Chapter 40 Basic Principles of Animal Form Function
Chapter 40: Basic Principles of Animal Form & Function (a) Tuna (b) Shark (c) Penguin (d) Dolphin (e) Seal Evolutionary convergence in fast swimmers
Chapter 40: Basic Principles of Animal Form & Function 1. How has exchange with the environment evolved? - Early: Simple diffusion from direct contact w/ environment - Advanced: Internal exchange thru moist medium
Figure 40. 3 Contact with the environment Mouth Diffusion Gastrovascular cavity Diffusion (a) Single cell (b) Two cell layers
Figure 40. 4 Internal exchange surfaces of complex animals External environment Food CO 2 Mouth Respiratory system d oo Bl 0. 5 cm Cells Heart Nutrients Circulatory system 50 µm Animal body 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). 10 µm Interstitial fluid Digestive system Excretory system The lining of the small intestine, a digestive organ, is elaborated with fingerlike projections that expand the surface area for nutrient absorption (cross-section, SEM). Anus Unabsorbed matter (feces) Metabolic waste products (urine) Inside a kidney is a mass of microscopic tubules that exhange chemicals with blood flowing through a web of tiny vessels called capillaries (SEM).
Chapter 40: Basic Principles of Animal Form & Function 1. How has exchange with the environment evolved? - Early: Simple diffusion from direct contact w/ environment - Advanced: Internal exchange thru moist medium 2. Reminder…what is the hierarchy of biological organization? Atoms molecules organelles cells tissues 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 Cuboidal epithelia Simple squamous epithelia Basement membrane 40 µm -Epithelial Tissue -Tightly packed sheets that cover the body, line organs & cavities w/in the body -Involved with secretion & absorption
CONNECTIVE TISSUE 100 µm Chondrocytes Chondroitin sulfate 100 µm Collagenous fiber Elastic fiber Cartilage Loose connective tissue -Connective Tissue -Binds & supports other tissues -3 types -Collagenous -non-elastic – skin won’t rip Fibrous connective tissue -Elastic -elastin – skin reshapes -Reticular Nuclei -Joins connective tissue 30 µm to neighboring tissue Adipose tissue 150 µm Fat droplets Blood Bone Central canal Red blood cells White blood cell Osteon 700 µm Plasma 55 µm
MUSCLE TISSUE 100 µm Muscle tissue -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 Skeletal muscle Multiple nuclei Muscle fiber Sarcomere Cardiac muscle Nucleus Intercalated disk Nucleus Smooth muscle Nervous tissue -Sense stimuli & transmits signals -neuron 50 µm Muscle fibers 25 µm NERVOUS TISSUE Process Neurons Cell body Nucleus 50 µm
Chapter 40: Basic Principles of Animal Form & Function 1. 2. 3. 4. How has exchange with the environment evolved? Reminder…what is the hierarchy of biological organization? What is a tissue & what are the 4 types? 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 External environment Animal body Digestion and absorption Heat Nutrient molecules in body cells Carbon skeletons Cellular respiration Energy lost in feces Energy lost in urine Heat ATP Biosynthesis: growth, storage, and reproduction Heat Cellular work Heat
Chapter 40: Basic Principles of Animal Form & Function 1. 2. 3. 4. How has exchange with the environment evolved? Reminder…what is the hierarchy of biological organization? What is a tissue & what are the 4 types? 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 40. 11 A nonliving example of negative feedback: control of room temperature Response No heat produced Heater turned off Room temperature decreases Set point is maintained Too hot Set point Too cold Set point Control center: thermostat Room temperature increases Heater turned on Response Heat produced
Chapter 40: Basic Principles of Animal Form & Function 1. 2. 3. 4. How has exchange with the environment evolved? Reminder…what is the hierarchy of biological organization? What is a tissue & what are the 4 types? 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 - (increased body heat leads to cooling) - Positive feedback - Response & stimulus are in the same direction - (increased Na+ transfer leads to more Na+ transfer—nerve impulses) - 6. What are the 2 types of thermoregulation? Ectothermic – heat & metabolism based on environment Endothermic – heat & metabolism regulated internally
Figure 40. 12 The relationship between body temperature and environmental temperature in an aquatic endotherm and ectotherm 40 Body temperature (°C) River otter (endotherm) 30 20 Largemouth bass (ectotherm) 10 0 10 20 30 Ambient (environmental) temperature (°C) 40
Chapter 40: Basic Principles of Animal Form & Function 1. 2. 3. 4. 5. 6. 7. How has exchange with the environment evolved? Reminder…what is the hierarchy of biological organization? What is a tissue & what are the 4 types? What is metabolism? What is homeostasis & how is it achieved? What are the 2 types of thermoregulation? How do organisms exchange heat with their environment?
