Transcript lect11-4cut
Respiratory System Respiratory System • Organs concerned with exchange of gases between animal and environment • Not ___________ respiration (glucose broken down to make ATP) Respiratory System • External respiration: exchange of gases between air in lungs and blood • Internal respiration: exchange of gases between blood and body tissues Respiratory System • Divisions of respiratory system – Upper respiratory system: Nose, throat and trachea – Lower respiratory system: Lungs (bronchi, bronchioles, alveoli) Respiratory System • Upper respiratory system – External nares (nostrils) – Nasal cavity: contains nasal turbinates (paper thin bones). Covered with mucous membranes. Functions: warm and humidify air, filter air (dust particles, etc.) Respiratory System • Upper respiratory system – Nasopharynx: contains tonsils. ________ tissue. Used to protect respiratory system from airborne infections, but not vital (often removed). Respiratory System • Upper respiratory system – Larynx: voicebox. Vocal cords: bands of connective tissue that __________ when air passed over them – Neck, cheek, mouth and tongue form sounds into words. Respiratory System • Lower respiratory system – – – – – Trachea Bronchus (left and right) Bronchioles Alveolar sacs Alveoli Respiratory System • Lower respiratory system – Diaphagm (only in mammals): made of muscles and tendons – Pleural cavity (partial ___________) – Intercostal muscles (between ribs) • Inhalation – – – – – Respiratory System 1) Intercostal muscles contract (ribcage raises) 2) Diaphragm contracts (moves downward) 3) Volume of pleural cavity increases 4) Internal lung pressure decreases 5) Air enters lungs • Exhalation – – – – – Respiratory System 1) Intercostal muscles relax (ribcage lowers) 2) Diaphragm relaxes (moves upward) 3) Volume of pleural cavity decreases 4) Internal lung pressure increases 5) Air leaves lungs Respiratory System • Sucking chest wound (not the song) – Pleural cavity unsealed – Lung collapses as air pressure difference between chest cavity and outside kept constant by wound (air flows in and out of wound) Respiratory System • Gas transport: overall plan – – – – 1) Heart pumps low oxygen blood to lungs 2) Oxygen in and carbon dioxide out 3) Blood returns to heart and is pumped to body 4) Oxygen out of blood and carbon dioxide in Respiratory System • Gas transport – Oxygen non-polar: not very __________ in water – Hemoglobin: protein that binds with oxygen. Contains Fe in each chain, which binds oxygen. Respiratory System • Red blood cell or rbc (ethrythrocyte) contains 300 million hemoglobin molecules. Each molecule binds to 4 oxygen molecules. 1200 million oxygen molecules on 1 rbc! Respiratory System • Carbon dioxide transported in 3 ways: – 1) Dissolved in plasma (_______% of CO2) as bicarbonate (HCO3-). – CO2 + H2O forms H2CO3 which forms H+ and HCO3– This also affects pH of blood. More CO2 means lower blood pH. Respiratory System • Carbon dioxide transported in 3 ways: – 2) Bound to hemoglobin (25%). Binds to amino acids, not to Fe. – 3) Dissolved in plasma as CO2 (8%). Respiratory System • Control of breathing: – Brain stem center monitors blood pH – If pH drops, then too much CO2 in blood – Breathing rate _____________ in response. Circulatory System Circulatory System • Functions: – 1. Transport of materials (gases, nutrients, wastes) – 2. Temperature regulation Circulatory System • Functions: – 1. Transport of materials (gases, nutrients, wastes) – 2. Temperature regulation – 3. Carries _____________ hormones – 4. Protection (immune defense, blood clotting) Circulatory System • Types in animals: – None! Phylum Platyhelminthes, Nematoda, Echinodermata, etc. Circulation can occur (ex, nematodes) due to body movements. Circulatory System • Types in animals: – Open. Phylum Arthropoda, Mollusca. No capillaries: have __________ into which blood flows from vessels. Circulatory System • Types in animals: – Closed. Phylum Annelida, Chordata. Blood always stays in vessels as it circulates. • Vessels: Circulatory System – Arteries (carry blood away from heart): large diameter – Thick elastic muscular walls. Can handle high blood pressure – Connective tissue sheath outside, endothelium inside. Circulatory System • Vessels: – Arterioles (carry blood away from heart): small diameter (microscopic) – Smooth muscle controls blood flow. Vasoconstriction is contraction to cut flow down – Vasodilation is relaxation to increase flow. Circulatory System • Vessels: – Precapillary sphincters: smooth muscle valves on some arterioles near capillaries. Can cut off blood flow – Important: most capillaries not open simultaneously (blood pressure would ___________ critically). Parts take turns. Circulatory System • Vessels: – Capillaries: very small diameter (8 micrometers: rbc only 5-7 micrometers wide). Where most exchange of materials takes place – Every cell in body within 100 micrometers of a capillary! – 250,000 capillaries in area size of little fingernail Circulatory System • Vessels: – Capillaries connect arteriole to venule – No smooth muscle, just endothelium (note diagram in error: capillary on upper right) • Vessels: Circulatory System – Venules (carry blood toward heart): small diameter (microscopic) – Smooth muscle thin. Pressure low (_____% of arteries). Connective tissue sheath outside, endothelium inside – Veins (carry blood toward heart): large diameter Note: labels for vein and capillary are reversed in diagram Circulatory System • Vessels: – Veins often have one-way valves. Muscle contractions can help move blood through valves Circulatory System • Vessels: – Varicose veins: weakened valves in legs allow backflow. Small veins bulge with venous blood. Circulatory System • Lymphatic system: open circulatory system Circulatory System • Blood plasma fluid in tissues (interstitial fluid) bathes tissues. Not all returns to blood capillaries • Lymphatic capillaries, vessels, nodes, organs • Capillaries collect __________ (lymph) and pass to larger vessels Circulatory System • Lymphatic system vessels: little smooth muscle in walls • Have series of one-way valves. Fluid moves mainly due to _____________ of nearby skeletal muscles Fluid moves left to right here Circulatory System • Lymph system functions • 1) Drain excess fluid from tissues (recall elephantiasis, where nematodes clog system) Circulatory System • Lymph system functions • 2) Involved in fat absorption from ____________ (covered) Circulatory System • Lymph system functions • 3) Fights infection at lymph nodes (about 100 in human body) – Bean shaped, various places. Circulatory System • Lymph system functions • 3) Produce B- and T-lymphocytes. These produce antibodies that detect foreign materials (ex, bacteria) – Nodes become _____________ in areas downstream of infection as lymphocytes attack invaders Heart • Major organ of circulatory system • Enclosed in membrane called pericardium • Pumps blood into arteries. Heart • Humans (vertebrates in general) have 4 chambered heart that functions in 2 sets of 2 chambers • Chambers called _________ receive blood, pump it into more muscular chambers called ventricles, which send blood away from heart. Heart • One set receives deoxygenated blood and sends it to lungs (pulmonary circulation) – Right atrium (receives deoxygenated blood) from superior (from head) and inferior (from lower body) vena cava arteries – Right ventricle (pumps it to lungs) via pulmonary _________. Heart • Second set receives oxygenated blood from lungs and sends it to body (systemic circulation) – Pulmonary vein brings oxygenated blood to left atrium – Left ventricle pumps oxygenated blood to body via _____. Heart • Note valves: prevent backflow of blood when chamber contracts • Tricuspid valve: between right atrium and ventricle • Bicuspid valve: between left atrium and ventricle Heart • Note valves: prevent backflow of blood when chamber contracts • Semilunar valves (aortic and pulmonary): between ventricles and arteries that receive blood from them. Heart • Chordae tendinae and papillary muscles keep bicuspid and tricuspid valves ___________. Heart • Beating controlled by special groups of cardiac muscle cells (called nodes) that generate impulse • Other cells then transmit impulse to one another via intercalated discs. Heart • SA node (right atrium) originates beat • Causes ________ to contract (ventricle relaxed at this time). Heart • AV node receives stimulus • Sends to ventricle cells through specialized cardiac muscle cells called Purkinje fibers • Ventricle cells then contract (after atria relax) Heart • Heart sound: Lub-dub • Lub: biscuspid and tricuspid valves closing as ventricles contract • Dub: aortic and pulmonary semilunar valves closing as ventricles re-fill Heart • Autonomic nervous system influences heartbeat rate – Sympathetic nerves: accelerate rate – Parasympathetic nerves: slow rate – Some hormones (ephinephrine = adrenalin): ______________ rate. Blood • Connective tissue: cells in matrix • Matrix: plasma. Blood • Plasma components: – 1. Water (______%) – 2. Salts (Ca, K, Na) – 3. Proteins • globulins: large immunoglobins (antibodies) • albumins: osmoregulation (most abundant blood protein) • fibrinogen: helps clotting. Serum is plasma minus fibrinogen – – – – – 4. Glucose (regulated by glucagon and insulin) 5. Glycerol and fatty acids 6. Hormones 7. Urea (nitrogenous waste) 8. Carbon dioxide and bicarbonate Blood • Cells (called formed elements) – Erythrocytes (red blood cells: rbcs): no nucleus, biconcave disc shape, flexible. Origin: red bone marrow Blood • Cells (called formed elements) – Leukocytes (white blood cells: wbcs): have nucleus. <___% of blood cells Blood • Cells (called formed elements) – Granular leukocytes (granulocytes) • Lobed nucleus and look grainy • Phagocytic cells. Fight infection, produced by red marrow • Types: neutrophils (stain well with neutral pH dye), basophils or mast cells (stain well with basic pH dye), eosinophils (stain well with eosin). Blood • Cells (called formed elements) – Agranular leukocytes • Large nucleus, no ___________ present • Formed in lymph nodes • Types: Monocytes (become macrophages in tissues, largest phagocytic cells, nucleus kidney bean shaped), Tlymphocytes (phagocytes), B-lymphocytes (make antibodies) Blood • Cells (called formed elements) – Thrombocytes (platelets) • No nucleus. Fragments of red bone marrow cells • Function in clotting of blood. Blood Summary • Cells (called formed elements) – Thrombocytes (platelets) • No nucleus. Fragments of red bone marrow cells • Function in clotting of blood Blood Clotting • Blood vessel wall broken • Platelets stick to each other and to break. Release___________ factors. Blood Clotting • Protein called prothrombin converted to thrombin, which causes fibrinogen in plasma to become fibrin (protein threads) • These threads bind together platelets and blood cells to make clot. How Phagocytic WBCs work • • • • Damage to tissues Mast cells release __________ Causes blood vessels to dilate Increases permeability of capillaries. How Phagocytic WBCs work • Neutrophils and monocytes stick to lining of capillary • Squeeze through wall into tissue • Locate and ________ invading cells.