Ch. 40 Warm up 1.Define and give an example of homeostasis. 2.Sequence the organization of living things from cell to biome. 3.Describe negative and positive feedback.

LECTURE PRESENTATIONS For CAMPBELL BIOLOGY, NINTH EDITION Jane B. Reece, Lisa A. Urry, Michael L. Cain, Steven A. Wasserman, Peter V. Minorsky, Robert B. Jackson © 2011 Pearson Education, Inc. Lectures by Erin Barley Kathleen Fitzpatrick Basic Principles of Animal Form and Function Chapter 40

Overview: Diverse Forms, Common Challenges Anatomy: the study of the biological form (STRUCTURE) of an organism Physiology: the study of the biological FUNCTIONS an organism performs Structure dictates function! © 2011 Pearson Education, Inc.

Figure 40.1

Concept 40.1: Animal form and function are correlated at all levels of organization Size and shape affect the way an animal interacts with its environment Many different animal body plans have evolved and are determined by the genome © 2011 Pearson Education, Inc.

Physical Laws Govern: Strength Diffusion Movement Heat exchange These interact to limit animal forms

Cells  Tissues  Organs  Organ Systems Hierarchical Organization of Body Plans © 2011 Pearson Education, Inc.

Four main types of tissues: 1.Epithelial: covers the outside of the body and lines the organs and cavities within the body 2.Connective: binds and supports other tissues (cartilage, tendons, ligaments, bone, blood) 3.Muscle: control body movement (skeletal, smooth, cardiac) 4.Nervous: senses stimuli and transmits signals throughout the animal (neurons, glia) © 2011 Pearson Education, Inc.

Coordination and Control Within a Body Endocrine system: transmits chemical signals (hormones) to receptive cells throughout body via blood –Slow acting, long-lasting effects Nervous system: neurons transmit info between specific locations –Very fast! –Info received by: neurons, muscle cells, endocrine cells © 2011 Pearson Education, Inc.

Homeostasis Maintain a “steady state” or internal balance regardless of external environment Humans: body temperature, blood pH, and glucose concentration kept constant Fluctuations above/below a set point serve as a stimulus; these are detected by a sensor and trigger a response The response returns the variable to the set point Negative Feedback: “More gets you less.” Positive Feedback: “More gets you more.” © 2011 Pearson Education, Inc.

Thermoregulation Maintain an internal temperature within a tolerable range Endothermic animals generate heat by metabolism; Ex. birds and mammals Ectothermic animals gain heat from external sources; Ex. invertebrates, fishes, amphibians, and nonavian reptiles Thermoregulation involves form, function and behaviour Q: Which is more active at greater temperature variations? Q: Which requires more energy? © 2011 Pearson Education, Inc.

Figure 40.10

Balancing Heat Loss and Gain Organisms exchange heat by four physical processes: radiation, evaporation, convection, and conduction © 2011 Pearson Education, Inc.

Five adaptations for thermoregulation: –Insulation (skin, feather, fur, blubber) –Circulatory adaptations (countercurrent exchange) –Cooling by evaporative heat loss (sweat) –Behavioral responses (shivering) –Adjusting metabolic heat production (“antifreeze”) © 2011 Pearson Education, Inc.

Figure 40.12

Figure 40.16

Metabolic rate: amount of energy an animal uses in a unit of time Basal metabolic rate (BMR): endotherm at rest at a “comfortable” temperature Standard metabolic rate (SMR): ectotherm at rest at a specific temperature Ectotherms have much lower metabolic rates than endotherms of a comparable size Energy Use © 2011 Pearson Education, Inc.

Figure 40.19

Torpor and Energy Conservation Torpor is a physiological state in which activity is low and metabolism decreases Save energy while avoiding difficult and dangerous conditions Hibernation: torpor during winter cold and food scarcity Estivation: summer torpor, survive long periods of high temperatures and scarce water © 2011 Pearson Education, Inc.