Chapter 40: Basic Principles of Animal Form & Function Test corrections due Wednesday We are counting down the days so stay focussed. (a) Tuna (b) Shark (c) Penguin (d) Dolphin (e) Seal Chapter 40: Basic Principles of Animal Form & Function Evolutionary convergence in fast swimmers Chapter 40: Basic Principles of Animal Form & Function 1.How has exchange with the environment evolved? -Simple diffusion from direct contact w/ environment -To internal exchange thru moist medium Figure 40.3 Contact with the environment Diffusion (a) Single cell Mouth Gastrovascular cavity Diffusion (b) Two cell layers Figure 40.4 Internal exchange surfaces of complex animals External environment FoodCO 2 O2O2 Mouth Animal body Respiratory system Circulatory system Nutrients Excretory system Digestive system Heart Blood Cells Interstitial fluid Anus Unabsorbed matter (feces) Metabolic waste products (urine) The lining of the small intestine, a diges- tive organ, is elaborated with fingerlike projections that expand the surface area for nutrient absorption (cross-section, SEM). A microscopic view of the lung reveals that it is much more spongelike than balloonlike. This construction provides an expansive wet surface for gas exchange with the environment (SEM). Inside a kidney is a mass of microscopic tubules that exhange chemicals with blood flowing through a web of tiny vessels called capillaries (SEM). 0.5 cm 10 m 50 m Chapter 40: Basic Principles of Animal Form & Function 1.How has exchange with the environment evolved? -Simple diffusion from direct contact w/ environment -To internal exchange thru moist medium 2.Reminderwhat is the hierarchy of biological organization? Atoms molecules organelles cells tissues organs organ systems 3.What is a tissue & what are the 4 types? -Group of cells in a matrix with a common structure & function -Epithelial -Connective -Muscular -Nervous EPITHELIAL TISSUE Columnar epithelia, which have cells with relatively large cytoplasmic volumes, are often located where secretion or active absorption of substances is an important function. A stratified columnar epithelium A simple columnar epithelium A pseudostratified ciliated columnar epithelium Stratified squamous epithelia Simple squamous epithelia Cuboidal epithelia Basement membrane 40 m -Epithelial Tissue -Tightly packed sheets that cover the body, line organs & cavities w/in the body -Involved with secretion & absorption Collagenous fiber Elastic fiber Chondrocytes Chondroitin sulfate Loose connective tissue Fibrous connective tissue 100 m Nuclei 30 m Bone Blood Central canal Osteon 700 m55 m Red blood cells White blood cell Plasma Cartilage Adipose tissue Fat droplets 150 m CONNECTIVE TISSUE -Connective Tissue -Binds & supports other tissues -3 types -Collagenous -non-elastic skin wont rip -Elastic -elastin skin reshapes -Reticular -Thin & branched -Made of collagen -Joins connective tissue to neighboring tissue MUSCLE TISSUE Skeletal muscle 100 m Multiple nuclei Muscle fiber Sarcomere Cardiac muscle Nucleus Intercalated disk 50 m Smooth muscle Nucleus Muscle fibers 25 m NERVOUS TISSUE Neurons Process Cell body Nucleus 50 m Muscle tissue (ch 49) -Long cells made of contractile proteins -Actin & myosin -3 kinds -Skeletal aka striated (w/ lines) -Cardiac heart branched cells -Smooth -no striations -In walls of digestive tract, bladder, arteries Nervous tissue (ch 48) -Sense stimuli & transmits signals -neuron Chapter 40: Basic Principles of Animal Form & Function 1.How has exchange with the environment evolved? 2.Reminderwhat is the hierarchy of biological organization? 3.What is a tissue & what are the 4 types? 4.What is metabolism? -All of the chemical rxns within an organism -Catabolism breaks bonds releases energy exergonic -Anabolism forms bonds requires energy endergonic Figure 40.7 Bioenergetics of an animal: an overview Organic molecules in food Digestion and absorption Nutrient molecules in body cells Cellular respiration Biosynthesis: growth, storage, and reproduction Cellular work Heat Energy lost in feces Energy lost in urine Heat External environment Animal body Heat Carbon skeletons ATP Chapter 40: Basic Principles of Animal Form & Function 1.How has exchange with the environment evolved? 2.Reminderwhat is the hierarchy of biological organization? 3.What is a tissue & what are the 4 types? 4.What is metabolism? -All of the chemical rxns within an organism -Catabolism breaks bonds releases energy exergonic -Anabolism forms bonds requires energy endergonic 5.What is homeostasis & how is it achieved? -Steady state -Negative feedback -the response is in the opposite direction of the stimulus Figure A nonliving example of negative feedback: control of room temperature Response No heat produced Room temperature decreases Heater turned off Set point Too hot Set point Control center: thermostat Room temperature increases Heater turned on Too cold Response Heat produced Set point Set point is maintained Chapter 40: Basic Principles of Animal Form & Function 1.How has exchange with the environment evolved? 2.Reminderwhat is the hierarchy of biological organization? 3.What is a tissue & what are the 4 types? 4.What is metabolism? -All of the chemical rxns within an organism -Catabolism breaks bonds releases energy exergonic -Anabolism forms bonds requires energy endergonic 5.What is homeostasis & how is it achieved? -Steady state -Negative feedback -the response is in the opposite direction of the stimulus -Positive feedback -Response & stimulus are in the same direction 6.What are the 2 types of thermoregulation? -Ectothermic heat & metabolism based on environment -Endothermic heat & metabolism regulated internally Figure The relationship between body temperature and environmental temperature in an aquatic endotherm and ectotherm River otter (endotherm) Largemouth bass (ectotherm) Ambient (environmental) temperature (C) Body temperature (C) Chapter 40: Basic Principles of Animal Form & Function 1.How has exchange with the environment evolved? 2.Reminderwhat is the hierarchy of biological organization? 3.What is a tissue & what are the 4 types? 4.What is metabolism? 5.What is homeostasis & how is it achieved? 6.What are the 2 types of thermoregulation? 7.How do organisms exchange heat with their environment? Figure Heat exchange between an organism and its environment Radiation is the emission of electromagnetic waves by all objects warmer than absolute zero. Radiation can transfer heat between objects that are not in direct contact, as when a lizard absorbs heat radiating from the sun. Evaporation is the removal of heat from the surface of a liquid that is losing some of its molecules as gas. Evaporation of water from a lizards moist surfaces that are exposed to the environment has a strong cooling effect. Convection is the transfer of heat by the movement of air or liquid past a surface, as when a breeze contributes to heat loss from a lizards dry skin, or blood moves heat from the body core to the extremities. Conduction is the direct transfer of thermal motion (heat) between molecules of objects in direct contact with each other, as when a lizard sits on a hot rock. Chapter 40: Basic Principles of Animal Form & Function 1.How has exchange with the environment evolved? 2.Reminderwhat is the hierarchy of biological organization? 3.What is a tissue & what are the 4 types? 4.What is metabolism? 5.What is homeostasis & how is it achieved? 6.What are the 2 types of thermoregulation? 7.How do organisms exchange heat with their environment? 8.How can organisms exchange heat within their bodies? - Countercurrent heat exchange Figure Countercurrent heat exchangers Arteries carrying warm blood down the legs of a goose or the flippers of a dolphin are in close contact with veins conveying cool blood in the opposite direction, back toward the trunk of the body. This arrangement facilitates heat transfer from arteries to veins (black arrows) along the entire length of the blood vessels. Near the end of the leg or flipper, where arterial blood has been cooled to far below the animals core temperature, the artery can still transfer heat to the even colder blood of an adjacent vein. The venous blood continues to absorb heat as it passes warmer and warmer arterial blood traveling in the opposite direction. As the venous blood approaches the center of the body, it is almost as warm as the body core, minimizing the heat lost as a result of supplying blood to body parts immersed in cold water. In the flippers of a dolphin, each artery is surrounded by several veins in a countercurrent arrangement, allowing efficient heat exchange between arterial and venous blood. Canada goose Artery Vein 35C Blood flow Vein Artery 30 20 10 33 27 18 9 Pacific bottlenose dolphin Chapter 40: Basic Principles of Animal Form & Function 1.How has exchange with the environment evolved? 2.Reminderwhat is the hierarchy of biological organization? 3.What is a tissue & what are the 4 types? 4.What is metabolism? 5.What is homeostasis & how is it achieved? 6.What are the 2 types of thermoregulation? 7.How do organisms exchange heat with their environment? 8.How can organisms exchange heat within their bodies? 9.How do we achieve homeostasis for body temperature? Figure The thermostat function of the hypothalamus in human thermoregulation Thermostat in hypothalamus activates cooling mechanisms. Sweat glands secrete sweat that evaporates, cooling the body. Blood vessels in skin dilate: capillaries fill with warm blood; heat radiates from skin surface. Body temperature decreases; thermostat shuts off cooling mechanisms. Increased body temperature (such as when exercising or in hot surroundings) Homeostasis: Internal body temperature of approximately 3638 C Body temperature increases; thermostat shuts off warming mechanisms. Decreased body temperature (such as when in cold surroundings) Blood vessels in skin constrict, diverting blood from skin to deeper tissues and reducing heat loss from skin surface. Skeletal muscles rapidly contract, causing shivering, which generates heat. Thermostat in hypothalamus activates warming mechanisms. Chapter 40: Basic Principles of Animal Form & Function 1.How has exchange with the environment evolved? 2.Reminderwhat is the hierarchy of biological organization? 3.What is a tissue & what are the 4 types? 4.What is metabolism? 5.What is homeostasis & how is it achieved? 6.What are the 2 types of thermoregulation? 7.How do organisms exchange heat with their environment? 8.How can organisms exchange heat within their bodies? 9.How do we achieve homeostasis for body temperature? 10. How do animals thermoregulate in temperature extremes? -Torpor physiological state in which activity is low & metabolism is decreased -Hibernation winter bears, Beldings ground squirrels -Estivation summer many reptiles, bees Figure Body temperature and metabolism during hibernation in Beldings ground squirrels Additional metabolism that would be necessary to stay active in winter Actual metabolism Body temperature Arousals Outside temperature Burrow temperature JuneAugustOctoberDecemberFebruaryApril Temperature (C) Metabolic rate (kcal per day)