Figure 40. 13 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. 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 lizard’s dry skin, or blood moves heat from the body core to the extremities. 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 lizard’s moist surfaces that are exposed to the environment has a strong cooling effect. 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. 2. 3. 4. 5. 6. 7. 8. How has exchange with the environment evolved? Reminder…what is the hierarchy of biological organization? What is a tissue & what are the 4 types? What is metabolism? What is homeostasis & how is it achieved? What are the 2 types of thermoregulation? How do organisms exchange heat with their environment? How can organisms exchange heat within their bodies? - Countercurrent heat exchange
Figure 40. 15 Countercurrent heat exchangers 1 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. Canada goose Artery 1 35°C 30º 2 Near the end of the leg or flipper, where arterial blood has been cooled to far below the animal’s core temperature, the artery Vein can still transfer heat to the even colder 3 blood of an adjacent vein. The venous blood 3 33° continues to absorb heat as it passes warmer and warmer arterial blood traveling in the opposite direction. 27º 20º 18º 10º 9º 2 Pacific bottlenose dolphin 1 Blood flow 3 Vein Artery 2 3 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.
Chapter 40: Basic Principles of Animal Form & Function 1. 2. 3. 4. 5. 6. 7. 8. 9. How has exchange with the environment evolved? Reminder…what is the hierarchy of biological organization? What is a tissue & what are the 4 types? What is metabolism? What is homeostasis & how is it achieved? What are the 2 types of thermoregulation? How do organisms exchange heat with their environment? How can organisms exchange heat within their bodies? How do we achieve homeostasis for body temperature? -insulation (fat, hair, etc. ) -circulatory adapations (vasodilation/vasoconstriction) -evaporative cooling (sweating/panting) -behavioral responses
Figure 40. 21 The thermostat function of the hypothalamus in human thermoregulation Sweat glands secrete sweat that evaporates, cooling the body. Thermostat in hypothalamus activates cooling mechanisms. Increased body temperature (such as when exercising or in hot surroundings) Blood vessels in skin dilate: capillaries fill with warm blood; heat radiates from skin surface. Body temperature decreases; thermostat shuts off cooling mechanisms. 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. How has exchange with the environment evolved? 2. Reminder…what 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, Belding’s ground squirrels - Estivation – summer – many reptiles, bees
Figure 40. 22 Body temperature and metabolism during hibernation in Belding’s ground squirrels Additional metabolism that would be necessary to stay active in winter Temperature (°C) Metabolic rate (kcal per day) 200 100 Actual metabolism 0 35 30 25 Arousals Body temperature 20 15 10 5 0 -5 -10 -15 Outside temperature June August Burrow temperature October December February April
Chapter 32 An Introduction to Animal Diversity 11. 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 12. How did animals evolve? - Current animal development
Figure 32. 2 Early embryonic development in animals (layer 1) Cleavage Zygote Eight-cell stage Cleavage – cell division w/out cytokinesis - More cells but same total volume – no cell growth
Figure 32. 2 Early embryonic development in animals (layer 2) Blastocoel Cleavage Zygote Eight-cell stage Blastula Cross section of blastula Blastula – hollow ball of cells -coelem – opening or cavity
Figure 32. 2 Early embryonic development in animals (layer 3) Blastocoel Cleavage Zygote Eight-cell stage Blastula Blastocoel Cross section of blastula Endoderm Ectoderm Gastrula Blastopore Gastrulation – movement of cells to form 2 layers Blastopore – opening where cells move into Ectoderm – outside layer Endoderm – inside layer
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 2. How did animals evolve? - Current animal development - Current hypothesis
Figure 32. 4 One hypothesis for the origin of animals from a flagellated protist Digestive cavity Somatic cells Reproductive cells Colonial protist, an aggregate of identical cells Hollow sphere of unspecialized cells (shown in cross section) Beginning of cell specialization Infolding Gastrula-like “protoanimal”
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