1. HISTOLOGY THE STUDY OF TISSUES

2. TISSUES Organization of similar cells embedded in a matrix (nonliving, intercellular material Matrix can be rigid, gel, fluid or nonexistent Specialize in performing at least one unique function essential for life

3. I. EPITHELIAL Covers and protects body surface Lines body cavities Secretes and absorbs substances into and out of blood Forms glands

4. II. CONNECTIVE Supports and connects body and its parts Transports substances throughout the body Protection from invading microbes Cells spread out; lots of matrix

5. III. MUSCLE Produces movement by shortening complex contractile proteins

6. IV. NERVOUS Communication between body parts and integration of their activities

7. 1. EPITHELIAL 2 types: 1. Membranous – covers and lines body 2. Glandular – exocrine and endocrine

8. FUNCTIONS Protection Secretion Absorption Excretion Sensory

9. CHARACTERISTICS Limited amount of matrix Basement membrane Avascular Held together by fused cell membranes Reproduce by mitosis Nutrients by diffusion Polarity

10. CLASSIFICATION OF MEMBRANOUS EPITHELIUM Based upon cell shape –Squamous (flat), cuboidal, or columnar Based upon # of cell layers –Simple (single) or stratified (layered)

12. Simple squamous

16. Simple cuboidal

20. Simple columnar

23. Pseudostratified

26. Transitional

28. Nonkeratinized stratified squamous

33. II. CONNECTIVE Most abundant and diverse Connects, supports, transports and defends Few cells, mostly matrix (nonliving extracellular material); various numbers and kinds of fibers

37. 1. AREOLAR Most common and widely distributed Matrix is soft gel – hyaluronic acid Matrix = collagen and elastin fibers Fibroblasts (secrete matrix) are the predominant cells Macrophages (phagocytosis) Mast cells – secrete histamine

38. Areolar

40. 2. ADIPOSE Mostly fat cells (adipocytes) Protection, insulation, energy storage

41. Adipose

43. 3. RETICULAR 3-D web Defense; reticular network filters harmful substances from lymph and blood Reticular cells phagocytic

44. Reticular

46. 4. DENSE REGULAR Mainly bundles of collagen arranged in parallel rows Few fibroblasts Ligaments (bone to bone) and tendons (muscle to bone)

47. Dense regular

48. 5. DENSE IRREGULAR Dermis of the skin

49. Dense irregular

50. 6. CARTILAGE One cell type: chondrocyte Chondrocytes produce fibers and tough gristlike material (chondroitin sulfate) Avascular – nutrients diffuse through perichondrium which surrounds cartilage mass

51. A. HYALINE CARTILAGE Shiny Most prevalent type Support tubes of respiratory system, ribs, ends of long bones that articulate at joints

52. Hyaline cartilage

54. B. ELASTIC Strong and flexible External ear, epiglottis, larynx

55. Elastic cartilage

57. C. FIBROCARTILAGE Strongest Shock absorbers Found between vertebrae and knee joints Rigid matrix filled with strong white fibers

58. Fibrocartilage

60. 7. BONE Osteocytes in matrix of collagen and mineral salts (65%) Support, protection, muscle attachment; mineral storage; hemopoiesis Haversian system

61. Bone

64. 8. BLOOD Liquid matrix Fibers only present at clotting Plasma = 55% Erythrocytes, leukocytes and platelets are the cells

65. Blood

67. III. MUSCLE 1. Skeletal –Multinucleate, cross striations 2. Cardiac –Heart wall; cross striations, intercalated disks, involuntary Visceral 3. Smooth –involuntary, one nucleus per cell, non striated

68. Skeletal muscle

70. Cardiac muscle

72. Smooth muscle

74. IV. NERVOUS Nerve cells –Neurons Cell body (soma), axons (away) dendrites (toward cell body) Neuroglia –Connecting and supporting cells

75. IV. Nerve