Please enable JavaScript.
Coggle requires JavaScript to display documents.
Circulation, Gas Exchange, and the Immune System - Coggle Diagram
Circulation, Gas Exchange, and the Immune System
Chapter 43: The Immune System
Two Lines of Defense
Innate Immunity: Rapid, non-specific, present in all animals.
Adaptive Immunity: Specific, slower, unique to vertebrates; has memory.
Innate Immunity
Barrier defenses: Skin, mucous membranes, secretions.
Internal defenses
Phagocytic cells: Neutrophils, macrophages.
Natural killer (NK) cells: Destroy infected or cancerous cells.
Antimicrobial proteins: Interferons, complement system.
Inflammatory response: Histamine release, increased blood flow, swelling, redness, and healing.
Adaptive Immunity
Lymphocytes
B cells: Mature in bone marrow; produce antibodies (humoral response).
T cells: Mature in thymus; target infected cells (cell-mediated response).
Antigen: Substance that triggers immune response.
Antibody: Protein that binds specifically to an antigen.
Clonal Selection
Activated B or T cells divide to form effector cells and memory cells.
Types of Immune Responses
Humoral immunity: B cells secrete antibodies into body fluids.
Cell-mediated immunity: Cytotoxic T cells destroy infected cells.
Helper T cells: Activate both B and T cells; release cytokines.
Immunological Memory
Primary response: First exposure; slower.
Secondary response: Faster and stronger due to memory cells.
Vaccination: Uses weakened/disabled pathogen to trigger memory formation.
Disorders of Immunity
Allergies: Overreaction to harmless antigens.
Autoimmune diseases: Immune system attacks own tissues.
Immunodeficiency: Reduced immune function.
Chapter 42: Circulation and Gas Exchange
Open Circulatory System
Blood (hemolymph) bathes organs directly.
Found in insects, arthropods, and mollusks.
Closed Circulatory System
Blood is confined to vessels and distinct from interstitial fluid.
Found in annelids, cephalopods, and vertebrates.
Allows higher pressure and more efficient transport.
Vertebrate Circulation
Fish: Single circulation
Amphibians: Double circulation
Mammals: Double circulation
Pulmonary circuit: Heart → lungs → heart.
Systemic circuit: Heart → body → heart.
Heart Anatomy
Right atrium: Receives oxygen-poor blood.
Right ventricle: Pumps it to lungs.
Left atrium: Receives oxygen-rich blood.
Left ventricle: Pumps it to body tissues.
Valves prevent backflow (AV and semilunar).
The Cardiac Cycle
Systole: Contraction (pumping).
Diastole: Relaxation (filling).
Pacemaker (SA node): Generates heartbeat rhythm.
Regulated by electrical impulses through AV node and Purkinje fibers.
Blood Vessels
Arteries: Carry blood away from heart; high pressure.
Veins: Carry blood to heart; have valves.
Capillaries: Thin walls for diffusion of gases/nutrients.
Blood Composition
Plasma: 55% of blood; water, ions, proteins.
Cells
Erythrocytes: Contain hemoglobin; carry oxygen.
Leukocytes: Defend against pathogens.
Platelets: Aid in clotting.
Gas Exchange Systems
Respiratory surfaces: Thin, moist, large area (gills, tracheae, lungs).
Partial pressure gradients drive diffusion of gases.
Hemoglobin binds oxygen reversibly.
CO₂ Transport: Dissolved in plasma, bound to hemoglobin, or converted to bicarbonate ions.