CIRCULATORY SYSTEM

The highway system of the body

Why Have One?

Small organisms with few cells don’t need one because…..

1. Most cells are in contact with their environment so….

oxygen, nutrients, and waste can easily diffuse across the cell membrane

• Larger organisms must have a circulatory system because….

their cells are NOT in contact with the environment

substances made in one part of the body need to be transported to another part

FUNCTION Transport

oxygen to cells nutrients to cells carbon dioxide away from cells wastes away from cells

TYPES

1. Open: blood leaves vessels and goes into tissues and surrounds cells

Ex: grasshopper

2. Closed: blood is completely contained invesselsEx: human

PARTS

1. Heart = pump 2. Blood vessels = tubes 3. Blood = liquid tissue

HEARTHEART

» Two pumps side by side» Has four chambers

» Two pumps side by side» Has four chambers

HEART PARTS

Pericardium: protective sac that surrounds the heart

Atria: upper chambers, thin walledVentricles: lower chambers, thick

walled

Valves: flaps of tissue between chambers

Prevent backflow of blood - keeps blood moving in one direction

Septum: thick, muscular wall that divides the heart in half

Heart DiagramHeart Diagram

• 1. Aorta: largest artery of the body - carries blood away from heart to the body

• 2. Pulmonary Arteries: carry blood to the lungs

• 3. Left Atrium: contraction sends blood to left ventricle

• 1. Aorta: largest artery of the body - carries blood away from heart to the body

• 2. Pulmonary Arteries: carry blood to the lungs

• 3. Left Atrium: contraction sends blood to left ventricle

• 4. Pulmonary Vein: bring blood from the lungs into the heart

• 5. Mitral Valve• 6. Valve• 7. Left Ventricle: sends blood out

through aorta to the rest of the body

• 4. Pulmonary Vein: bring blood from the lungs into the heart

• 5. Mitral Valve• 6. Valve• 7. Left Ventricle: sends blood out

through aorta to the rest of the body

• 8. Septum: wall• 9. Right Ventricle: sends blood out

through pulmonary arteries to lungs• 10. Inferior Vena Cava: brings

blood from lower parts of body into heart

• 11. Tricuspid Valve

• 8. Septum: wall• 9. Right Ventricle: sends blood out

through pulmonary arteries to lungs• 10. Inferior Vena Cava: brings

blood from lower parts of body into heart

• 11. Tricuspid Valve

• 12. Right Atrium: receives blood from all parts of the body except lungs

• 13. Pulmonary Veins• 14. Pulmonary Arteries• 15. Superior Vena Cava: brings

blood from the upper parts of the body to the heart

• 12. Right Atrium: receives blood from all parts of the body except lungs

• 13. Pulmonary Veins• 14. Pulmonary Arteries• 15. Superior Vena Cava: brings

blood from the upper parts of the body to the heart

CIRCULATIONCIRCULATION

• Pulmonary• Right side of the heart pumps oxygen

poor blood from the heart to the lungs

• Pulmonary• Right side of the heart pumps oxygen

poor blood from the heart to the lungs

CIRCULATIONCIRCULATION

• Systemic• Oxygen rich blood comes back to the

left side of the heart• Blood is pumped out to the cells of

the body

• Systemic• Oxygen rich blood comes back to the

left side of the heart• Blood is pumped out to the cells of

the body

PATHWAYPATHWAY

• Right atrium ->• Right ventricle ->• Pulmonary artery ->• Lungs ->• Pulmonary vein ->• Left atrium ->• Left ventricle ->• Aorta ->• Arteries, capillaries, veins ->• Vena cava -> right atrium

• Right atrium ->• Right ventricle ->• Pulmonary artery ->• Lungs ->• Pulmonary vein ->• Left atrium ->• Left ventricle ->• Aorta ->• Arteries, capillaries, veins ->• Vena cava -> right atrium