MODULE 1: Cardiac Muscle And Hemodynamics Flashcards
(306 cards)
1
Q
What is the structure and function of the pericardium?
A
Forms a “sac” around the heart
2 layers (visceral and parietal pericardium; Form the pericardial cavity which is filled with pericardial fluid)
*PROTECTS the heart and allows it to contract in a frictionless surfec
2
Q
A positive inotropic stimulus will lead to an increased ___, a decreased
ESV, leading to increased SV and increased ____
A
EDS = End diastolic stimulus
ESV = end systolic volume
SV= stroke volume
CO = cardiac output
3
Q
Name the layers of the heart from center to outside.
A
Endocardium
Myocardium
Epicardium
4
Q
Name the chambers and valves of the heart
A
*Chambers of The Heart
• Left and Right Atria
• Left and Right Ventricles
- Valves of The Heart
• Right Atrioventricular (AV) Valve
—Tricuspid / Right AV Valve
• Left Atrioventricular (AV) Valve
—Bicuspid / Mitral / Left AV Valve
• Semilunar Valves
—Pulmonary Valve
—Aortic Valve
5
Q
Heart valve do what?
A
Prevent the back flow of blood
6
Q
The myocardium consists of ___________
A
Cardiomyocytes (myocytes)
7
Q
Myocyte Histology Highlights
A
• Single nucleus
• Myofibrils
• Myofilaments and sarcomeres
8
Q
Two Intercalated Disc Features
A
• 1. Desmosomes
Binds/Connects cells together • Allow cells to “pull together” for
maximum efficiency
• 2. Gap (Electrical) Junctions
Allow for movement of ions from one cell the the next. Depolarisation
9
Q
All the options are true regarding the heart, except?
• A. The mitral valve separates the left atrium from left ventricle
• B. The aortic valve contains chordae tendineae
• C. The epicardium is technically part of the pericardium
• D. The left AV has two cusps
A
B
10
Q
Describe the function of the heart valves.
A
Prevent backflow of blood through the heart
11
Q
Describe the function of the intercalated discs
A
Allow for the movement of ions from one cardiac muscle cell to
another- creating the ability to transfer the propagation of an action
potential
12
Q
T or F
The semilunar valves (Pulmonary and aortic) valves of the heart contain chordae tendineae
A
F
Only the AV valves contain chordae tendineae
13
Q
Describe the pathway of blood flow through the heart
A
** COME BACK
14
Q
What are the two sets of cells in the myocardium? What do they do?
A
• 1. Non-Contractile (Nodal) Cells Nodal AP
• AKA Conducting Cells
• Pacemaker cells- Initiate the action potential
• About 1% of overall number of cells
- Contractile Cells Myocyte AP
• Myocytes
15
Q
Explain what is involved in Nodal (Non-contractile) cells AP process.
A
Nodal (Non-Contractile) Cells
• Possess the ability to generate action
potentials spontaneously
• Spontaneously depolarizing, generating an
action potential ”passing” it to the next
myocytes via the intercalated discs
• Process of generating spontaneously action
potentials is unique and different from
contractile myocytes • Part of the cardiac conduction system and set
the heart rate
• SA Node
16
Q
Explain what is involved in Myocyte (Contractile) cells AP process.
A
Myocyte (Contractile) Cells
• Myocytes that undergo contraction
• Have actin, troponin, tropomyosin, myosin, sarcoplasmic reticulum
• Sarcomeres
• Undergo the same crossbridge and power stroke process as skeletal muscle
17
Q
What is the BIG PICTURE of cardiac muscle AP
A
BIG PICTURE
• SA Node non-contractile (nodal) cells spontaneously generate action potentials
• Action potentials travels to myocardial (contractile) cells in the atria then ventricles via gap junctions and along the cardiac conduction system
• Electrical impulse (action potentials) travels along cardiac conduction system and
into myocardial cells • Allows for the heart to contract in a COORDINATED, organized fashion
18
Q
What are the Myocyte AP unique characteristics and phase overview?
GRAPH on slide 19
A
• 1. Five Phases
• 2. Long Duration
150 - 300 ms
Skeletal muscle is a under 5 ms
• 3. RMP
-90 mV
•4. Plateau Phase
• 5. Ions Involved
Sodium, Potassium, Calcium
19
Q
Myocyte AP PHASES explained on slide 22!!
Briefly explain these
A
Phase 0 = SA Node (nodal) cells spontaneously undergo AP. Cations (+) leak into the myocytes via the gap
junctions from SA Node cells
• Intercalated discs Fast voltage-gated Na+ channels open and K+ channels close
Phase 1= Voltage-gated Na+ channels close
Fast voltage-gated K+ channels transiently open
Phase 2 = Voltage-gated K+ channels close
Slow delayed rectifier K+ channels open (Neutral b/c both positive K and Na are switching)
Phase 3 = Ca2+ channels close
Fast delayed rectifier K+ channels open
Phase 4 = Resting membrane potential
*Cell is at rest • RMP: -90mV • Membrane is most permeable
to potassium (K +) ions • Potential Threshold
• -70mV to -65mV
20
Q
Refractory Periods For Myocyte AP
SLIDE 31
A
During phases 0, 1, 2, and part of phase 3- the cell is refractory to the initiation of new action potentials
• *Absolute Refractory Period (ARP)
• Incapable of generating a second action potential (ABSOLUTELY NOT
HAPPENING)
• *Relative Refractory Period (RRP)
• Possible to generate a second action potential
• Greater-than-normal stimulus is required
21
Q
What ions are entering or leaving the myocyte during each phase?
• A. Phase 0:
• B. Phase 1:
• C. Phase 2:
• D. Phase 3:
• E. Phase 4:
A
• A. Sodium ions in
• B. Potassium ions out
• C. Calcium ions in/Potassium ions out
• D. Potassium ions out
• E. RMP
22
Q
Why does the plateau occur and what is its importance?
A
Positive calcium ions are moving in; Positive potassium ions are
moving out; Calcium ions moving in stimulate muscle contraction
23
Q
Describe how an action potential initiates an action potential in
another myocyte?
A
Gap junctions allow for positive ions to move from one myocyte
to another allow for initiation of an action potential
24
Q
The nodal cells are known as what?
A
Non-contractile cells (cardiac conduction system!)
25
Nodal (Non-Contractile) Cells spontaneously create an action potential
• Have their own mechanism to create this
• Nodal Cells (SA Node) action potentials spread through two areas?
• Cardiac Conduction System
• Gap junctions with the myocytes
26
What are the three phases of the SA node AP?
Phase 4
Phase 0
Phase 3
27
Explain phases 4, 0, and 3 of nodal cells AP
Phase 4 -
• Spontaneous depolarization triggers the
action potential
• Once membrane potential reaches
potential threshold- stimulates opening of calcium ion voltage gated channels
• -40 mV
Phase 0 -
- Depolarization phase of the action
potential
• Funny Sodium (Na +) channels activate
Calcium (Ca2+) channels to open
• Technically, two types of calcium channels:
1. T-type Calcium (Ca 2+) channels open first
2. L-type Calcium (Ca 2+) channels open second
Phase3 -
Repolarization phase • Potassium (K+) voltage gated channels
open • Calcium voltage gated channels close • Cell is fully repolarized when it reaches
about -60 mV
• Causes Sodium (Funny) channels to open again
Cycle is spontaneously repeated after Phase 3
28
What phase allows sodium, calcium, and potassium ions to move
into the nodal cells?
• A. Phase 0
• B. Phase 1
• C. Phase 2
• D. Phase 3
• E. Phase 4
• Sodium: phase 4
• Calcium: phase 0
• Potassium: phase 3
29
30
What’s the significance of the Phase 4 of the nodal cell action
potential?
The rate of spontaneous depolarization determines heart rate
31
T or F
Cardiac Muscle has gap junctions (electrical synapse)
T
32
T or F
Cardiac muscle has T-tubules and sarcoplasmic reticulum
T
33
T or F
Cardiac muscle undergoes the same cross-bridge and power stroke
process as skeletal muscle
T
34
What are the 2 Mechanisms That Release Calcium From Sarcoplasmic Reticulum ?
