Animal Form and Function Ch 40 AP Biology

Overview Anatomy: the structure of an organism Physiology: the processes and functions of an organism “STRUCTURE = FUNCTION”

40.1 Animal Form and Function are correlated at all levels of organization “What they look like” “What they do”

Physical Constraints Physical laws constrain evolution Ex: Fusiform marine body shapes Ex: Maximum body size (weight of bones, muscles, etc)

Exchange with Environment Nutrients, waste products, and gases must be exchanged with the environment (aqueous) Rate of exchange : Surface Area Amount to exchange : Volume What is the relationship between size and SA:V? (Whale vs fruit fly) Larger, complex animals exchange nutrients between interstitial fluid and circulatory fluid Interstitial Fluid = fluid between cells

Organization of Body Plans Cells Tissues Organs Organ systems Organism Know Chart from Bozeman on systems

Tissues Epithelial Connective Muscle Nervous *Study Figure 40.5

Epithelial Tissue Function: Organ and body cavity lining Outer covering Protection against: pathogens, damage, fluid loss Environmental interface Shapes of cells: cuboidal, columnar, squamous (thin and flat) Arrangements: simple, stratified, psuedostratified

Connective Tissue Function: bind and support other tissues in the body Cells are suspended in extracellular matix (fibers in various forms of liquid or jelly-like solids). 6 Types: Loose connective tissue Cartilage Fibrous connective Blood Adipose Bone

Extra Cellular Matrix

Major Connective Tissue Cells Fibroblasts: secrete protein ingredients of extracellular fibers Macrophages: engulf foreign particles and debris by phagocytosis

Muscle Tissue Function: body movement Most abundant tissue in animals Muscle cells contain actin and myosin filaments Consumes A LOT of energy Which organelle would you expect to find in abundance? 3 types: skeletal, cardiac, smooth

Coordination and Control Signals Endocrine system  Hormones Slow- Acting Longer- Lasting Hormones sent throughout the body are received by specific cells Nervous System  electrical impulses along neurons Specific signal sent on a SPECIFIC pathway Fast response, short-lived Received by: neurons, endocrine, exocrine, and muscle cells

Nervous Tissue Function: sense stimuli and transmit impulses Cell categories: neurons and glia

40.2 Feedback control loops maintain the internal environment in many animals

Regulating and Conforming Regulator: maintains internal conditions regardless of the environment Conformer: allows internal condition to conform to external changes

Homeostasis Homeostasis: “steady state, internal balance” Temperature, pH, solutes (glucose)

Feedback Loops Negative Feedback loop: response reduces stimulus Ex: evaporative cooling Normal range vs. set point Normal range can change! Ex: hormones during puberty Acclimatization: process by which an animal adjusts to its external environment. Ex: training in Colorado Positive Feedback loop: amplifies stimulus Ex: childbirth

40.3 Homeostatic processes for thermoregulation involve form, function, and behavior

Thermoregulation Thermoregulation: process by which animals maintain an internal temperature within a tolerable range. Temperature affects: Membrane fluidity (increase temp, increase fluidity) Enzyme activity

Endothermy vs. Ectothermy Endothermic: warmed by metabolism Ex: Birds and Mammals, some fish, most insects Require more food Exothermic: warmed by external sources Ex: amphibians, lizards, snakes, turtles, fish, etc Sources: water, sun, rocks, etc Eat less

Heat Exchange Radiation Evaporation Conduction Convection

Adaptations Insulation: fat, blubber, feathers, skin, etc Circulation Vasodilation: increase in diameter of blood vessels  increase blood flow, increase heat loss Vasoconstriction: decrease diameter  decrease blood flow, decrease heat loss Concurrent exchange : flow of adjacent fluids in opposing directions that maximizes transfer rates of heat or solutes

Coutercurrent heat flow animation a/uploads/zoology/counter%20current.html a/uploads/zoology/counter%20current.html

Countercurrent Exchange

Behavioral Thermoregulation Exposure to sunlight or shade: posture & position Group “huddling”

Other Mechanisms Metabolic Heat Production Thermogenesis; Ex: Shivering Nonshivering Thermogenesis: Mitochondria produce heat instead of ATP Heat Acclimatization: increased RBC production, “cellular antifreeze” Video Video Physiological “thermostat” – hypothalamus

Thermogenesis in Mitochondria

40.4 Energy Requirements are related to animal size, activity, and environment

Bioenergetics: The overall flow and transformation of energy in an organism Metabolic Rate: amount of energy an animal uses in a unit of time Minimum metabolic rate Basic cell functions Basal Metabolic Rate in Endotherms (BMR) Standard Metabolic Rate in Ectotherms (SMR) Ectothermy requires less energy Ectotherms use about 1/200 the energy of the same sized endotherm

Metabolic Rate Size Body size is directly proportional to energy cost A mouse uses more energy to support 1g of its body than an elephant does to support 1 g of its body Activity Energy Budget  Torpor Hibernation

Energy Budget

BMR and body size relationship A mouse uses more energy to support 1g of its body than an elephant does to support 1 g of its body. (SA:V ratio?)