Heart: Exam 1

1. Which of the following factors does not influence heart rate?

Gender

Body temperature

Age

Skin color

2. The P wave of a normal electrocardiogram indicates _____________________________.

Atrial depolarization

Atrial re-polarization

Ventricular depolarization

Ventricular re-polarization

3. Compared to skeletal muscle, cardiac muscle ___________________________________.

Has gap junctions that allow it to act as a functional syncytium

Lacks striations

Has more nuclei per cell

Cells are larger than skeletal muscle cells

4. The left ventricular wall of the heart is thicker than the right wall in order to ___________________________.

Expand the thoracic cage during diastole

Pump blood with great pressure

Pump blood through a smaller valve

Accommodate a great volume of blood

5. Select the correct statement about cardiac output.

A slow heart rate increases end diastolic volume, stroke volume, and force of contraction

Stoke volume increases if end diastolic volume decreases.

If a semilunar value were partially obstructed, the end systolic volume in the affected ventricle would be decreased.

Decreased venous return will result in increased end diastolic volume

6. Which of these vessels receives blood during ventricular systole?

Both the aorta and pulmonary track

Pulmonary veins only

Aorta only

Pulmonary arteries only

7. If cardiac muscle is deprived of its normal blood supply, damage would primarily result from __________________________.

A decrease in the number of available mitochondria for energy production

An inadequate supply of lactic acid

Decreased delivery of oxygen

A lack of nutrients to feed into metabolic pathways

8. Small muscle masses attached to the chordae tendineae are the _______________________

Venae cavae

Trabecular carneae

Pectinate muscles

Papillary muscles

9. When viewing a dissected heart, it is easy to visually discern the right and left ventricles by ______________________.

Locating the apex

Finding the papillary muscles

Tracing out where the auricles connect

Noticing the thickness of the ventricle walls

10. The term for pain associated with deficient blood delivery to the heart that may be caused by the transient spasm of coronary arteries is __________________________.

Ischemia

Myocardial infarct

Angina pectoris

Pericarditis

11. The fact that the left ventricle of the heart is thicker than the right ventricle reveals that it _________________________.

Expands the thoracic cage

Pumps blood against a greater resistance

Sends blood through a smaller valve

Pumps a greater volume of blood

12. The second heart sound is heard during which phase of the cardiac cycle?

Isovolumetric contraction

Ventricular ejection

Isovolumetric relaxation

Ventricular filling

13. Damage to the __________________ is referred to as heart block.

AV valves

SA node

AV node

AV bundle

14. Hemorrhage with a large loss of blood causes _________________________.

A rise in blood pressure due to change in cardiac output

A lowering of blood pressure due to change in cardiac output

No change in blood pressure but a slower heart rate

No change in blood pressure but a change in respiration

15. The source of blood carried to capillaries in the myocardium would be the __________________________.

Coronary veins

Coronary sinus

Fossa ovalis

Coronary arteries

16. Which of the following is not an age-related change affecting the heart?

Atherosclerosis

Decline in cardiac reserve

Fibrosis of cardiac muscle

Thinning of the valve flaps

17. The time of day most hazardous for heart attacks is ________________.

Morning

Noontime

Evening

During sleep

18. Select the correct statement about the heart valves.

Aortic and pulmonary valves control the flow of blood into the heart

The tricuspid valve divides the left atrium from the left ventricle

The mitral valve separates the right atrium from the right ventricle

19. If the vagal nerves to the heart were cut, the result would be that ____________________________

Parasympathetic stimulation would increase, causing a decrease in heart rate

The heart rate would increase by about 25 beats per minute

The heart would stop, since the vagal nerves trigger the heart to contract

The AV node would become the pacemaker of the heart

20. During contraction of heart muscle cells _________________________________.

Calcium is prevented from entering cardiac fibers that have been stimulated

The action potential is prevented from spreading from cell to cell by gap junctions

The action potential is initiated by voltage-gated slow calcium channels

21. Norepinephrine acts on the heart by __________________________

Decreasing heart contractility

Blocking the action of calcium

Causing a decrease in stroke volume

Causing threshold to be reached more quickly

22. If the length of the absolute refractory period in cardiac muscle cells was the same as it is for skeletal muscle cells _______________________.

Tetanic contractions might occur, which would stop the heart's pumping action

It would be less than 1--2 ms

It would be much longer before cardiac cells could respond to a second stimulation

Contractions would last as long as the refractory period

23. Which vessel of the heart receives blood during right ventricular systole?

Aorta

Venae cavae

Pulmonary veins

Pulmonary trunk

24. During the period of ventricular filling ______________________________________.

The atria remain in diastole.

It is represented by the P wave on the ECG

Blood flows passively through the atria and the open AV valves into the ventricles

Pressure in the heart is at its peak

25. To auscultate the aortic semilunar valve, you would place your stethoscope in the ___________________________.

Fifth intercostal space inferior to the left nipple

Second intercostal space to the right of the sternum

Second intercostal space to the left of the sternum

Fifth right intercostal space

26. Commotio cordis is heart failure due to a ___________________.

Severe electrical shock to the body

Mild electrical shock to the heart itself

Loss of blood from an artery

Relatively mild blow to the chest that occurs during a vulnerable interval (2 ms) when the heart is re-polarizing

27. Isovolumetric contraction ___________________________.

Refers to the short period during ventricular systole when the ventricles are completely closed chambers

Occurs immediately after the aortic and pulmonary valves close

Occurs only in people with heart valve defects

Occurs while the AV valves are open

28. Normal heart sounds are caused by which of the following events?

Closure of the heart valves

Opening and closing of the heart valves

Friction of blood against the chamber walls

Excitation of the SA node

29. Which of the following is not part of the conduction system of the heart?

AV node

AV valve

SA node

Bundle of His

30. Select the correct statement about the function of myocardial cells.

The entire heart contracts as a unit or it does not contract at all

Each cardiac muscle cell is innervated by a sympathetic nerve ending so that the nervous system can increase heart rate.

The influx of potassium ions from extracellular sources is the initiating event in cardiac muscle contraction

The refractory period in skeletal muscle is much longer than that in cardiac muscle

31. Select the correct statement about the structure of the heart wall.

The heart chambers are lined by the endomysium

The myocardium is the layer of the heart that actually contracts

Connective tissue in the heart wall aids in the conduction of the action potential

The fibrous skeleton forms the bulk of the heart

32. The tricuspid valve is closed _________________________.

By the movement of blood from atrium to ventricle

While the ventricle is in diastole

While the atrium is contracting

When the ventricle is in systole

33. Blood within the pulmonary veins returns to the _________________.

Left atrium

Left ventricle

Right ventricle

Right atrium

34. Foramen ovule _____________________________.

Connects the two atria in the fetal heart

Is a connection between the pulmonary trunk and the aorta in the fetus

Is a shallow depression in the inter ventricular septum

Is a condition in which the heart valves do not completely close

35. Which of the events below does not occur when the semilunar valves are open?

Ventricle are in systole

Blood enters pulmonary arteries and the aorta

Ventricles are in diastole

AV valves are closed

36. If we were able to artificially alter the membrane permeability of pacemaker cells so that sodium influx is more rapid, ________________________________________.

Heart rate would decrease, but blood pressure would rise due to the excess sodium present

Potassium channels compensate and no change in heart rate would occur

Threshold is reached more quickly and heart rate would increase

Tetanic contraction would occur due to the short absolute refractory period of cardiac muscle