Adult Cardio 1 (Normal anatomy and physiology of the cardiovascular system) Flashcards
1
Q
What are the two purposes of the circulatory system?
A
-To deliver oxygen, nutrients, and other substances to all the body’s cells
-To remove the waste products of cellular metabolism
2
Q
Delivery of oxygen and nutrients, as well as the removal of waste, is achieved by a complex array of tubing (___ ___) and a pump (the ___)
A
Blood vessels, heart
3
Q
Cardiovascular function is ____ and ____, with cooperation from other systems, specifically the nervous system and endocrine system
A
Continuous; automatic
4
Q
Nutrients and oxygen are supplied by the ____ and ____ systems
A
Digestive; respiratory
5
Q
Gaseous waste is removed by the ____
A
Lungs
6
Q
Other waste products are removed by the ___ and ___
A
Liver and kidneys
7
Q
The heart structures are categorized by what 3 functions?
A
-Structures that support the circulation of pulmonary and systemic blood flow through the heart
-Structures that maintain the cells of the heart
-Structures that stimulate and control the heart action
8
Q
What structures support the circulation of pulmonary and systemic blood flow through the heart?
A
-Heart wall and fibrous skeleton
-Valves
-Great vessels
9
Q
What structures maintain the cells of the heart?
A
-Vessels of the coronary circulation
-Lymphatic vessels of the heart
10
Q
What structures stimulate and control the heart action?
A
Nerves and specialized muscle cells that direct rhythmic contraction and relaxation of heart muscles
11
Q
The heart is shaped as a quadrangular pyramid and is orientated as if the pyramid has fallen onto one of its sides so that its base faces the ___ ___ ___ and its apex is pointed towards the ___ ____ ____
A
-Posterior thoracic wall
-Anterior thoracic wall
12
Q
The anterior surface of the heart contains almost all of the ___ ___
A
Right ventricle
13
Q
The inferior surface of the heart is also known as the ____ surface
A
Diaphragmatic
14
Q
The inferior (diaphragmatic) surface of the heart contains…
A
Mostly right ventricle and some of the left ventricle
15
Q
The right lateral surface of the contains the ___ ___
A
Right atrium
16
Q
The left lateral surface of the heart contains…
A
The left ventricle and a small part of the left atrium
17
Q
The posterior surface of the heart contains…
A
The left ventricle and most of the left atrium
18
Q
The broad end of the heart (base) is _____, while the tip (apex) is ____
A
Superior; inferior
19
Q
Since the heart sits on the diaphragm, it can cause symptoms like ___ and ___
A
Nausea/vomiting
20
Q
The heart is rotated ___ and ___
A
Laterally, inferiorly
21
Q
The apex of the heart lies under the ___ ___
A
Left nipple
22
Q
Most of the left ventricle is back under the ___ and towards the ___
A
Arm, back
23
Q
The ____ is the membrane that separates the right and left ventricle
A
Septum
24
Q
The ____ is the outermost layer of the heart
A
Epicardium
25
The ____ is the middle layer of the heart
Myocardium
26
The ____ is the inner surface of the heart
Endocardium
27
The ___ ____ ____ prevents friction from the heart beating (acts as lubricant)
Pericardial cavity fluid
28
With too much pericardial cavity fluid, the heart would not be able to ____
Pump
29
The ____ layer encapsulates the heart in the chest and separates it from the lungs
Parietal
30
Layers of the heart (starting with the outermost layer):
-Fibrous pericardium
-Parietal layer of pericardium
-Pericardial cavity
-Epicardium
-Myocardium
-Endocardium
-Heart chamber
31
The heart wall contains what layers?
-Epicardium
-Myocardium
-Endocardium
32
A heart contains how many chambers?
4 (2 upper, 2 lower)
33
The upper chambers contain...
-Right atrium
-Left atrium
34
The role of the upper chambers is to...
Recieve incoming blood
35
The lower chambers are more muscular and contain...
-Right ventricle
-Left ventricle
36
The role of the lower chambers is to...