1. PHASE 2 of the Action Potential (Plateau)
• What’s going on? • Calcium (Ca2+) ions are entering the cell due to L-Type Voltage Gated
Calcium (Ca2+) ion channels being open
2. Calcium Induced Calcium Release
• Calcium (Ca2+) ions bind to Ryanodine receptors on the Sarcoplasmic
Reticulum • Causes the release of more Calcium (Ca 2+) ions into the sarcoplasm
55
• Calcium (Ca2+) ions entering the myocyte from the action potential
(phase 2) is not significant enough to stimulate muscle contraction
** Need the influx of calcium ions entering the cell to activate ryanodine
receptor to release calcium ions from the sarcoplasmic reticulum
• Calcium Induced – Calcium Release
35
The magnitude of the tension developed by myocardial cells is _________ to the intracellular calcium (Ca 2+) ion concentration
Proportional
36
Less Ca2+ in the sarcoplasmic reticulum means?
Less cross bridges and less forcefulness of contraction occurring
37
2 Mechanisms Needed To Occur for Cardiac Muscle Relaxation are?
• 1. Non-Contractile (nodal) cells have to stop action potential
generation
• Causes the action potential to stop in within contractile cells
• 2. Calcium (Ca 2+) ions must be pumped from the sarcoplasm back
into the Sarcoplasmic Reticulum and/or ECF
• Calcium ATPase pump on the sarcolemma
• Sodium – Calcium Exchanger
• SERCA Pump
• Sarco/endoplasmic reticulum Calcium (Ca 2+) ATPase
38
Cardiac muscle has the same myofilaments as skeletal muscle.
T or F
T
39
All of the statements are true, except?
• A. Most of the calcium utilized to stimulate contraction is released from the sarcoplasmic
reticulum
• B. Calcium ions entering the myocyte stimulate the release of calcium ions from the sarcoplasmic reticulum
• C. Calcium ions entering the cell are associated with with phase 1 of the action potential • The SERCA pump, like in skeletal muscle, plays a role in cardiac muscle relaxation
C
Should be phase 2
40
Discuss the process of cardiac muscle relaxation.
Must remove calcium from sarcoplasm via Calcium ATPase pump,
Sodium – Calcium Exchanger, and SERCA
41
If phase 2 was lengthened or shorten, how would it influence cardiac muscle
contraction?
It would shorten or lengthen the contraction time, respectively
More Ca2+ would lengthen for a longer period of contraction time
42
The intensity of cardiac muscle contractility correlates directly with
the intracellular Calcium (Ca 2+) concentration
This depends on what?
the amount of Calcium (Ca 2+) released from sarcoplasmic
reticulum stores
43
What influences the release of Calcium (Ca 2+) ions from the
sarcoplasmic reticulum?
• Size of the inward calcium (Ca 2+) ions during the plateau of the myocardial
action potential • Amount of calcium (Ca 2+) ions previously stored in the sarcoplasmic
reticulum for release
44
What are chronotropic, dromotropic, inotropic?
What do they entail?
What are there sympathetic nervous system effects? (+)
These are cardiac muscle contraction variables.
Chronotropic - Affect the HR and rhythm; affecting the electrical conduction system of the heart and the nerves that influence it; specifically, the SA node
+ Positive Chronotropic Effects — Increases the heart rate
— Norepinephrine (SNS) activates β 1 Adrenergic Receptors in the SA node
— Increases rate of depolarization in nodal cells
— Increases rate of action potential formation
2. Dromotropic
• Alters the rate action potentials are
conducted from the atria to the ventricles • Affects the conduction speed thru the AV
node
+ Positive Dromoptopic Effects — Increase in conduction velocity through the AV node
— Increase of action potential speed through the AV node
3. Inotropic
• Alters the force of muscular contractions
• Myocytes have more contractility force
+ Positivve Inotopic Effects
—Increases the strength of contractility in the Atria and Ventricles
— Influences the amount of calcium ions in the sarcoplasm
45
46
What are the PARASYMPATHETIC NERVOUS SYSTEM EFFECTS for negative (-) chronotropic and Dromotropic?
• Negative Chronotropic Effects
— Decreases the heart rate
—Acetylcholine released from parasympathetic nerve fibers
activates muscarinic (M2) receptors in the SA node
—Decreases rate of depolarization in nodal cells
—Overall decreases rate of action potential formation
• Negative Dromotropic Effects
—Decrease in conduction velocity through the AV node
—Decrease of action potential in the AV node
47
What are the prescription medications for cardiac muscle contraction?
• Antagonistic receptor blockers
• Agonistic receptor blockers
• Positive and negative chronotropic medications
• Positive and negative dromotropic medications
• Positive and negative inotropic medications
• Calcium Channel Blockers
• Beta Blockers
48
If a stimulus led to a decrease heartrate, what would be it labeled?
• A. Dromotropic
• B. Chronotropic
• C. Ionotropic
• D. Ratotropic
B (negative chronotropic)
49
Compare and contrast sympathetic and parasympathetic nervous
system effects on the heart.
Sympathetic increases contraction force and heart rate;
parasympathetic decreases contraction force and heart rate
50
What phase or phases of the cardiac myocyte action potential would
an inotropic stimuli influence?
Phase 2
51
What are the cardiac conduction system components? (4 total in order)
1. SA Node (Pacemaker)
• Cells spontaneously depolarize and undergo action potentials
• Action potential travels through the CCS and myocytes (how?)
• Sets the rhythm and rate of heart
• Influenced by ANS and various chemicals/drugs
*The SA node signals the atria to contract
2. AV Node
• Serves as an electrical relay system receiving electrical impulse form SA Node
• Slows the electrical impulse down before allow it to pass through the
interventricular bundle
• The gateway to the ventricles
*The AV node signals the ventricles to contract
3. AV Bundle and Bundle Branches
• Pass the electrical impulse down the
interventricular septum and to the lateral walls of the ventricles
4. Purkinje Fibers
• Carry the electrical signal from bundle
branches to the myocardium
52
The cardiac conduction system (CCS) does what?
Cardiac Conduction System (CCS) allows the heart to beat in an organized and coordinated pattern
• Coordinates myocyte contraction activity
CCS generates the electrical impulse (action potential) and
transmit it through the heart in a specific order/direction
53
54
Name the main focused EKG Graph components (5 total)
What does each component represent?
**Picture on SLIDE 90 w/ labeling chart
P Wave - Atrial Depolarization
QRS Complex - Ventricular Depolarization
T Wave - Ventricle Repolarization
PR (or PQ) segment - Atrial Contraction
ST Segment - Ventricular contraction
55
What are the electrocardiogram rhythms? What do they entail? (2 total)
Sinus Rhythm
• Normal heartbeat • Three criteria must be met
• 1. AP must originate in the SA node
• 2. SA nodal impulses must occur regularly at a rate of 60–100 impulses per minute
• 3. The activation of the myocardium must occur in the correct sequence and with the
correct timing and delays
Heart Arrythmia
• Cardiac conduction system does not work properly • Causes to heart to contract abnormally: too fast, too slow, irregular • Can be identified on an EKG
56
This portion of the CCC provides an electrical signal to the lateral
wall of the ventricles.
• A. Sinoatrial node
• B. Atrioventricular node
• C. Purkinje fibers
• D. Atrioventricular bundle
C
57
The AV node allows for the slowing down of the electrical impulse
to allow for the ventricle myocytes to contract in unison.
• A. True • B. False
F
58
What portion of the EKG represents ventricular repolarization?
• A. QRS complex
• B. P wave
• C. T wave
• D. QT interval
C
59
What does the ST segment represent?
• A. Depolarization of the ventricle myocytes
• B. Contraction of the ventricle myocytes
• C. Contraction of the atrial myocytes
• D. Repolarization of atrial myocytes
B
60
All of the options are features of action potentials in cardiac muscle, except?
A. Action potentials in the contractile myocytes and non-contractile myocytes are different.
B. Calcium (Ca2+) enter the myocyte during phase 03 of the action potential.
C. Gap junctions play a vital role in the formation of action potentials in contractile myocytes.
D. The action potentials of cardiac muscle have longer duration (time) than skeletal muscle action potentials.
B
61
The Cardiac Conduction System leads to coordinated muscle contraction in the heart so that the right side of the heart contracts then the left side contracts.
T or F
F
62
Cardiac muscle cells undergo contraction in which phase(s) of the action potential?
Phase 2.
Phase 3.
Phase 3 and 4.
Phase 1 and 2.
Phase 2
63
Choose the correct conductive pattern of the cardiac conduction system.
D. AV node - SA node - Purkinje fibers - Bundle Branches - Bundle of His.
A. SA node - AV node - Bundle of His - Bundle branches - Purkinje fibers.
B. SA node - Bundle of His - Bundle branches - AV node - Purkinje fibers.
C. SA node - Purkinje fibers - Bundle of His - Bundle branches - AV node.
A
64
Depolarization of the ventricles is represented on an electrocardiogram by the:
A. P wave.
B. T wave.
C. QRS complex.
D. ST segment
C
65
Which option would be accurate regarding a negative dromotrophic effect?
