Circulatory System "The Heart"

Fun facts: You have 96 000km of blood vessels You have 100 trillion cells that need transport Your heart is about the size of your fist and has a mass of about 300g Heart beats about 70 times/minute Every minute 5L of blood cycles through the heart and lungs Your circulatory system is closed. Your blood is your immune system!!

Review: How blood is transported Arteries: Vessels that carry blood away from the heart Tough but elastic. Able to withstand the pressure of blood pumped by the heart Veins: Thinner walls as there is no more blood pressure Have “one way” valves to keep blood moving towards heart. Capillaries: Very narrow tubes between arteries and veins where diffusion occurs

Characteristics It connects all parts of an organism in a way that allows individual cells to thrive as well as for organisms to function as a unit It is an entirely closed system

Functions:

Major Components 1. Pump (heart) 2. Network of tubes 3. Blood Continuously circulates blood 2. Network of tubes Arteries- blood away from heart Veins- blood back to the heart 3. Blood Fluid that fills the circulatory system

Accessory Organs Lungs - organ where oxygen is taken up and CO2 is released Kidneys - organ where wastes are removed from blood; critical in regulating fluids in the body Small intestine - digestion Large intestine - water absorption

The Heart The human heart is a two-sided, 4 chambered structure with muscular walls. The four chambers are: Left ventricle Right ventricle Left atrium Right atrium

The Heart: Parts

Pulmonary veins aorta Pulmonary artery vena cava Tricuspid valve aortic valve pulmonary valve Mitral valve Right atrium left atrium Right ventricle Left ventricle

What do valves do? The valves are one directional They keep blood moving in the right direction.