Pump blood out of the heart
37
The role of the right atrium:
Receives oxygen-poor blood from the body and pumps it to the right ventricle
38
The role of the right ventricle:
Pumps oxygen-poor blood to the lungs
39
The role of the left atrium:
Receives oxygen-rich blood from the lungs and pumps it to the left ventricle
40
The role of the left ventricle:
Pump oxygen-rich blood to the body
41
The ___ ventricle is thicker than the ____
Left; right
42
The left ventricle is a ___-___ system
High-pressure
43
The left ventricle has ____ contractions
Concentric (more round)
44
The right ventricle is a ___-___ system
Lower-pressure
45
The right ventricle has ____ contractions
Bellows
46
The ____ ventricle has more workload because it has to pump blood further/harder
Left
47
The left ventricle is more ____, so it will generate a strong pressure even with little effort
Circular
48
The right ventricle is more ____ and causes a bellow contraction
Angular
49
The left ventricle pumps blood to the rest of the body, so it needs more ____
Pressure
50
If you want blood to pump from left to right, we need to have more pressure on the ____
Left
51
Blood flows in circulation not only because of the beating of the heart, but because it is a continuous cycle of ___ ____ on one side and ___ ___ on the other side
High pressure; low pressure
52
Heart ____ are parts of your heart that act like doors by opening and closing to let blood flow from one area of the heart to another
Valves
53
Valves help ensure that blood moves at the right ___ and in the correct ____
Time; direction
54
What are the four valves of the heart?
-Aortic valve
-Mitral valve
-Pulmonic valve
-Tricuspid valve
55
Step 1 in the route of blood:
Blood that needs oxygen flows from your body into the right atrium
56
Step 2 in the route of blood:
The blood flows through the tricuspid valve to the right ventricle
57
Step 3 in the route of blood:
The right ventricle pumps the blood through the pulmonary valve and into your lungs, where it picks up oxygen
58
Step 4 in the route of blood:
The oxygen-rich blood then flows to the left atrium
59
Step 5 in the route of blood:
The heart pumps through the mitral valve into the left ventricle
60
Step 6 in the route of blood (last step)
From the left ventricle, the blood flows through the aortic valve to the rest of your body
61
The Tricuspid valve has 3 leaflets, which are:
-Anterior
-Posterior
-Septal
62
The tricuspid valve and its leaflets allow blood to flow from the ___ ___ to the ___ ___
Right atrium to right ventricle
63
The tricuspid valve also prevents blood from flowing ____
Backward
64
What are the three leaflets of the pulmonary valve?
-Right
-Left
-Anterior
65
The pulmonic valve and its leaflets allow blood to pump from the ___ ____ to the ___ ____
Right ventricle; pulmonic artery
66
The pulmonic artery leads to the ____ where the blood picks up oxygen
Lungs
67
The pulmonic valve also prevents blood from flowing ____
Backward
68
What are the two leaflets of the mitral valve?
-Anterior
-Posterior
69
The mitral valve and its leaflets allow blood to flow from the ____ into the ___ ___
Lungs; left atrium
70
The mitral valve and its leaflets also prevent blood from flowing ___
Backward
71
What are the three leaflets of the aortic valve?
-Right
-Left
-Posterior
72
The aortic valve and its leaflets open to let blood flow from your heart's ___ ____ to the ___
Left ventricle; aorta
73
The ____ is the largest blood vessel in your body
Aorta
74
The aorta brings ____ ____ from your heart to the rest of the body
Oxygenated blood
75
The aortic valve prevents blood from flowing ___
Backward
76
When the heart is enlarged, the muscles are going to stretch and pull the leaflets open which causes blood to squeeze back and cause a ____ by moving backward
Leak
77
Both the left coronary artery and the right coronary artery start at the ___ ____
Aortic arch
78
The right coronary artery supplies blood to the ___ ___ and ___ ___
Right atrium and right ventricle
79
Branches of the right coronary artery supply the ____ node and the ____ node
-Sinoatrial (SA)
-Atrioventricular (AV)
80
The sinoatrial and atrioventricular nodes send ___ ___ through your heart
Electrical signals
81
Branches of the right coronary artery also deliver blood to 1/3 of the _____ ____, which is the wall between the heart's 2 chambers
Interventricular septum
82
The left coronary artery supplies blood to your ___ ___ and ___ ____
Left atrium and left ventricle
83
The left coronary artery is where ___ ___ arrives from your lungs before your heart pumps it out to the rest of the body
Oxygenated blood
84
Branches of the left coronary artery supply blood to the other 2/3 of your ___ ___
Intraventricular septum
85
The coronary veins return deoxygenated blood from the myocardium back to the ____ ____
Right atrium
86
Coronary venous anatomy is highly variable, but it is generally comprised of what three groups?
