Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

1020 Human Physiology > Module 8 - Cardiac Cycle > Flashcards

Module 8 - Cardiac Cycle Flashcards

1
Q

Functions of Cardiac Cycle

A
  • Transport O2 & nutrients to all cells of body
  • Transport CO2 & waste from cells
  • Regulate body temperature & pH
  • Transport & distribute hormones & other substances
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Right Atrium & Ventricle Function

A
  • Pumps blood to lungs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Left Atrium & Ventricle Function

A
  • Pumps blood to entire body
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Left Ventricle

A
  • Contracts more forcefully to propel blood through entre circulatory system
  • Thicker wall
  • Requires more muscle
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Right Ventricle

A
  • Thinner walls
  • Only pumps blood to lungs
  • Less forceful contraction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Heart Valves Purpose

A
  • Ensure 1 way flow of blood through heart (atrium to ventricle)
  • Prevent blood from backing up (returning to atrium during ventricle contraction)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Right Atrioventricular (AV) Valve

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

Left Atrioventricular (AV) Valve

A
  • Bicuspid valve
  • Mitral valve
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Aorta Function

A
  • Distributes blood from ventricle throughout body
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Pulmonary Artery Function

A
  • Transports blood from right ventricle to lungs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Pulmonary Vein Function

A
  • Delivers blood back to heart after passing through lungs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Inferior Vena Cava Function

A
  • Delivers blood to heart from torso & lower limbs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Superior Vena Cava Function

A
  • Delivers blood from head & upper limbs to heart
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Bundle of His Function

A
  • conduct action potentials from AV node to base(apex) of heart
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Contractile Cells of Heart Components

A
  • Same proteins as actin/myosin
  • Arranged in bundles of myofibrils surrounded by SR
  • One nucleus
  • Many mitochondria
  • Short, branched cells
  • Joined by intercalated discs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Intercalated Disc Components

A
  • Tight junctions, bind cells
  • Gap junctions, movement of ions & current
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Gap Junction Function

A
  • Allow myocardial cells to conduct action potentials from cell to cell
  • Without nerves
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Nodal Cells

A
  • Contract weakly
  • Few contractile elements (myofibrils)
  • Spontaneously generate action potentials without nervous input
  • Self-excitable
  • Generate & transmit impulses through heart
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Self-Excitability Pathway

A
  • Impulses originate in SA node (sinoatrial node)
  • Atria
  • AV node
  • Bundle of his
  • Purkinje fibers
  • Ventricular node
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Sinoatrial Node (SA node) Permeability

A
  • Greater Na+ & Ca+ permeability
  • K+ permeability decreases overtime
  • Na+ permeability slightly higher than other cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Sinoatrial Node (SA node) Characteristics

A
  • Fastest self-excitability
  • Slowest conduction speed
  • Located in upper posterior wall of right atrium
  • First to spontaneously depolarize
  • No stable resting potential
  • Create pacemaker potential
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Threshold of SA Node

A
  • -40mV
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Resting Potential of SA Node

A
  • -60mV
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Steps of SA Node Action Potential

