Unit 5 Cardiac Cycle Flashcards
1
Q
Cardiac Muscle
A
- Striated
- Involuntary
- Walls of heart
- Contain sarcomere
2
Q
Cardiac Cells
A
- Joined end to end
- Connected by intercalated discs
- Central nuclei (2)
3
Q
Cardiomyocyte Types
A
- Pacemaker
- Non-pacemaker
4
Q
Pacemaker Cells
A
- Auto-rhythmic
- Spontaneous contraction
- SA node, AV node, bundle of His, purkinje fibers
5
Q
Non-Pacemaker Cells
A
- Majority of heart cells
- Basic contractability
- Depolarization induced by adjacent cell depolarization
6
Q
Syncytia
A
- Atria & ventricle
- Allow for atrial contraction prior to ventricle contraction
7
Q
Syncytium
A
- Cardiomyocyte cells
- Connected by intercalated discs
8
Q
Pacemaker Depolarization
A
- Slow response
- Autorhythmic
9
Q
Myocyte Depolarization
A
- Faster response
- Caused by Na+ & Ca++
10
Q
SA Node
A
- Pacemaker
- Origin of cardiac impulse
- Induces depolarization on adjacent cells
- Signal transmits through atria down to AV node
11
Q
AV Node
A
- Center of heart
- Connects to atria & ventricles via bundle of his
- Slows down SA node signal
- Allows of atria to empty into ventricles
12
Q
Contraction Pathway
A
- SA node
- Atria & AV node
- Ventricles
13
Q
ECG Function
A
- Measure charges in electrical signals within chromocytes
- Via electrodes placed on chest
14
Q
Blood Flow
A
- High to low pressure
- Contraction increases pressure
- Relaxation/emptying decreases pressure
15
Q
Valve Movement
A
- Open/close based on pressure gradient
- Atria always filling
- No valves in vena cava & pulmonary veins
16
Q
Heart Sounds
A
- Caused by closing of valves
- S1, left AV valve (mitral)
- S2, semilunar valve (aortic)
17
Q
Atrial Systole (1)
A
- Atria contract
- Increased pressure in atrium
- Push blood into ventricles
- End diastolic volume
- AV valve closes (S1)
- QRS wave begins
18
Q
Isovolumetric Contraction (2)
A
- Atria relax
- Ventricles contact
- No blood ejection
- QRS wave
19
Q
Rapid Ejection (3)
A
- Aortic & pulmonary valves open
- Blood rushes into aorta & pulmonary trunk
- Ventricular volume decrease
- Ventricular pressure increase
20
Q
Reduced Ejection (4)
A
- Aorta pressure decrease
- Atria pressure increase
- Atria volume increase
- T wave
- Ventricles repolarize
21
Q
Isovolumetric Relaxation (5)
A
- Semilunar valves close (S2)
- Ventricle diastole
- ESV
22
Q
Rapid Filling (6)
A
- Atria pressure increase
- AV valve opens
- Ventricular volume increase
23
Q
Reduced Filling (7)
A
- Blood into ventricles
- AV valves open
- Ventricular volume increase
- Ventricular pressure increase
- P wave