-Cardiac veins
-Anterior cardiac veins
-Venae cordis minimae
87
Cardiac veins drain into the ___ ___
Coronary sinus
88
Cardiac veins that drain into the coronary sinus include...
-Great cardiac vein
-Middle cardiac vein
-Small cardiac vein
-Posterior vein of the left ventricle
-Vein of Marshall
89
Anterior cardiac veins drain directly into the ___ ___
Right atrium
90
The venae cordis minimae are the smallest cardiac veins and they drain directly into all four chambers, but are more frequent int the ___ ___
Right atrium
91
Takeoff of coronary arteries is immediately beyond the ___ ___ in the aorta
Aortic valve
92
The ___ ___ has minimal blood flow during systole (when aortic valve leaflets open)
Coronary Ostia
93
The coronary artery fills with blood during ____
Diastole
94
___ ____ peaks during diastole
Coronary circulation
95
____ occurs when the heart contracts to pump blood out to the rest of the body
Systole
96
Diastole is when the heart relaxes after ____ and blood comes back to the heart to refill it before it contracts again
Contraction
97
Coronary blood flow is approximately ____ cc/min (4-5% of total CO)
225
98
Coronary blood flow ____ in systole
Decreases
99
Coronary blood flow ____ in diastole
Increases
100
Coronary blood flow is greatest during ___ ___
Early diastole
101
If diastolic time is shortened, coronary flow is ____
Decreased
102
Coronary artery blood flow moves from ____ to ____ surfaces
Epicardial to endocardial
103
Epicardial coronary artery blood flow is impinged by ___ ___, affecting subendocardial vessels the greatest
Cardiac contraction
104
____ is where the most work happens within the heart
Systole
105
We want blood to flow from the ___ down to the ___
Myocardium, epicardium
106
Blood flows on the surface first, and then through the arteries to get to the epicardium, meaning that the epicardium is ____ last
Oxygenated
107
If we do not have enough oxygen, the epicardium will get oxygenated before the ____, leaving it with no oxygen
Endocardium
108
In ____, there is low pressure with maximum blood flow in intra-myocardial vessels
Diastole
109
In ____, there is a circumferential squeeze around intra-myocardial vessels
Systole
110
Tachycardia is harmful because you are spending more time in ___
Systole
111
___ ____ are given to those with tachycardia to slow heart rate
Beta-blockers
112
What are the two main mechanisms in which coronary blood flow is controlled?
1. Coronary supply
2. Myocardial demand
113
Coronary supply is regulated almost exactly in proportion to the need of ___ ____ (supply=demand)
Cardiac musculature
114
Even in a resting state, __-__% of oxygen is extracted from blood in coronary circulation
65-75%
115
To increase oxygen availability, blood flow must ___
Increase
116
What must happen to increase delivery of oxygen?
-Increase heart rate
or
-Increase arterial diameter
or both
117
Possible mechanisms for coronary artery dilation in response to increased oxygen needs:
-Release of adenosine by myocardial cells
-Release of other vasodilator substances (K+, H+, CO2, bradykinin, PGE)
-Relaxation of vessel walls in response to oxygen deficiency
-Nervous control of coronary blood flow
118
The parasympathetic nervous system has ___ inflence on coronary blood flow
Negligible
119
The sympathetic nervous system can heavily influence coronary blood flow by causing what two things?
-Epicardial vessel preponderance of alpha receptors
-Intramuscular vessel preponderance of beta receptors
120
___ ___ is determined more by intraventricular pressure than by work of the heart
Myocardial demand
121
____ ____ is not as closely related to the work of the heart as it is to the increase in pressure
Oxygen consumption
122
___ ____ ____ is the primary determinant of oxygen consumptions
Peak muscle tension
123
Heart chamber ____ (even in diastole) results in increased muscle tension
Dilation
124
La Place's Law states that wall tension is ____ related to the product of intraventricular pressure and internal radius, and ____ related to wall thickness
Directly, inversely
125
La Place's Law Formula:
(Pressure x radium)/(2 x wall thickness)
126
A network of specialized muscle cells found in the heart's walls send signals to the rest of the heart to cause contraction; this group of muscle cells is known as the ___ ____ ____
Cardiac conduction system
127
What are the 5 main parts of the cardiac conduction system?