A. An extended T wave.
B. A decreased ST segment.
C. A decreased P wave.
D. An increased distance between the P wave and QRS complex.
D
66
Drugs that increase the heart rate are classified as:
A. Negative inotropic.
B. Negative chronotropic.
C. Positive chronotropic.
D. Positive inotropic
C
67
T or F
During cardiac muscle relaxation, calcium (Ca2+) ions are pumped from the sarcoplasm back into the sarcoplasmic reticulum and ECF.
T
68
The PR Interval represents:
Signal conduction through the AV node signals
69
Which option represents when phase 2 of the action potential is occurring within the ventricles?
A. T Wave
B. ST Segment
C. QRS Complex
D. PT Segment
B
70
In cardiac muscle tissue (contractile cells), potassium (K+) voltage gated channels are open during which phase(s) of the action potential?
Phases 2, 3.
Phases 3, 4.
Phases 1, 2, 3.
Phase 4.
Phase 0.
Phases 1, 2, 3
71
In which phase of the myocyte (contractile cells) action potential are potassium (K+) gated channels and calcium (Ca+2) channels open simultaneously?
A Phase 2.
B Phase 4.
C Phase 0.
D Phase 3.
A
72
On an EKG, the atrial repolarization wave is visible:
T or F
F
73
Physical activity that would require about 30 seconds of movement would primarily utilize what type of ATP production
A. ATP storage.
B. Creatine phosphate.
C. Anaerobic respiration.
D. Aerobic respiration
C
74
Regarding cardiac muscle cells (contractile cells), which of the following occurs during Phase 0 of the action potential?
A. Opening of the calcium (Ca2+) voltage gated channels.
B. Opening of the potassium (K+) voltage gated channels.
C. Closing of the calcium (Ca2+) voltage gated channels.
D. Opening of the sodium (Na+) voltage gated channels
D
75
Regarding the action potential of the SA node, which one of the following statements is TRUE?
A. Phase 0 involves the opening of calcium (Ca2+) channels.
B. The repolarization of the SA node action potential is produced by the opening of sodium (Na+) channels.
C. The SA node can spontaneously generate action potentials, but needs neural input from the ANS to spontaneously undergo action potentials.
D. In the action potential of the SA node, there is a long plateau of depolarization.
A
76
The magnitude of the tension developed by myocardial cells is proportional to the loss of intracellular potassium (K+) concentration?
T or F
F
77
The P wave of the electrocardiogram represents:
A. Repolarization of the atria.
B. Depolarization of the AV node.
C. Depolarization of the atria.
D. Depolarization of the ventricles.
C
78
The role of troponin in cardiac muscle cell contraction is:
A. To bind calcium (Ca2+) ions.
B. To bind the myosin head allowing the cross bridge formation to occur.
C. To pump calcium (Ca2+) ions back into the sarcoplasmic reticulum.
D. None of the options are accurate.
A
79
What best describes the role of the Purkinje fibers?
A. Transmits the action potential down the interventricular septum.
B. Spontaneously depolarizes to generate action potentials.
C. Transmits the action potential to the lateral walls of the ventricle myocardium.
D. Slows the conduction velocity of the action potential down
C
80
What option best represents what would happen if the SERCA (sarco/endoplasmic reticulum Calcium ATPase) pump stopped working?
A. The muscle contraction process would last longer.
B. The crossbridge formation would be disrupted.
C. It would lead to an increase of potassium (K+) ions in the ICF.
D. Phase 0 of the action potential would be disrupted.
A
81
What option is TRUE regarding Phase 4 of the SA nodal cells' action potential?
A. Sodium (Na+) ions entering the cell.
B. Potassium (K+) ions entering the cell.
C. Voltage gated calcium (Ca2+) ions opening.
A
82
What term represents the parasympathetic nervous system's effect on the conduction velocity in the heart?
Negative inotropic.
Positive dromotropic.
Positive inotropic.
Positive chronotropic.
Negative dromotropic.
Negative chronotropic.
Negative Dromotropic
B/c dromotropic alters the rate action potentials are conducted from T he atria to the ventricles, affects the conduction speed thru the AV node; SO THIS decrease the conduction velocity through the AV node and AP in the AV node
83
What term represents the sympathetic nervous system's effect on the contraction strength in the myocytes?
Negative dromotropic.
Negative inotropic.
Negative chronotropic.
Positive chronotropic.
Positive dromotropic.
Positive inotropic
Positive Inotropic
B/c Inotorpic alters the force of muscular contraction; and positive increases the strength of contractile in the atria and ventricles (influences the mount of calcium ions in the carcoplasm)
84
Which of the following best describes PHASE 0 of the SA node action potential?
A. Voltage gated calcium (Ca+) ions opening.
B. Potassium (K+) ions entering the cell.
C. Potassium (K+) ions exiting the cell.
D. Sodium (Na+) ions entering the cell
A
85
What option is TRUE regarding gap junctions?
A. None of the options are true.
B. Once activated by binding cations, they open voltage-gated channels.
C. They are only found in the nodal cells of the myocardium.
D. They assist in holding the cardiac muscle cells together.
A
86
This portion of the EKG is associated with ventricular repolarization?
A.T wave.
B.S-T segment.
C.QRS complex (wave)
D. P wave.
A
87
All of the options would be true if the SERCA (sarco/endoplasmic reticulum Calcium ATPase) increased its activity, except?
A. There would be less calcium in the sarcoplasm of the myocyte.
B. The ST segment would increase.
C. Phase 02 of the action potential process would be shortened.
D. The contraction force would decrease.
B
88
If a medication caused a negative dromotropic effect on the heart, it would increase the distance between P waves on an ECG.
True
False
T
89
All of the options are variables necessary for a sinus rhythm, except?
A. The action potential must originate in the SA node.
B. Activation of the myocardium must occur in the correct sequence.
C. SA nodal impulses must occur regularly at a rate of 60-100 impulses per minute.
D. The action potential must speed up through the AV node.
D
90
All of the options directly influence the contraction force of the myocardium, except?
A. SERCA pump.
B. Sodium-Calcium exchanger.
C. Gap junctions.
D. Phase 2 of the myocyte action potential.
C
91
What option is accurate regarding the difference between skeletal and cardiac muscle cell contraction?
A. Cardiac and skeletal muscles are both dependent upon gap junctions for action potential propagation.
B. The movement of calcium ions into the sarcoplasm from the extracellular fluid is only necessary for cardiac muscle contraction.
C. Only skeletal cells have T-tubules and a sarcoplasmic reticulum.
D. Cardiac muscle contraction only involves myosin, actin, and tropomyosin.
B
92
If the AV node stopped the action potential process, what part or parts of the ECG would be affected?
QRS complex and T wave.
QRS complex.
T wave and ST segment.
S-T segment.
P wave.
QRS complex, T wave, and ST segment.
P wave and T wave.
QRS complex, T wave, and ST segment
93
Phase 2 of the ventricular myocyte action potential activity would correlate with what portion of the EKG?
PQ segment.
QRS complex (wave).
PR interval.
It is actually hidden on the EKG.
ST segment.
T wave.
ST segment
94
What component is not necessary for cardiac muscle relaxation?
Sodium-Calcium exchanger
SERCA pump
Calcium ATPase pump on the sarcolemma
Ryanodine pump
Ryanodine pump
95
If a medication extended phase 2 of the myocyte action potential, it could be referred to as:
Positive chronotropic.
Positive inotropic.
Negative chronotropic.
Positive dromotropic.
Negative dromotropic.
Negative inotropic.
Positive Inotropic
96
A positive chronotropic effect on the heart would increase its muscle contractility force.
True
False
F
97
Which phase or phases of the myocyte action potential allow for potassium ions to rush out of the cell?
Phase 1, 3.
Phase 0.
Phase 3.
Phase 2.
Phase 4.
Phase 1.
Phase 1, 2, 3.
Phase 0, 3.
Phase 1, 2, 3
98
The Depolarization phases of the nodal cells and myocytes both have sodium ions rush into the cells.
True
False
F
99
Which option would be accurate regarding a negative dromotrophic effect?
A. An extended T wave.
B. A decreased ST segment.
C. A decreased P wave.
D. An increased distance between the P wave and QRS complex
D
100
The QRS complex/wave is associated with Phase 0 of the atrial myocyte action potentials.
