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

Functions Transport oxygen and carbon dioxide Distribute nutrients Transport wastes Distribute hormones Regulate body temperature

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

One Way Streets Blood Vessels

Blood Vessels resemble very long and skinny tunnels that are all through your body.

Arteries/arterioles – have smooth muscle in walls, take blood away from the heart. Capillaries – very small, place where most gas exchange occurs Veins/venues – have valves, no muscle, take blood toward the heart

The Heart

Lub If you listen to your heartbeat, it makes a lub dub sound. The lub is when blood is pushed out of the heart into the body and the dub is the reloading of the heart with more blood ready to push it out to the body Dub

The Heart Cardiac cycle Systole – ventricle contraction Diastole – relaxation of all chambers following contraction of atria

Blood’s Path Through the Heart - Deoxygenated 1.Vena cava 2.Right atrium 3.Right ventricle 4.Pulmonary Arteries 5.Lungs

Blood’s Path Through the Heart - Oxygenated 6.Lungs 7.Pulmonary Veins 8.Left atrium 9.Left ventricle 10.Aorta 11.Body

Influence on Heart Rate Nervous system Hormones

Functions of Blood Transport –Nutrients –Gasses –Hormones –Waste Products Immune Response

Blood Composition Plasma 55-60% Red blood cells – carry oxygen White blood cells - immunity Platelets – clotting ***Blood is mostly saltwater!***