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Biology 1030 Winter 2009 Meeting Tissue Needs Chapter 41 (41.1–4) Chapter 42 (42.1,5–7) Winter 2009 L t Lectures 10 13 10-13 Scott circa 2009 Cellular Work • Cellular work • Source of energy – Cellular currency • Cellular respiration – Reactants – Products Scott circa 2009 1 Biology 1030 Winter 2009 Trafficking • Each cell needs: – A supply of each reactant • Digestive system • Respiratory system – A waste removal system • Respiratory system • Renal system y • A mechanism to connect these systems Scott circa 2009 A Matter of Size • Diffusion • Bulk flow • Size matters – No circulatory system – Gastrovascular cavity – Open circulatory system – Closed circulatory system Scott circa 2009 2 Biology 1030 Winter 2009 Gastrovascular Cavity • GVC and body shape • C Cnidarians id i – Diploblastic – Fairly big • Platyhelminths – Triploblastic – Very thin • Diffusion Scott circa 2009 Open Circulatory Systems 1. 2. 3. 4. Heart pumps hemolymph Open-ended arteries Sinuses, no veins Openings in the heart • One body fluid • Seen in: – Arthropods, Arthropods Brachiopods, Brachiopods Mollusks, Mollusks tunicates and lancelets • Advantages Scott circa 2009 3 Biology 1030 Winter 2009 Closed Circulatory Systems 1. 2. 3. 4. Heart pumps blood Arteries to tissues Capillaries Veins to heart • Advantages – Pressure – Flow – Portal veins • Two separate fluids – Blood – Interstitial fluid (lymph) • Seen in: – Annelids, Cephalopods, Echinoderms, Vertebrates Scott circa 2009 Collection Sites • Intestine – Facilitated diffusion • Respiratory surface – Diffusion Scott circa 2009 4 Biology 1030 Winter 2009 Vertebrate Circulatory Systems • Evolution of complexity Fish • A simple 2 chamber heart – 1 Atrium – 1 Ventricle • One circulatory loop Scott circa 2009 Vertebrate Circulatory Systems Amphibians • Three chambered heart At i – 2 Atria – 1 Ventricle • Double circulation – Pulmocutaneous circuit – Systemic circuit • Advantages Scott circa 2009 5 Biology 1030 Winter 2009 Vertebrate Circulatory Systems Reptiles • Double circulation – Pulmonary circuit P l i it – Systemic circuit • Three chambered heart – Ventricle has a partial septum • Advantages Scott circa 2009 Vertebrate Circulatory Systems Birds and Mammals • Double circulation P l i it – Pulmonary circuit – Systemic circuit • Four chambered heart – Complete septum • Advantages Scott circa 2009 6 Biology 1030 Winter 2009 Basic Nutrition • Heterotrophy • Carbon compounds p – Generation of ATP – Generation of macromolecules • Essential nutrients – Some amino acids – Some fatty acids • Vitamins • Minerals & Electrolytes Scott circa 2009 Essential Nutrients • 20 amino acids – ~ ½ can be synthesized • N source – ~ ½ are essential • Complete proteins – Animal proteins • Incomplete proteins – Plant proteins • Deficiency – Salt licks Scott circa 2009 7 Biology 1030 Winter 2009 Essential Nutrients • Osteophagia Scott circa 2009 Getting Nutrients – Ingestion • Suspension or Filter feeding • Substrate feeding • Fluid feeding • Bulk feeding Scott circa 2009 8 Biology 1030 Winter 2009 Filter Feeding • Evolution of specific structures – Appendages, Pharynx, Teeth, Gills – Secreted S t d mucus sacs • Is filter feeding restricted to small organisms? Scott circa 2009 Substrate Feeding • Eat your environment – Earthworm – Apple maggots – Leaf miner insects Scott circa 2009 9 Biology 1030 Winter 2009 Fluid Feeding • Parasitizing a living host • Specialized mouthparts – Thin, sharp, hollow stylets Aphid Mosquito Scott circa 2009 Fluid Feeding – Aphids • Photosynthates as food • Aphid exploitation Scott circa 2009 10 Biology 1030 Winter 2009 Blood Feeding • Specialized fluid feeders – Anticoagulants Scott circa 2009 Vampires Scott circa 2009 11 Biology 1030 Winter 2009 Bulk Feeding • Ingestion of entire prey – Adaptations of jaws • Ingestion of smaller bits – Adaptations of teeth Scott circa 2009 Bulk Feeding SA64 = 6×64 = SA = 4×4×6 = SA1 = 1×1×6 = • The derived behaviour is to tear off pieces – Adaptations evolved – Teeth, claws, etc. • Advantages? Scott circa 2009 12 Biology 1030 Winter 2009 Food Processing 1. Ingestion – Is this inside the body? 2. Digestion – Mechanical – Chemical 3 Absorption 3. 