1. Tissues Histology- the study of tissue Groups of cells that are similar in structure and perform a common or related function.

2. 4 primary types: Epithelial (covering) Connective (support) Muscle (movement) Nervous (control)

3. Epithelial- Used for covering (ex: organs) or Glands

4. Epithelial Function- protection, absorption, filtration, excretion, secretion, sensory reception

5. Characteristics of Epithelial: Innervated Avascular High regenerative capacity Polar- Apical surface= free Basal surface= attached Lots of cells / form sheets

6. 2 names for epithelia: Layers: simple or stratified Shapes: Squamous Cuboidal Columnar

7. Simple Squamous- thin, permeable, for filtration or exchange, found in lungs, kidneys

8. 2 types: Endothelium- inner covering, slick friction reducing lining vessels Mesothelium- middle covering lining the ventral body cavity

9. Simple Cuboidal- secretion and absorption, found in glands

10. A gland consists of one or more cells that make and secrete a product

11. Endocrine gland- ductless, absorb and secrete product by diffusion (thyroid, adrenals, pituitary) Exocrine gland- ducts (salivary, oil, liver, pancreas)

12. Simple Columnar- lines the digestive tract from stomach to rectum

13. Examples: Microvilli- lines intestine, absorbs nutrients Goblet Cells- secretes protective lubricating mucus

14. Stratified Squamous Stratified Squamous- is most widespread, thick, protective, is the external part of skin, covers tongue, lines mouth, throat, esophagus, anal canal, vagina

15. Epidermis- the outer layer of the skin that contains a protective protein called keratin

16. Stratified cuboidal and stratified columnar are rarer types (make up some ducts)

17. Connective Tissue

18. 2 Parts Cells (living) Fibroblast Chondroblast Osteoblast Hemocytoblast Matrix (non-living) 1) Ground Substance: Amorphous material 2) Fibers: Collagen Elastin Reticular

19. Mesenchyme (embryonic origin) Fibroblast Chondroblast Osteoblast Hematoblast Fibrocyte Chondrocyte Osteocyte Blood Cells Connective Tissue Cartilage Bone Blood Proper

20. Connective Tissue Proper 1)Loose Connective * Areolar * Adipose * Reticular 2) Dense Connective * Regular * Irregular

21. Areolar (connective tissue proper) Gel like, wraps and cushions organs

22. Adipose (fat) connective tissue proper Matrix contains stored neutral fat oil Shock absorber and insulator

23. Reticular Connective tissue proper Forms a soft internal skeleton (stroma) Found in lymphoid organs

24. Dense Regular connective tissue proper Parallel collagen fibers Tendons, Ligaments

25. Dense Irregular connective tissue proper Thicker bundles of collagen fiber Form sheets in body areas where tension is exerted in different directions Fibrous Joint Capsules, dermis

26. Cartilage -Tough but flexible -Avascular -Devoid of nerves -80% water -Heals slowly

27. Cartilage-3 Types 1) Hyaline Cartilage 2) Fibrocartilage 3) Elastic Cartilage

28. 1) Hyaline Cartilage Embryonic skeleton ends of long bone costal cartilage (rib) Nose trachea, larynx supports, reinforces flexible

29. Fibrocartilage Thick collagen fibers Intervertebral Discs

30. Elastic Cartilage More elastin fibers Ear, Epiglottis

31. Bone 1) Compact bone 2) Spongy bone

32. Bone Hard calcified matrix Very well vascularized Gives support

33. Mesenchyme (embryonic origin) Fibroblast Chondroblast Osteoblast Hematoblast Fibrocyte Chondrocyte Osteocyte Blood Cells Connective Tissue Cartilage Bone Blood Proper

34. Blood Various Complex Cells

35. Blood Atypical Connective tiusse Blood Cells= macrophages, wbc, rbc Matrix= plasma Fibers=soluable proteins that are visible in clotting -Carries gas, nutrients, waste, etc.

36. Nervous Tissue

37. Makes up brain, spinal cord, nerves Neurons- highly specialized nerve cells generate and conduct nerve impulses Supporting cells- no conducting, support, insulate, and protect neurons

38. Muscle Tissue Highly vascular Highly cellular Function= movement

39. Skeletal Muscle Tissue Voluntary Attaches to bone, skin Gross body movements Long cylindrical, many nuclei Striated (banded)

40. Skeletal Muscle Picture

41. Cardiac Muscle Tissue Involuntary Walls of the heart Striated Branched Fit together by intercalated discs

42. Cardiac Muscle Picture

43. Smooth Muscle Tissue Involuntary Function= to propel (squeeze) Found: in walls of hollow organs (uterus), digestive sys., urinary sys., blood vessels Spindle shape Central nucleus NO STRIATIONS

44. Smooth Muscle Picture

45. Functions of Tissue Protection Mechanical protection= (barrier) skin, mucosa Ciliary protection= epithelial (trachea) Chemical protection= glands

46. Inflammatory response Occurs when tissues are injured Non-specific

47. Immune Response Specific Takes longer to come to action Involves antibodies

48. Tissue Repair Three steps: – Inflammation – Organization – Regeneration

49. Inflammation Histamine  macrophage, mast cell Capillaries dilate Leak clotting proteins Clot  scab

50. Organization Clot  Granulation tissue New blood vessels  collagen fibers  scar

51. Regeneration Epithelial cells migrate across granulation tissue and thickens

52. The ability to regenerate: Good: Epithelial (skin, epidermis, mucosa) Limited: Smooth muscle, dense regular connective (ligaments, tendons) Poor: Skeletal muscle, Cartilage