Cardiovascular System

Blood vessels in the human body are divided into two systems: .

-The pulmonary system is responsible for carrying deoxygenated blood from the right ventricle to the lungs and bringing oxygenated blood back to the left atrium. -The systemic system is responsible for carrying away blood from the left ventricle to the entire body and then back to the right atrium

The aorta is the largest artery in the body and transports oxygenated blood from the left ventricle to the entire body. The pulmonary artery is the only artery in the body that carries deoxygenated blood. Deoxygenated blood is moved from the right ventricle to the lungs.

Aorta and Pulmonary Artery

The vessels are classified based on their structure and function:

Arteries are responsible for carrying oxygenated blood away from the heart. Capillaries are the microscopic vessels that facilitate exchange of oxygen and carbon dioxide in the tissues. Veins are responsible for carrying deoxygenated blood back to the heart.

The heart has four chambers:

Atria are the two top chambers that receive blood. Ventricles are the two bottom chambers that pump blood out of the heart.

Two coronary arteries branch from the aorta above the aortic valve. Coronary arteries:

Carry oxygen and nutrients to the myocardium. Provide constant blood flow to the layers of the heart. Maintain proper functioning of the atria, ventricles, and conduction system.

The venae cavae are responsible for carrying deoxygenated blood to the right atrium.

Deoxygenated blood enters the smallest veins, called venules, after leaving the capillary beds. Then, blood flows into larger veins until it reaches the largest veins, called inferior and superior venae cavae.

Capillary walls are thin and allow the exchange of nutrients and gases at the cellular level.

Erythrocytes, or red blood cells, contain molecules called hemoglobin which carry oxygen. While the blood is in the capillary bed, oxygen that is bound to hemoglobin is released and supplied to surrounding tissues. The oxygen level in the blood is now depleted, and a new cycle begins.

The heart has several valves that regulate the flow of blood and prevent backflow within the heart and between the heart, lungs, and the rest of the body.

Pulmonary valve, Tricuspid valve, Mitral/bicuspid valve, Aortic valve.

Mitral/bicuspid valve

Separates left atrium and left ventricle.

Aortic valve

Separates left ventricle from aorta.

Tricuspid valve

Separates right atrium and right ventricle.

Pulmonary valve

Separates right ventricle from pulmonary artery.

The heart has three layers:

The epicardium is the outer layer of the heart. The myocardium, or middle layer, is the muscle of the heart and constitutes the largest part of the heart wall. The endocardium, or inner layer, consists of heart valves that divide the heart into four chambers.

Mitral/bicuspid valve Separates left atrium and left ventricle.

The left atrium receives oxygenated blood through pulmonary veins, which are the only veins that carry oxygenated blood. The left atrium contracts and the blood moves through the mitral valve, also known as the bicuspid valve, into the left ventricle. After the atria pump blood through the mitral and tricuspid valves, the chordae tendineae tightly close the valves to prevent leaking of blood back into the atria.

Tricuspid valve Separates right atrium and right ventricle.

The right atrium initially receives deoxygenated blood from the inferior and superior venae cavae. Then the atria contract and blood moves through the tricuspid valve into the right ventricle.

Pulmonary valve Separates right ventricle from pulmonary artery.

The right ventricle contracts and the blood moves through the pulmonary valve into the pulmonary artery, which carries deoxygenated blood into the lungs. The pulmonary artery is the only artery in the body that carries deoxygenated blood. Oxygenation of blood occurs in the alveoli of the lungs.

Aortic valve Separates left ventricle from aorta.

When the ventricles contract, the oxygenated blood from the left ventricle passes through the aortic valve into the aorta, which then distributes blood to the whole body.

The systemic system is responsible for carrying away

blood from the left ventricle to the entire body and then back to the right atrium

Which are parts of the electrical conduction system of the heart? Select all that apply.

bundle of his, SA node, AV node (sinoatrial) (Atrioventricular)

Arteries are responsible for

carrying oxygenated blood away from the heart.

The cardiovascular system is also called the circulatory system

circulatory system

Venules

collect blood from capillaries and begin the return journey to the heart.

Veins :

collect blood from the venules and return blood to the heart. Medium to large veins have valves, which help keep blood moving in one direction. The skeletal muscle contractions help move the blood toward the heart. Vessel walls are thinner and less rigid than arteries (see Table 10.1). Veins hold about 70% of the blood supply at any one time.

The pulmonary artery carries

deoxygenated blood away from the heart to the lung. (Every artery, except for the pulmonary artery, carries oxygenated blood. )

Veins are responsible for carrying

deoxygenated blood back to the heart.

-The pulmonary system is responsible for carrying

deoxygenated blood from the right ventricle to the lungs and bringing oxygenated blood back to the left atrium.

Capillaries are the microscopic vessels that

facilitate exchange of oxygen and carbon dioxide in the tissues.

Arterioles

smaller arteries that move blood to the capillaries and also involved with maintaining the blood pressure. (blood to the capillaries ) (maintaining the blood pressure.)

Arteries

strong, stretchy, thick-walled vessels that carry blood from the heart. They are made to withstand the pressure of the blood being pumped out from the heart. Arteries are involved with maintaining the blood pressure. (carry blood from the heart. )

The septum (SEP tum) is the

thick muscular wall that divides the heart into a right and left section.

Capillaries

thin-walled vessels that allow for exchange of oxygen, nutrients, waste products, and other substances between the blood and cells. The diameter of the capillaries is so tiny that only one blood cell can pass through at a time. (exchange of oxygen, nutrients, waste products, and other substances between the blood and cells)