Block 1 - Cardiac Flashcards
Within the right coronary artery, the marginal branch supplies what portion of the heart?
The marginal branch supplies the right ventricle.
The structures of coronary circulation can be described as the coronary _______, coronary _______, and the coronary ________.
arteries; veins; sinus
In fetal cardiac anatomy, what structure shunts blood from the pulmonary artery to the arch of the aorta?
The ductus arteriousus
Pectinate muscles are found in what structures of the heart?
the right atrium; right and left auricle
What are the three regions (cusps) of the pulmonary valve?
anterior semilunar, right semilunar, left semilunar
In Frank-Starling Law, ________ is proportional to __________ volume.
preload; end-diastolic
How many auscultation sites are there for heart sounds?
4
What special feature is found in the anterior portion of the right atrium; and also found in the left and right auricle?
pectinate muscles
True or false: An inotrope is something that alters the force of the conductivity.
False; force of the contraction.
With regard to heart sounds, what causes the sound of the S1?
In S1, the blood turbulence caused by the closure of AV valves soon after the ventricular systole begins
True or False:
Skeletal muscle can build action potential on top of action potential for stronger contraction.
True.
What does the right coronary artery divide into?
the posterior interventricular branch and the marginal branch
Mitochondria make up what percentage in:
Cardiac tissue = ______ % of the cystolic
Skeletal tissue = ______ % of the cystolic
25%; 2%
True or false: During ventricular dystole the ventricles relax and the atriaventricular valves close and the semilunar valves open.
False; the atriaventricular valves open and the semilunar valves close.
Choose one:
The posterior interventricular branch lies in the (posterior/anterior) interventricular sulcus and supplies the (posterior inferior / anterior inferior) wall of the (right/left) ventricle and part of the interventricular septum.
posterior; posterior inferior; left
The action potential (increases / decreases) considerably at the atriaventricular (AV) node.
decreases (slows)
The “right” heart surface that faces the right lung is mostly made of the _________ .
right atrium
The S4 heart sound is caused by what?
The blood turbulence during atrial systole (contraction).
The increased influx through the cell membrane of which cation can alter the action potential and strengthen the contraction?
Ca2+
An increase in afterload causes stroke volume to __________. This causes more blood to remain in the ventricles.
A.) increase
B.) fluctuate
C.) decrease
D.) rebound
C.) decrease
The “open end” of the fibrous pericardium is fused to the connective tissues of what cardiac structure?
The great vessels; pulmonary trunk
Within contractile fibers there is a “resting period” until what occurs?
…until a signal (action potential) from conductive fibers occurs
Choose one:
Repolarization is the (recovery / activation) within the myocardium.
recovery
How long, respectively, are these periods:
Atrial systole:
Ventricular systole:
Relaxation period:
Atrial systole: .1 second
Ventricular systole: .3 second
Relaxation period: .4 second
True or False: The tendon-like cords connected to papillary muscles that connect the cusps of the aortic and pulmonary valves are called the chordae tendineae.
False; the chordae tendineae connect the cusps of the tricuspid and bicuspid valves.
What is the term for the .5 second(s) when both the atriaventricular valves and the semilunar valves are closed?
isovolumetric contraction
The inferior heart surface is formed by the 2/3rd of the _______ ventricle and 1/3rd of the _________ ventricle and rests on what part of the diaphragm?
left; right; central tendon of the diaphragm
The “left” heart surface that faces the left lung and along the pulmonary border is mostly made of the _________.
left ventricle
Within the pericardium, the heart is confined to its position in the ______________.
mediastinum
What artery lies in the anterior interventricular sulcus and supplies the bulk of the left ventricle (middle to lower portions) and a large portion of the interventricular septum?
The left anterior descending (LAD)/anterior interventricular artery
What layer houses the beginning of the blood vessels and lymphatic tissues that supply the all three layers of the heart wall?
the epicardium
What two valves are semi-lunar valves?
