1. AN INTRODUCTION TO ANIMAL STRUCTURE AND FUNCTION CHAPTER 40

2. LEVELS OF ORGANIZATION Hierarchy = cell, tissue, organs, organ systems Hierarchy = cell, tissue, organs, organ systems Tissue = group of cells with common structure and function Tissue = group of cells with common structure and function Cells held together by sticky coating or woven in fibers Cells held together by sticky coating or woven in fibers

3. Figure 40.1 The structure and function of epithelial tissues

4. CATEGORIES OF TISSUES Epithelial Tissue Epithelial Tissue  Tightly packed cells with tight junctions  Covers outside of body and lines organs and body cavities  Free surface exposed to air or fluid and cells at base of barrier attached to basement membrane

5.  Types (may occur in combination)  Simple – one layer of cells  Stratified – multiple layers  Cuboidal – dice  Columnar – bricks  Squamous – flat tiles

6. Figure 40.1x Epithelial tissues

7. Connective tissue Connective tissue  Few cells scattered throughout extracellular matrix  Binds and supports tissues  Loose weave of three types proteinaceous fibers  Collagenous – collagen; strong and resist stretching  Elastic – elastin; return to original shape  Reticular – branched, join to adjacent tissues

8.  Types of Connective Tissue  Loose Fibroblasts secrete proteins (for fibers)Fibroblasts secrete proteins (for fibers) Macrophages immune defenseMacrophages immune defense  Adipose Insulates and stores fuelInsulates and stores fuel Fat dropletFat droplet

9.  Fibrous Bundles of collagenous fibersBundles of collagenous fibers Found in tendons and ligamentsFound in tendons and ligaments  Cartilage Collagenous fibers embedded in chondroitin sulfate secreted by chondrocytesCollagenous fibers embedded in chondroitin sulfate secreted by chondrocytes

10.  Bone MineralizedMineralized Osteoblasts deposit collagen and calcium phosphate which hardens into hydroxyapatiteOsteoblasts deposit collagen and calcium phosphate which hardens into hydroxyapatite  Blood Plasma, water, salts, proteinPlasma, water, salts, protein

11. Blood CellsBlood Cells –Erythrocytes (red) – carry O 2 and CO 2 –Leukocytes (white) – fight disease –Platelets (fragments) – clot

12. Figure 40.2 Some representative types of connective tissue

13. Figure 40.2x Connective tissue

14. Nervous Tissue – transmit signals Nervous Tissue – transmit signals  Neuron – nerve cell  Dendrites – extensions conduct to cell body  Axons – extensions conduct away from cell body

15. Figure 40.3 The basic structure of a neuron

16. Muscle Tissue Muscle Tissue  Cells contract  Actin and myosin are contractile proteins  Types of muscle  Skeletal Voluntary movementsVoluntary movements striatedstriated

17.  Cardiac Contractile wall of heartContractile wall of heart Striated and branchedStriated and branched  Smooth Walls of internal organsWalls of internal organs Involuntary movementsInvoluntary movements Not striatedNot striated

18. Figure 40.4 Three kinds of vertebrate muscle

19. Figure 40.4x Three kinds of vertebrate muscle

20. Figure 40.5x Stomach: Stomach wall showing the three tunics (left), gastric glands and pits (right)

21. Controlling internal environment Regulator – an animal that uses internal control mechanisms to regulate something in response to environment Regulator – an animal that uses internal control mechanisms to regulate something in response to environment  Homeostasis – maintaining a steady state Conformer – an animal that allows the internal condition to conform to the external changes Conformer – an animal that allows the internal condition to conform to the external changes

23. BIOENERGETICS Metabolic rate – total amount of energy an animal loses per unit time; usually measured in calories or kilocalories Metabolic rate – total amount of energy an animal loses per unit time; usually measured in calories or kilocalories  Measured by amount of oxygen used or amount of heat loss

24. Minimum rates support basic functions of life Minimum rates support basic functions of life Maximum rates occur during peak activity Maximum rates occur during peak activity Endotherms – generate their own body heat metabolically Endotherms – generate their own body heat metabolically  Examples: birds and mammals  Basal metabolic rate (BMR) – under resting, fasting, non- stressful conditions

25.  Average female BMR = 1300 - 1500 kcal/day  Average male BMR = 1600 – 1800 kcal/day Ectotherms – acquire most of their body heat from environment Ectotherms – acquire most of their body heat from environment  Examples: most fish, amphibians, reptiles, and invertebrates

26. Figure 40.12 Maximum metabolic rates over different time spans

27.  Standard metabolic rate (SMR) – under controlled temp, resting, fasting, and non-stressful conditions Metabolic rate per gram is inversely related to body size among similar animals Metabolic rate per gram is inversely related to body size among similar animals  Smaller animals consume more calories per gram than larger animals

28. Figure 40.13a Annual energy budgets for four animals: Total annual energy expenditures

29. Figure 40.13b Annual energy budgets for four animals: Energy expenditure per unit mass

30. BODY PLANS AND ENVIRONMENT Physical support on land depends on adaptations of body proportions and posture Physical support on land depends on adaptations of body proportions and posture In mammals and birds, leg position more important than leg bone size In mammals and birds, leg position more important than leg bone size

31. Animal cells must have enough surface area in contact with aqueous medium Animal cells must have enough surface area in contact with aqueous medium  Upper limits of cell size imposed by surface to volume ratio  As cell size increases, volume increases proportionally more than surface area  Maximize surface area

32. Figure 40.8 Internal exchange surfaces of complex animals

33. REGULATING INTERNAL ENVIRONMENT Homeostasis – dynamic equilibrium Homeostasis – dynamic equilibrium  Receptor – detects internal change  Control center- processes info from receptor and directs effector to respond  Effector – provides the response

34. Figure 40.10 Bioenergetics of an animal: an overview

35. Negative feedback – stops or reduces intensity of original stimulus and thus the new change is opposite in direction the initial change Negative feedback – stops or reduces intensity of original stimulus and thus the new change is opposite in direction the initial change  Most common homeostatic mechanism in animals  Thermostat control  Hypothalamus detects high blood temp, so increases sweating to induce evaporative cooling

36. Figure 40.9a An example of negative feedback: Control of room temperature

37. Figure 40.9b An example of negative feedback: Control of body temperature

38. Positive feedback – enhances the initial change in a variable Positive feedback – enhances the initial change in a variable  More rare  During childbirth, pressure against uterine opening stimulates contractions which causes greater pressure against uterine opening