1. CHAPTER 4

2.  Study of different tissues  Abnormal cells and tissues can be compared to normal tissues to identify disease, such as cancer  Being able to know and recognize normal tissues under the microscope is the first step

3.  PRACTICE  There are thousands of images, virtual labs and practice quizzes online  DON’T MEMORIZE  Tissues from the same organ will look vastly different  RECOGNIZE PATTERNS  Don’t get lost in the big picture, look for patterns in how cells are organized  FORM = FUNCTION  Keep in mind the function of the tissue and the organ

4.  Tissues are collections of cells and cell products that perform specific, limited functions  Histology = study of tissues  There are 4 types of tissues 1. Epithelial – cover and protection 2. Connective - support 3. Muscle - movement 4. Neural – signaling and communication

5. READ ONLY!!!

7.  Covers body surfaces and lines cavities  Forms most glands  Characteristics  Cells are tightly packed together  Free surface exposed to environment = APICAL SURFACE  Attached to underlying connective tissue (basement membrane)  Avascular (no blood supply) – nutrients must diffuse  Continually replaced at exposed surface

8. 1. Protection from abrasion, dehydration, destruction 2. Regulate gas and nutrient exchange 3. Provide sensation 4. Secrete substances such as sweat, hormones, mucus and enzymes

9. 1. First name indicates number of layers  Simple: one layer of cells  Stratified: more than one layer of cells  Pseudostratified: appears to be stratified but is not

10. 2. Second name describes the shape of the cells  Squamous: thin and flat  Cuboidal: cube shaped  Columnar: tall, slender rectangles

12. 1. Simple Squamous ▪ Description: single layer of flat cells ▪ Functions: passage of material by simple diffusion and filtration; secretes lubricating substances ▪ Location: alveoli of lungs

13. 1. Simple Squamous Simple squamous lining the walls of the capillary

14. 2. Simple Cuboidal ▪ Description: single layer of cube-shaped cells ▪ Functions: absorption and secretion ▪ Locations: Sweat glands, ducts, kidney tubules, thyroid gland

15. 3. Simple columnar ▪ Description: single layer, tall cells ▪ Function: protection, absorption, secretion ▪ Locations: Lining of the nasal passages, stomach and intestines ▪ Other: : Cells are very long and often have cilia

16. 4. Stratified Squamous ▪ Description: many layers of flat cells (look at the shape of the cells at the apical surface) ▪ Functions: Protection from abrasion, pathogens, and chemicals ▪ Locations: surface of skin, lining of mouth, throat, esophagus, rectum, anus and vagina

17. 5. Pseudostratified ciliated columnar ▪ Description: single layer of columnar cells but the position of the nuclei make it appear as there are many layers; often ciliated ▪ Functions: Protection and secretion ▪ Locations: lining of nasal cavity, trachea and bronchi and portions of male reproductive tract

18. 6. Transitional ▪ Description: transitions from one shape to the next; often has a scalloped apical edge ▪ Functions: permits expansion and recoil after stretching ▪ Locations: bladder, renal pelvis, ureters

19. Practice Identifying epithelial tissues Pseudostratified

20. Practice Identifying epithelial tissues Simple Squamous

21. Practice Identifying epithelial tissues Simple Cuboidal

22. Practice Identifying epithelial tissues Stratified Squamous

23. Practice Identifying epithelial tissues TRANSITIONAL

24. Practice Identifying epithelial tissues Simple Columnar

26.  Most diverse tissue of the body  Most abundant  Not as dense as epithelial tissue  Highly vascular  Composed of: 1. Cells 2. Protein Fibers (the matrix) 3. Ground Substance (extracellular components)

28.  Specialized cells  Mast cells (prevent blood clots)  Macrophages (phagocytic)  Fibroblasts (produce the tissue)  Protein fibers form the matrix  Collagen (thick)  Elastin (thin)

29. A. Collagen fibers B. Fibroblasts C. Mast cells D. Macrophages E. Elastic fibers F. Blood vessel/cells G. Fat cells

30. 1. Support and protection 2. Transportation of materials 3. Storage of energy reserves (fat) 4. Fights infection, repairs tissue

32. 1. Connective Tissue Proper a) Loose Connective b) Adipose c) Dense Connective 2. Cartilage a) Hyaline b) Elastic c) Fibrocartilage 3. Other Tissues a) Bone b) blood