The pulmonic/pulmonary and aortic valve.
Blood passes from the right atrium into the right ventricle through the _________ valve, also known as the right __________ valve.
tricuspid; atrioventricular
The left side of the heart leads to which type of closed circuit circulation?
systemic
What is the remnant structure of the ductus arteriousus once it is closed (normally) after birth?
The ligamentum arteriousium
When pressure in the ventricle falls below the pressure of the atria, what occurs in the atriaventricular valves?
the AV valves open allowing for the ventricle to fill again
The anterior heart surface is formed by the 2/3rd of the _______ ventricle and 1/3rd of the _________ ventricle.
right; left
What structure in the conductive system initiates an action potential about every .6 seconds?
the sinoatrial (SA) node
Once the blood unloads oxygen and other nutrients and picks up carbon dioxide and other wastes in the capillaries, the dexoygenated blood flows into what circulatory system structure?
A.) veins
B.) arteries
C.) venules
D.) the right atrium
C.) venules
Inherent rates of the conductive system are:
_____ _____= 60-100 AP/min
_____ _____= 40-60 AP/min
_____ _____ = 20-40 AP/min
Fill in the blank with:
Purkinje Fibers / SA node / AV node
SA Node = 60-100 AP/min
AV Node = 40-60 AP/min
Purkinje Fibers = 20-40 AP/min
Choose one:
Depolarization is the (recovery / activation) within the myocardium.
activation
The pressure that must be exceeded before ejection of blood from ventricles can be defined as, ______________. What are those pressures for the aorta and pulmonary trunk, respectively?
afterload; aorta-80mmHg, pulmonary trunk-20mmHg
Which coronary vein drains the superior portion of the right ventricle and opens directly into the right atrium-bypassing the coronary sinus?
the anterior cardiac vein
What layer of tissue is tough, inelastic, and dense while also preventing the over-stretching the heart itself?
The fibrous pericardium.
What hormone is triggered and released from the impulses of accelerator nerves?
norepinephrine.
The movement of ions into a cell is __________.
The movement of ions out of a cell is __________.
influx; efflux
A normal adult ventricle can hold ______ mL of blood before it is full.
130mL
In fetal cardiact anatomy, what structure allows blood that has made it into the right ventricle and pulmonary trunk to bypass the lungs ?
The ductus arteriousus
What type of fiber is “stair-step” in appearance and usually has one centrally located nucleus but may sometimes have two?
cardiac fibers
The serous pericardial layer is made up of what to sub-layers?
The parietal (cavity lining) layer; and the visceral (organ lining) layer
Into what heart structure does most of the deoxygenated blood from the coronary vessels drain?
the large vascular sinus
What type of fibers of the fibrous skeleton are between heart chambers and around heart valves?
collagen and elastic fibers
In Phase 2, the _______ phase, of action potential of contractile fibers, there is a slow influx of ______ balanced with an efflux of _____ ions. The influx of ____ initiates the activation of __________ and _________ causing the cell to contract.
plateau; Ca2+; K+; Ca2+; troponin and myosin
What are the series of grooves on the surface of the heart?
The sulci
The volume of blood ejected from the left ventricle (or the right ventricle) into the aorta (or the pulmonary trunk) per minute is defined as?
Cardiac Output (CO)
What special feature of the heart externally separates the atria from the ventricles?
the coronary sulcus
During atrial systole, what amounts are moved into the ventricle:
___ mL pours in by weight/volume alone
___ mL is forced in by atrial systole
___ mL is usually there from the previous cycle
45 / 25 / 60
From what heart structures does the right atrium receive the blood?
the superior vena cava, the infrerior vena cava, and the coronary sinus
When a ventricle contracts, the lumen size __________ thus increasing the pressure within the ventricle.
decreases
What is the resting heart rate of an infant?
120bpm
True or false: During ventricular systole the ventricles contract, the atriaventricular valves close and semilunar valves open.
