Unit A, Lesson 1: Structure of the heart

-With each beat, the heart pumps blood into two loops: systemic circulation (rest of the body) and pulmonary circulation (the lungs). -The right side of the heart is the pump for the pulmonary circulation. It receives deoxygenated blood from the body and pumps it to the lungs to get it oxygenated. -The left side of the heart is the pump for the systemic circulation. It receives freshly oxygenated blood from the lungs and pumps it to the rest of the body.

Blood circulation

- There are certain valves in the heart that help direct blood flow from the left ventricle to the body. -The path that blood follows through the heart, beginning with deoxygenated blood entering from the vena cavae, is as follows: right atrium > right ventricle > pulmonary artery> lungs> pulmonary veins > left atrium > left ventricle > aorta. -The valves located in the heart are one way so that backflow can be prevented in the blood flow. -The Right side of the heart receives deoxygenated blood from the body and is therefore the pump for the pulmonary circulation. -The deoxygenated blood travels from the heart to the lungs, and exchanges carbon dioxide for oxygen in the lungs. -The oxygenated blood returns to the heart to be distributed to the body.

Blood flow

The heart circulates blood through BLOOD VESSELS

How does the blood circulate?

The main function of a heart atrium is to receive blood from the body and lungs.

Main function of the atrium

the arteries that take deoxygenated blood from the right ventricle to the lungs.

Pulmonary Arteries

the veins that bring OXYGENATED blood from the lungs back to the heart.

Pulmonary Veins

A thick muscular wall that divides the heart into the left and right sides.

Septum

-Strongest muscle of the body. -The heart is the central muscular organ that pumps blood throughout the body.

The heart

-The lungs receive deoxygenated blood from the heart through the pulmonary arteries. -These are the only arteries in the human circulatory system that carry deoxygenated blood. -The Carbon dioxide (CO2) in the blood is exchanged for oxygen (O2) in the lungs. -The oxygenated blood is returned to the heart via pulmonary veins. -These are the only veins in the human circulatory system that carry oxygenated blood.

The lungs

Bottom 2 chambers of the heart

Ventricle

The blood carries nutrients, essential gases, waste products, and hormones to all the body tissues.

What does the blood carry? To where?

1. The deoxygenated blood carrying carbon dioxide flows into the right atrium through a one-way valve, then pumps into the right ventricle. 2. Now the heart contracts and pushes out the blood in the right ventricle via the pulmonary arteries to the lungs. 3. The backflow of the blood from the right ventricle to the right atrium is prevented by the valve located in between. -The Pulmonary artery and Right ventricle both have to do with deoxygenated blood.

Where does deoxygenated blood go?

-The oxygenated blood flows into the left atrium from the lungs, and then pumps into the left ventricle through the one-way valve. -The hearts contracts and pushes the oxygenated blood in the left ventricle to exit through the one-way valve via the aorta — the largest artery in your body to the rest of the body. -The Left atrium and Pulmonary veins both have to do with oxygenated blood.

Where does oxygenated blood go?

The main artery of the body supplying oxygenated blood to the circulatory system.

aorta

The heart is divided into 4 chambers that control the blood flow through the use of valves.

chambers of the heart

The upper chamber of the heart where oxygen-rich blood returns from the lungs via the pulmonary arteries and veins.

left atrium

The lower chamber of the heart that pumps oxygen-rich blood to the rest of the body.

left ventricle

-The heart is 2 pumps working side by side one pump with upper and lower chambers pushes blood to lungs where blood picks up oxygen. -Blood flows back from lungs to other side of heart. These 2 chambers pump blood everywhere else in the body.

pumps of the heart

The upper chamber of the heart that receives oxygen-depleted blood via the superior vena cava and the inferior vena cava.

right atrium

The lower chamber of the heart that pumps oxygen-poor blood into the lungs. Blood comes into the right ventricle from the right atrium.

right ventricle

moving or operating in a single direction

unidirectional

a membrane structure allowing blood to flow in one direction only

valve

-thick-walled blood vessels that carry blood away from the heart. -In the human circulatory system, almost all of the arteries carry oxygenated blood from the heart to the rest of the body. Hence, the arteries are associated with the red colour, indicating the oxygenated blood. -pulmonary arteries are the only arteries that are coloured blue in the entire human circulatory system. Likewise, the pulmonary veins are the only veins that are coloured red in the entire human circulatory system.

Arteries

- The valves are unidirectional — they only open in one direction, ensuring that blood only flows from the right ventricle into the pulmonary arteries. -There are 4 valves in the heart: --The mitral valve is located between the left atrium and left ventricle. --The Pulmonary valve is located between the right ventricle and the pulmonary artery. --The Aortic valve is located between the left ventricle and the aorta. --The Tricuspid valve is located between the right atrium and right ventricle. -The valves help to keep the blood in different chambers of the heart.

valves

thin-walled blood vessels with valves that carry the blood toward the heart

veins

the veins that bring deoxygenated blood into the heart.

vena cava

Top 2 chambers of the heart

Atrium