of depolarization and repolarization throughout the heart tissue
242
3rd AV block
243
What is the kinetic energy of blood flow
Accelerates blood into the great arteries (minor fraction of heart work)
244
Diffusion is important at what levels of the body
Capillaries, interstitial fluid and cell membranes
245
Lead two positive lead goes where
Left ankle
246
Radius changes within vessels due to
Smooth muscle, dilation and constriction
247
Fluid moves from an area of
High pressure to an area of low pressure
248
T wave precedes
Ventricular diastole
249
What occurs during the C curve
Fluctuation in pressure due to AV valve closure
250
What prevents prolapse into the atria of AV valve
Chordae tendineae and papillary muscles
251
Purpose of systole
Generate pressure to perform the work of moving blood
252
What is the basic flow equation
= change in pressure/ resistance to flow
253
Negative lead for aVF
Left wrist and right wrist
254
What is work output of the heart
The amount of energy that the heart converts to work during each heartbeat
255
How is the SA node self excited and has inherent rhythmicity
Sodium leak, higher resting membrane potential, lower threshold
256
List the conduction system parts in order of fastest to slowest inherent firing rate
SA node, AV node, purkinje system
257
Ventricular systole has how many phases
2, early and late
258
What does every cell need for survival
Oxygen, nutrients, removal of CO2 and metabolic waste, optimal temperature
259
Urea and other metabolic wastes left in blood causes
Anorexia, lethary, decreased mental acuity and coma, nausea, vomiting, bone pain, itch, SOB, seizures and death
260
What are the different types of AV blocks
1st, 2nd and 3rd degree
261
What is the source of blood flow
Heart
262
The pattern of ventricular repolarization begins from
Apex towards the base of the heart
263
Premature contractions are what
Contraction of the heart before the time they are normally expected
264
What cardiac muscle tissue has the fastest inherent firing rate
SA node
265
How to plot QRS axis
Take two leads and plot direction and magnitude, draw right angles, where they intersect is the axis of ventricular depolarization
266
How much of the blood moves to the ventricles from the atria during atrial systole
20%
267
Definition of pressure
The magnitude of the force F exerted by a fluid on the surface, divided by the surface area A
268
What are the three atrial pressure curves
A, C and V curve
269
To plot the QRS axis based on limb lead what is required
Use of any two of the six limb leads
270
Blood flow occurs when what exists
Change in pressure, one pressure exceeds the other
271
Reason for bradycardia
Athlete, vagal stimulation
272
Where is the atrial repolarization
Hidden behind QRS
273
Current of injury is shown where EKG
ST segment
274
How to determine SA block
P wave missing, slower HR
275
1st degree AV blood shows what
P to R interval long, delayed QRS
276
Parts of the right heart
IVC, SVC, coronary sinus, right atrium, tricuspid valve, right ventricle, pulmonary valve
277
AV node slows velocity or rate
Slows velocity
278
Diastole aka
Relaxation
279
What is the electrode that is placed on the right ankle
Ground electrode
280
SA node AKA
Pacemaker
281
What happens to pressure in ventricle during diastole
Decreases
282
Describe the SR of cardiac cells
Not well developed
283
What is cardiac output
Blood from the heart
284
What occurs during the V curve
Increase in pressure as atrium fills
285
What occurs during incisura
Pressure fluctuation due to closing of the aortic valve
286
An action potential is
Electrical events in a cell
287
The isoelectric line aka
Zero line
288
Positive lead for aVF
Left ankle
289
Nutrients are needed by the cell for what
Energy, building blocks, etc
290
Normal QRS voltage of sum of 1, 2, 3 should equal
2-4 mV
291
Functions of the right heart
Receives blood from the body, pumps blood to the lungs
292
Basic flow equation AKA
Ohm’s law
293
Electrocardiogram has electrodes placed
Outside of cell and has mass effect in bundle of cells
294
A fib or V fib triggered by
Electrical shock, ischemia, dilated hearts, high potassium or tachycardia
295
What is preload
End diastolic pressure in the ventricle, or length muscle is stretched before contraction, “filling”
296
What occurs during atrial flutter
A single large wave that goes around the atria
297
Gap junctions form what between cells
Electrical synapses
298
Oxygen is needed by the cell for what
Aerobic respiration
299
What are the four factors that influence the strength of the contraction
Preload, afterload, contractility, and heart rate
