Introduction to Animal Organization and Physiology

1. Introduction to Animal Organization and Physiology Chapter 36

2. Learning Objectives

3. 36.1 Organization of the Animal Body • In animals, specialized cells are organized into tissues, tissues into organs, and organs into organ systems

4. Organization of the Animal Body (1) • Cells • Are specialized and organized into tissues • Tissue • A group of cells with the same structure and function, working as a unit to carry out one or more activities

5. Organization of the Animal Body (2) • Organ • An assembly of tissues integrated into a structure that carries out a specific function • Organ system • A group of organs that carry out related steps in a major physiological process

6. 36.2 Animal Tissues • Epithelial tissue forms protective, secretory, and absorptive coverings of body structures • Connective tissue supports other body tissues • Muscle tissue produces the force for body movement • Nervous tissue receives, integrates, and transmits information

7. Animal Tissues • Classified as: • Epithelial • Connective • Muscle • Nervous • Properties of cells in tissues determine the tissues’ structures and functions

8. Organ system: A set of organs that interacts to carry out a major body function Organ: Body structure that integrates different tissues and carries out a specific function Stomach Epithelial tissue: Protection, transport, secretion, and absorption Connective tissue: Structural support Muscle tissue: Movement Nervous tissue: Communication, coordination, and control Fig. 36.2, p. 833

9. Cell Junctions • Junctions link cells in a tissue • Anchoring junctions “weld” cells together • Tight junctions seal cells into a leak-proof layer • Gap junctions form direct avenues of communication between the cytoplasm of adjacent cells in the same tissue

10. Epithelial Tissue • Consists of sheetlike layers of cells • Covers surfaces of body and internal organs • Lines cavities and ducts within the body

11. Epithelial Tissues

12. a. Patterns by which cells are arranged in epithelia Simple epithelium Stratified epithelium Free surface Epithelium Fig. 36.3a, p. 834

13. b. The three common shapes of epithelial cells Squamous epithelium Cuboidal epithelium Columnar epithelium Description: Layer of cubelike cells; free surface may have microvilli Description: Layer of tall, slender cells; free surface may have microvilli Description: Layer of flattened cells Common locations: Walls of blood vessels; air sacs of lungs Common locations: Lining of gut and respiratory tract Common locations: Glands and tubular parts of nephrons in kidneys Function: Secretion, absorption Function: Diffusion Function: Secretion, absorption Fig. 36.3b, p. 834

14. Glands • Secretory structures derived from epithelia • Exocrine glands • Connected to an epithelium by a duct that empties on the epithelial surface • Endocrine glands • Ductless; no direct connection to an epithelium

15. Secretory product Pore Epithelium Exocrine gland cell (mucous gland) Exocrine gland cell (poison gland) a. Examples of exocrine glands: The mucus- and poison-secreting glands in the skin of a blue poison frog Fig. 36.4a, p. 836

16. Thyroid Epithelium Endocrine gland cell Blood vessel b. Example of an endocrine gland: The thyroid gland, which secretes hormones that regulate the rate of metabolism and other body functions Fig. 36.4b, p. 836

17. Connective Tissue • Consists of cell networks or layers and an extracellular matrix (ECM) • Supports other body tissues • Transmits mechanical and other forces • In some cases acts as a filter

18. Loose connective tissue Bone tissue Cartilage Fibrous connective tissue Adipose tissue Blood Six Types of Connective Tissues

19. Loose Connective Tissue • Consists of sparsely distributed fibroblasts surrounded by a network of collagen and other glycoproteins • Supports epithelia and body organs • Covers blood vessels, nerves, and some internal organs

20. Fibrous Connective Tissue • Contains sparsely distributed fibroblasts in a matrix of densely packed, parallel bundles of collagen and elastin fibers • Forms high tensile-strength structures such as tendons and ligaments

21. b. Fibrous connective tissue Common locations: Tendons, ligaments Collagen fibers Function: Strength, elasticity Fibroblast Description: Long rows of fibroblasts surrounded by collagen and elastin fibers in parallel bundles with a dense extracellular matrix Fig. 36.5b, p. 837

22. Cartilage • Consists of sparsely distributed chondrocytes surrounded by a network of collagen fibers embedded in a tough but highly elastic matrix of branched glycoproteins • Provides support, flexibility, low-friction surface for joint movement

23. c. Cartilage Common locations: Ends of long bones, nose, parts of airways, skeleton of vertebrate embryos Collagen fibers embedded in an elastic matrix Function: Support, flexibility, low-friction surface for joint movement Chondrocyte Description: Chondrocytes embedded in a pliable, solid matrix of collagen and chondroitin sulfate Fig. 36.5c, p. 837

24. Cartilage • Consists of sparsely distributed chondrocytes surrounded by a network of collagen fibers embedded in a tough but highly elastic matrix of branched glycoproteins • Provides support, flexibility, low-friction surface for joint movement

