1. Circulatory System Structure and Function

2. Function of the Circulatory System. – The circulatory system transports energy, nutrients, and gases throughout the body and aids in defense against infection.

3. 2 Types of Circulatory Systems Systemic Circulation takes the oxygen-rich blood from the pulmonary circulation and pumps it to all tissues of the body (except the lungs) and returns it to the heart. Pulmonary Circulation Transports oxygen-poor blood to the lungs, where it picks up oxygen and loses carbon dioxide, then returns it to the heart.

4. Circulatory System Systemic vs. Pulmonary Diagram

5. Circulatory System Organ: Heart Structure – The heart is a fist-sized, muscular pump with four chambers: two atria (left/right) two ventricles. (left/right) Function – The heart is the pump that drives the pulmonary and systemic circulation.

6. Circulatory System Organ: Heart How does it carry out its job? – The atria fill with blood as the heart relaxes. The right atrium fills with oxygen-poor blood returning from the systemic circulation. The left atrium fills with oxygen-rich blood returning from the pulmonary circulation. Blood passes into the ventricles. When the heart contracts the blood is pumped from the right ventricle into the pulmonary artery into the lungs. The blood in the left ventricle is pumped through the aorta and onto the other tissues of the body (the systemic circulation). The left ventricle is the most powerful chamber of the heart. (or watch the video on the following slide)

7. Circulatory System Heart circulation animation http://www.youtube.com/watch?v=D3ZDJgFD dk0 http://www.youtube.com/watch?v=D3ZDJgFD dk0

8. Circulatory System Organ: Blood Vessels Arteries: carry blood away from the heart. Main artery carrying oxygen to the body is the aorta Veins: carry blood toward the heart. Capillaries: mini vessels between venuoles (veins) and arterioles (arteries). Site of gas exchange

9. Circulatory System Organ: Blood Purpose: – transports nutrients, energy ( from small intestine - digestive system) and oxygen (from lungs- respiratory system) to every cell of the body. – transports waste products away from the cells to the lungs carbon dioxide - which is transported to the lungs and expelled from the body during exhalation.

10. Organ: Blood What is blood made of? – Cells Red blood cells (a.k.a. RBC or erythrocytes) deliver oxygen White blood cells (a.k.a. WBC or leucocytes) fight infection Platelets (thrombocytes) helps to clot blood Liquid/ plasma – a combination of water and dissolved substances