Structure of the Heart-Wack

What is the significance of the difference in the thickness of the ventricular walls?

The right ventricle is smaller/thinner as it only has to pump blood through the lungs and back to the right side of the heart. The left side is much thicker/stronger/larger as it has to get the blood to go throughout the whole body.

Compare the structure of the tricuspid valve with that of the pulmonary valve.

The tricuspid valve is between the right atrium and ventricle. The pulmonary valve is where the blood flows out of the right ventricle, into the pulmonary circuit.

The large fibers on the distal side of the AV node make up the

AV bundle

The what is located in the inferior portion of the inter arterial septum?

AV node

The first sounds of a cardiac cycle occurs when the

AV valves are closing

Gives rise to left and right pulmonary arteries

L. pulmonary trunk

The fibers that carry cardiac impulses from the interventricular septum into the myocardium are called

Purkujie fibers

Normally, the what serves as the PACEMAKER of the heart

SA node

distributes blood to body organs (systemic circuit) except lungs

a. aorta

What is the significance of the difference in thickness between the wall of the aorta and the wall of the pulmonary trunk

aorta is thicker because it has greater out flow of pressure to deal from the left ventricle blood leaving the heart into the aorta has greater pressure because the blood has to be carried all over the body whereas the pulmonary trunk only pumps blood to lungs

During ventricular relaxation the AV valves

are open

The P wave corresponds to depolarization of the muscle fibers in teh

atria

Prevents blood movement from left ventricle to left atrium

c. mitral (bicuspid) valve

An ECG is a recording of electrical changes occurring in the myocardium during the

cardiac cycle

During ventricular contraction, the AV valves (tricuspid and mitral valves) are

closed

drains blood from myocardial capillaries

d. cardiac vein

The period during which a heart chamber is relaxing is

diastole

supplies blood to heart muscle

e. coronary artery

Drains blood from myocardium into right atrium

f. coronary sinus

Prevents blood movement from right ventricle to right atrium

m. tricuspid

Describe the function of chordae tendinae and papillary muslces

papillary muscle - contract when the rght ventricle contracts, as the tricuspid valve closes the muscles pull on the chordinae tendinae and prevent the cusps from swinging backwards into the right atrium. as the papillary muscles contract and relax chrodae tendinae transmit the resulting increase and decrease in tension respective to the valves

Between cardiac cycles, cardiac muscle fibers remain how? with no detectable electrical changes

polarized

The second sound of a cardiac cycle occurs when the

pulmonary and aortic valves are closing

The period during which a heart chamber is contracting is called

systole

list in order all the parts of the Blood Flow through the heart

vena cava, right atrium, tricuspid valve, right ventricle, pulmonary valve, pulmonary trunk, pulmonary arteries, lungs, pulmonary vein, left atrium, mitral valve, left ventricle, aortic valve, aorta

The QRS complex corresponds to depolarization of the muscle fibers of the

ventricles

The T wave corresponds to re polarization of the muscle fibers of the

ventricles

The pulmonary and aortic valves open when the pressure in the what exceeds the pressure in the pulmonary trunk and aorta?

ventricles

Heart sounds are due to what in heart tissues created by changes in blood flow?

vibrations

space containing serous fluid to reduce friction during heartbeats

j. pericardial cavity

Membranes around heart

k. pericardial sac

inner lining of heart chamber

g. endocardium

Layer largely composed of cardiac muscle tissue

h. myocardium

Structure from which chordae tendinae originate

i. papilliary muscle