1. THE CIRCULATORY, RESPIRATORY & IMMUNE SYSTEMS

2. HW: P. 950 #1-4

3. Circulatory system is composed of the heart, blood vessels and blood that flows within. Main function is to transport oxygen and nutrients and dispose of waste.

4. The heart is an organ that pumps blood. It is mostly composed of layers of muscle, myocardium. 4 Chambers: Left/Right Atrium: receives blood Left/Right Ventricle: pumps blood out of heart Left = oxygenated (red) Right = deoxygenated (blue) Pulmonary Circulation: pumps blood between heart and lungs Systemic Circulation: pumps blood between heart and body Valves: close when ventricles contract; keep blood moving in one direction

5. Pacemaker: group of cells in the SA node that “set the pace” of the heart Impulse spreads from SA node to atria then to AV node and ventricles

6. Three Types: Arteries: thick vessels that carry blood Away from the heart; high pressure Capillaries: smallest vessels; where exchange occurs Veins: vessels that return blood to the heart; some contain valves to keep blood flow in one direction; skeletal muscles increase venous return

7. Blood pressure: pressure of blood on vessel walls Sphygmomanometer: device used to measure blood pressure Normal measurement: 120/80 First measurement: systolic pressure Second measurement: diastolic pressure Medulla oblongata regulates blood pressure with neurotransmitters

8. Atherosclerosis: plaques (fat deposits) form on vessel walls Narrowed arteries make the heart work harder to pump blood Clots can form and break off into vessels of the brain, causing a stroke.

9. HW: P. 955 #1-4

10. Blood collects… Oxygen from lungs Nutrients from digestive system Waste from tissues Blood composition: 45% cells 55% plasma (fluid in blood, mostly water)

11. Red Blood Cells (RBCs): Carry oxygen Hemoglobin: iron-containing protein that binds oxygen Biconcave shape No nuclei; life cycle ~120 days White Blood Cells (WBCs): Guard against infection, fight parasites and attack bacteria Phagocytes “eat” pathogens Lymphocytes: immune response (T-cell, B-cells)

12. Platelets: fragments of large cells found in bone marrow “sticky” platelets clump together and form a clot at damaged sites; a protein cascade forms tough fibers to seal the wound Can you think of a disease where clotting factors are mutated?

13. Lymphatic system: network of vessels, nodes, and organs that collect fluid lost by the blood and return it back to the circulatory system. Lymph carries lymphocytes throughout the body. Thymus: gland where T- cells mature

14. HW: P. 1042 # 1-4

15. Function: to fight infection through immunity, the production of cells that inactivate foreign substances or cells. Two types of defenses: Nonspecific: keep things out (fortress walls) Specific: track down pathogens that enter the body (security guards)

16. 1 st line of defense: skin, mucus, sweat and tears act as a barrier 2 nd line of defense: inflammatory response (WBCs migrate to injury site) Fever: increased body temperature can kill many pathogens Interferons: proteins that interfere with viral replication

17. Humoral immunity (fig. 40-9, p. 1039): B cells attack antigens in body fluids by producing antibodies, Y-shaped proteins that target pathogens for destruction Cell-mediated immunity (fig. 40-10, p. 1040): killer T cells track down and destroy cells infected from the inside (assassins of the WBCs) Immune Response: specific defenses that attack invading pathogens (antigens)

18. Active immunity: developed after exposure to an antigen (i.e. vaccines or natural exposure to infection cause the body to produce antibodies) Passive immunity: injection of antibodies from another organism (i.e. mother’s antibodies during breastfeeding temporarily provides immunity for the baby)

19. HW: P. 963 #1-4, P. 967 #1-10

20. Respiration: Food  Energy (cellular) Gas exchange Function: gas exchange (O2 and CO2) between blood, the air, and tissues Organs: nose, pharynx (throat), larynx, trachea (windpipe), bronchi, and lungs

21. Pharynx: passage of air and food Trachea: passage of air Epiglottis: tissue blocks trachea during swallowing (prevents choking) Cilia and mucus: warm, moisten, and filter air to keep lungs clean Larynx: vibration of vocal cords produce sound (voice box) Bronchi: branch into the lungs Bronchi  Bronchioles  Alveoli Alveoli: tiny air sacs surrounded by capillaries; where gas exchange occurs (fig. 37-14, p. 958)

22. Occurs between the alveoli and capillaries Oxygen: alveoli  blood Carbon dioxide: blood  alveoli

23. Diaphragm: flat muscle underneath lungs (CNS control) Pressure controls breathing (high  low) Inhale (breath in): diaphragm contracts, chest rises, low lung pressure Exhale (breath out): diaphragm relaxes, chest lowers, high lung pressure

24. Nicotine: addictive chemical, increases heart rate and blood pressure Carbon monoxide: prevents oxygen binding to hemoglobin Tar: cancerous compounds