-SA node
-AV node
-Bundle of HIS
-Bundle branches
-Purkinje fibers
128
Within the cardiac conduction system, the ___ ___ starts the sequence by causing the atrial muscle to contract
SA Node
129
Since the SA node starts the contraction, many times it is referred to as the ___ ___
Anatomical pacemaker
130
After the SA node causes contraction of the atrial muscles, where does the signal continue to travel?
-To the AV node
-Through the bundle of HIS
-Down the bundle branches
-Through the Perkinje fibers (causing the ventricles to contract)
131
Cardiac myocytes are composed of myofibrils that contain ____
Myofilaments
132
Myofibrils have distinct, repeating units called ____ which represent the basic contractile units of the myocyte
Sarcomeres
133
The sarcomere is defined as the region of microfilament structures between two ___-___
Z-lines
134
The sarcomere is composed of thick and thin filaments called ___ and ___
Actin and myosin
135
Chemical and physical interactions between the actin and myosin cause the sarcomere length to shorten, and therefore the myocyte to ____ during the process of excitation-contraction coupling
Contract
136
The interactions between actin and myosin serve as the basis for the ___ ___ theory of muscle contraction
Sliding filament
137
Electricity in the heart comes from what three things?
-Sodium
-Potassium
-Polarity (more sodium outside, more potassium inside)
138
The inside of the cell is negatively charged so the membrane has ___ ____
Action potential
139
What two ions mainly exist in the extracellular space (outside of the cells)?
-Sodium
-Calcium
140
When the membrane of a cell becomes permeable, sodium and calcium rush into the cell and give it a large ____ charge (potassium has the opposite effect)
Positive
141
Once the ventricle is stimulated, there is an impulse that would cause a ___-___ ion channel to open and sodium to rush in
Voltage-gated
142
When sodium rushes in, it ____ the cell and causes a positive charge inside the cell and a negative charge on the outside of the cell
Depolarizes
143
____ recognizes the change in polarity of the cell (caused by sodium) and will come into the cell and send potassium out to bring the membrane potential/polaity closer to resting (negative)
Calcium
144
The calcium controls everything and is a ____
Messenger
145
Once inside the cell, calcium goes to the ____ ____ to tell it to release its stores of calcium which causes lots of calcium in the cytoplasm
Sarcoplasmic reticulum
146
Calcium acts on actin as a messenger which opens the gate and causes the ____ and ____ to get shorter
Myosin, sarcomere
147
Once the sarcomere has contracted, the sarcoplasmic reticulum basically collects the ____ back
Calcium
148
The cardiac muscle tissue is also known as the ____
Myocardium
149
When a cardiac muscle cell contracts, the ___ filaments pulls the ____ filament toward each other, causing the cell to shrink
Myosin; actin
150
A single myosin filament connects to ___ actin filaments on either side; this unit is what makes up a sarcomere
2
151
Intercalated discs connect cardiac muscle cells and ____ ____ relay electrical impulses from one cardiac muscle cell to another
Gap junctions
152
____ are structures present within intercalated discs that hold cardiac muscle fibers together
Desmosomes
153
The ____ is the cell membrane of muscle cells and is made up of longitudinal units
Sarcolemma
154
___ ___ are extensions of cell membranes into cells and allow for the transmission of action potential into the depths of cells
Transverse tubules
155
The ___ ____ is located around the myofibrils; when an action potential is transmitted through the transverse tubules, this releases its stored calcium which activates actin and myosin
Sarcoplasmic reticulum
156
Actin and myosin filaments are composed of ____ protein molecules
Polymerized
157
Actin and myosin lie __ by ___, with approximately 1500 myosin and 3000 actin filaments per myofibril
Side by side
158
Actin filaments are very ___
Thin
159
Myosin filaments are thicker and contain ___ ___ ___
Hinged cross bridges
160
Actin and myosin partially interdigitate, causes the myofibril to have alternate ___ and ___ bands
Light and dark
161
Actin filaments are attached to a ___ ___/___
Z membrane/disk
162
Z membranes pass from myofibril to myofibril, attaching them to each other and forming __ ___
Z bands
163
