Exploring Animal Form and Function: From Cells to Systems

1. Chapter 40 Basic Principles of Animal Form and Function

2. Diverse Forms, Common Challenges

3. 40.1 Animal Form and function are correlated at all levels of organization • Not a process of conscious invention but the result of a pattern of development programmed by the genome • Physical constraints on size and shape – physical laws that govern strength, diffusion, movement, and heat exchange • Ex) fusiform body shape/convergent evolution • http://www.captseaweed.com/dolphin-videos.html#stampede • http://www.discovery.com/tv-shows/shark-week/videos/how-sharks-swim/ • http://www.livescience.com/24122-why-insects-are-not-bigger.html

4. 40.1(con’t) • Exchange with the Environment – such as? - recall lab with agar cubes

5. 40.1(con’t) • How is exchange accomplished in more complex animal? • https://cms.webstudy.com/WebstudyFileSystem/testovaci/GetFile/293875/Ch%2022/Ch22a/figure_22_22b_labeled.jpg • http://sphweb.bumc.bu.edu/otlt/MPH-Modules/PH/Ph709_RespiratoryHealth/TerminalBronchiole-Alveoli.png • http://biowiki.ucdavis.edu/@api/deki/files/2070/Figure_41_03_03.png?revision=1

6. 40.1(con’t) What are the advantages of a complex body plan compared to a simpler one?

7. 40.1(con’t) • Hierarchical Organization of Body Plans – cells tissues organs organ system(table 40.1 p. 855) • Largest organ? Function? • Multifunctional organ? Function? • Tissue Structure and Function – 4 main categories 1. epithelial 2. connective 3. muscle 4. nervous

8. 40.1 (con’t) • Epithelial Tissue – outside covering/lines organs and cavities • tight junctions • barrier against mechanical injury, pathogens, and fluid loss • Cell shape – cuboidal, columnar, or squamous • Simple, stratified, or pseudostratified • Shape is related to function

9. 40.1(con’t) • Connective tissue – bind and support other tissues in the body/sparse population of cells scattered throughout an extracellular matrix • 6 major types – loose c.t., cartilage, fibrous c.t., adipose tissue, blood, and bone • Connective tissue fibers – collagenous, elastic, and reticular • Collagenous – strength and flexibility • Elastic – easily stretched, but resilient • Reticular – thin and branched/join c.t. to adjacent tissue • Cell types – fibroblasts –secrete protein of extracellular fibers and macrophages – roam to engulf foreign particles and debris of dead cells

10. 40.1(con’t) • Muscle Tissue – responsible for body movement/actin and myosin/energy consuming • Types – skeletal, cardiac, and smooth • Nervous tissue – to sense stimuli and transmit signals in the form of nerve impulses from one part of animal to another • Neurons, glial cells

11. 40.1(con’t) • Coordination and control – endocrine and nervous/gradual vs immediate and rapid response • Hormones – only cells with receptors respond/cells can have more than 1 receptor type/slow acting but can be long lasting • Nerve impulse – axons • Impulse received by: other neurons, muscle cells, endocrine cells, and exocrine cells • Both chemical and electrical • Fast acting, short duration

12. 40.2 Feedback control loops maintain the internal environment in many animals • Regulating and Conforming – regulate internal conditions despite fluctuations in the environment/internal conditions conform to external conditions • May regulate some internal conditions and not others • http://www.bbc.co.uk/education/guides/zg2xxnb/revision/6

13. 40.2(con’t) • Homeostasis – steady state or internal balance • Ex) body temperature, pH of blood, solute concentration of glucose in blood - Mechanisms – see Fig. 40.8 – set point, stimulus, sensor, response - Feedback Loops –negative(a response that reduces the stimulus) vs positive(amplify the stimulus – do not usually contribute to homeostasis) - Ex) exercise  produce heat sweat evaporative cooling - acclimatization – temporary change during an animal’s lifetime http://www.higherpeak.com/altitudechart.html

14. 40.3 homeostatic processes for thermoregulation involve form, function, and behavior • Thermoregulation – critical to survival – why? • Endothermy and ectothermy – birds and mammals vs amphibians, lizards, snakes, turtles, many fishes, and most invertebrates • Heat generated by metabolism vs gained from environment • Variation in body temperature – poikilotherm vs homeotherm(constant body temperature) • Balancing heat loss and gain – conduction, convection, radiation, and evaporation

15. 40.3(con’t) • Insulation – reduces flow of heat between an animal and its environment • Ex) hair, feathers, layers of fat

16. 40.3(con’t) • Circulatory Adaptations – regulate blood flow/heat flow • Vasodilation – increase in diameter of blood vessels • Vasoconstriction – reduces blood flow and heat transfer • Countercurrent exchange – the flow of adjacent fluids in opposing directions that maximizes transfer rates of heat or solutes

17. 40.3(con’t)

18. 40.3(con’t) • Cooling by evaporative heat loss – water absorbs heat when it evaporates • Panting, sweating • Behavioral responses – hibernation, migration • Sun or shade for ectotherms • Bees huddle together