2. Chapter 5 - Tissues Groups of cells that have specialized structural and functional roles

3. There are 4 types of tissues in the human body.

4. 1.Epithelial – covering, lining 2.Muscle – contracts 3.Connective – bone, adipose (fat), blood, etc. 4.Nerve – sends impulses

5. Epithelial Tissue Anchored to a basement membrane that is anchored by its underside to connective tissue. The basement membrane is NONLIVING. Always has a free space exposed to the outside or open space internally - lumen

6. Characteristics of Epithelial Tissues Usually lack blood vessels Readily divide Tightly packed for protection Secretion, absorption, excretion, sensory reception

7. Organized by layering and cell shape

8. By layering Simple – extends from basement membrane to lumen – 1 layer Stratified – layered from basement membrane to lumen area Pseudostratified – “seemingly-layered”, but not Nuclei at various levels of cells makes the appearance of layers

9. By cell shape Squamous – flat cells Cuboidal – cube-shaped Columnar – elongated and thin – like columns

10. Usually both designations are used to distinguish the type of epithelial tissue!!! ** Denotes that you should know of an example or where these are located in the human body. You will be expected to know this.**

11. **Simple Squamous Epithelium

12. What would this be used for or where would we find it? Nuclei are broad and thin Diffusion occurs here Where? –Alveoli –Capillary walls

13. Simple Cuboidal Epithelium

14. What would this be used for or where would we find it? Nuclei are spheres Secretion and absorption More protection than previous kind Where? –Lines kidney tubules –Ducts of salivary glands and pancreas

15. Simple Columnar Epithelium

16. What would this be used for or where would we find it? Thicker than either previous ones Nuclei near basement membrane Have microvilli and goblet cells Where? –Lines uterus –Lines most organs of digestive tract

17. **Pseudostratified columnar Epithelium

18. What would this be used for or where would we find it? Appear layered, but are not (nuclei at various levels) Commonly have cilia and goblet cells Where? –Line respiratory tract

19. **Stratified Squamous Epithelium

20. What would this be used for or where would we find it? Many layers thick Division of cells in deep layer push old out Where? –Epidermis of skin – keratin –Mouth lining –Vagina lining –Anal canal

21. Stratified Cuboidal Epithelium

22. What would this be used for or where would we find it? More protection than simple 2 or 3 layers of cuboidal cells that form lining of lumen Where? –Lines mammary glands –Sweat glands –pancreas

23. Stratified Columnar Epitheliem

24. What would this be used for or where would we find it? Layers Where? –Male urethra and vas deferens –pharynx

25. **Transitional Epithelium

26. What would this be used for or where would we find it? Changes in response to an increase in tension Where? –Inner lining of urinary bladder –Lines urethra

27. **Glandular Epithelium

28. There are two basic kinds of glands: Exocrine – secrete products into ducts Endocrine – secrete products into tissue fluid or blood

29. Cells in these glandular tissues secrete fluids a number of ways: Merocrine – release watery, protein-rich fluids by exocytosis Apocrine – lose small portions during secretion Holocrine – entire cell lyses during secretion Kinds of fluids: Serous cells – watery fluids released Mucous cells – thicker mucin released

30. Section 5.3 – Connective Tissues

31. Connective tissue serves many purposes in the body: binding supporting protecting forming blood storing fats filling space

32. There is a matrix of fibers, cells, and ground substance Usually, the cells can divide and have a good blood supply and nourishment.

33. Major Cell Types: Fibroblasts – large, star-shaped Macrophages – “wandering cells” – are scavengers and defensive cells – phagocytes Mast cells – large and located near blood vessels – release heparin and histamine

34. Connective Tissue Fibers 1.Collagenous Fibers – thick threads of the protein collagen – form dense, connective tissue – appear white - in ligaments and tendons 2.Elastic Fibers – composed of thinner elastin – allow stretching – appear yellow – in vocal chords 3.Reticular Fibers – thin, collagenous fibers – branched for delicate support

35. Collagen Fibers

36. Elastin Fibers

37. Types of Connective Tissue 1. Loose Connective Tissue (areolar) 2. Adipose Tissue 3. Dense Connective Tissue 4. Cartilage 5. Bone 6. Blood

38. 1. Loose Connective Tissue – (Areolar) Delicate, thin, membranes Contains many fibroblasts located apart that secrete collagen and elastin fibers Fills spaces Binds skin to underlying organs **See transparency

39. 2. Adipose Tissue Fat Forms when connective tissue stores fat in droplets and they enlarge to crowd out other cells

40. 3. Dense Connective Tissue Closely-packed, thick, collagenous fibers Few cells Very strong Ligaments and Tendons See transparency

41. 4. Cartilage Rigid Chondrocytes Perichondrium NO direct blood supply to cartilage

42. Hyaline Cartilage Most common Ends of bones, soft part of nose, between ribs

43. Elastic Cartilage Elastic fibers Flexible External ears, larynx

44. Fibrocartilage Tough tissue with many collagenous fibers Shock absorber Pads between bones

45. 5. Bone Most rigid of connective tissue Mineral salts and collagen Supports, portects, forms blood cells, stores Ca and P Osteonic canals Osteocytes canaliculi

46. 6. Blood RBC’s, WBC’s, platelets, plasma

47. Section 5.4 – Muscle Tissues – contractile fibers

48. Skeletal Muscle Attach to bones Voluntary Striations A nerve impulse stimulates contraction

49. Smooth Muscle No striations Involuntary On walls of internal organs

50. Cardiac Muscle Only in heart Striations Involutary Branched fibers Intercalated discs

51. Section 5.5 – Nervous Tissues

52. Neurons In brain, spinal cord, and peripheral nerves Sense and respond by sending impulses to muscles or glands Coordinate, regulate, and integrate functions **Neuroglial cells