The ___ filaments reside between the actin filaments
Myosin
164
The potion of the myofibril that lies between two successive Z bands is a ___
Sarcomere
165
In the relaxed state, the ends of the actin filaments from two successive Z membranes barely ____, while at the same time completely covering the myosin filaments
Overlap
166
In the contracted state, the actin filaments are pulled inward along the ___ ___ so that they overlap each other to a major extent, and the Z membranes are pulled inward until they touch the myosin filaments
Myosin filaments
167
Each myosin filament is a coil of 2 chains wrapped around each other; at the end of each chain is a ___ ___ that looks like a two-headed golf club (called the head)
Globular region
168
Myosin molecules are combined into ____, which are stalks of myosin from which the heads protrude at regular intervals
Filaments
169
In the resting muscle, the myosin binding sites are covered by ____ and ____
Troponin and tropomyosin
170
When the action potential reaches the muscle cell, ___ ___ carry the message deep into the sarcoplasm where the sarcoplasmic reticulum releases calcium
Transverse tubules
171
Once calcium is released, it binds to ____ which makes tropomyosin move to uncover the myosin binding site
Troponin
172
Then, the myosin heads bind to actin filaments to create ___-___ between the myosin and actin binding sites to cause contraction
Cross bridges
173
The combined effects of actin-myosin interactions within all of the myofibrils produce muscle ____
Contraction
174
5 steps of actin-myosin interactions leading to contraction:
-Calcium binds to troponin, leading to a conformational change that displaces tropomyosin from the actin binding sites
-Crossbridge formation occurs with ATP hydrolyzed into ADP+P
-Power stroke moves actin filament toward the center of the sarcomere; ADP+P are now released from the myosin heads
-Actin released with ATP binding to myosin. Myosin heads cocked back into firing position, ready to make crossbridges further downstream
-The cycle continues until calcium levels decrease, allowing calcium to dissociate from troponin. Tropomyosin returns to original conformation that blocks actin binding site.
175
During contraction, there is progressively ___ overlap of the actin and myosin which causes the dark bands tp get darker
More
176
____ is the main regulator of contraction
Calcium
177
How does calcium initiate muscle contraction?
-Calcium enters the cell and goes to the sarcoplasmic reticulum
-Calcium-induced calcium release from sarcoplasmic reticulum
-Calcium binds to troponin to cause tropomyosin to move away from actin binding site
178
How does calcium cause muscle relaxation?
-Cessation of inward flow of calcium
-Uptake and storage of calcium into the sarcoplasmic reticulum (active transport)
-Drop in intracellular calcium
179
The composition of ___ and ____ ions in myocardial cells is different
Intracellular, extracellular
180
At rest, the internal cellular environment is more ____ charged as compared to the external environment
Negatively
181
Substances can travel through the cell membrane by what two methods?
-Assisted diffusion (mediated transport)
-Active transport
182
With assisted diffusion, you can have either ___ or __ __ ___ __
Pores, voltage-gated ion channels
183
What are two examples of active transport?
-Sodium potassium pump
-Sodium calcium pump
184
At baseline, the sodium-potassium pump maintains a ___ charge inside the myocardial cell
Negative
185
The ____ of the membrane to the ions determines the electrical environment of the cell
Permeability
186
At rest, the membrane integrity is such that only a slight movement of the ions is permitted, so the relative ___ charge of the internal environment is preserved
Negative
187
Upon stimulation, the voltage-gated pores on the cell membrane are activated such that the permeability to ___ and ___ are changed; this causes assisted-diffusion to occur, resulting in elctropositivity in the cell
Sodium and potassium
188
Next, the ___ ___ ___ will be activated
Active transport pumps
189
Upon stimulation, the influx of sodium through the inward sodium channels reverses the ____ of the cell
Polarity
190
The reverse polarity triggers the influx of potassium through the outward potassium channels, which ____ polarity
Restores
191
What are the 4 phases of an action potential?