True
False
F
101
Which phase or phases of the myocyte action potential is a vital component of myocyte contraction?
Phase 1.
Phase 2.
Phase 1, 2.
Phase 3.
Phase 0.
Phase 1, 3.
Phase 2
102
Which phase of the nodal cell action potential is related to the spontaneous depolarization?
Phase 1.
Phase 4.
Phase 3.
Phase 0.
Nodal cells do not undergo spontaneous depolarization.
Phase 2.
Phase 4
103
The magnitude of the tension developed by myocardial cells is associated with Phase 3 of the action potential process.
True
False
F
104
What option is TRUE regarding action potentials in the myocardium of the heart?
A. Phase 0 in both the nodal cells and myocytes has calcium ions rush into the cell.
B. Only nodal cell action potentials start with a slow depolarization phase that is spontaneous.
C. Only myocytes (contractile cells) undergo action potentials.
D. Both nodal cells and myocytes have a stable resting membrane potential.
B
105
In general
Blood flow = _______/_______
BF = pressure/resistance
106
Define BF
Define Blood perfusion
BF = Movement of blood through a vessel, tissue, or organ, and is usually expressed in
terms of volume of blood per unit of time (ml/min)
Blood Perfusion
= Blood flow through a particular volume or mass of tissue
107
BP is typically measured at what artery?
Brachial artery
108
Systolic pressure
Ventricular contraction
109
Diastolic pressure
Pressure when the ventricles are not contracting
110
Pulse Pressure
Difference between systolic and diastolic blood
pressure • Maximum force/stress forced placed on small
arteries
111
Pulse Rate
Expansion and recoiling effect of the arteries
during systole and diastole • Effect diminishes over distance from the heart
112
Mean arterial pressure (MAP)
Average arterial pressure throughout one cardiac cycle • Average force driving blood into vessels that serve the tissues
MAP = Diastolic Pressure + (Pulse Pressure/3)
Example:
• If BP is 135/90, what’s the MAP?
• MAP = 90 + (45/3) = 105 mm Hg
113
Peripheral resistance
Opposition of blood flow that blood faces in blood vessels
Resistance of the arteries to blood flowing through them
• Pressure is affected by resistance
• Blood flow is affected by both pressure and resistance
114
Pulse pressure is the difference between systolic and diastolic blood
pressure.
• A. True • B. False
T
115
Systolic blood pressure refers to the pressure in the blood vessels when the
ventricles are not contracting.
• A. True
• B. False
F
116
All of the options are associated with peripheral resistance, except?
• A. Blood vessel length
• B. Blood viscosity
• C. Blood flow
• D. Blood vessel diameter
C
117
Name and describe the blood vessel layers. (3)
• Tunica Externa (Adventitia)
• Loose connective tissue
• Adheres vessel to surrounding tissues
• Tunica Media
• Commonly the thickest
• Smooth muscle and collagen fibers
• Strengthens the vessel
• Regulates diameter of blood vessel
• Tunica Interna (Intima)
• Endothelium- single layer squamous epithelium and thin basement
membrane
• Continuous of the endocardium of heart
118
Smallest version of arteries?
Overview
Arterioles
Always tonically active
• Meaning always contracted to some degree • Innervated by the sympathetic nervous system
• α1-Adrenergic Receptors: Cause vasoconstriction
• β2-Adrenergic Receptors: Cause vasodilation
• Only in skeletal muscle
maintenance and tissue perfusion
• Site of highest resistance in the vasculature
• Sympathetic NS
• Myogenic
• Local Factors • Tremendous influence for blood pressure
119
How are arteries innervated by the sympathetic nervous system?
• α1-Adrenergic Receptors: Cause vasoconstriction
• β2-Adrenergic Receptors: Cause vasodilation
• Only in skeletal muscle
120
Describe capillaries what do they consist of?
Nutrient and waste exchange
• Consist only of endothelium and basal lamina
• Single layer of epithelial cells and basement membrane
121
What lipid-soluble substances (O2 and CO2) function within capillaries?
Cross the capillary wall by diffusing through the endothelial plasma membranes
122
How does water-soluble substances (electrolytes) interact with capillaries?
Cross the capillary wall through intracellular clefts (spaces) or through large pores in
the walls of some capillaries
123
T or F
NOT all capillaries have perfusion of blood at all times
T
124
T or F
Most cells are not close to the nearest capillary
F
Most cells are extremely close to
the nearest capillary
125
Name and describe the (three) types of capillaries.
• 1. Continuous Capillaries
I will ask you about this • Most common type in the body
content over and over and over again
*Have intercellular clefts
• Spaces between endothelial cells • Allow smaller molecules to pass through
*Some have pericytes
• Assist with regulating flow of blood through capillary
• 2. Fenestrated Capillaries
*Have filtration pores scattered throughout them
• Allow quick passage of smaller molecules out of capillary but maintain larger ones in
• Commonly found in kidneys, endocrine glands, and GI system
• 3. Sinusoids
• Irregular blood-filled spaces in the liver, spleen, and bone marrow
*Endothelial cells have wide gaps b/w them
• Important to have these large spaces so larger protein molecules can pass through them
123
126
What are capillary beds?
• How capillaries are organized • Supplied blood by an arteriole • Most of the body’s capillary beds are
closed
• Precapillary Sphincter
• Closely tied to the lymphatic system
127
Ideas to reconsider:
• Blood is composed of:
• Formed Elements (Blood Cells); (45%)
• Plasma; (55%)
• Formed Elements (cells)
• Erythrocytes
• Leukocytes
• Thrombocytes
• Plasma
• Water
• Plasma Proteins
• Solutes
• Erythrocytes (RBCs)
• 99% of formed elements
• Carry oxygen
• Hemoglobin
• Heme
• Globin
• Role of iron
• Clotting
• Leukocytes (WBCs)
• Immunity function
• Thrombocytes
• Platelets
• Hemostasis process
128
Blood: formed elements overview.
— Leukocytes = Granulocytes and Agranulocytes
Neutrophils are majority of our innate immune system (first responders)
Lymphocytes = Antigen and antibody reaction; Adaptable immune system
129
Blood components: Plasma
- water (92%)
- Solutes (1%)
- Plasma protiens (7%)
Name the three Plasma proteins.
1. Albumin (54%)
Most abundant of the plasma proteins
• Made by the liver
• Helps to transport molecules in blood
• Most significant contributor to the osmotic pressure of blood
2. Globulins (38%)
• Alpha, beta, and gamma globulins
• Alpha and Beta help transport molecules produced by liver
• Gamma globulins are involved in immunity
• More commonly known as antibodies
3. Fibrinogen (8%)
• Necessary for blood clotting
• Made by the liver
130
Blood Flow: left side of heart
Left Atrium: receives blood from __________ ___________
Pulmonary circuit
• Pulmonary veins
• Oxygenated
131
Left Atrium pumps blood through the Left
_________ _____
Atrioventricular valve
AKA: bicuspid, mitral valve
132
______ ventricle receives blood from the _____ atrium
Left
133
Left Ventricle pumps blood through the ____ _____ into aorta
Aortic valve
- oxygenated
134
_____ transports blood to systemic circuit
Aorta
- gas and nutrient exchange
135
Right Atrium receives blood from the ______ ______
Systemic circuit
• Inferior and superior vena cava
• Deoxygenated
136
_____ _____pumps blood through the Right
Atrioventricular Valve
• AKA: Tricuspid
Right atrium
137
Right Ventricle receives blood from _____ Atrium
Right
138
Right Ventricle pumps blood through the Pulmonary
Valve into the ________ ______
• Deoxygenated blood
Pulmonary artery
139
Pulmonary artery transports blood to ________ _____
Pulmonary circuit
- gas exchange within lungs
140
What type of blood vessel has the highest resistance in the
vasculature?
• A. Capillaries • B. Veins • C. Arterioles • D. Arteries
C
141
What type of capillary has the largest gaps within the endothelium?
Sinusoid capillary
142
What type of plasma protein has an impact on osmotic pressure? How
does it?
Albumin- it increases solute concentration (osmolarity)
143
What is the blood flow through the body and heart?
Describe it
144
three critical variables affecting peripheral resistance of blood flow
• 1. Viscosity (η) of blood
• 2. Vessel length (λ)
• 3. Radius (r) of vessel
145
What is the viscosity of blood?
Thickness of fluids that affects their ability to flow
• Think 50 ml of water compared to 50 ml of honey
• Viscosity of blood is directly proportional to resistance and inversely proportional to flow
146
What are the variables that can influence blood viscosity?
