Chapters 40 & 41 Lecture

1. Animal Form & Function Chapters 40 & 41 Lecture AP Biology Mrs. Hennings Animal Nutrition

2. Anatomy & Physiology • Anatomy- biological form • Physiology- biological function • The body plan of animals are a result of the programmed genome- millions of years into evolution.

3. Physical Constraint on Animal Size and Shape • Physical laws are in charge of strength, diffusion, movement, and heat exchange with a narrow limit for animals. • Natural selection often shapes animals to be adapted to such physical laws such as the density of water- streamlined body. • Maximum size- as body size increases need a larger and thicker support- skeleton. As you increase size and weight of skeleton- you restrict mobility.

4. Exchange with Environment • Depending on the membrane surface area- the rate of exchange of nutrients, waste and gases are regulated. • What kinds of adaptations to humans have to maximize surface area? • Folded surfaces- increases surface area • Spaces between cells- interstitial fluid

5. Hierarchical Organization • Cells organized into tissues- groups of cells that have common look and function. • Tissues organized into organs- functional units. • Organ systems- groups of organs that work together. Think of all the organ systems in the human body- Digestive, Circulatory, Respiratory, Immune, Excretory, Endocrine, Reproductive, Nervous, Integumentary, Skeletal, and Muscle! Wow that’s a lot of organ systems!

6. Tissue Structure & Function • Animal tissues fall into 4 main categories: • Epithelial Tissue • Connective Tissue • Muscle Tissue • Nervous Tissue

7. Epithelial tissue • Sheet of cells • Covers outside of body • Lines organs • Close packed cells involved “tight junctions” • Barrier against injury and pathogens • Tissue called “epithelium” • Cell shape may be cuboidal ( dice), columnar ( bricks on end), or squamous ( floor tiles) • Cells can be arranged simply- simple epithelium, stratified ( multiple layers), or pseudostratified ( 1 layer varying in height).

9. Connective tissue • Bind and support other tissues • Sparsely populated cells scattered through matrix • Variation in ECM ( extracellular matrix) • Six major types of connective tissue: • Loose • Cartilage • Fibrous • Adipose • Blood • bone

10. Connective Tissue contd. • Made of protein • 3 kinds: • Collagenous- strength and flexibility – made of collagen which is the most abundant protein! • Elastic-easily stretched- resilient-long threads- made of protein called elastin. • Reticular- very thin and branched- made of collagen and continuous with collagenous fibers- form tight woven fabric that joins connective tissues. • Connective tissue contains- • Fibroblasts- secrete protein ingredients of EC- fibers. • Macrophages- cells that roam and eat up debris

12. Muscle tissue • Responsible for movement • Filaments containing actin and myosin (proteins) which let muscles contract • Muscle is the most abundant tissue in animals • Three types of muscle tissue: • Skeletal • Cardiac • Smooth

14. Nervous tissue • Function is to sense and transmit signals in form of nerve impulses • Contains neurons- nerve cells • Neurons have extensions called axons that are specialized to transmit signals • Also has glial cells ( glia) help nourish, insulate and replenish neurons

16. Coordination & control • Tissues, organs and systems must work together in harmony! • Coordination requires communication. • Two major systems: endocrine system and nervous system. • Endocrine- signaling molecules (hormones) put into blood by endocrine cells go throughout body • Nervous- neurons transmit info to specific locations

17. homeostasis • Steady state • Stable internal environment • Temperature, pH, glucose etc.

18. Mechanisms of homeostasis • Set point – exact level set • Stimulus • Sensor • Response I like it nice And icy!

19. Feedback loops in homeostasis • Homeostasis relies on negative feedback • Negative feedback: a response that reduces the stimulus • Exercise -produce heat- increase body temp- sense and sweat- as you sweat the evaporation cools you helps your body return to- homeostasis. • Additional fluctuations when the variable has a range- upper and lower limit • Positive feedback do not usually contribute to homeostasis. Positive feedback triggers mechanisms that amplify rather than decrease a stimulus

20. Negative Feedback

21. Alterations in homeostasis • Lower body temp when asleep • Particular stage in life • Hormone cycles • Acclimatization- animal adjusts to changes in external environment • Hiking at high altitudes… increased blood flow and increased production of RBC that carry oxygen • This is a temporary change it is different than adaptation

22. Thermoregulation • Form and function ( Again!) • Process by which animals maintain a tolerable internal temperature • Critical to survival • Biochemical and physiological processes sensitive • Each animal has optimum temperature

23. Endothermy and ectothermy • Endothermic: warmed mostly by heat made through metabolism. • Endotherms • Can maintain temp even when outside changes dramatically • Ectothermic: gain most of heat from external sources. • Ectotherms • Adjust temp by behavior means • Tolerate larger swings in internal temps

24. insulation • Major thermoregulatory adaptation • Reduces flow of heat between animal and environment • Land mammals and birds react to cold by raising fur or feathers- helps trap thicker layer of air • Secrete oily substances- repel water • Humans rely on fat- goose bumps from old days of raising hair

25. Circulatory adaptations • Major route for heat flow between inside and outside of body • Vasodilation- increases superficial blood flow • Vasoconstriction- decreases it • Birds and mammals- countercurrent exchange- flow of fluids in opposite directions maximizes transfer rate • Arteries ( away from heart- warm) • Veins ( toward the heart – cold) • Arteries give heat to colder blood in veins because run next to each other.