25. c. Cartilage Common locations: Ends of long bones, nose, parts of airways, skeleton of vertebrate embryos Collagen fibers embedded in an elastic matrix Function: Support, flexibility, low-friction surface for joint movement Chondrocyte Description: Chondrocytes embedded in a pliable, solid matrix of collagen and chondroitin sulfate Fig. 36.5c, p. 837

26. Bone Tissue • Osteocytes are embedded in a collagen matrix hardened by mineral deposits • Osteoblasts secrete collagen and minerals for the ECM • Osteoclasts remove the minerals and recycle them into the bloodstream

27. d. Bone tissue Common locations: Bones of vertebrate skeleton Fine canals Function: Movement, support, protection Central canal containing blood vessel Osteocytes Description: Osteocytes in a matrix of collagen and glycoproteins hardened with hydroxyapatite Fig. 36.5d, p. 837

28. Adipose Tissue • Consists of cells specialized for fat storage • Cushions and rounds out the body • Provides an insulating layer under the skin

29. e. Adipose tissue Common locations: Under skin; around heart, kidneys Function: Energy reserves, insulation, padding Nucleus Fat deposit Description: Large, tightly packed adipocytes with little extracellular matrix Fig. 36.5e, p. 837

30. Blood • Consists of a fluid matrix (plasma) in which erythrocytes and leukocytes are suspended • Erythrocytes carry oxygen to body cells • Leukocytes produce antibodies, initiate immune response against disease-causing agents

31. f. Blood Common locations: Circulatory system Function: Transport of substances Leukocyte Erythrocyte Platelet Plasma Description: Leukocytes, erythrocytes, and platelets suspended in a plasma matrix Fig. 36.5f, p. 837

32. Muscle Tissue 1.Skeletal muscle • Long contractile cells (muscle fibers) • Moves body parts and maintains posture 2. Cardiac muscle • Short contractile cells with a branched structure • Forms the heart 3. Smooth muscle • Spindle-shaped contractile cells • Forms layers surrounding body cavities and ducts

33. a. Skeletal muscle Typical location: Attached to bones of skeleton Width of one muscle cell (muscle fiber) Function: Locomotion, movement of body parts Cell nucleus Description: Bundles of long, cylindrical, striated, contractile cells called muscle fibers Fig. 36.6a, p. 839

34. b. Cardiac muscle Location: Wall of heart Function: Pumping of blood within circulatory system Cell nucleus Intercalated disk Description: Cylindrical, striated cells that have specialized end junctions Fig. 36.6b, p. 839

35. c. Smooth muscle Typical location: Wall of internal organs, such as stomach (cells separated for clarity) Function: Movement of internal organs Description: Contractile cells with tapered ends Fig. 36.6c, p. 839

36. Nervous Tissue • Neurons communicate information between body parts (electrical and chemical signals) • Glial cells support neurons or provide electrical insulation between them

37. Dendrites Cell body Axon Axon terminals Direction of signal Nucleus Fig. 36.7, p. 840

38. 36.3 Coordination of Tissues in Organs and Organ Systems • Organs and organ systems function together to enable an animal to survive

39. Vital Tasks of Organs and Organ Systems • Maintenance of internal body conditions • Nutrient acquisition, processing, distribution • Waste disposal • Molecular synthesis • Environmental sensing and response • Protection against injury and disease • Reproduction

40. Nervous Endocrine Muscular Skeletal Integumentary Circulatory Lymphatic Immune Respiratory Digestive Excretory Reproductive 12 Major Organ Systems

41. Nervous System Endocrine System Muscular System Skeletal System Integumentary System Circulatory System Lymphatic System Main organs: Brain, spinal cord, peripheral nerves, sensory organs Main organs: Pituitary, thyroid, adrenal, pancreas, and other hormone- secreting glands Main organs: Skeletal, cardiac, and smooth muscle Main organs: Skin, sweat glands, hair, nails Main organs: Heart, blood vessels, blood Main organs: Bones, tendons, ligaments, cartilage Main organs: Lymph nodes, lymph ducts, spleen, thymus Fig. 36.8a, p. 840

42. Respiratory System Excretory System Reproductive System Digestive System Main organs: Lungs, diaphragm, trachea, and other airways Main organs: Pharynx, esophagus, stomach, intestines, liver, pancreas, rectum, anus Main organs: Kidneys, bladder, ureter, urethra Main organs: Female : ovaries, oviducts, uterus, vagina, mammary glands Male : testes, sperm ducts, accessory glands, penis Fig. 36.8b, p. 841

43. 36.4 Homeostasis • Homeostasis is accomplished by negative feedback mechanisms • Animals also have positive feedback mechanisms that oppose homeostasis

44. Homeostasis • Process by which animals maintain their internal fluid environment under conditions which their cells can tolerate • Dynamic equilibrium • Internal adjustments are made continuously to compensate for environmental changes

45. Negative Feedback Mechanisms • Sensor • Detects a change in an external or internal condition • Integrator • Compares the detected change with a set point • Effector • Returns the condition to the set point if it has varied