2. Respiratory System

4. Composition of Air All Oxygen comes from PHOTOSYNTHESIS 78% N 2, 21% O 2,.93% Noble gases,.03% CO 2 Less Oxygen at Higher Altitudes Air Pressure measures 760 mm of Hg at Sea Level

5. Structure of Respiratory System Pair of lungs in Thoracic cavity Both Bronchi connected to a single Trachea Trachea passes upward Pass Larynx to rear of mouth Air enters nostrils, Hair filters out particles Each Bronchus divides into many Bronchioles Which leads to Alveoli

6. Mechanics of Breathing Intrapleural fluid supports & applies even pressure to all lungs System analogous to 1 balloon inside another – Space between balloons filled with fluid – Inner balloon(lung) opens to atmosphere – Pressure on inner balloon= air pushing out + H 2 O pushing in

7. Mechanics of Breathing ( Continued) Walls of chest cavity expand with Inhalation – Chest cavity (outer Balloon) is enlarged – Expansion of the fluid space Decreases fluid pressure – Pressure Less than the internal pressure in the Lungs – Air moves in from atmosphere to Equalize pressure

8. The Structure of Lungs Alveoli – Exchange zones in the Lungs – Increases the surface area – Short path length increases diffusion

9. How The Lungs Work Function as one-cycle pump – Chest walls expand during Inspiration – Enlarges the chest – Rib cage moves upward & outward – Diaphragm moves downward – See Figure 50-15

10. Gas Transport & Exchange Association of Respiratory & Circulatory Systems – Transport of O 2 very slow if by Diffusion – Transported by CIRCULATORY SYSTEM via CARRIER PROTEINS HEMOGLOBIN: O 2 carrier protein in Blood – Bright RED when bound with O 2, – O 2 bounded to IRON portion of Protein HEMOCYANIN: O 2 carrier protein in invertebrates – Bright BLUE when bound with O 2 – O 2 bounded to COPPER portion of Protein

11. OXYGEN Transport Only 5% transported in blood plasma 95% bound to HEMOGLOBIN in RBCs Partial Pressure of OXYGEN= PO 2 – If higher in lungs MORE O 2 will dissolve in blood and combine with Hemoglobin – Lower at tissues so Hemoglobin gives up O 2 to tissues Presence of CO 2 at tissues – Causes Hemoglobin to change its shape thus UNLOADING O 2

12. The Exchange Process Oxygen-rich air interfaces with Oxygen-poor blood at Alveoli – Oxygen in plasma diffuses into red blood cells CO 2 Transport – As RBCs Unload O 2, Blood absorbs CO 2 from tissues – RBCs carry CO 2 back to Lungs as Bicarbonate ions

13. Looking Ahead to CIRCULATION At Lungs RBCs Acquire O 2 & Release CO 2 At Tissues RBCs Acquire CO 2 & Release O 2

14. Circulatory System

15. Function Of Circulatory System 1. Nutrient & Waste Transport 1. Nutrients enter blood through small intestines 2. Carried to Liver for storage or Metabolism 3. Dissolved Glucose & Metabolites carried to ALL body cells 4. Waste carried to Kidney for removal

16. Function Of Circulatory System 2. Oxygen & Carbon Dioxide Transport 1. O 2 diffuses into blood through the lungs 2. O 2 accumulates in Hemoglobin of erythrocytes 3. O 2 released at metabolizing cells 4. CO 2 is released by cells in blood 5. Waste CO 2 carried back to Lungs & released 3. Temperature Maintenance 1. Heat distributed by circulating blood 4. Hormone Circulation

17. Pathway of Blood Superior & Inferior Vena Cava Right Atrium Tricuspid Valve Right Ventricle Right Semi lunar valve Rt & Lt Pulmonary Arteries Lungs Rt. & Lt. Pulmonary veins Left Atrium Bicuspid valve (Mitral Valve) Left Ventricle Left semi lunar valve Aorta Arteries Arterioles Capillaries, Venules, Veins

18. The Cardiovascular System 1. 3 Elements of Closed Circulatory System 1. Heart: muscular pump 2. Blood Vessels 1. Arteries: direct flow AWAY from the heart 2. Arterioles: Smaller vessels leading AWAY 3. Capillaries: Exchange of gases in tissues 4. Venules: small vessels that collect blood from capillaries 5. Veins: Large vessels that carry blood to heart 3. Blood: circulating fluid

19. Arteries: Highways from the heart Walls are composed of 4 layers – Innermost endothelial cells – Thick layer of elastic fibers – Layer of smooth muscle – Encased in connective tissue Elastic sheath allows artery to expand & increase its volume Muscle layer prevents over expansion Connective tissue protects vessels

20. Arterioles: Little arteries Hormones, Metabolites can relax muscle layer thus increases the blood flow Nerve stimulation contracts muscle, decreases blood flow Capillaries: where exchange takes place – Single cell layer thick – They directly connect arterioles with venules – Found in the tissues

21. Veins & Venules Returns blood to the Heart One-way valves direct flow toward the heart Blood flow assisted by movement of muscles Lymphatic System: recovers lost fluid – Collects fluid & returns it to the blood – Lymphatic vessels contain vein-like one-way valves – Fluid movement assisted by muscle

22. Blood Blood plasma: the Blood’s fluid 1. Water 2. Metabolites & wastes 1. Metabolites, vitamins, hormones, & wastes 3. Salts & Ions 1. Primary Na, Cl, & Bicarbonates 4. Proteins 1. Antibodies & Globulin proteins of immune system 2. Fibrinogen…Blood clotting 3. Serum Albumin…maintains osmotic counterforce

23. Blood Cells Erythrocytes: Red Blood Cells – 45% of Blood Volume – Cells produced in Bone Marrow – 120 days Leukocytes: White Blood Cells – Less than 1% of total Blood cells – Function to defend body against pathogens – 2 years life span Platelets: Thrombocytes… Helps blood to Clot – (10 days)

24. Blood Groups O= 45% US Caucasians A= 40% US Caucasians B= 11% US Caucasians AB= 4% US Caucasians O AB

25. Rh System 1. Rh+= 87% Rh-= 13% 2. During Pregnancy Mother: Rh-Baby: Rh+ 1 st Pregnancy: Rh+ may leak into mother’s circulation system, causing mother to produce anti-Rh antibodies. 2 nd Pregnancy: Mother’s anti-Rh antibodies may cross placenta & destroy Fetus’s RBC’s