33. 1. Loose Connective Tissue (Areolar Tissue)  Structure: More ground substance, less fibers  Functions: cushion, support, movement, defense against pathogens  Locations: between other tissues and organs, beneath skin, digestive, respiratory and urinary tracts, between muscles, around blood vessels, nerves and joints

34. 1. Loose Connective Tissue (Areolar Tissue)

35. 2. Adipose (FAT)  Structure: Fibroblasts enlarge and store fat, very little matrix  Functions: stores energy, insulates and protects organs  Locations: beneath the skin and around organs especially at sides, buttocks, breasts, around eyes and kidneys

36. 2. Adipose Tissue

37. 3. Dense Regular (Fibrous)  Structure: tightly organized bundles of collagen  Functions: Tendons (connect muscles to bone) and Ligaments (connect bones to bones)

38. 3. Dense Regular

39.  Gel-type ground substance  For shock absorption and protection  No blood vessels  Types of cartilage include  Hyaline cartilage  Elastic cartilage  Fibrous cartilage

40. 1. Hyaline Cartilage  Most common  Very fine, white collagenous fibers  Covers ends of bones and joints and respiratory passages

41. 2. Elastic Cartilage  Elastic fibers in addition to collagen  More flexible and elastic  External ear

42. 3. Fibrous Cartilage (fibrocartilage)  Very tough, large numerous collagen fibers  Provides strong support and handles heavy pressure  Intervertebral discs

43.  Most rigid connective tissue  Rigid due to mineral salts  Bone cells called osteocytes  Periosteum (Covers bone surfaces)

44. HOMEWORK

45.  Physical barriers  Line internal spaces of organs and tubes that open to the outside  Line body cavities  Different types of membranes\  Mucous  Serous  Cutaneous  Synovial

46.  Mucous = protection  Line passages that have external connections  Lining of digestive, respiratory, urinary and reproductive tracts  Epithelial surfaces are moist to reduce friction and help absorption and excretion

47.  Line cavities not open to outside  Are thin but strong  Have fluid to reduce friction  Three serous membranes  Pleura – lungs  Peritoneum – abdomen  Pericardium - heart

48.  Outer covering of body  Skin  Thick, waterproof and dry  Stratified keratinized squamous epithelium

49.  Line freely movable joint cavities  Secrete synovial fluid into joint cavity – provides lubrication  Protects the end of bones  Lacks a true epithelium

51.  Specialized for contraction  Produces all body movement  Three types 1. Skeletal 2. Cardiac 3. Smooth

52. 1. Skeletal Muscle  Voluntary  Cells are long, cylindrical, striated and multinucleate  Specialized for contraction

53. 2. Cardiac Muscle  Involuntary  Cells are short, branched and striated usually with a single nucleus  Found only in the heart

54. 3. Smooth muscle  Involuntary  Cells are short, spindle-shaped and non-striated with a single central nucleus  Walls of hollow, contracting organs (blood vessels digestive, respiratory, urinary and reproductive tracts)

56.  Specialized for conducting electrical impulses  Rapidly senses internal or external environment  Processes information and controls responses  Concentrated in the central nervous system  Brain and spinal cord  Two kinds of neural cells  Neurons = neurons  Neuroglia = supporting cells

57.  A.k.a nerve cells  Perform electrical communication  Parts of a neuron  Cell body – contains the nucleus  Dendrites – receive incoming signals  Axon (nerve fiber) – long thin extension of the cell body which carries outgoing electrical signals to the effector

58.  Supporting cells  Repair and supply nutrients to neurons

59. Tissues respond to injury to maintain homeostasis

60.  Inflammatory response  The tissue’s first response to injury  Signs and symptoms of the inflammatory response  Swelling, redness, heat, pain  Can be triggered by  Trauma (physical injury) or infection

61.  Fibroblasts produce dense network of collagen fibers (scar tissue)  Most successful in…  epithelia, connective tissues and smooth muscle  Least successful in…  Neural tissue, cardiac muscle

62.  Speed and efficiency of tissue repair decrease with age due to  Slower rate of energy consumption (metabolism)  Hormonal alterations  Reduced physical activity  Osteoporosis – age related reduction in bone strength of women

63. Tissue ID quizlet