• A) Formed Elements
—Anything that influences erythropoiesis
• B) Plasma Proteins
—Overall concentration of plasma proteins (made by the liver), especially that main
one…that main one?
Albumin
• C) Dehydration
147
Why would blood vessel length influences BF
• Length of a vessel is directly proportional to its resistance
• The longer the vessel, the greater the resistance and the
lower of blood flow
• As an adult- fairly consistent
A) Weight Gain/Loss
• An individual weighing 150 pounds has approximately 60,000
miles of vessels in the body • Gaining about 10 pounds adds from 2000 to 4000 miles of
vessels
• Skeletal muscle has more need for vessels than adipose tissue
148
How does blood vessel radius influence peripheral blood resistance?
Fastest and most significant change to resistance!
• A lot of variables that influence vessel radius • VASOMOTOR of the vessel is the contractile state of the smooth muscle
• Vasoconstriction
• Vasodilation
149
BLOOD VESSEL RADIUS (r) VARIABLES:
*Vasomotor Center
• Located in the Medulla
* Compliance
• The ability of a blood vessel to expand and accommodate increased volume of
blood
• Think metal pipe vs water balloon
• As compliance is reduced: resistance to blood flow is increased
150
What variable has the biggest impact on resistance and blood flow?
Blood vessel radius
151
Describe the relationship of viscosity of blood and blood flow.
Increased viscosity causes increased blood pressure, and decreased
blood flow
152
How could the body change the viscosity of the blood?
Changing blood volume, plasma proteins, or erythrocyte volume
153
Describe the relationship of blood vessel radius and blood flow
Decreased radius causes increased blood pressure, and decreased
blood flow
154
How does blood vessel compliance influence blood flow and pressure?
Decreased compliance causes increases blood pressure and decreased
blood flow
155
You can measure heart rate, identify abnormal rhythms created by ectopic foci on an electrocardiogram.
True
False
T
156
What phase or phases of the myocyte and nodal cell action potential match with the same ion movement into or out of the cell?
Phase 4.
Phase 2.
Phase 3.
Phase 0.
3
157
All of the features are necessary to be labeled as a sinus rhythm, except:
A. SA nodal impulses must occur regularly at a rate of 60 to 100 impulses per minute.
B. Activation of the myocardium must occur in the correct sequence.
C. Must have either a positive or negative dromotrophic stimulus.
D. AP must originate in the SA node.
C
158
This part of the electrocardiogram represents ventricle contraction?
QT interval.
QRS complex.
ST segment.
PQ segment.
ST segment
159
This type of heart block has a consistent, extended PR interval without blockage of the action potential traveling through the AV node.
Second-degree heart block; Type 2.
Third-degree heart block.
First-degree heart block.
Second-degree heart block; Type 1.
First-degree heart block is characterized by a consistently prolonged PR interval (>200 ms), but every atrial impulse is conducted to the ventricles — meaning no dropped beats.
There is no blockage of the action potential, just a delay in conduction through the AV node.
160
Three Main Factors That Influence Blood Pressure
1. Autoregulatory mechanisms
Autoregulation refers to the ability of tissues to regulate their own
blood flow
• Chemical signals work at the level of the precapillary sphincters to
trigger either vasoconstriction or vasodilation
2. Neural
Baroreceptors: Cardiovascular Centers: Regulates HR
* Provides input regarding changes in BP (MAP)
• As BP increases, rate of AP increases
• Found in the carotid sinus and aorta
• Negative feedback loop- part of what concept?
• Short-term influence on BP
Chemoreceptors: Vasomotor Center: Regulates BP
* Provide input on changes with primarily pH and CO 2 & O2
• Found in the carotid and aortic bodies
• Primary Role
- Adjust respiration rate in changes to blood chemistry (pH) • Secondary Role
- Vasomotor influences
3. Hormonal
Hormones can exert influence on BP via vasomotor and/or water
(plasma) regulation
• Hormones we will discuss:
• Aldosterone
• Antidiuretic Hormone (ADH)
• Natriuretic Peptides (ANP)
• Epinephrine and Norepinephrine
• Adrenaline and Noradrenaline
• Angiotensin II
161
Explain the affects of aldosterone on blood pressure
Mineralocorticoid steroid hormone produced by adrenal
glands
TWO MAIN FUNCTIONS
• Primarily promotes sodium (Na +) ion reabsorption in kidneys
• Leads to secretion of potassium (K+) ions into the urine
Aldosterone gets more sodium into the blood, water follows sodium and this increases BP
162
How does antidiuretic hormone affect blood pressure?
Produced by the hypothalamus and stored in the posterior pituitary
The antidiuretic hormone is secreted out to increase water reabsorption in the kidneys
Increase in water = increase BP
FUNCTION
• Assists in the regulation of plasma osmolarity
• Stimulates the collecting duct in the kidneys to reabsorb water
163
Is ADH secreted in response to hypertonic or hypotonic blood plasma?
Hypertonic to bring down the osmolarity
164
How does atrial natriuretic peptide affect blood pressure?
Synthesized, stored, and released by atrial myocytes in response to atrial
stretch
ANP kicks sodium from kidneys to urine thus water goes into the urine and decrease in BP
FUNCTION
• Reduce arterial pressure by decreasing blood volume and systemic peripheral
resistance
• Primary effect is to stimulate the release of sodium (Na +) from kidneys
165
How do catecholamines affect BP?
What are the catecholamines?
Adrenaline noradrenaline
• Catecholamines bind to adrenergic receptors on smooth muscle of
most blood vessels
• FUNCTION
• Causes vasoconstriction
166
How does Angiotensin II impact BP?
RAAS regulation
1. Blood volume
2. Peripheral Resistance
3. Indirectly influences CO and BP
Important Molecules To This System
1. Renin
2. Angiotensinogen (liver makes this)
3. Angiotensin I
4. Angiotensin II
5. Angiotensin converting enzyme (ACE) (ACE comes from the lungs)
6. Aldosterone
• Renin is secreted by the kidneys due to:
• Renal artery hypotension
• Decreased sodium within the distal tubules of the kidney • Renin Function
• Converts Angiotensinogen to Angiotensin I • Angiotensin I is converted to Angiotensin II by Angiotensin Converting Enzyme
(ACE) • Angiotensin Converting Enzyme (ACE)
• Secreted by endothelial cells primarily in lungs (and kidneys) • Converts Angiotensin I to Angiotensin II
178
167
Angiotensin II Function:
• 1. Stimulate the release of aldosterone
• 2. Directly stimulates kidneys to reabsorb sodium (Na +) ions
• 3. Increases thirst for increased water intake
• 4. Stimulates the release ADH
• 5. Stimulates the Sympathetic Nervous System
168
Blood Vessel Compliance
The ability of a blood vessel to expand and accommodate increased
volume of blood
• Think metal pipe vs water balloon
• As Compliance of a blood vessel decrease ——>BP increases
• Lose compliance in vessels as you age (thank you, time)
169
• 1. Describe the association of autoregulation and hypoxia.
Hypoxia leads to vasodilation
170
Hey, why can you have hypoxia without ischemia, but you can never have
ischemia without hypoxia?
Hypoxia is reduction in O2 levels and ischemia is reduction in BF
171
How do baroreceptors maintain appropriate MAP?
Baroreceptors detected MAP and adjust blood pressure
accordingly
172
Aldosterone causes the excretion of sodium ions and the reabsorption of
potassium ions in the kidneys.
• A. True • B. False
B
Is causes the opposite
173
How does ADH cause increased blood pressure?
Increases water retention within the kidneys and leads to
increased blood volume
174
What is the role of renin in the RAAS?
Converts angiotensinogen to angiotensin I
175
All of the options are necessary to activate angiotensin II, except?
A. Renin.
B. Angiotensinogen
C. Aldosterone.
D. Angiotensin-converting enzyme.
C
176
Fibrinogen is the main plasma protein that influences blood viscosity.
True
False
F
177
All of the options are true regarding blood, except?
A. Most of the plasma is composed of plasma proteins.
B. Fibrinogen assists with the hemostasis process.
C. Albumin assists with molecule transport.
D. Erythrocytes have the highest concentration of formed elements.
A
178
Albumin has a role in molecular transport and colloidal pressure within the blood.
True
False
T
179
What option is TRUE?
A. Arterioles are classified as resistance arteries and assist in blood pressure regulation.
B. The most common type of capillary is the fenestrated capillary, which allows for nutrient exchange.
C. Gamma globulins assist with osmotic pressure.
D Platelets assist with transporting nutrients..
