Physio (The Cardiac Cycle) Flashcards
1
Q
- energy needed by heart
- convert work
- pumping blood into arteries
A
Stroke Work
2
Q
- total energy
- converted to work in 1 minute
A
minute workout
3
Q
action potential (sinus node) –> A-V bundle –> ventricles
A
Cardiac Cycle
4
Q
- major proportion of energy
- low-pressure veins –> high pa
- low veins –> high arteries
A
volume-pressure
5
Q
- minor proportion of energy
- accelerates blood
- velocity of ejection through aortic & pulmonary valve
A
kinetic energy of blood flow
6
Q
- 1/6th work output of left ventricle
- six-fold difference in systolic pressure
A
right ventricular external work output
7
Q
- blood flows with great velocity through the stenosed valve
- 50% of total work output may be required to create kinetic energy of blood flow
A
aortic stenosis
8
Q
-specify degree of tension on muscles contracting
A
Preload
9
Q
- specify load against
- muscle exerts contractile force
A
afterload
10
Q
- preload
- beginning of systole
A
end-diastolic volume (EDV)
11
Q
- EDV
- Directly related
A
myocardial sacromeres
12
Q
- stops ejections
- ventricular pressure
- myocardial contraction < arterial pressure
A
end-systolic volume
13
Q
- decreased preload
- e.g., nitroglycerin
A
vENodilators
14
Q
- decrease afterload
- e.g., hydralazine
A
vASodilators
15
Q
-increase with excercise
(slightly)
-increases blood volume
(transfusion)
-excitement (sympathetics)
A
preload
16
Q
- at rest
- severve exercise
- intrinsic cardiation
- control of heart rate & strength of heart pumping
- frank-starling mechanism
- frank-starling relationship
- ejection fraction
A
regulation of heart pumping
17
Q
- heart pump
- 4 to 6 L blood/min
A
at rest
18
Q
-4 to 7 times blood/min , than normal (4-6L)
A
severe exercise
19
Q
- intrinsic cardiation
- control of heart rate & strength of heart pumping
A
volume pumped by heart regulation
20
Q
- response to
- change in volume
- blood flowing into the heart
A
intrinsic cardiation
21
Q
-control of heart rate & strength of heart pumping
A
ANS
22
Q
- heart adapts
- increase volumes of inflowing blood
- > heart muscle stretch, > amount of blood pumped into the aorta
A
Frank-Starling mechanism
23
Q
- increase stroke volume
- increase cardiac output
- response to increase of venous return
- OR response to increase EDV
A
frank-starling relationship
24
Q
SV/EDV=?
A
ejection fraction
25
- increase K in ECF
- decrease in membrane potential
- increase calcium ions
- decrease of Ca ions
Effects of K & Ca ions on heart function
26
- decrease resting membrane potential
| - contractions of heart progressively weaker
decrease membrane potential
27
- decrease resting membrane potential
| - cardiac muscle fibers
increase K (in ECF)
28
- heart --> spastic contraction
- Ca ions initiate cardiac contractile process
- opposite of K effect
increase Ca Ions
29
- -dilated
- -flaccid
- -slow heart rate
Heart becomes: increase K (in ECF)
30
- -large quantities of K
| - -from atria --> ventricles (through A-V bundle)
block conduction fo cardiac impulse: increase K (in ECF)
31
- -elevation of K
- -2 to 3 times the normal valve
- -weakness of heart
- -abnormal rhythm (may cause death)
K concentration of 8-12 mEq/L: increase K (in ECF)
32
-flaccidity
| similar to increase in K
decrease of Ca ions
33
- fever
| - increased heart rate
increase body temp
34
-decreased heart rate
(few beats/min)
-hypothermia
decrease body temp
35
results b/c:
-heat increase permeability
(cardiac muscle membrane --> ions control heart rate)
-increase self-excitation process
effects of temp on heart function
36
-prolonged elevation of increased temp
(exhaust metabolic system,
causes weakness)
- moderate increase in temp
(e. g., body excercise)
-why the heart depends on control of body temp; VIA temp control mechanism
contractile strength of heart
37
- beta blockade
- heart failure
- acidosis
- hypoxia/hypercapnia
decreased stroke volume
AND
decreased contractility
38
- increased preload
- increased contractility
- decreased afterload
Increase stroke volume
39
- btw 2nd & 3rd intercostal spaces
- at RIGHT UPPER sternal border
- area of auscultation
AoRtic region
40
- btw 2nd & 3rd intercostal spaces
- at LEFT UPPER sternal border
- area of auscultation
puLmonic region
41
- btw 3rd - 6th intercostal spaces
- at the left lower sternal border
- area of auscultation
tricuspid region
42
- near apex of heart
- btw 5th & 6th intercostal spaces
- in the midline
- area of auscultation
mitral region
43
- loudest at mitral area
| - mitral and tricuspid valve closure
S1
44
-aortic & pulmonary valve closure
S2
45
- associated with increased filling pressure
- more common in dilated ventricles
- early diastole
- during rapid ventricular filling phase
- normal in children & pregnant women
S3
46
- high atrial pressure
- late diastole
- associated with ventricular hypertrophy
S4
47
-atrial contraction
A wave
48
-right ventricle contraction
C wave
49
-increased atrial pressure
V wave
50
- a wave
- c wave
- v wave
jugular venous pulse
51
-timing and pattern of electrical activation of the heart are normal
normal sinus rhythm
52
- action potential that originates in the SA nodes
- SA nodes impulses regularly at a rate of 60-100 bpm
- activation of the myocardium is in the right sequence with the right timing
normal sinus rhythm qualifications
53
-determined by potassium ions (K+)
resting membrane potential
54
- inward current
| - net movement of positive charge into the cell
depolarization
55
- outward current
| - net movement of positive charge out of the cell
hyperpolarization
56
? = EDV - ESD
SV
