Introduction to Tissues: Epithelial, Connective, Muscle, and Nervous Tissue

1. Chapter 5 Tissues

2. Introduction • Tissues: groups of cells that have specialized structural and functional roles • 4 major types: epithelial, connective, muscle, and nervous tissue

3. Epithelial Tissue • The covering of the body surfaces, lining of most internal organs, and major tissues of glands • basement membrane: anchors the underside of the tissue

4. Lack blood vessels, nurished by underlying connective tissue • reproduce readily, heal fast • skin, lining of stomach and intestine • secretion, absorption, excretion, and sensory receptors

5. Types of Epithelial Tissue • Squamous, Cuboidal, Columnar, Pseudostratified columnar, Stratified squamous, Stratified cuboidal, Stratified columnar, Transitional, and Glandular

6. Squamous Epithelial Tissue • Single layer of thin flattened cells, sudstances easily pass through • lining of air sacs, capillaries, blood vessels, and covers membranes that line the body cavity • easily damaged p. 98

7. Simple Cuboidal Epithelium • Cube shaped cells, single layer • cover ovaries, line kidney tubules, and ducts of glands • help with secretion, and absorption p.98

8. Simple Columnar Epithelium • Elongated tissue that line the uterus, most organs of the digestive tract • thick and protective • microvilli: extensions of this tissue that increase surface area p. 99

9. Pseudostratified Columnar Epith. • Appear stratified or layered • covered in cilia • located in the respiratory, and reproductive linings • p. 99

10. Stratified Squamous Epith. • Many cell layers, thick • protects underlying layers • covers the skin, lining the mouth, vagina, throat, and anal cavities • p.100

11. Stratified Cuboidal Epith. • Cube shaped cells • two layers • lines the larger ducts of the mammary glands, sweat, salivary, and panceas • p. 100

12. Stratified Columnar Epith. • The top layer of cells that contains elongated columns • lines the urethra, vas deferens, and parts of the pharnyx • protects and secretes • p. 101

13. Transitional Epith. • This tissue is specialized to change under tension • lines the walls of various organs of the urinary system

14. Glandular Epith. • Cells that specialize in the excretion of substances • glands consist of one or more layers • Exocrine: secrete into ducts • Endocrine: secrete into tissue fluids, or blood

15. Exocrine glands are classified as to the method they secrete things. • Merocrine glands: secrete fluid without the loose of cytoplasm • serous: secrete watery fluid with high enzyme content • mucous: secrete musous

16. Apocrine glands: lose portions of the cell during secretion • Holocrine glands: release cells filled with secretory products • p. 103

17. Connective Tissues • Connect, support, protect, provide frameworks, fill spaces, store fats, produce blood cells, protect against infection, and help repair damaged tissues

18. Cells of connective tissue are separated by considerable intercellular material (matrix) • consists of fibers, and a ground substance

19. Major cell types • Fibroblasts: produce collagenous and elastic fiber • macrophages: phagocytes • mast cells: release histamine, and heparine, located near blood vessels

20. Connective tissue fibers • Collagenous fibers: composed of collagen, have great tensile strength • Dense Connective tissue: largely composed of collagenous fibers

21. Elastic fibers: composed of microfibrils embedded in elastin, are very elastic • Reticular fibers: very fine collagenous fibers • Loose fibrous connective tissue: forms thin membranes between organs, found beneath skin, between muscles

22. Adipose tissue: a specialized form of loose fibrous tissue that stores fat. • Found beneath the skin in various joints, certain membranes of the abdominal area, around the kidneys, and heart

23. Dense Fibrous Tissue: composed largely of strong collagenous fibers • found in tendons, ligaments, white portions of the eye, and deep layer of the skin • Cartilage: provides a supportive framework, composed of fibers, and gel-like ground substance

24. Housed in perichondrium • lacks direct blood supply, slow to heal • 3 major types of cartilage: hyaline, elastic, fibrocartilage • Bone: intercellular matrix contains mineral salts, and collagen

25. The cells are usually organized into circles around osteonic canals and are interconnected by canaliculi • bone is an active tissue, heals rapidly

26. Blood: transports substances and helps maintain a stable internal environment • composed of red, and white blood cells, and platelets suspended in plasm • blood cells develop in the red marrow of long bones

27. Muscle Tissue • Muscle tissues contract, moving the structures they are attached to • 3 types: skeletal, smooth, cardiac

28. Voluntary: consciously controlled contractions • Striation: the light and dark cross sections of skeletal muscle

29. Skeletal Muscle • Usually attached to bones, and controlled by conscious effort. • Muscle fibers are long and threadlike • muscle fibers contract when stimulated by nerve action and then relax immediately.

30. Control things like: writing, facial expression, talk, sing, chew, swallow, breathe, moving the head, trunk, and limbs

31. Smooth Muscle • Tissue that lines the walls of hollow internal organs. (Intestines, stomach) • controlled by involuntary activity • spindle like in shape • Involuntary: lack conscious action

32. Moves food through digestive tract, constrict blood vessels, empties urinary bladder

33. Cardiac Muscle • Tissue only formed in the heart • cells are joined by intercalcated disks and form branched networks • involuntarily controlled • pumps blood into the blood vessels

34. Nervous Tissue • Found in the brain, spinal cord, and peripheral nerves • neurons: nerve cells • transmit signals of change to the central nervous area via nerve fibers

35. Neuroglial Cells: some forms bind and support nervous tissue • carry out phagocytosis • connect neurons to blood vessels