True
True or False: The atria contracts AFTER the AV valve opens.
True.
Another action potential cannot occur normally during the action potential phases of contractile fibers. This period is referred to as what?
The absolute refractory period
During ventricular systole, the ventricular pressure rises to what pressure in the right and left ventricles, respectively:
Right: ____ mmHG
Left:____ mmHG
Right: 25-30 mm;
Left: 120 mmHG;
What is the role of the coronary sinus?
The coronary sinus returns coronary blood back into the right atrium.
Why is the contractility of ventricles not well controlled by parasympathetic impulses?
There are very few fibers that terminate in the ventricular muscle.
“If the left side pumps more blood than the right, the volume returning to the right ventricle increases. This increased end-diastolic volume (EDV) causes the right ventricle to contract more forcefully.” - This is an example of what?
the Frank-Starling Law
In ECGs, the three waves are:
__ wave - _______ ______________
_ _ _ ______ - rapid _______ _______________
__ wave - __________ ________________
P wave - atrial depolarization
QRS complex - rapid ventricular depolarization
T wave - ventricular repolarization
What are the cone-shaped trabeculae carneae found in the ventricles?
the papillary muscles
There are two types of cardiac muscle fibers - name them and describe their roles.
Autorhythmic/excitatory/conductive fibers: these fibers initiate and conduct action potentials that help to control rhythmical beatings of the heart.
Atrial/ventricular muscle (contractile) fibers: require an action potential from conductive fibers in order to contract
Within the heart itself, the myocardium has its own network of blood vessels called ________ _________.
coronary circulation
During ventricular systole, the ventricular ejection of blood occurs when both _____________ valves are open.
semilunar valves
What hormone increases the conduction of action potentials through the SA/AV nodes and also increases Ca2+ entry into contractile fibers which increases contractility?
norepinephrine
What does the right coronary artery supply?
It supplies the small atrial branches and feeds the right atrium.
The fossa ovalis is a depression in the interatrial septum that is a remnant of the ______ ________.
foramen ovale
True or False: Although it is striated like skeletal muscle, it is cardiac muscle so therefore it is voluntary.
False; it is involuntary
Blood passes from the right ventricle into the pulmonary trunk through the ________ valve.
pulmonic (semi-lunar valve)
The fibrous pericardial layer of the pericardium is attaches and is continuous with what part of the body?
The central tendon of the diaphragm.
What is the formula to calculate cardiac output?
Cardiac output = stroke volume (mL/beat) x heart rate (beats/min)
While in motion, autonomic nerve impulses and hormones are released by the ________ system.
sympathetic
Choose one:
Pacemaker potential is between the (highest / lowest) membrane potential (mV) and the threshold membrane potential (mV).
lowest
These receptors monitor the stretching of major arteries and veins caused by blood pressure flowing through them. There are important receptors of this type located in the aortic arch and the carotid arteries.
Baroreceptors (baro-pressure)
The ventricular myocardium receives action potential from what type of fibers in the conductive system of the heart?
Purkinje fibers
When the autonomic nervous system is STIMULATED, what hormones are released to increase contractility which, in turn, would increase stroke volume?
Epinephrine, norepinephrine, digitalis
What segment represents ventricular depolarization during the plateau phase (end of contraction)?
S-T segment
What does the “small cardiac vein” do?
Drains the portion of the right ventricle and atrium
What interval is the beginning of ventricular depolarization to the end of ventricular repolarization?
Q-T interval
Valves open and close in response to what?
A.) electrical charge of the septum
B.) pressure due to the weight/volume of blood in the chamber
C.) contractions of the ventricles
B.) Pressure due to the weight/volume of blood in the chamber
What structure branches from the proximal ascending aorta and encircle the heart?
the coronary artery
Vagal axons terminate in what areas of the heart?
in the SA node; AV node; and atrial myocardium