The transport system of the body

Cardiovascular System OR The Circulatory System

The Circulatory Systemconsists of

*the heart,

*the blood vessels,

and

*around 5 litres of blood

Function: transports oxygen, nutrients, hormones, and cellular waste products throughout the body.

The Heart

The Heart

The Hearta muscular pumping organ located between the lungs

behind the sternum. It is the body’s hardest-

working organ and only about the size of a closed fist.

Two pumps in one small package

RIGHT side pumps blood to the lungs

LEFT side pumps blood to the body

Valves in the heartAct to prevent blood from flowing backwardsSlam shut every time the heart contracts to build pressure and drive blood forwardshttp://youtu.be/JA0Wb3gc4mE

CHORDAE “The heart strings” Tether the valve to the heart wall

like parachute strings Hold the valve in place

Heart Strings

Blood Vessels are the body’s

highways that allow blood to flow quickly

and efficiently from the heart to every region of the body

and back again.

Arteries *blood vessels carrying blood away from the heart to tissues*thick muscular walls *hold blood under very high pressure

Capillaries *the smallest branches of the circulatory system*have thin leaky walls to allow materials to pass out and into the blood

Capillary facts:>10 billion capillariesbarely the diameter of a single red blood cell If all the capillaries in your body were placed end to end, they would circle the globe

Fibrous Connective Tissue shows that every cell is not far from a capillaryhttp://bcrc.bio.umass.edu/histology/?q=node/233&size=_original

Capillaries in Lung tissue

Blood vessels preserved in the hand

Preserved vascular system

Hand

Veins *carry blood back to the heart*have thin walls compared to arteries, because blood pressure is low*They have valves to prevent back flow.

Relative size of arteries, veins and capillaries

Blood A type of connective tissue Made up of a base fluid called

plasma Erythrocytes (RBC) Leukocytes (WBC) Platelets Dissolved chemicals such as

glucose, fatty acids, proteins, amino acids, hormones,