Animal Tissues and Organ Systems

1. Animal Tissues and Organ Systems Chapter 20

2. Stem Cells • Undifferentiated cells with potential to develop into many cell types • Embryonic stem cells, more versatile • Adult stem cells, less versatile

3. Body Organization • Tissue • Group of cells performing same task • Organ • Two or more tissues performing same task • Organ system • Two or more organs performing same task

4. Tissues • Groups of cells and intercellular substances that interact in one or more tasks • Example: muscle tissue

5. Organs • Group of tissues organized to perform a task or tasks • Example: Heart is an organ that pumps blood through body • Heart consists of muscle tissue, nervous tissue, connective tissue, and epithelial tissue

6. Organ Systems • Groups of organs that interact physically and/or chemically to perform a common task • Example: Circulatory system includes heart, arteries, and other vessels that transport blood through the body

7. Homeostasis • Stable operating conditions in the internal environment • Brought about by coordinated activities of cells, tissues, organs, and organ systems

8. 4 Types of Tissues • Epithelial tissues • Connective tissues • Muscle tissues • Nervous tissues

9. Epithelial Tissues • Line body surfaces, cavities, ducts, and tubes • One free surface faces a body fluid or the environment simple squamous epithelium basement membrane connective tissue

10. Epithelium free surface of epithelium simple epithelium basement membrane connective tissue

11. Glands • Secretory organs derived from epithelium • Exocrine glands have ducts or tubes • Endocrine glands are ductless

12. Cell Junctions • Tight junctions prevent leaks • Gap junctions connect abutting cytoplasms • Adhering junctions cement cells together Tight junctions Adhering junction Gap junctions

13. Connective Tissues • Most abundant tissues in the body • Fibroblasts secrete • polysaccharide “ground substance” that surrounds and supports cells • fibers of collagen and/or elastin

14. Soft Connective Tissues • Loose connective tissue • Dense, irregular connective tissue • Dense, regular connective tissue

15. Specialized Connective Tissues • Cartilage • Bone tissue • Adipose tissue • Blood

16. white blood cell platelet red blood cell cells and platelets of blood Fig. 20-3g, p.342

17. Muscle Tissue • Cells contract when stimulated • Moves body and specific body parts • 3 types • Skeletal • Cardiac • Smooth

18. Skeletal Muscle • Attaches to and moves bones • Long, cylindrical cells • Striated cells • Voluntary control nucleus

19. Smooth Muscle • Located in soft internal organs and blood vessels • Cells taper at ends • Cells not striated • Not under voluntary control where abutting cells meet

20. Cardiac Muscle • Present only in heart • Cells are branching • ends of cells joined by communication junctions • Cells striated • Not under voluntary control cell nucleus

21. Nervous Tissue • Detects stimuli, integrates information, and relays commands for response • Consists of excitable neurons and supporting neuroglial cells

22. Neurons Functional zones of a motor neuron

23. Neurons • Excitable cells • Stimulus sends electrical impulse along plasma membrane • Transmits information to other neurons, muscles or glands

24. Neuroglia • Neuroglial cells make up more than half of nervous tissue • Protect and support neurons

25. 11 Major Organ Systems • Integumentary • Nervous • Muscular • Skeletal • Circulatory • Endocrine • Lymphatic • Respiratory • Digestive • Urinary • Reproductive

26. 11 Major Organ Systems Integumentary System Nervous System Muscular System Skeletal System Circulatory System Endocrine System Fig. 20-6, p.344a1

27. 11 Major Organ Systems Lymphatic System Respiratory System Digestive System Urinary System Reproductive System Fig. 20-6a2, p.344

28. Position References:Animals dorsal surface midsagittal plane anterior posterior transverse plane frontal plane ventral surface Fig. 20-6b, p.345

29. Position References: Humans frontal plane (aqua) transverse plane (yellow) midsagittal plane (green)

30. Major Body Cavities • Cranial cavity • Spinal cavity • Thoracic cavity • Abdominal cavity • Pelvic cavity

31. cranial cavity spinal cavity thoracic cavity abdominal cavity pelvic cavity Fig. 20-6d, p.345

32. Primary Tissues • Three primary tissues in vertebrate embryos give rise to all adult tissues: Ectoderm Mesoderm Endoderm

33. Skin: An Organ System • Epidermis: Stratified epithelium • Dermis: Dense connective tissues • Hypodermis: Loose connective tissue and adipose tissue

34. hair epidermis dermis sensory neuron hypodermis (below skin, not part of it) sweat gland oil gland hair follicle smooth muscle blood vessels Fig. 20-7a, p.346

35. outermost epidermal layer (all dead cells) keratinized cells being flattened rapidly dividing cells of epidermis dermis Fig. 20-7b, p.346

36. Functions of Human Skin • Protects body from injury, dehydration, UV radiation, and some pathogens • Helps control temperature • Receives external stimuli • Involved in vitamin D production

37. Sun Damages Skin • UV light stimulates melanin production • tans skin • Tan protects inner layers against UV damage • UV exposure causes • elastin fibers to clump • skin to age prematurely • skin cancer

38. Langerhans Cells • White blood cells in skin • Attack viruses and bacteria • Stimulate immune system • Are damaged by UV exposure

39. Epithelial Tissues