Cardiovascular System Notes

What is the Myocardium?

The muscular wall of the heart.

What is the Pericardium?

The membrane enclosing the heart, consisting of an outer fibrous layer and an inner double layer of serous membrane.

What is the Endocardium?

The inner layer of tissue that lines the chambers of the heart.

Where is the heart located?

Within the thoracic cavity, medial to the lungs, and in the mediastinum.

What membrane separates the heart from other mediastinal structures?

The pericardium.

Where is the base of the heart located?

At the level of the third costal cartilage.

Where is the apex of the heart located?

Just to the left of the sternum, between the junction of the fourth and fifth ribs.

What are the four chambers of the heart?

Left and right atria and ventricles.

What is the pericardium?

The membrane that directly surrounds the heart.

What are the layers of the pericardium?

Fibrous pericardium and serous pericardium (parietal and visceral).

What are the three layers of the heart wall?

Epicardium, myocardium, and endocardium.

Which blood vessels empty into the right atrium?

Superior vena cava (SVC), inferior vena cava (IVC), and coronary sinus.

What is the function of the chordae tendineae?

Strong strands of connective tissue attached to the valve flaps of atrioventricular valves, connecting them to papillary muscles.

What valve guards the opening between the right atrium and right ventricle?

The tricuspid valve.

Where does the right ventricle eject blood?

Into the pulmonary trunk.

What type of valve is located at the base of the pulmonary trunk?

Pulmonary semilunar valve.

Where does oxygenated blood flow into?

The left atrium.

What valve is located between the left atrium and left ventricle?

The bicuspid or mitral valve.

Which chamber is the major pumping chamber for systemic circulation?

The left ventricle.

What are the four heart valves?

Aortic semilunar valve, tricuspid valve, pulmonary semilunar valve, and bicuspid valve.

What is the purpose of the pulmonary circuit?

To carry deoxygenated blood away from the heart, to the lungs, and return oxygenated blood to the heart.

What is the systemic circuit?

The part of the cardiovascular system that transports oxygenated blood to virtually all tissues of the body and returns relatively deoxygenated blood and carbon dioxide to the heart to be sent back into pulmonary circulation.

Outline the blood flow through the heart.

Vena cava → right atrium → tricuspid valve → right ventricle → pulmonary valve → pulmonary arteries → lungs → pulmonary veins → left atrium → bicuspid valve → left ventricle → aortic valve → aorta → arteries → arterioles → capillaries → venules → veins.

What is the role of coronary arteries?

To supply blood to the myocardium and other components of the heart.

What is the purpose of cerebral circulation (Circle of Willis)?

To supply the brain with oxygen and nutrients and dispose of waste.

What is the function of fetal circulation?

Temporary circulation between developing fetus and mother allows the fetus to exchange oxygen and nutrients with its mother and to get rid of fetal waste products.

What is the role of the Ductus Arteriosus in fetal circulation?

It usually diverts blood from the pulmonary artery to the aorta, preventing large amounts of blood from entering the capillaries of the lungs.

What purpose does the Foramen Ovale serve in fetal circulation?

Directs blood flow from the right atrium to the left atrium, reducing blood flow to the lungs.

What is the sinoatrial node (SA)?

Specialized clump of myocardial cells in the superior wall of the right atrium, acting as the pacemaker of the heart.

What are the main components of the conduction system of the heart?

SA node → AV node → AV bundle (Bundle of His) → Right and left bundle branches → Purkinje fibers

What is the normal heart rate initiated by the SA node?

60-100 bpm.

What happens if the SA node fails?

The AV node will take over, beating at 40-60 bpm.

List the five prominent points on an Electrocardiogram (ECG/EKG)?

P wave, QRS complex, and T wave

Describe what each of the following corresponds to: P wave, QRS complex, and T wave.

P wave: Depolarization of the atria; QRS complex: Depolarization of the ventricles, Repolarization of the atria; T wave: Repolarization of the ventricles.

What is Cardiac output (CO) and how is it calculated?

Amount of blood pumped by each ventricle in one minute. Calculated by: CO = SV mes HR (Stroke Volume x Heart Rate)

Explain Systole and Diastole.

Systole: period of contraction that the heart undergoes while it pumps blood into circulation. Diastole: period of relaxation that occurs as the chambers fill with blood.

What are the two audible heart sounds and what causes them?

S1: created by the closing of the atrioventricular valves during ventricular contraction (LUB); S2: created by the closing of the semilunar valves during ventricular diastole (DUB).

How is Stroke volume (SV) calculated?

EDV - ESV

What are the factors affecting blood pressure (BP)?

Cardiac output, Blood volume, Blood viscosity, and Peripheral resistance

List the Pulse Points

Temporal artery: On the side of the forehead, near the temple.; Carotid artery: In the neck, along the windpipe.; Brachial artery: In the upper arm, near the elbow.; Radial artery: On the thumb side of the wrist.; Femoral artery: In the