240 likes | 382 Views
Chapter 38. Circulation. Circulatory System. Carries blood & related cells through body Move nutrients Move gases Move wastes Fight disease Maintain temperature Maintain homeostatis. No Circulatory System. Osmosis & diffusion Exchanges across cell membrane P rotozoans
E N D
Chapter 38 Circulation
Circulatory System • Carries blood & related cells through body • Move nutrients • Move gases • Move wastes • Fight disease • Maintain temperature • Maintain homeostatis
No Circulatory System • Osmosis & diffusion • Exchanges across cell membrane • Protozoans • Exchanges across epidermal & gut walls • Cnidarians, flatworms, roundworms • Exchanges with coelomic fluids • Echinoderms
Open Circulatory System • Most mollusks, all arthropods • Heart, open vessels • Hemolymph • Colorless • No respiratory pigments • Doesn’t transport gasses • Hemocoel • Hemocyanin • Pigment in most mollusks, some arthropods • 25% as efficient as hemoglobin • Efficient due to lack of gas transport
Closed Circulatory System • Annelids, cephalopods, all vertebraes • Blood confined to heart & blood vessels • Capillaries—site of exchange • Hemoglobin • Gas & nutrient carrier • Specialized organs for gas exchange
Closed Circulatory System • 2 Chambered Heart • Sharks, fish • One atrium, one ventricle • 3 Chambered Heart • Amphibians, reptiles • Two atria, one ventricle • Oxygenated & deoxygenated blood mix • 4 Chambered Heart • Alligators/crocodiles, birds, mammals • Two atria, two ventricles • Oxygenated & deoxygenated blood separate
Heart • Atria • Thin-walled • Receive blood from veins • Ventricles • Thick-walled • Receive blood from atria • Pump blood to lungs/gills & body • Atrioventricular valves • Tricuspid—Right atrium & ventricle • Mitral (bicuspid)—Left atrium & ventricle • Semilunar valves • Pulmonary—Right atrium & pulmonary artery • Aortic—Left atrium & aorta
Blood Vessels • Arteries • Carry blood away from heart • Usually carry oxygenated blood • Thick, muscular walls • Arterioles • Smaller arteries • Regulate blood pressure through constriction & dilation
Blood Vessels • Capillaries • Simple squamous epithelium • Most numerous vessels • Site of nutrient & gas exchange
Blood Vessels • Veins • Carry blood towards heart • Usually carry unoxygenated blood • Thin walls • Low blood pressure • One-way valves • Blood moves by muscle contraction
Blood • Plasma • 90% water • Ions, gasses, nutrients, proteins, wastes • Transport medium • Approximately 55% of total blood volume • Cells • White, red, platelets • Made in red marrow
Blood • Erythrocytes (red blood cells, RBCs) • Contain hemoglobin • Non-nucleated in mammals • Live 120 days • Thrombocytes (platelets) • Blood clotting • Live 7 days
Leukocytes (white blood cells, WBCs) • Neutrophils • 40-75% • Phagocytize bacteria, fungi • Lymphocytes • 20-45% • Cells w/ viruses & bacteria • Tumor cells • Monocytes • 2-6% • Bacteria, fungi, cellular debris • Eosinophils • 1-6% • Parasites, allergies • Basophils • <1% • Allergies
Blood Types • Antigens on surface of RBCs • Body “reads” these, develops antibodies to any not “self” • At next exposure, antibodies attach, causing clumping • Blood groups vary by animals • Humans—4 • A, B, AB, O • Cats—3 • A (vast majority), B, AB • Dogs—8 • DEA 1-8 (DEA 4 & 6 on 98%) • Horses—8 • A, C, D, K, P, Q, T, U
Blood Types • ABO—Humans • Type O • 45% of population • Neither A nor B antigen • Anti-A, Anti-B • Receive only from O • “Universal donor” • Type A • 41% of population • A antigen • Anti-B • Receive from A or O • Type B • 10% of population • B antigen • Anti-A • Receive from B or O • Type AB • 4% of popuation • A and B antigen • No antibodies • “Universal recipient”
Blood Types • Rhesus factor • Rh positive—have antigen (85%) • Rh negative—do not have antigen, produce anti-Rh antibodies (15%) • If mother is Rh- and baby is Rh+, her antibodies can attack baby’s RBCs • First child usually normal
Lymphatic System • Collects excessive fluid filtered out in capillaries • Returns excessive water & solutes to blood stream • Movement due to valves, muscle contraction
Lymphatic System • Functions as part of immune system • Lymph nodes • Destroy pathogens & cellular debris • Cells rapidly divide with infecion • Spleen • Filters pathogens • Filters dead or dying RBCs