Chapter 20 Heart

Which of the following are true? 1. ANS regulation of the heart rate originates in the cardiovascular center of the medulla oblongata 2. Proprioceptor input is a major stimulus that accounts for the rapid rise of heart rate due to physical activity. 3. The vagus nerves release norepinephrine causing the heart rate to increase. 4. Hormones from the adrenal gland and the thalamus can cause increased heart rate. 5. Hypothermia increases heart rate

1,2,4

Choose the correct route of blood flow through the heart from the systemic circulation to the pulmonary circulation and back to the systemic circulation. 1. Left atrium 2. Right atrium 3. Left ventricle 4. Right ventricle 5. Tricuspid valve 6. Pulmonary semilunar valve 7. Mitral or bicuspid valve 8. Aortic semilunar valve

1,7,3,8,2,5,4,6

Which order of the following represents the correct pathway for conduction of an action potential through the heart. 1. AV node 2. AV bundle 3. SA node 4. Purkinje fibers 5. Bundle branches

3, 1,2, 5, 4

Drain the right ventricle and open directly into the right atrium

Anterior cardiac veins

Lies in the anterior interventricular sulcus; supplies oxygenated blood to both ventricles.

Anterior interventricular branch

Separate the upper and lower heart chambers, preventing back flow of blood from the ventricles back into the atria

Atrioventricular valves

Increase blood holding activity in the atria

Auricles

A softball player is found to have a resting cardiac output of 5 liters per minute and a heart rate of 50 beats per minute. What is her stroke volume? A. 10ml B. 100ml C. 1000ml D. 250ml E. Insufficient info

B

Left atrioventricular valve

Bicuspid valve

Which of the following would not increase stroke volume? A. Increased CA2+ in the interstitial fluid B. Epinephrine C. Increased K+ in the interstitial fluid D. Increase in venous return E. Slow resting heart rate

C

Difference between a persons maximum cardiac output and cardiac output at rest

Cardiac reserve

Tendon like cords connected to the av valve cusps which, along with the papillary muscles, prevent valve eversion

Chordae tendineae

Lies in the coronary sulcus; supplies oxygenated blood to the walls of the left ventricle and the left atrium.

Circumflex branch

Blood vessels that pierce the heart muscle and supply the blood to the cardiac muscle fibers

Coronary circulation

Located in the coronary sulcus on the posterior of the heart; receives most if the deoxygenated blood from the myocardium.

Coronary sinus

The external boundary between the atria and the ventricles is the ________.

Coronary sulcus

Amount of blood contained in the ventricles at the end of ventricular relaxation

End-diastolic volume

Amount of blood remaining in the ventricles following ventricular contraction

End-systolic volume

Endothelial cells lining the interior of the heart; are continuous with the endothelium of the blood vessels.

Endocardium

Inner visceral layer of the pericardium; adheres tightly to the surface of the heart.

Epicardium

True or false: In auscultation, the lubb represents the closing of semilunar valves and the dupp represents the closing of the atrioventricular valves.

False

The superficial dense irregular connective tissue covering the heart.

Fibrous pericardium

The remnant of the foramen ovale, an opening in the inter atrial septum of the fetal heart.

Fossa ovalis

Lies in the anterior interventricular sulcus; drains the walls of both ventricles and the left atrium

Great cardiac vein

The gap junction and des sooner connections between individual cardiac muscle fibers.

Intercalated discs

Period of time when cardiac muscle fibers are contracting and exerting force but not shortening

Isovolumetric contraction

Period of time when all four valves are closed and ventricular blood volume does not change.

Isovolumetric relaxation and isovolumetric contraction

Collects oxygenated blood from the pulmonary circulation.

Left atrium

Major branch from the ascending aorta; passes inferior to the left auricle

Left coronary artery

Pumps oxygenated blood to all body cells, except the air sacs of the lungs.

Left ventricle

The chamber of the heart with the thickest myocardium is the ______.

Left ventricle

Lies in the coronary sulcus; supplies oxygenated blood to the walls of the right ventricle

Marginal branch

Lies in the posterior interventicular sulcus; drains the right and left ventricles

Middle cardiac vein

Cardiac muscle tissue

Myocardium

Represents atrial depolarization

P wave

Represents the conduction time from the beginning of atrial excitation to the beginning of ventricular excitation

P-Q interval

Their contraction pulls on and tightens the chordae tendineae preventing the valve cusps from everting

Papillary muscles

Outer layer of the serous pericardium; is fused to the fibrous pericardium.

Parietal pericardium

Lies in the posterior inter ventricular sulcus; supplies the walls of the ventricles with oxygenated blood

Posterior interventricular branch

Represents the time from the beginning of ventricular depolarization to the end of ventricular repolaration

Q-T interval

Represents the onset of ventricular depolarization

QRS complex

Collects deoxygenated blood from the systemic circulation

Right atrium

Major branch from the ascending aorta; lies inferior to the auricle.

Right coronary artery

Pumps deoxygenated blood to the lungs for oxygenation

Right ventricle

Represents the time when the contractile fibers are fully depolarized; occurs during plateau phase of the action potential

S-T segment

Prevents backflow of blood from the arteries into the ventricles.

Semilunar valves

Internal wall dividing the chambers of the heart.

Septum

Lies in the coronary sulcus; drains the right atrium and right ventricle

Small cardiac vein

Amount of blood ejected per beat by each ventricle.

Stroke volume

Grooves on the surface of the heart which delineate the external boundaries between the chambers

Sulci

The phase of heart contraction is called ____ and the phase of relaxation is called _____.

Systole, diastole

Indicates ventricular repolarization

T wave

Ridges formed by raised bundles of cardiac muscle fibers

Trabeculae carneae

Prevents back flow from the right atrium into the right ventricle.

Tricuspid valve

True of false: The frank-starling law of the heart equalizes the output of the right and left ventricles and keep the same volume of blood flowing to both the systematic and pulmonary circulations.

True

Period of time when the semilunar valves are open and blood flows out of the ventricles

Ventricular ejection