*Cardiovascular: HEART* Flashcards
What structures are found in the mediastinum?
Esophagus, heart, thymus gland, and trachea
The heart lies obliquely in the mediastinum.
True
The epicardium:
Is the visceral pericardium.
The heart valves have a double layer of ________ with a layer of ________ in between.
Endocardium; connective tissue
Musculi pectinati are found in the __________ ; trabeculae carneae are found in the __________ .
Auricles; Ventricles
What structure delivers blood to the left atrium?
Pulmonary Veins
The anterior interventricular artery is a branch of the:
left coronary artery
The valve located between the left atrium and left ventricle is the:
Bicuspid (mitral) valve
Strong connective tissue strings that are attached to papillary muscles and to the cusps of the atrioventricular valves are:
Chordae Tendinease
Arrange them in the order in which an erythrocyte would pass through them after returning to the heart from the left arm.
- aortic semilunar valve
- bicuspid (mitral) valve
- pulmonary semilunar valve
- tricuspid valve.
4,3,2,1
- Tricuspid Valve
- Pulmonary semilunar valve
- Bicuspid Valve
- Aortic semilunar valve
The skeleton of the heart:
electrically insulates the atria from the ventricles.
what are the structures present in cardiac muscle cells?
- Desmosomes
- Gap junctions
- Smooth Sarcoplasmic Reticulum
- Transverse (T) tubules
The group of modified cardiac muscle cells that delays action potentials between the atria and the atrioventricular bundle is called the:
AV node
If the SA node becomes damaged and nonfunctional, which of these is the most likely to occur?
Another part of the heart, possibly the AV node, will become the pacemaker.
Cardiac muscle has a prolonged period of slow repolarization called the plateau phase.
True
Action potentials pass rapidly from one cardiac muscle cell to another because of:
intercalated disks and numerous gap junctions.
The depolarization phase of the cardiac muscle action potential occurs when:
voltage-gated Na+ ion channels open.
Early repolarization of cardiac muscle cells occurs when:
- Voltage-gated K+ ion channels open
- Voltage-gated Na+ ion channels open
Which of these conditions occur in the cardiac muscle cell during the plateau phase?
- Voltage gated Ca2+ ion channels are open
- Voltage-gated K+ ion channels are open
- Voltage-gated Na+ ion channels are open
Unlike other cardiac muscle cells, the movement of ____ into the pacemaker cells is primarily responsible for the depolarization phase of the action potential.
Ca2+ ions
Which of these conditions results in a prepotential in pacemaker cells?
Na+ ions move into the cell through specialized Na+ ion channels.
In an EKG, the P wave represents:
depolarization of the atria
During the QT interval of the EKG, the:
ventricles contract and being to relax
what condition is most likely to cause bradycardia?
excessive parasympathetic stimulation
During the period of ejection in the cardiac cycle, the atrioventricular valves are __________ and the semilunar valves are __________ .
closed; open
Blood flows neither into nor out of the ventricles during:
- The period of isovolumic contraction
- The period of isovolumic relaxation
At the end of __________ , the ventricles are 70% filled.
Passive ventricular filling
The average end-diastolic volume of the ventricles is about __________ , whereas the end-systolic volume is about __________ .
125 mL, 55 mL
During the period of ejection, the left ventricular pressure reaches a high point of approximately
120 mm hg
The second heart sound, described as “dupp” is actually the sound of the:
semilunar valves closing.
If the heart rate for a patient is 80 bpm, and her stroke volume is 70 mL/beat, then her cardiac output is:
5600 mL/min
Preload:
Is the extent to which the ventricular walls are stretched.
Increased venous return to the heart causes increased:
- stroke volume
- Preload
- Cardiac Output
- Force of contraction
Parasympathetic nerve fibers:
Extend to terminal ganglia within the wall of the heart
When normal arterial blood pressure decreases, baroreceptors cause a response that
returns blood pressure to normal
If blood pH decreases and blood carbon dioxide increases:
heart rate increases
increased sympathetic stimulation of the heart:
- increases the force of ventricular contraction
- opens a larger number of calcium slow channels
- increases the heart rate
- increases cardiac output
Generally, an increase in extracellular Ca2+ ions causes __________ force of contraction, and __________ heart rate.
increased; decreased
Excess K+ ions in cardiac tissue cause heart rate and stroke volume to __________ and decreased extracellular K+ ions result in a __________ in heart rate.
Decrease; decrease