26. Cooling by evaporative heat loss • Mammals and birds live where it is needed to cool also! • If temp increases too much- then evaporation can stop it. • Terrestrial animals evaporate across skin and when they breathe • Panting important • Some birds have a pouch in floor of mouth that can flutter and release heat • Sweat glands

27. Behavioral responses • Ectotherms- hibernation or migration- • Endotherms- different!

28. Adjusting metabolic heat production • Endotherms have higher temp than environment- must counteract heat loss. • Thermogenesis- heat production • Hormones can increase mitochondria to increase metabolic rate • Brown fat- between neck rapid heat production

29. Acclimatization in thermoregulation • Acclimatization to seasonal temperatures- • Growing thicker fur • Shedding fur • Cellular level- different enzymes

30. Physiological thermostats & fever • Sensors that control thermoregulation in hypothalamus • Hypothalamus- in brain near ears • Thermometer in ear specific temp! • Fever- artificially raising temp of hypothalamus can decrease body temp if fever! • Only endotherms get fevers!

31. Energy requirements • Animals need chemical energy for: • Growth, repair, activity and reproduction • Overall flow and transformation of energy is called BIOENERGETICS.

32. Chapter 41 : Animal nutrition • Nutrition: food being consumed & digested • Herbivores, Carnivores, Omnivores

33. Essential nutrients • Food provides fuel to make ATP • Food provides raw materials for biosynthesis • Essential nutrients: Materials animals need but can’t make themselves • Adequate diet: • Chemical energy • Organic building blocks • Essential nutrients

34. Essential amino acids • Animals need 20 amino acids to make proteins • Most animals can make about half as long as diet has organic nitrogen • Remaining amino acids must be taken in from food. These are called essential amino acids. • Most animals require 8 amino acids- infants need 9- histadine also. • Malnutrition- not enough- delayed physical and mental development • Animal proteins- complete • Plant proteins - incomplete

35. Essential fatty acids • Animals can make most- not all • Essential fatty acids are those they can’t make = so they are essential to be taken in! • Some fatty acids are unsaturated ( double bonds)

36. vitamins • Organic molecules with many functions • Required in diet in very small amounts • There are 13 essential vitamins for humans • Water soluble or fat soluble • Water soluble- B complex, coenzymes, vitamin C • Fat soluble- Vitamin A, Vitamin K, Vitamin D • If poor diet- then take supplements • Do massive doses help? • Moderate overdoses of water soluble- excreted in urine. • Moderate overdoses of fat soluble- toxicity.

37. minerals • Inorganic nutrients such as zinc and potassium • Vary requirements among species • Need large amounts of: • Calcium • Phosphorus • Sulfur • Potassium • Chlorine • Sodium • Magnesium

38. Dietary deficiencies • Diets that don’t meet basic needs • Undernourishment- consistently less than need • Malnourishment-long term absence of one or more essential nutrients • Both of these have negative impacts on health and survival

39. undernourishment • Body uses up stored fat • Begins to break down muscle • Muscles decrease in size • Brain becomes protein deficient • If energy intake remains less than output- will result in death • Most common in areas of drought, war • AIDS in Africa- 200 million children and adults not enough food • Eating disorders- anorexia, bulemia

40. malnourishment • Potential effects: • Deformities, disease, death • Simple rice diets lack vit A- blindness and death • Golden Rice- genetically engineered to have vitamin A

41. Digestive compartments • How can animals digest food with enzymes that don’t digest their own cells? • Intracellular- food vacuoles • Extracellular- digestive organs and systems

42. Mammalian digestion • Alimentary canal • Food pushed through with peristalsis • There are sphincters- valves

43. Oral cavity, pharynx and esophagus Mechanical Digestion Salivary glands Salivary amylase Bolus Esophagus

44. stomach • Stores food and continues digestion • Can get as large as 2 L • Gastric juice- HCl and protease or pepsin • Mixes with bolus- now called chyme

45. Small intestine • Most breakdown of food happens here • Over 6 m long • Longest part • Small diameter • First part is duodenum

46. pancreas • Aids in chemical digestion makes an alkaline solution high in bicarbonate and enzymes • Bicarbonate acts as a buffer against acid • Trypsin and chympotrypsin

47. liver • Bile- mixture of substances made in liver • Contains “bile salts” act as detergents or emulsifiers break down fats • Bile is stored and concentrated in gallbladder • Breaks down toxins • Helps balance nutrients • Destroys old RBC • Bile pigments eliminated in feces

48. Large intestine • Colon, cecum and rectum • Colon leads to rectum and anus • Cecum – ferments materials such as plants • Appendix- extension of cecum- role in immunity • Colon- recovers water back into body • Feces- solid waste- 12-24 hours to travel through

49. Dental adaptations

50. Stomach and intestinal adaptations • Large expandable stomach- carnivores spread out eating • Herbiovores and omniovores have longer GI than carnivores • Vegetation harder to digest