4. Elimination Scott circa 2009 Teeth & Mastication • The mammalian mouth – – – – Incisors Canines Premolars Molars • Modifications based on diet Scott circa 2009 13 Biology 1030 Winter 2009 Teeth & Mastication • Herbivores – Grinding & pulverizing molars – Cutting incisors Scott circa 2009 Teeth & Mastication • Carnivores – Capture & killing canines – Shearing premolars – Molars? Scott circa 2009 14 Biology 1030 Winter 2009 Chemical Digestion Oral groove Cell mouth • Where Does Chemical Digestion Occur? • Intracellular – All protists – Sponges – Tripeptides Food vacuoles • Extracellular – Chamber Scott circa 2009 Digestion • Gastrovascular cavity – Cnidaria – Platyhelminthes • Alimentary canal – Most other phyla Anus Mouth Scott circa 2009 15 Biology 1030 Winter 2009 Alimentary Canals • Regional Specialization Mouth Esophagus Crop Gizzard Intestine Esophagus Pharynx Stomach Gizzard Intestine Crop Anus Anus Mouth Foregut Midgut Hindgut Rectum Anus Esophagus Crop Mouth Gastric cecae Scott circa 2009 Digesting Carbohydrates • The average human diet • The major dietary carbohydrates are: – – – – Starch & glycogen Sucrose Lactose Maltose Scott circa 2009 16 Biology 1030 Winter 2009 Digesting Carbohydrates • Absorption is limitted • Amylase • Maltase • Sucrase • Lactase • Facilitated diffusion Scott circa 2009 Digesting Proteins NH3 COOH NH3 NH3 COOH COOH NH3 COOH • Acid hydrolysis 1 Endopeptidases 1. E d tid – Pepsin, trypsin, chymotrypsin Scott circa 2009 17 Biology 1030 Winter 2009 Digesting Proteins NH3 NH3 COOH NH3 COOH COOH NH3 COOH 2. Exopeptidases – Carboxypeptidases, aminopeptidases • Facilitated diffusion • Intracellular digestion Scott circa 2009 Digesting Lipids • Triglycerides – Fats and oils • Oil and water don’t mix! – Emulsification – Bile salts from micelles • Lipase • Reassembled in cell • Chilomicrons Scott circa 2009 18 Biology 1030 Winter 2009 Maximizing Surface Area • Maximizes digestion and absorption – Villi and Microvilli Scott circa 2009 Maximizing Surface Area • Typhlosole of earthworm (big fold) • Gastric caeca of insects (branches of gut) • Spiral valve of sharks Scott circa 2009 19 Biology 1030 Winter 2009 Adaptation to Diet • Eating meat • Eating E ti plants l t Small intestine Stomach Small intestine Cecum Colon Carnivore Herbivore Scott circa 2009 No Digestion? • Cestodes – Habitat • Absorption of predigested material – Integument Scott circa 2009 20 Biology 1030 Winter 2009 Digesting Cellulose • Complex glucose polymer – Not digestible – Microscopic organisms can • Symbiotic relationships • Fermentation chambers • Multiple stomachs • Reprocessing food Scott circa 2009 Other Alternatives • Symbiotic cellulases – The termite • Wood = cellulose • Endosymbiotic protists – Leafcutter & gardening ants • Exosymbiotic fungi • ‘Compost’ piles Scott circa 2009 21 Biology 1030 Winter 2009 Other Alternatives • A second precessing – Absorption in the small intestine – Microorganisms Mi i live li in i the th large l intestine i t ti & cecum – Therefore many animals practice coprophagy Scott circa 2009 Cellular Respiration vs. Respiration • One is the reason for the other Scott circa 2009 22 Biology 1030 Winter 2009 Movement of Gases • Simple diffusion – Concentration gradient • Diffuse away • Efficiency of diffusion – Slow and short – Maximum efficient distance • All cells must be close to source Scott circa 2009 Gas Exchange Requirements • Requirements for gas exchange: 1 Moist surface 1. 