A
  • Membrane depolarizes to threshold
  • Special Ca++ channels open
  • Ca++ flows into cell
  • Ca++ channels close at same time K+ channels open
  • K+ flows out to repolarize cell
  • Cell returns to resting potential
  • Pacemaker potential begins depolarizing cell
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Myocardial Steps of Action Potential
- Action potential from SA node spreads through atrial muscle via gap junctions - Causing atrial contraction - Action potential travels to ventricles through AV node - Action potential travels through each branch of bundle of his to apex - Propagates through purkinje fibers - Rapidly distributes to ventricular muscle causing contraction
26
Action Potential Conduction Throughout Heart
- Speeds up through atrial muscle to ensure simultaneous contraction - AV node slows, holds up action potential (ensure atria finishes contraction) - Fast through bundle of his
27
Electrocardiogram (ECG)
- Represents electrical activity in areas of heart
28
P Wave of ECG
- Depolarization of atrial muscle - Leading to contraction
29
QRS Complex of ECG
- Depolarization of ventricular muscles - Leading to contraction - Longest waveform
30
T Wave of ECG
- Repolarization of ventricular muscles
31
Systole Phase
- Period of time heart muscle is contracting
32
Diastole Phase
- Period of time heart muscles relax - Chamber fills with blood
33
Cardiac Cycle Characteristics
- Combines heart events - Pressure & volume changes - ECG & valvular activity - Pressure changes for blood flow - Pressure gradient from high to low
34
Atrial Systole Phase
- Depolarization of atria (P wave) - Atrial pressure > ventricular pressure - AV valve already open - Blood flows into ventricles continuously - Ventricular volume increases - 20-30% of blood filling (end diastolic volume) - Atria contraction
35
Isovolumetric Ventricular Contraction Phase
- Depolarization of ventricles (QRS complex) - Ventricles contract - Increase in ventricular pressure - Ventricular pressure > atrial pressure - AV valve closes - No volume changes - Aortic pressure > ventricular pressure (aortic valve closes)
36
Ventricular Systole Phase
- Repolarization of ventricles (T wave) - Ventricular pressure > aortic pressure - Aortic valve opens - Blood leaves ventricles and flows into aorta - Ejection of blood from heart - Ventricular volume decreases - Some blood returns (end systolic volume)
37
Isovolumetric Relaxation Phase
- Ventricles relax causing pressure drop - Ventricular pressure < aortic pressure - Aortic valve closes - Ventricular pressure > atrial pressure - AV valve remains closed - No change in volume
38
Late Ventricular Diastole Phase
- Ventricles continue relaxing - Ventricular pressure < atrial pressure - AV valve opens - Blood flows into ventricles from atria - 80% of ventricular filling - Volume increases - P wave begins
39
Order of ECG Events
- atrial systole - iosvolumetric ventricular contraction - ventricular systole - isovolumetric relaxation - late ventricular diastole
40
Ventricular Filling
- 70-80% of blood enters relaxed ventricles during late ventricular diastole - 20-30% of blood enters during atria systole
41
Ejection Period
- Ventricular pressure > aortic pressure - Ventricles empty blood into aorta
42
LUB 1st Sound
- AV valve closes - During isovolumic ventricular contraction
43
DUB 2nd Sound
- Aortic & pulmonary semilunar valve close - During isovolumic relaxation
44
Cardiac Output (CO)
- Amount of blood in each ventricle pumps per minute - L/min
45
Heart Rate (HR)
- Number of heart beats per minute
46
Stroke Volume (SV)
- Amount of blood pumped by each ventricle during 1 contraction - Amount of blood ejected - mL/beat
47
End Diastolic Volume (EDV)
- Amount of blood in ventricle at end of diastole - mL
48
End Systolic Volume (ESV)
- Amount of blood in ventricles at end of systole - mL
49
Cardiac Output Equation
CO = HR x SV
50
Stroke Volume Equation
SV = EDV - ESV
51
Resting Values
- HR 70bpm - SV 70mL/beat - CO 5L/min - EDV 120mL - ESV 50 mL
52
Increasing Cardiac Output
- Increasing SV - Increasing HR - Increasing SV & HR
53
Altering Stroke Volume (SV)
- Input from ANS - ESV - EDV & preload
54
EDV & Preload Alteration
- Load on heart prior to contraction - Blood in ventricle stretches heart muscles - More blood in ventricles = higher EDV - More Ca++ into cell - More blood ejected & more forceful contraction - Lower ESV & higher SV
55
ESV Alteration
- Constriction on veins via ANS - Increases venous return - Repeated contraction & relaxation (exercise) - Pumps blood back to heart - Increases EDV, SV & CO
56
ANS Controls
- HR - Force of contraction
57
PSNS Controls
- Mostly SA & AV nodes - Atrial & ventricular muscles to lesser extent - Decreases HR through SA & AV Node - Decrease force of contraction to lesser extent
58
SNS Controls
- SA & AV nodes - Strongest on ventricular muscle - Increase HR & force of contraction
59
PSNS Activation
- Always activated at rest - Vagus nerve transmits signals to heart (vagal tone) - Shifts off if HR > 100bpm
60
PSNS Ach Release
- Nerves to heart activate release of Ach onto SA & AV nodes - Ach causes K+ channels to open - K+ leave cell creating hyperpolarization - Pacemaker potential decreases - Membrane takes longer to meet threshold & HR slows
61
SNS Ne Release
- Nerves to heart activate release of norepinephrine onto SA & AV Nodes - Causing Na+ & Ca++ channels to open - More positive ions enter SA nodal cell - Rapid depolarization & increase in pacemaker potential - Membrane reaches threshold faster & HR increases
62
Frank Stirling Law
- Increase of EDV causes increase in SV (vice versa) - Increase of blood volume causing increased stretch of muscles increasing force to pump blood out

1020 Human Physiology (16 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions