Chapter 32 An Introduction to Animal Diversity 1.What is an animal? -Multicellular, heterotrophic eukaryote – ingestion -Structural support from structural proteins – NOT cell walls -Nervous tissue & muscle tissue for impulse conduction & movement -Sexual reproduction with motile sperm swimming to non-motile egg

Chapter 40: Basic Principles of Animal Form & Function 1.What is an animal? 2.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 µm 50 µm

Chapter 40: Basic Principles of Animal Form & Function 1.What is an animal? 2.How has exchange with the environment evolved? -Simple diffusion from direct contact w/ environment -To internal exchange thru moist medium 3. Reminder…what is the hierarchy of biological organization? Atoms  molecules  organelles  cells  tissues  organs  organ systems… 4. What is a tissue & what are the 4 types? -Group of cells in a matrix with a common structure & function -Epithelial -Tightly packed sheets that cover the body, line organs & cavities w/in the body -Involved with secretion & absorption -Connective -Binds & supports other tissues -3 kinds - collagenous, elastic, reticular -Muscular -Long cells made of contractile proteins (actin & myosin) -3 kinds - skeletal, smooth, cardiac -Nervous -Sense stimuli & transmits signals -Neuron – basic unit/cell

Chapter 40: Basic Principles of Animal Form & Function 1.What is an animal? 2.How has exchange with the environment evolved? 3.Reminder…what is the hierarchy of biological organization? 4.What is a tissue & what are the 4 types? 5.What is metabolism? -All of the chemical rxns within an organism -Catabolism – hydrolysis breaks bonds – releases energy – exergonic -Anabolism – dehydration rxns 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.What is an animal? 2.How has exchange with the environment evolved? 3.Reminder…what is the hierarchy of biological organization? 4.What is a tissue & what are the 4 types? 5.What is metabolism? -All of the chemical rxns within an organism -Catabolism – hydrolysis breaks bonds – releases energy – exergonic -Anabolism – dehydration rxns forms bonds – requires energy – endergonic 6. 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.What is an animal? 2.How has exchange with the environment evolved? 3.Reminder…what is the hierarchy of biological organization? 4.What is a tissue & what are the 4 types? 5.What is metabolism? 6.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 7. 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.What is an animal? 2.How has exchange with the environment evolved? 3.Reminder…what is the hierarchy of biological organization? 4.What is a tissue & what are the 4 types? 5.What is metabolism? 6.What is homeostasis & how is it achieved? 7.What are the 2 types of thermoregulation?

Chapter 40: Basic Principles of Animal Form & Function 1.What is an animal? 2.How has exchange with the environment evolved? 3.Reminder…what is the hierarchy of biological organization? 4.What is a tissue & what are the 4 types? 5.What is metabolism? 6.What is homeostasis & how is it achieved? 7.What are the 2 types of thermoregulation? 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 animal’s 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 35°C Blood flow Vein Artery 30º 20º 10º 33° 27º 18º 9º Pacific bottlenose dolphin

Chapter 40: Basic Principles of Animal Form & Function 1.What is an animal? 2.How has exchange with the environment evolved? 3.Reminder…what is the hierarchy of biological organization? 4.What is a tissue & what are the 4 types? 5.What is metabolism? 6.What is homeostasis & how is it achieved? 7.What are the 2 types of thermoregulation? 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 36–38  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.What is an animal? 2.How has exchange with the environment evolved? 3.Reminder…what is the hierarchy of biological organization? 4.What is a tissue & what are the 4 types? 5.What is metabolism? 6.What is homeostasis & how is it achieved? 7.What are the 2 types of thermoregulation? 8.How do organisms exchange heat with their environment? 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, Belding’s ground squirrels -Estivation – summer – many reptiles, bees

Figure Body temperature and metabolism during hibernation in Belding’s 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)