1. Circulatory and Respiratory Systems Chapter 37

2. Circulatory System Transports oxygen, nutrients, and hormones throughout body Transports oxygen, nutrients, and hormones throughout body Removes waste products from cells Removes waste products from cells –CO 2, urea

3. The Heart Four Chambers Four Chambers –Left and Right Atria Receive bloodReceive blood –Left and Right Ventricles Pump blood outPump blood out Septum divides left and right sides Septum divides left and right sides Left side – oxygenated blood Left side – oxygenated blood Right side – deoxygenated blood Right side – deoxygenated blood

5. Circulation Pulmonary Pulmonary –Right Vent.  Pulmonary Arteries  Lungs  Pulmonary Veins  Left Atrium Systemic Systemic –Left Vent.  Aorta  Body  Vena Cava  Right Atrium

6. Circulation

7. Heartbeat Controlled by the pacemaker (sinoatrial node) Controlled by the pacemaker (sinoatrial node) Atria contract first, ventricles contract second Atria contract first, ventricles contract second

8. Blood Vessels Arteries – away from heart Arteries – away from heart –Have smooth muscle in walls –Ventricles push blood through Capillaries – nutrient/waste exchange Capillaries – nutrient/waste exchange –RBC must line up single file to fit Veins – to the heart Veins – to the heart –Have valves to prevent backflow –Skeletal muscles push blood through

9. Blood Vessels

10. Blood Plasma – liquid, 55% of volume Plasma – liquid, 55% of volume –Carries dissolved nutrients, hormones and wastes Erythrocytes (RBC) Erythrocytes (RBC) –Made in red bone marrow –No organelles –Full of hemoglobin Binds O 2 in lungsBinds O 2 in lungs

11. Blood Leukocytes (WBC) Leukocytes (WBC) –Made in red bone marrow –Have organelles –No hemoglobin –Attack foreign substances or organisms Platelets – cell fragments Platelets – cell fragments –Create blood clots

12. Blood Red Blood Cell White Blood Cell Platelets

13. Lymphatic System Lymph vessels collect excess fluid from tissues and return it to the blood (3L/day) Lymph vessels collect excess fluid from tissues and return it to the blood (3L/day) Lymph nodes filter lymph fluid for bacteria Lymph nodes filter lymph fluid for bacteria –Swollen glands

14. Respiratory System Path of inhaled air: Path of inhaled air: –Nose/sinuses –Pharynx – where trachea and esophagus are one pipe –Larynx – voice box –Trachea – cartilage ringed windpipe –Bronchi – one to each lung –Alveoli – tiny air sacs in lungs

15. Respiratory System

16. Gas Exchange 350 million alveoli 350 million alveoli Alveoli are surrounded by capillaries Alveoli are surrounded by capillaries O 2 diffuses into blood, CO 2 into alveoli O 2 diffuses into blood, CO 2 into alveoli Hemoglobin binds O 2 Hemoglobin binds O 2

17. Breathing Diaphragm contracts = inhale Diaphragm contracts = inhale Diaphragm relaxes = exhale Diaphragm relaxes = exhale

18. Control of Breathing CO 2 in blood becomes carbonic acid CO 2 in blood becomes carbonic acid –Lowers the pH of blood –Triggers receptor neurons in brain –Tells diaphragm to contract harder Breathing is controlled by CO 2 levels, not O 2 levels Breathing is controlled by CO 2 levels, not O 2 levels