Anatomy and Physiology of the Heart

What are the major vessels leading to and from the heart?

1. Vena cava: the superior vena cava returns blood from the upper portion of the body while the inferior vena cava returns blood from the rest of the body. 2. Pulmonary artery: carries blood from the heart to the lungs for oxygenation 3. Pulmonary veins: carries blood from the lungs to the heart 4. Aorta: carries blood from the heart to the rest of the body. 5. Coronary arteries: supply blood (oxygen, nutrients) to the heart muscle itself. 6. Flow is one way: valves prevent the backflow from one area to the previous one. 7. Triscupid valve: valve from the right atrium to right ventricle. 8. Semilunar valve: valve from the right ventricular to the pulmonary artery 9. Biscupid valve: valve from left atrium to left ventricle 10. Aortic valve: valve from the left ventricle to the aorta.

What must each pump (when blood circulates) do?

1. produce enough force to push the liquid all the way through the system 2. overcoming resistance 3. push liquid in only one direction 4. allow for sufficient filling 5. respond to the need for changes in output

What is the purpose of the heart?

1. to oxygenate blood 2. to circulate blood (pumping)

How many chambers are there in each pump?

2 chambers. One to receive the blood (atrium). One to pump the blood (ventricle).

How many times does the heart pump blood?

2 times. The right heart pumps blood through the pulmonary circuit for oxygenation while the left heart pumps oxygenated blood through the systemic circuit.

How many chambers does the human heart have?

4 chambers

Describe the direction of flow

Blood enters the vena cava to the right atrium to the right ventricle to the pulmonary artery to the pulmonary capillary bed to the pulmonary vein to the left atrium to the left ventricle to the aorta.

What kind of signals does the heart respond to?

Electrical

What are the papillary muscles?

It is attached to the chordae tendinae to the heart wall.

What is the chordae tendinae?

It is the anchor the cusps of the valves to maintain one-way movement

Three types of heart muscle cells

contractile cells autorhythmic cells conducting cells

Depolarization

rapid changes in ion concentration across the muscle cell membrane

Systole

the muscle cells of the ventricle begin to contract. this increases the pressure within the chamber. the bicuspid and tricuspid valves close, preventing backflow the semilunar and aortic valves open, allowing blood to leave the heart for the lungs and body

Diastole

the muscle of the chamber is relaxed. volume of the space within the chamber is larger. larger volume =less fluid pressure blood flows along its pressure gradient and therefore enters the chamber. when ventricle is almost full, the atria begins to contract, which completes filling. stretches the contractile cells increasing the strength of contraction.

When is the arterial pressure greater than the ventricular pressure?

when the ventricles begin to relax and the semilunar and aortic valves also close.