1. 1 What things to animals do to maintain homeostasis?

2. 2 Lecture 9 Outline (Ch. 40) I.Brief Organ Systems Overview II.Animal Size/Shape and the Environment III.Tissues A.Epithelial B.Connective C.Muscle D.Nervous IV.Feedback Control and Heat Balance V.Metabolic Rate and Energy Use VI.Preparation for next lecture

3. 3 Overview: Diverse Forms, Common Challenges Anatomy: study of biological form of an organism Physiology: study of biological functions of an organism Evolutionary convergence: reflects different species’ adaptations to similar environmental challenge (a) Tuna (b) Penguin (c) Seal

4. Organ Systems 4 Communication and integration –detect external stimuli, coordinate the body’s responses Support and movement

5. 5 Organ Systems Regulation and maintenance –regulate and maintain the body’s chemistry

6. Reproduction and development –In females, also nurtures developing embryo/fetus 6 Organ Systems Defense

7. 7 Levels or organiziation: smallest  largest? Hierarchical Organization of Body Plans Vertebrates have a “tube within a tube” structure

8. 8 Exchange 0.15 mm (a) Single cell 1.5 mm (b) Two layers of cells Exchange Mouth Gastrovascular cavity Rate of exchange related to SA Amount of exchange related to V Overview: Diverse Forms, Common Challenges

9. 9 0.5 cm Nutrients Digestive system Lining of small intestine Mouth Food External environment Animal body CO 2 O2O2 Circulatory system Heart Respiratory system Cells Interstitial fluid Excretory system Anus Unabsorbed matter (feces) Metabolic waste products (nitrogenous waste) Kidney tubules 10 µm 50 µm Lung tissue More complex organisms have highly folded internal surfaces Overview: Diverse Forms, Common Challenges Cells bathed in interstitial fluid

10. 10 Tissues are classified into four main categories: epithelial, connective, muscle, and nervous Tissue Structure and Function Humans: 210 different cell types – can you name them?! ;)

11. 11 Epithelial Tissue Cuboidal epithelium Simple columnar epithelium Pseudostratified ciliated columnar epithelium Stratified squamous epithelium Simple squamous epithelium Note differences in cell shape and type of layering Tissue Structure and Function

12. 12 Apical surface Basal surface Basal lamina 40 µm Tissue Structure and Function Epithelial cells are attached to a basal lamina at their base.

13. 13 Connective Tissue Connective tissue mainly binds and supports other tissues It contains sparsely packed cells scattered throughout an extracellular matrix The matrix consists of fibers in a liquid, jellylike, or solid foundation There are six main types of connective tissue.

14. 14 Connective Tissue Collagenous fiber Loose connective tissue Elastic fiber 120 µm Cartilage Chondrocytes 100 µm Chondroitin sulfate Adipose tissue Fat droplets 150 µm White blood cells 55 µm Plasma Red blood cells Blood Nuclei Fibrous connective tissue 30 µm Osteon Bone Central canal 700 µm Tissue Structure and Function

15. 15 Muscle Tissue Muscle tissue consists of long cells called muscle fibers, which contract in response to nerve signals It is divided in the vertebrate body into three types: –Skeletal muscle, or striated muscle, is responsible for voluntary movement –Smooth muscle is responsible for involuntary body activities –Cardiac muscle is responsible for contraction of the heart

16. 16 Muscle Tissue 50 µm Skeletal muscle Multiple nuclei Muscle fiber Sarcomere 100 µm Smooth muscle Cardiac muscle Nucleus Muscle fibers 25 µm Nucleus Intercalated disk Tissue Structure and Function

17. Glial cells Nervous Tissue 15 µm Dendrites Cell body Axon Neuron Axons Blood vessel 40 µm 17 Tissue Structure and Function Nervous tissue senses stimuli and transmits signals throughout the animal Nervous tissue contains: Neurons, or nerve cells, transmit nerve impulses Glial cells, or glia, help nourish, insulate, and replenish neurons

18. Which animals tissue below is connective? 1.Cardiac cells 2.Glia 3.Lining of intestines 4.Tendons 5.Neurons

19. 19 Self-Check Tissue CategoryTissues/Cells Included; Functions Epithelial Connective Muscle Nervous

20. 20 Response: Heater turned off Stimulus: Control center (thermostat) reads too hot Room temperature decreases Set point: 20ºC Room temperature increases Stimulus: Control center (thermostat) reads too cold Response: Heater turned on Feedback control loops maintain the internal environment in many animals Examples of negative and positive feedback?

