Blood & circulation

Circulation Your body resembles a large roadmap, There are routes or “arteries” that take you downtown to the “heart” of the city.

3 Major Parts of the Circulatory system Blood Vessels - routes blood travels Heart – pumps or pushes blood through body Blood – carries important “ *stuff ” through body * Stuff – includes oxygen, food, & waste

# 1 Blood Vessels : One Way Streets Blood Vessels resemble very long and skinny tunnels that are all through your body.

3 Types of Blood Vessels Arteries Capillaries Veins * Click on each blood vessel to explore its function in circulation

ARTERIES Carry blood away from the heart. The blood in the arteries is under high pressure and so: Arteries have thick outer walls Arteries have thick layers of muscles and elastic fibres VEINS Carry blood to the heart. The blood in the veins is under low pressure and so: Veins have thin walls Veins have thin layers of muscle and elastic fibres.

Unlike arteries, veins have one-way valves in them to keep the blood moving in the correct direction.

Blood that contains oxygen Mainly found in arteries Oxygenated blood - Blood that contains oxygen Mainly found in arteries Deoxygenated blood - Blood that does not contain oxygen Mainly found in veins http://www.bbc.co.uk/schools/gcsebitesize/science/21c/disease/heartdiseaserev2.shtml http://www.bbc.co.uk/schools/gcsebitesize/science/21c/disease/heartdiseaserev3.shtml

Structure of the Heart

Location of the heart.

Structure of the Heart

The heart is made up of cardiac muscle and is divided into 4 different chambers. The top two compartments are called atria, while the bottom two compartments are called ventricles. The right atria and ventricle receive deoxygenated blood from the body whereas the left atria and ventricle receive oxygenated blood from the lungs. The pulmonary arteries carry deoxygenated blood away from the heart to the lungs. This is unusual because almost all other arteries carry oxygenated blood.

The pulmonary vein is a large blood vessel that carries blood from the lungs to the left atrium of the heart. They carry oxygenated blood, which is unusual since almost all other veins carry deoxygenated blood. Vena Cava are the veins that return deoxygenated blood from the body into the heart. They both empty into the right atrium. The aorta is the largest artery in the body. The aorta distributes oxygenated blood to all parts of the body.

Double Circulation

The heart is a DOUBLE PUMP: 1st - blood is pumped to the lungs & returns to the heart, 2nd - blood is pumped to respiring muscles & back to the heart again. 1. Deoxygenated blood is pumped from the heart to the lungs 2. The blood receives oxygen and is pumped back to the heart 4. The oxygen leaves the blood to be used for respiration in the body and the blood goes back to the heart 3. The oxygenated blood is then pumped to the rest of the body

Task: Students draw the flow of blood, in the heart, with the help arrows depicting the same.

Blood pressure

Sphygmomanometer – Apparatus used to measure Blood pressure.

A blood pressure reading has a top number (systolic) and bottom number (diastolic). The ranges are: Normal: Less than 120 over 80 (120/80) Prehypertension: 120-139 over 80-89 Stage 1 high blood pressure: 140-159 over 90-99 Stage 2 high blood pressure: 160 and above over 100 and above People whose blood pressure is above the normal range should consult their doctor about steps to take to lower it.

Video related to Blood pressure. http://watchlearnlive.heart.org/CVML_Player.php?moduleSelect=highbp http://www.youtube.com/watch?v=oioFVbsiwEk