Circulatory System

What is the circulatory system? The circulatory system carries blood and dissolved substances to and from different places in the body. The Heart has the job of pumping these things around the body. The Heart pumps blood and substances around the body in tubes called blood vessels. The Heart and blood vessels together make up the Circulatory System.

Components of our Circulatory System Blood Heart Blood Vessels

Functions of our Circulatory System Main function  transport substances around the body Transports nutrients absorbed in the intestine to all body cells Picks up oxygen at lungs and delivers it to all body cells Carries carbon dioxide from all cells to lungs where it’s released Transports wastes to the kidneys where they are filtered and excreted Regulation of body temperature Transport of disease fighting white blood cells

Our circulatory system is a double circulatory system. This means it has two parts parts. Lungs Body cells the right side of the system deals with deoxygenated blood. the left side of the system deals with oxygenated blood.

now lets look inside the heart This is a vein. It brings blood from the body, except the lungs. These are arteries. They carry blood away from the heart. 2 atria Coronary arteries, the hearts own blood supply 2 ventricles The heart has four chambers now lets look inside the heart

The Heart Artery to Lungs Artery to Head and Body Vein from Head and Body Vein from Lungs Right Atrium Left Atrium Left Ventricle Right Ventricle

blood from the heart gets around the body through blood vessels There are 3 types of blood vessels a. ARTERY b. VEIN c. CAPILLARY

WHY ARE VEINS BLUE AND ARTERIES RED?

Arteries carry blood away from the heart. The ARTERY Arteries carry blood away from the heart. the elastic fibres allow the artery to stretch under pressure thick muscle and elastic fibres the thick muscle can contract to push the blood along.

Veins carry blood towards from the heart. The VEIN Veins carry blood towards from the heart. Veins have valves which act to stop the blood from going in the wrong direction. thin muscle and elastic fibres Body muscles surround the veins so that when they contract to move the body, they also squeeze the veins and push the blood along the vessel to the heart.

The CAPILLARY Capillaries link Arteries with Veins Blood vessels that exchange materials between the blood and other body cells. the wall of a capillary is only one cell thick The exchange of materials include gases, nutrients, and wastes

What’s in Blood? BLOOD digested food red blood cells white blood cells oxygen waste (urea) platelets carbon dioxide hormones plasma

The Blood white blood cells (fight off diseases) red blood cells (carry oxygen) Plasma (liquid part) Platelets (help blood clot)

Red Blood Cells Make up almost half blood volume Biconcave disk shaped; lack a nucleus Contain haemoglobin, a protein to which oxygen binds, thus enabling red blood cells to transport oxygen. Oxygen diffuses into red blood cells at the lungs Oxygen diffuses out of red blood cells at the body cells Carbon dioxide also binds to haemoglobin

White Blood Cells Make up less than 1% of blood volume Larger than red blood cells; only blood cells that contain a nucleus Our body’s army; they are infection fighting cells, destroying bacteria and viruses

Platelets Make up less than 1% of blood volume Tiny pieces/fragments of cells Involved in clotting blood

Plasma Makes up over half of blood volume A yellowish protein rich liquid that moves the other three blood components around our body. Maintains osmotic fluid balance in body

What blood type are you? BLOOD TYPES There are 4 different blood types: 1) AB 2) A 3) B 4) O What blood type are you?

Human Heart Average Size: about the size of your fist. Location: Centre of the chest, slightly to the left Structure: Made up of cardiac muscle tissue, nerve tissue, and connective tissue. Function: contracts and relaxes to pump blood throughout the body.

Heart Facts Beats over 3 Billion times during a lifetime The ribcage protects the heart The heart can continue to beat even when removed from the body. Physical activity, stress, temperature, general health and drugs affect our heat rate. Video

SUMMARY Arteries take blood ______ from the heart. The walls of an artery are made up of thick _________ walls and elastic fibres. Veins carry blood ________ the heart and also have valves. The _________ link arteries and veins, and have a one cell thick wall. Blood is made up of four main things ______, the liquid part of the blood; Red Blood Cells to carry ______; White Blood cells to protect the body from disease and _________ to help blood clot. away muscular towards capillaries plasma oxygen platelets