A
180
What statement is accurate regarding blood vessels?
A. Sinusoid capillaries have large and wide intercellular gaps.
B. The tunica interna commonly includes smooth muscle.
C. Distributing arteries (muscular arteries) are the primary site of resistance for blood flow.
D. Arteries and veins both have a thick tunica media layer providing structural support.
A
181
What statement is TRUE?
A. If blood viscosity increases, blood flow increases.
B. If blood volume decreases, blood pressure decreases too.
C. If the vessel radius increases, blood pressure increases.
D. If vessel length increases, resistance decreases.
B
182
What option is TRUE regarding blood pressure?
A. The mean arterial pressure is measured by subtracting the diastolic pressure from the systolic pressure.
B. Renin will convert angiotensin I to angiotensin II.
C. Aldosterone secretion leads to decreased blood pressure.
D. Autoregulation of blood pressure is commonly controlled by hypoxic levels.
D
183
What option best describes pulse pressure?
A. The difference between systolic and diastolic pressures.
B. The average blood pressure in the arteries during a cardiac cycle.
C. It is the expansion of the blood vessel when you are taking an individual's pulse.
D. The variance in systolic pressure from each cardiac cycle.
A
184
All of the options are true regarding blood flow, except?
A. As blood vessel compliance decreases, blood pressure increases.
B. Increased blood vessel length will lead to decreased resistance.
C. Dehydration can change the viscosity of blood.
D. Increased erythrocyte production will lead to decreased blood flow.
B
185
All of the options are true regarding hormonal control of blood pressure, except:
A. Angiotensin II will lead to increased aldosterone secretion.
B. ADH stimulates the increased reabsorption of water and sodium ions.
C. Atrial natriuretic peptide causes the increased excretion of sodium ions into the urine.
D. Norepinephrine secretion will cause an increase of blood pressure.
B
186
If a baroreceptor detects a decrease in mean arterial pressure, then
A. Baroreceptors stimulate the release of aldosterone to increase the blood pressure.
B. It leads to the activation of the parasympathetic nervous system.
C. Baroreceptor action potential formation increases, which stimulates the vasomotor center to activate the sympathetic nervous system.
D. Baroreceptor action potential formation increases, causing an increase in blood pressure.
C
187
What variable has the largest impact on resistance regarding blood flow?
A. Blood vessel length.
B. Radius of blood vessel.
C. Blood viscosity.
D. Albumin levels in the plasma.
B
188
All of the options are functions associated with the circulatory system, except?
Immune support.
Hemostasis.
Actually, all of the options are functions associated with the circulatory system.
Transportation of nutrients and waste products.
Thermoregulation.
All of the options
189
All of the options are an outcome of angiotensin II activation, except?
A. Decreased blood plasma osmolarity.
B. Increased aldosterone secretion.
C. Increased antidiuretic hormone secretion
D. Stimulation of the kidneys to decrease reabsorption of sodium ions.
D
190
Pressure Gradient
Difference of fluid pressure between two locations
• Blood moves from an area of HIGH to LOW pressure
• Down the pressure gradient
191
Stroke Volume (SV)
• Amount of blood ejected from each ventricle
during ventricular contraction
• Default is the left ventricle
• SV = EDV - ESV
192
End Diastolic Volume (EDV
And
End Systolic Volume (ESV)
End Diastolic Volume (EDV)
• The volume of blood in the VENTRICLES right
before contraction
End Systolic Volume (ESV)
• The volume of blood in the VENTRICLES right
after contraction
193
Isovolumetric Contraction
And
Isovolumetric Relaxation
Isovolumetric Contraction
When the ventricles are CONTRACTING and PRESSURE is INCREASING
with NO CHANGES to the volume of blood in ventricles
Isovolumetric Relaxation
• When the ventricles are RELAXING and PRESSURE is DECREASING with
NO CHANGES to the volume of blood in ventricles • Semilunar valves close and right before the AV valves start to open
194
Step of isovolumic ventricular contraction
We are not gaining or losing blood yet because the AV valves closed.
195
Cardiac Cycle Steps **** SLIDES 194-203
196
Ventricular systole and diastole highlights: SLIDES 204-205***look at
197
The S2 heart sound is produced due to increasing pressure within the
ventricles.
• A. True • B. False
B
198
The aortic valve closes due to pressure within the left ventricle
becoming higher than the pressure in the aorta.
• A. True
• B. False
B
199
The ESV measurement occurs during what phase of the cardiac cycle?
Isovolumetric relaxation
200
The S1 heart sound would correlate with what wave on the ECG?
ST segment
201
What are the unique features of isovolumetric contraction?
Ventricle myocytes are contracting but the semilunar and AV
valves are closed- so no change in blood volume
202
S1 =
S2 =
S1 = AV Valve
S2 = are the semilunar valves
203
204
Cardiac output (CO) is the amount of blood pumped from each
ventricle in one minute
• Varies wildly to meet metabolic demands of the body .
Cardiac Output Equation:?
• Stroke Volume (x) Heart Rate = Cardiac Output
• SV x HR = CO
Cardiac Output Example
• 80 mL x 137 bpm – 10,960 mL/minute
• 11.0 liters
205
Stroke Volume (SV)
• The amount of blood pumped from a ventricle with each contraction
• EDV – ESV = SV
206
There are Three Major Variables That Influence Stroke Volume
• 1. Preload
• Stretch on the ventricles prior to contraction
• 2. Contractility
• Force or strength of the contraction
• 3. Afterload
• Force the ventricles must generate to pump blood against the resistance in
the vessels
207
• Preload Affecting Stroke Volume
• Stretch on the ventricles prior to contraction
• Related to the sarcomere length at the end of diastole • All about the EDV and FILLING TIME of the ventricle
• The greater the EDV….the greater the _______
Preload
208
With Increased Ventricular Filling
What happens?
• Preload increases
• Ventricular muscle is increasingly stretched
• Sarcomere length increases
209
What is SARCOMERE STRETCH (TIME OUT)
?? This is referred to as Frank-Starling Mechanism. Why is this important?
• As sarcomeres are stretch, they will contract more forcefully
• There is an optimal length of stretch
Important to understand there is an optimal length/stretch placed upon the sarcomeres that will correlate to the optimal force of contraction
210
T or F
The more EDV, increases the contraction
T
Frank starling mechanism
211
Explain Contractility Affecting Stroke Volume
• The greater the contraction force, the greater the stroke volume
• What happens to ESV?
• Intrinsically: Frank Starling Mechanism
• Extrinsically: Positive and Negative Inotropic Agents
212
What are the positive Inotropic agents of stroke volume- contractility?
• 1. Sympathetic Nervous System
• 2nd Messenger system
• 2. Drugs/actions that increase Calcium (Ca 2+) ion concentration
• Cardiac glycosides
• Digitalis • Inactivation of Sodium/Potassium ATPase pump • Keeps Calcium (Ca 2+) ions within the cell
213
What are the negative Inotropic agents of stroke volume- contractility?
Negative Inotropic Agents
• Parasympathetic Nervous System
• Beta Blockers
• Calcium Channel Blockers
• Hypoxia, hypercapnia (increased CO 2), acidosis
• Lead to a negative inotropic effect
214
What are the two types of hypertension?
Systemic Vascular Resistance
• Resistance of blood flow through all
of the body’s vessels except pulmonary circuit
Pulmonary Vascular Resistance
• Resistance of blood flow through
only the pulmonary circuit
215
How is SV affected if end diastolic volume increases?
SV increases
216
How is is ESV affected if SV increases?
ESV decreases
217
What happens to ESV if SV decreases?
Increases
218
What happens to EDV if SV decreases?
EDV decreases
219
What happens to ESV if SV decreases?
Increases
220
What happens to ESV if SV increases?
Decreases
221
Ejection fraction
Measurement (in percentage) of how much blood is pumped out
with each contraction in the left ventricle
It is a measurement of how well (healthy) the heart is
• Ejection Fraction = Stroke Volume / End Diastolic Volume
• EF = SV / EDV
222
A positive inotropic stimulus will lead to an ________ EDS, a
decreased ESV, leading to _________ SV and increased CO
Increased
Increased
223
All of the options affect stroke volume, except?
• A. Afterload
• B. ESV
• C. Preload
• D. Contractility
B
224
Explain why increased EDV leads to increased cardiac output.
Frank Starling Law
Stretch of sarcomeres which increases the optimisation
225
A negative chronotropic stimulus will increase cardiac output.