-Depolarization
-Plateau
-Final Repolarization
-Return to RMP
192
What happens during the depolarization phase of an action potential?
-Sodium influx
-Cell interior becomes more positive
-At threshold, fast channels open causing a rush of sodium inward with briefly allows the cell to become more positive than the outside
193
What happens during the plateau phase of an action potential?
-Rapid influx of sodium is terminated
-Sodium-potassium and sodium-calcium pumps become active
-Calcium entering the cell stimulates further release of calcium from sarcoplasmic reticulum causing contraction
194
What happens during the final repolarization phase of an action potential?
-Preventing further inflow of sodium and calcium
-Continues potassium efflux out of the cell
-Intracellular environment becomes more negative
-Reestablish resting membrane potential
195
What happens during the 4th and final phase of an action potential?
-Final cleanup of sodium by the sodium-potassium pump
-Intracellular calcium restored by active transport to the sarcoplasmic reticulum (needs magnesium)
196
What are the 4 steps of signal propagation?
1. Sinus node impulse
2. Impulse passes through atrioventricular node
3. Ventricular impulses
4. Recovery
197
The ____ period is the period following depolarization during which no ew cardiac action potential can be initiated by a stimulus
Refractory
198
The ____ (absolute) refractory period corresponds to the time needed for the reopening of channels that permit sodium and calcium influx (phase 0 through half of phase 3)
Effective
199
The ____ refractory period occurs near the end of repolarization (following the effective refractory period); during this time, the membrane can be depolarized again, but only by a greater than normal stimulus
Relative
200
The phases of depolarization and repolarization occur somewhat differently in the ___ and ____ nodes; this allows these cells to generate action potentials independently and automatically
SA and AV
201
Depolarization begins with a less ___ resting membrane potential, then proceeds to a slow upstroke (Phase 0) and usually lack a plateau phase (phase 2)
Negative
202
There is also a ___ ___ ___ mediated by calcium (transient and long-lasting channels) and sodium ions flowing through "slow channels" of the cell membrane are responsible for the action potential of the SA and AV nodes
Slow inward current
203
A take home message is that cardiac output is the result of the synchrony between ___, ____, and ____ events of the heart
Cellular, electrical, mechanical
204
Stroke volume is governed by what two things?
-Entropy
-Preload
205
At a heart rate of 75 BMP, ___ seconds are spent in systole and ___ second in diastole for each minute
23; 37
206
____ time is constant, therefore as heart rate increases, ____ decreases
Systolic; diastolic
207
At heart rate of 120 BMP, there is ___ seconds spent in systole and ____ seconds spent in diastole
36; 24
208
____ compromises diastolic time and reduces vascular circulation
Tachycardia
209
___ ____ is the amount of blood ejected by the heart per beat (mL)
Stroke volume
210
___ ___ is the total volume of blood ejected per minute (L/min)
Cardiac output
211
___ ___ is the amount of blood ejected in relation to the total amount available (%)
Ejection fraction
212
___ ____ explains how cardiac output is adjusted for body surface area (L/min/m^2)
Cardiac index
213
Formula for calculating cardiac output:
CO= stroke volume x heart rate
214
____ is the volume of blood in ventricles at the end of diastole (end diastolic pressure)
Preload
215
What conditions can increase preload?
-Hypervolemia
-Regurgitation of cardiac valves
-Heart failure
216
____ is the resistance that the left ventricle must overcome to circulate blood
Afterload
217
What conditions may increase afterload?
-Hypertension
-Vasoconstriction
218
An increased afterload causes an increased ___ ___
Cardiac workload
219
Ventricular end-diastolic volume imposes stretch on the ____; the relationship between the length and tension of this indicates that when there is the right amount of stretch (not overstretched or understretched), there is the highest contractile strength
Sarcomeres
220
Circulatory blood flow is ____ related to pressure and ____ related to resistance
Directly; indirectly
221
Resistance is ____ proportional to fluid viscosity and length of the circuit and ___ proportional to vessel diameter
Directly; indirectly
222
Formula for calculating volume flowrate:
F= (P1-P2)/R
