Cardiovascular System 1

What does the term 'cardiovascular' refer to?

The cardiovascular system refers to the heart (cardio) and blood vessels (vascular).

What is the primary function of the pulmonary circuit?

Transports deoxygenated blood from the right side of the heart to the lungs for gas exchange.

What type of blood does the systemic circuit deliver to the body?

Delivers oxygenated (O2 rich, CO2 poor) blood to the rest of the body.

What are the main components of blood?

Plasma, red blood cells (erythrocytes), white blood cells (leukocytes), and platelets.

What are the components of plasma?

Water, electrolytes, proteins (such as albumin, fibrinogen, and globulins), nutrients, hormones, and waste products.

What are erythrocytes and their function?

Erythrocytes, or red blood cells, transport oxygen and carbon dioxide throughout the body.

What does the term 'haematocrit' refer to?

Hematocrit refers to the percentage of erythrocytes (RBCs) in a blood sample.

What are the three main functions of blood?

Distribution of oxygen and nutrients; Regulation of body temperature, pH, and fluid volume; Protection against blood loss and infection.

What is the pH range of blood?

Typically between 7.35 and 7.45.

What are the main blood types in the ABO system?

A, B, AB, and O.

What is an antigen in relation to blood types?

A cell surface protein that determines blood type.

What is the composition of blood type A?

A antigens on the surface of erythrocytes and anti-B antibodies in the plasma.

What is the composition of blood type B?

B antigens on the surface of erythrocytes and anti-A antibodies in the plasma.

What is the composition of blood type AB?

Both A and B antigens on the surface of erythrocytes and no anti-A or anti-B antibodies in the plasma.

What is the composition of blood type O?

Neither A or B antigens on the surface of erythrocytes and both anti-A and anti-B antibodies in the plasma.

What is the Rh factor?

A specific surface antigen that determines whether blood type is Rh-positive (presence of the antigen) or Rh-negative (absence of the antigen).

Why is the Rh factor important in blood transfusions?

Receiving blood with an incompatible Rh factor can cause an immune reaction, leading to serious complications.

What is the approximate size of the heart?

Roughly the size of a fist, about 12 cm (5 inches) long and 9 cm (3.5 inches) wide.

Where is the heart located in the body?

Located in the thoracic cavity, between the lungs and above the diaphragm.

What are the chambers of the heart?

Two atria (left and right) and two ventricles (left and right).

What is the function of the right atrium?

Receives deoxygenated blood from the body through the superior and inferior vena cavae.

What is the function of the right ventricle?

Pumps deoxygenated blood to the lungs through the pulmonary artery.

What is the function of the left atrium?

Receives oxygenated blood from the lungs via the pulmonary veins.

What is the function of the left ventricle?

Pumps oxygenated blood to the entire body through the aorta.

What is the inter-ventricular septum?

The muscular wall that separates the left and right ventricles of the heart.

What is the pericardium?

A double-walled sac that encases and protects the heart.

What are the layers of the pericardium?

The fibrous pericardium (outer layer) and the serous pericardium (inner layer), which has parietal and visceral components.

What are the layers of the heart wall?

The epicardium (outer layer), myocardium (muscle layer), and endocardium (inner layer).

What are the heart valves?

The tricuspid valve, pulmonary valve, mitral valve, and aortic valve, which ensure unidirectional blood flow.

What are the features of the tricuspid valve?

Has three cusps, is located between the right atrium and right ventricle, and prevents backflow of blood during ventricular contraction.

What are the features of the pulmonary valve?

Has three semilunar cusps, is located between the right ventricle and pulmonary artery, and prevents backflow of blood into the ventricle after contraction.

What are the features of the mitral valve?

Has two cusps, is located between the left atrium and left ventricle, and prevents backflow of blood during ventricular contraction.

What are the features of the aortic valve?

Has three semilunar cusps, is located between the left ventricle and aorta, and prevents backflow of blood into the ventricle after contraction.

What are trabeculae carneae?

Muscular ridges and columns found in the ventricles of the heart that help prevent the walls from sticking together.

What are papillary muscles and their function?

Conical muscle projections in the ventricles that anchor the chordae tendineae, helping to prevent valve prolapse during contraction.

What is the role of the chordae tendineae?

Tendons that connect the AV valves to the papillary muscles, aiding in the opening and closing of the valves.

What is the function of the coronary arteries?

Supply oxygen-rich blood to the heart muscle (myocardium).

What are the branches of the left coronary artery?

Branches into the left anterior descending artery (LAD) and the circumflex artery.

What are the branches of the right coronary artery?

Branches into the right marginal artery and the posterior interventricular artery.

What is the function of the coronary veins?

Drain deoxygenated blood from the heart muscle back to the right atrium.

What are the three main coronary veins?

The great cardiac vein, middle cardiac vein, and small cardiac vein.

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

The SA node, AV node, Bundle of His, bundle branches, and Purkinje fibers.

What is the first step in the heart's conduction system?

The sinoatrial (SA) node initiates the electrical impulse.

What happens after the SA node in the conduction system?

The electrical impulse travels to the atrioventricular (AV) node.

What is the role of the AV node in the conduction system?

Serves as a gatekeeper, slowing down the impulse before it moves to the ventricles.

What follows the AV node in the conduction system?

The impulse proceeds to the Bundle of His.

What do the bundle branches do in the conduction system?

Split the impulse into left and right pathways towards the ventricles.

What are Purkinje fibers and their function?

Distribute the electrical impulse throughout the ventricles,

What is the pathway of blood flow through the heart?

Blood flows from the body into the right atrium, through the right ventricle to the lungs, back to the left atrium, and then to the left ventricle before being pumped to the body.

What does the first heart sound (S1) represent?

Represents the closing of the atrioventricular (AV) valves.

What does the second heart sound (S2) represent?

Represents the closing of the semilunar valves (aortic and pulmonary) at the end of ventricular systole.

What happens during the cardiac cycle?

Includes one complete contraction (systole) and relaxation (diastole) of the heart's chambers.

How is cardiac output calculated?

The product of heart rate (HR) and stroke volume (SV), CO = HR x SV.