Nexus Nursing Circulatory System (Layers, chambers, valves)

Where is the heart located?

Between the fifth and sixth ribs on the left side of the chest

What is the innermost layer of the heart?

Endocardium

What type of cells make up the endocardium?

Simple squamous epithelial cells (endothelium)

What is the middle layer of the heart?

Myocardium

What is the function of the myocardium?

Contracts to pump blood throughout the body

What is the outermost layer of the heart?

Epicardium (visceral pericardium)

What are the two layers of the pericardium?

Visceral pericardium and parietal pericardium

What separates the left and right sides of the heart?

Septum

How many chambers does the heart have?

Four (right atrium, right ventricle, left atrium, left ventricle)

What does the right atrium do?

Receives deoxygenated blood from the body via the superior and inferior vena cava

What valve separates the right atrium and right ventricle?

Tricuspid valve (right AV valve)

Where does the right ventricle send blood?

To the lungs via the pulmonary arteries

What happens in the lungs during pulmonary circulation?

Carbon dioxide is exchanged for oxygen

What returns oxygenated blood to the heart?

Pulmonary veins

Where does oxygenated blood enter the heart?

Left atrium

What valve separates the left atrium and left ventricle?

Bicuspid valve (mitral valve, left AV valve)

Where does the left ventricle pump blood?

Into the aorta for systemic circulation

What do the AV valves prevent?

Backflow of blood from the ventricles to the atria

What are the AV valve leaflets supported by?

Chordae tendineae (heart strings)

Why is the right AV valve called tricuspid?

It has three cusps

Why is the left AV valve called bicuspid or mitral?

It has two cusps

What is the semilunar valve between the right ventricle and pulmonary artery?

Pulmonary semilunar valve

What is the semilunar valve between the left ventricle and aorta?

Aortic semilunar valve

What is the main function of semilunar valves?

Prevent blood from flowing backward into the ventricles

Why is knowing the blood flow through the heart important?

Helps answer test questions even without knowing all the terms

What does systemic circulation refer to?

Blood flow from the heart to the rest of the body

What does pulmonary circulation refer to?

Blood flow from the heart to the lungs and back