• A. True
• B. False
B
226
Hypertension will have what effect on cardiac output and how?
Decreased CO by increasing peripheral resistance and increasing
ESV
227
All of the options are accurate regarding the Frank-Starling law, except?
A. It will influence end diastolic volume (EDV).
B. It will influence stroke volume.
C. All of the options true. None are False.
D. It relates to preload concepts associated with the ventricles.
A
228
All of the options are variables that influence stroke volume, except?
A. Resistance in the blood vessels.
B. Venous blood return to the heart.
C. Stretch placed on the sarcomeres.
D. All of the options affect stroke volume.
D
229
All of the options will increase cardiac output, except?
A. Increased myocardium contractility.
B.Increased venous return.
C.Increase end diastolic volume (EDV).
D. Peripheral resistance.
D
230
If end-systolic volume (ESV) increases, more stretch will be placed on the myocardial cells (sarcomeres) causing them to contract more forcefully.
True
False
F
231
The Frank-Starling law of the heart describes the proportional relationship between which of the following pairs?
A. Stroke volume and cardiac output.
B. Systemic vascular resistance and stroke volume.
C. The blood volume in the atria and stroke volume.
D. End-diastolic volume (EDV) and stroke volume.
D
232
What is true of positive inotropic agents?
A. They will decrease end-systolic volume (ESV).
B. They will increase end-systolic volume (ESV).
C. They will decrease end-diastolic volume (EDV).
D. They will increase end-diastolic volume (EDV).
A
233
What option is accurate for a negative chronotropic agent/stimulation?
A. End diastolic volume (EDV) will increase.
B. Two of the options are accurate.
C. Cardiac output will decrease.
D. Cardiac output will increase
B
234
What option is accurate of increased hypertension (increase afterload)?
A. Increased end-systolic volume (ESV).
B. Decreased end-diastolic volume (EDV).
C. Increased stroke volume.
D. Two of the options are correct.
A
235
When sarcomeres are stretched to their optimal level, what option is accurate?
A. End-diastolic volume (EDV) volume will increase.
B. Two of the options are accurate.
C. The myocytes will contract more forcefully.
D. End-systolic volume (ESV) volume will increase
C
236
End diastolic volume (EDV) is measured:
A. Atrial systole.
B. Ventricle diastole.
C. Right before isovolumetric contraction.
D. Right before isovolumetric relaxation.
C
237
Isovolumetric relaxation phase of the cardiac cycle starts when:
A. Semilunar valves open.
B. Atrioventricular valves close.
C. Atrioventricular valves open.
D. Semilunar valves close.
D
238
Stroke volume is the amount of blood pump out by the atria and ventricles during one contraction?
True
False
F
239
What happens during atrial systole?
A. The atria contract pumping blood into the ventricles.
B. The atrioventricular valves close.
C. Two of the options are correct.
D. The atria fill up with blood.
A
240
What is true about isovolumetric contraction?
A. The pressure in the ventricle increases, but the volume of blood stays the same.
B. Causes the increase of end diastolic volume.
C. The volume of blood increases slowly.
D. Only the semilunar valves are closed.
A
241
What option is true?
A. Semilunar valves close at the beginning of ventricle systole.
B. S1 heart sound is generated during ventricular systole.
C. Atrial diastole is associated with the T wave on the ECG.
D. The QRS complex is directly associated with the isovolumetric contraction phase of the cardiac cycle.
B
242
What part of the heart or body would have deoxygenated blood?
A. Aorta.
B. Pulmonary arteries.
C. Pulmonary veins.
D. Left ventricle.
B
243
What portion of the ECG would be most accurate and associated with isovolumetric relaxation?
A. P wave.
B. PR segment.
C. T wave.
D. QRS complex.
C
244
What produces the S1 heart sounds?
A. Atrioventricular valves closing.
B. Semilunar valves closing.
C. Atrial systole.
D. Semilunar valves opening.
A
245
What is the best definition of the cardiac cycle?
A. One complete sequence of electrical and mechanical events of the heart.
B. The process of heart sounds being generated.
C. The time between two atrial contractions.
D. The period of time between two ventricular systoles.
A
246
The first heart sound (S1) is associated with which of the following events?
A. Opening of the aortic valve.
B. Closing of the semilunar valves.
C. Opening of the AV valves.
D. Closing of the AV valves.
D
247
All of the options would directly affect stroke volume, except?
A. Peripheral resistance in the circuits.
B. Venous return to the heart.
C. Duration of atrial repolarization.
D. End diastolic volume.
C
248
Isovolumetric contraction is associated with what portion of the ECG?
PR interval.
P wave.
ST segment.
PQ segment.
T wave.
QRS complex.
ST segment
249
All of the options would increase cardiac output, except?
A. Positive chronotropic stimulus.
B. Increased ST segment on an ECG.
C. Increased end diastolic volume (EDV).
D. Increased end systolic volume (ESV).
D
250
What option is accurate regarding vasodilation within the systemic circuit (decreased afterload)?
A1. Increased cardiac output.
A. Two of the options are correct.
B. Increased end-systolic volume (ESV).
C. Decreased stroke volume.
D. Decreased end-diastolic volume (EDV).
A1
251
Which option summarizes the Frank-Starling mechanism most accurately?
A. Increased end diastolic volume causes an increased stretch on the sarcomeres of the myocytes, leading to a more forceful contraction.
B. Increased venous returns cause a negative dromotropic effect.
C. Decreased end-systolic volume leads to a more forceful contraction of the ventricular myocytes.
D. Increased end diastolic volume causes increased release of calcium from the sarcoplasmic reticulum.
A
252
All of the following will lead to an increase in cardiac output, except?
A. Decrease EDV.
B. Positive inotropic stimulus.
C. Decrease ESV.
D. Increased HR.
A
253
The S1 heart sounds are associated with a portion of the cardiac cycle or EKG?
A. P wave.
B. Two answers are correct.
C. Isovolumetric contraction.
D. Isovolumetric relaxation.
E. PQ segment
C
254
Why does increasing the duration of Phase 2 of the ventricular action potential increase stroke volume?
A. It will increase the concentration of calcium ions in the sarcoplasm.
B. It enhances sodium influx for depolarization.
C. It decreases afterload on the ventricles.
D. It delays repolarization and slows the heart rate.
A
255
A negative inotropic stimulus on the heart will have what effect?
A. Increased cardiac output.
B. Two of the options are correct.
C. Increased end-systolic volume.
D. Decreased stroke volume.
B
256
The S2 heart sound is associated with what portion of the ECG?
A. QRS complex.
B. PQ segment.
C. T wave.
D. P wave.
C
257
Ventricular systole occurs due to what phase of the action potential?
A.Phase 3.
B.Phases 0, 1, 2.
C.Phase 4.
D.Phase 0.
E.Phase 2.
F.Phase 1.
E
258
End diastolic volume (EDV) of the ventricles is measured during what portion of the cardiac cycle?
A. Right before isovolumetric contraction occurs.
B. Right after isovolumetric relaxation occurs.
C. Right before the AV valves open.
D. Atrial systole.
A
259
What is associated with the isovolumetric relaxation phase of the cardiac cycle?
A. Closure of the AV valves.
B. Diastole of the atria.
C. None of the options are associated with isovolumetric relaxation.
D. Systole of the ventricles.
E. Filling of the ventricles.
C
260
Ejection fraction would increase if end systolic volume (ESV) increases?
True
False
F
261
A positive chronotropic stimulus will increase stroke volume and increase end-systolic volume (ESV).
True
False
F
262
Microcirculation
• The flow of blood within the smallest blood vessels, the capillaries, and associated lymphatic vessels
263
Mechanisms of Movement Through Capillary Walls (4)
1. Diffusion:
LIPID SOLUBLE MOLECULES
• Solutes and gases readily cross the capillary wall by diffusing through the
endothelial cells
• Down their concentration gradient
• Oxygen, carbon dioxide, steroid base molecules
WATER SOLUBLE (non-lipid soluble)
Cannot cross the endothelial cell membranes
• Pass through the intercellular clefts/fenestrations (filtration pores) down
their concentration gradient • Water, glucose, electrolytes
2. Transytosis
3/4. Filtration and Reabsorption
• Filtration
—Fluid and solutes are filtered (pushed) out of the capillary on the arterial side
• Reabsorption
— Fluid and solutes are reabsorbed (pushed) back in the capillary on the venule side
***Driven by Two Forces/Pressures/Gradients
1. Hydrostatic pressure 2. Osmotic pressure (colloidal pressure)
**Referred To As The Starling Forces
• Movement of fluids between the microvasculature and
interstitial space • Determined by the balance of hydrostatic and osmotic
pressure gradients
264
What are the two forces/pressures/gradients that are involved in filtration and reabsorption?