2. Adequate surface area • Larger animals have more cells Scott circa 2009 23 Biology 1030 Winter 2009 Respiratory Surfaces 1. Body surface – Cutaneous respiration • Specific respiratory surfaces 2. Gills 3. Lungs Scott circa 2009 Gas Exchange • Size and Habitat Diffusion • Porifera • Cnidaria • Platyhelminthes Diffusion + Circulation • Highly vascularized • Capillaries – Pick up oxygen – Drop off carbon dioxide • Most of the other phyla Scott circa 2009 24 Biology 1030 Winter 2009 Cutaneous Respiration • When does this work? – Dependent on water • Aquatic or damp terrestrial – Thin skin Scott circa 2009 Cutaneous Respiration • Amphibians – Not completely aquatic – Rely on water Scott circa 2009 25 Biology 1030 Winter 2009 Water Breathing • Large aquatic organisms – Evaginations (outgrowths) • Thin-walled Thin walled structures • Why not cutaneous respiration? • External Gills • Internal Gills Scott circa 2009 Water Breathing • The Polychaetes – Parapodia N • Numerous • Relatively thin • Rich blood supply – Palps • Multitasking structures • Ventilation Scott circa 2009 26 Biology 1030 Winter 2009 Ventilation • Internal gills • Water current – Gill bailers – Cilia Scott circa 2009 Ventilation • Ram-jet ventilation • Buccal pump Scott circa 2009 27 Biology 1030 Winter 2009 Gas Exchange – Aquatic Water Blood 1. Concurrent exchange – E ilib i Equilibrium Scott circa 2009 Gas Exchange – Aquatic 2. Countercurrent exchange – V Very efficient! ffi i t! Scott circa 2009 28 Biology 1030 Winter 2009 Air Breathing • Lungs • Invaginations – Moist – Large surface area • Water loss Scott circa 2009 Ventilation • Essential • Inhalation 1. Active contraction 2. Lungs expand • Negative pressure Scott circa 2009 29 Biology 1030 Winter 2009 Ventilation • Exhalation 3. 3 Muscles relax 4. Lungs recoil • Positive pressure Scott circa 2009 Gas Exchange – Terrestrial • Variable efficiency • Frogs have: – Small lungs – Parasitic flukes • How is this possible? • Need to keep moist – Amphibious – Mucus Scott circa 2009 30 Biology 1030 Winter 2009 Other Vertebrate Lungs Branch of pulmonary vein (oxygen-rich blood) Branch of pulmonary artery (oxygen-poor blood) Terminal bronchiole • Alveoli – air sacs – Gas exchange – Numerous capillaries N ill i • Incredible surface area – ~100 m2 in humans Alveoli SEM 50 µm Colorized SEM 50 µm Scott circa 2009 Other Vertebrate Lungs Anterior air sacs Posterior air sacs Air Trachea – Breath 2 • Fresh air to lungs St l air i outt • Stale Lungs Air Lungs INHALATION Air sacs fill • Birds Air tubes (parabronchi) in lung – Air sacs expand EXHALATION Air sacs empty; lungs fill – Breath 1 • Fresh air to posterior sacs • Stale air to anterior sacs Scott circa 2009 31 Biology 1030 Winter 2009 Air Breathing • The Insects – Tracheal system • Spiracles • Tracheae & tracheoles Tracheae Spiracle • Direct air supply Body cell Tracheole Air sac Trachea Body wall 2.5 µm Air Scott circa 2009 Gas Transport • Oxygen • Metalloproteins – Hemocyanin – Hemoglobin Iron Heme Scott circa 2009 32 Biology 1030 Winter 2009 Gas Transport Body tissue CO2 produced Interstitial fluid CO2 Plasma within capillary CO2 Red blood cell • Carbon dioxide • Carbonic anhydrase Capillary wall Hb + CO2 transport from tissues Hemoglobin g picks up ~5% CO2 H+ Scott circa 2009 Waste Removal Ammonia Urea Uric acid • Carbon dioxide – Respiratory surface R i t f • Nitrogenous waste – Amino & nucleic acid metabolism Scott circa 2009 33