21. Feedback control loops maintain the internal environment in many animals Animals manage their internal environment by regulating or conforming to the external environment

22. 22 Feedback control loops maintain the internal environment in many animals Thermoregulation: process by which animals maintain an internal temperature (a) A walrus, an endotherm (b) A lizard, an ectotherm Endothermic animals generate heat by metabolism (birds and mammals) Ectothermic animals gain heat from external sources (invertebrates, fishes, amphibians, and non- avian reptiles)

23. 23 Five general adaptations help animals thermoregulate: –Insulation –Circulatory adaptations –Cooling by evaporative heat loss –Behavioral responses –Adjusting metabolic heat production Balancing Heat Loss and Gain Dragonfly “obelisk” posture

24. 24 Bioenergetics: overall flow of energy in an animal Determines how much food is needed due to animal’s size, activity, and environment Organic molecules in food External environment Animal body Digestion and absorption Nutrient molecules in body cells Carbon skeletons Cellular respiration ATP Heat Energy lost in feces Energy lost in nitrogenous waste Heat Biosynthesis Heat Cellular work Energy Allocation and Use

25. 25 Metabolic rate is the amount of energy an animal uses in a unit of time Energy Use Measured by amount of oxygen consumed or carbon dioxide produced Basal metabolic rate (BMR) is the metabolic rate of an endotherm at rest at a “comfortable” temperature

26. 26 Shrew Harvest mouse Mouse Ground squirrel Rat Cat Dog Sheep Human Horse Elephant Body mass (kg) (log scale) BMR (L O 2 /hr) (log scale) (a) Relationship of BMR to body size 10 –3 10 –2 10 –1 1 1 10 10 2 10 3 10 10 2 10 3 Energy Use

27. 27 10 3 10 2 10 1 10 –1 10 –2 10 –3 0 1 2 3 4 5 6 7 8 Body mass (kg) (log scale) (b) Relationship of BMR per kilogram of body mass to body size BMR (L O2/hr) (per kg) Shrew Harvest mouse Mouse Rat Ground squirrel Cat Sheep Dog Human Horse Elephant Energy Use Human average daily metabolic rate is only 1.5X BMR!

28. 28 Annual energy expenditure (kcal/hr) 60-kg female human from temperate climate 800,000 Basal (standard) metabolism Reproduction Thermoregulation Growth Activity 340,000 4-kg male Adélie penguin from Antarctica (brooding) 4,000 0.025-kg female deer mouse from temperate North America 8,000 4-kg female eastern indigo snake EndothermsEctotherm Energy Budgeting Torpor is a physiological state in which activity is low and metabolism decreases – allows animals to save energy while avoiding difficult and dangerous conditions Hibernation is long-term torpor that is an adaptation to winter cold and food scarcity

29. Which animal would have the highest BMR per unit body weight? 1.human 2.dog 3.mouse 4.whale 5.turtle

30. 30 Additional metabolism that would be necessary to stay active in winter Actual metabolism Arousals Body temperature Outside temperature Burrow temperature Metabolic rate (kcal per day) Temperature (°C) JuneAugustOctoberDecemberFebruaryApril –15 –10 –5 0 5 15 10 25 20 35 30 0 100 200 Energy Use

31. Things To Do After Lecture 9… Reading and Preparation: 1.Re-read today’s lecture, highlight all vocabulary you do not understand, and look up terms. 2.Ch. 40 Self-Quiz: #1, 2, 3, 4, 5, 6 (correct answers in back of book) 3.Read chapter 40, focus on material covered in lecture (terms, concepts, and figures!) 4.Skim next lecture. “HOMEWORK” (NOT COLLECTED – but things to think about for studying): 1.Describe the relationship between surface area and volume for a small cell compared to a large cell. Which is more efficient at exchange with the environment? 2.List the four types of tissues in animals – for each one, give several examples. 3.Define basal metabolic rate. Which would use more energy for homeostatic regulation, a human or a snake? Why? 4.Explain the difference between torpor and hibernation.