*these forces oppose each other
1. Hydrostatic pressure (blood pressure) = Filtration
2. Osmotic pressure (colloidal pressure) = reabsorption
265
T or F
On the arterial end of the capillary the hydrostatic pressure is higher, and on the opposite side (venous end of capillary) the pressure is lower
T
Because on with the higher pressure we need to push things out and reabsorb on the osmotic side
266
T or F
The hydrostatic pressure decreases from arterial side of capillary to venous and the osmotic pressure increases
F!!
Hydrostatic pressure decreases but osmotic pressure stays the same
267
What is the net filtration pressure (NFP)
The difference between Hydrostatic Pressure and Osmotic Pressure
in capillary
Determines the movement of water
268
Hydrostatic pressure is related to the blood pressure of the
capillary.
• A. True • B. False
T
269
Formed elements have a role within colloidal pressure.
• A. True
• B. False
B,
Bc white and red blood cells/platelets, but albumin and plasma proteins do
270
Describe the difference between hydrostatic pressure and
osmotic pressure.
Hydrostatic pressure (think blood pressure) allows for filtration.
Osmotic pressure (think osmosis- high to low movement of water)
allows for reabsorption within the capillaries (from ISF back into
capillaries)
271
Lymphatic System
• Network of vessels
• Tissues and organs that support immune cells and function
• Lymph Nodes • Spleen • Tonsils • Thymus • Red bone marrow
272
T or F
Lymphatic vessels are found in cartilage, bone tissue, and bone marrow, eye
F
Penetrate and are found in nearly
every tissue of the body
• Not found in cartilage, bone tissue,
bone marrow, eye
273
Lymphadenopathy
Inflammatory lymph node
274
Eventually, filtered lymphatic fluid is dumped back into _____ _____, specifically the
subclavian vein
Venous system
275
Roughly only about ___%of the fluid that is loss due to hydrostatic
pressure is reabsorbed
85%
15% is not reabsorbed
276
• Edema is the accumulation of excess fluid in within tissues
• Is caused when there is more fluid filtered out of the capillaries that is being
reabsorbed back into the capillaries or lymphatics
Edema Has Four Main Causations:
• 1. Increased hydrostatic pressure
• 2. Reduced osmotic pressure
• 3. Lymphatic obstruction
• 4. Increase vascular permeability (inflammation)
277
What are the functions of the lymphatic system?
There are 3 functions- one oddball function till we get to the
digestive system
278
Explain the role of a lymph node.
Filtering what? Lymph
Activation of what? Immune system
279
How does deep vein thrombosis lead to edema?
Increased hydrostatic pressure
280
How can liver disease lead to edema?
What does the liver make that can influence colloidal pressure?
*loss of liver means loss of albumin and thus we loose osmolarity and the concentration of high and low pressures will be lower = more water stays outside of the vessel
281
What is the best definition of microcirculation?
A. The movement of blood through the arterioles, capillaries, and venules
B. The circulation of blood through the heart and lungs
C. The oxygenation of blood in the lungs
D. The filtration of blood in the kidneys
A
282
Which of the following is NOT one of the four mechanisms of movement across capillaries?
A. Active transport
B. Vesicular transport
C. Diffusion
D. Filtration
A
283
How do lipid-soluble molecules like oxygen typically move through capillary walls?
A. By vesicular transport
B. Through tight junctions
C. Through fenestrations
D. Through endothelial cell membranes
D
284
Water-soluble molecules pass through capillary walls primarily by:
A. Osmosis across tight junctions
B Passing through intercellular clefts or fenestrations
C. Diffusion through the lipid bilayer
D. Endocytosis
B
285
What drives filtration at the arterial end of a capillary bed?
A. High osmotic pressure
B. High hydrostatic pressure
C. Lymphatic suction
D. Low hydrostatic pressure
B
286
What causes reabsorption at the venule end of capillaries?
A. Arteriole constriction
B. Decreased blood volume
C. Increased blood osmotic pressure
D. Increased tissue hydrostatic pressure
C
287
Which of the following best describes net filtration pressure (NFP)?
A. The reabsorption capacity of kidney nephrons
B. The speed at which blood moves through arteries
C. The balance between hydrostatic and osmotic pressures
D. The pressure in lymphatic vessels
C
288
Hydrostatic pressure is influenced by:
A. Concentration of plasma proteins
B. Capillary osmotic strength alone
C. Lymphatic drainage only
D. Arterial pressure and capillary wall tension
D
289
Osmotic pressure in microcirculation is primarily generated by:
A. Carbon dioxide levels
B. Red blood cells
C. Plasma proteins like albumin
D. Water movement across membranes
C
290
What is the main function of the lymphatic system in fluid balance?
A.Generating ATP
B. Returning excess interstitial fluid to the bloodstream
C. Filtering electrolytes from blood
D. Synthesizing plasma proteins
B
291
Where are lymph nodes typically located?
A. Inside cardiac muscle
B. Only in the gastrointestinal tract
C. Along lymphatic vessels in areas like the neck, armpits, and groin
D. Inside bone marrow only
C
292
Which best describes the function of lymph nodes?
A. Generating nerve impulses
B. Synthesizing hormones
C. Transporting oxygen
D. Filtering lymph and housing immune cells
D
293
How does the lymphatic system support microcirculation?
A. By collecting and returning excess interstitial fluid
B. By producing red blood cells
C. By breaking down waste products
D. By storing nutrients
A
294
What is edema?
Thickening of arterial walls
Rupture of a lymphatic vessel
Accumulation of fluid in tissues
An infection in lymph nodes
Accumulation of fluid in tissues
295
Increased capillary hydrostatic pressure can cause:
Dehydration of surrounding tissue
Lymph node enlargement
Reabsorption of water into blood
Fluid movement out of capillaries into tissue
Fluid movement out of capillaries into tissue
296
Which best explains why low plasma protein levels can lead to edema?
A. They reduce osmotic pressure that pulls fluid back into capillaries
B. They increase blood viscosity
C. They block lymphatic return
D. They lower capillary hydrostatic pressure
A
297
All of the options are functions of the lymphatic system, except?
A. Assist with the absorption of lipids within the digestive system.
B. Assist with filtering the plasma of the blood.
C. Assist in immune function.
D. All of the options are associated with functions associated with the lymphatic system
D
298
How do lipid-soluble molecules like oxygen typically move through capillary walls?
Through tight junctions.
Through fenestrations.
By vesicular transport.
Through endothelial cell membranes
D
299
All of the options are variables affecting a capillary's ability to filter fluids into the surrounding tissues, except?
A. Increased blood pressure.
B. Increased production of albumin.
C. All of the options would affect a capillary's ability to filter fluids.
D. Increased water volume of blood.
B
300
All of the options are true regarding lymph nodes, except?
A.Can undergo inflammation upon infection.
B.Assist with filtering lymph fluid.
C.They are only found in a few areas of the body.
D.Assist with immune cell activation.
C
301
The hydrostatic pressure increases and the osmotic pressure decreases as blood flows from the arteriole to the venule side of the capillary.
True
False
F
302
All of the options can lead to edema, except?
Liver disease.
increased hydrostatic pressure.
Inflammation.
Increased erythrocyte production.
Lymphatic vessel obstruction.
D
303
Assuming a normally functioning lymphatic system, how would a venous thrombosis (increased venous pressure) lead to:
Decreased reabsorption of fluids from surrounding tissues.
Decreased filtration of fluids into surrounding tissues.
Increased filtration of fluids into surrounding tissues.
Increased reabsorption of fluids from surrounding tissues.
C
304
A hypertonic plasma solution within the venule side of the capillary would cause:
Decreased reabsorption of fluids from surrounding tissues.
Increased filtration of fluids into surrounding tissues.
Decreased filtration of fluids into surrounding tissues.
Increased reabsorption of fluids from surrounding tissues.
D
305
This type of capillary is most commonly found throughout the body and intercellular clefts that allow for filtration and reabsorption processes.
Filtrated capillary.
Continuous capillary.
Sinusoid capillary.
Fenestrated capillary
B
306
What causes reabsorption at the venule end of capillaries?
Arteriole constriction.
Higher blood osmotic pressure.
Decreased blood volume.
Increased tissue hydrostatic pressure.
B
