Tissues Groups of cells that are similar in structure and function Have a common origin

1. TissuesGroups of cells that are similarin structure and functionHave a common origin

2. ABOUT TISSUES • How do cells stay together? • How do they “communicate”? ( allow chemical ions to tra vel to and fro) We call these JUNCTIONS ( Next)

3. Membrane Junctions • Gap Junctions- These spaces allow chemicals,ions to pass through thereby allowing cell to cell communication. CONNEXONS are the tubes which are seen between gap junctions. • Desmosomes- Anchoring junctions; prevent cells from being pulled apart. • Tight Junctions- Impermeable Junctions. While cells are bound together they are leakproof at these junctions.

4. Plasma Membrane Specializations • Membrane junctions • Tight junctions • Desmosomes • Gap junctions Figure 3.3

5. Basement Membrane and Below

6. Skin

7. Tissue TypesEpithelialConnectiveMuscleNerve

8. Epithelial tissue Covers surfaces Lines tubes and body cavities open to outside

9. Epithelial tissue Covers surfaces Lines tubes and body cavities open to outside

10. Functions • protection • absorption • filtration • excretion • secretion • sensory reception

11. Characteristics Cells fit tightly together, bound by specialized junctions Have apical surface—free edge Cells attached to or supported by basement membrane Avascular Regenerate if well nourished

12. Classification Number of layers One--simple Two or more--stratified Shape of cell Irregular, flat--squamous Box-like--cuboidal Column-shaped--columnar

13. Squamous Epithelium

14. Where Do We Find Simple Squamous Epithelium? • Found where we here filtration or exchange..like circulatory system so… • Lines blood and Lymph vessels) • The serous linings of pericardium, pleura and peritonium.

15. Simple squamous epithelium

16. Single epithelial cell

17. Simple Columnar Epithelium

18. Where Do We Find Simple Columnar Epithelium? • Places that involve ABSORPTION and SECRETION…like the gallbladder and the duodenum ( SMALL INTESTINE!!) • CE cells that Secrete contain GOBLET cells which secrete MUCUS. These lubicate the epithelium. • Note that gallbladder cell contain NO goblets as they are absorptive NOT secretive.

19. Simple Columnar Epithelium with Goblet cells secreting mucus

20. Simple Cuboidal Epithelium

21. Where do we find Simple cuboidal Epithelial? • Collect tubules of KIDNEYs • Thyroid Gland • ASSOCIATED w/ secretion.

22. Simple Cuboidal Epithelium

23. Ciliated Pseudostratified Columnar Epithelium

24. Where Do We Find Pseudostratified Columnar Epitheium? • The Respiratory track is lined with this tissue. • Lots of Goblet cells to create mucus • Cilia sweep material in one direction along surface of epithelia.

25. Stratified Squamous Epithelium

26. Stratified Squamous Epithelium • It can be found….. • 1) upper layer of skin ( keratinized) • 2) oral cavity, pharynx, vagina (non-keratinized)

27. Transitional Epithelium • Is a Stratified epithelium which contains cells that, due to stretching, change their shape, hence the name “TRANSITIONAL”. • This properties allows for liquid to be store i.e. urine in the bladder ( an organ where this tissue is found) • The apical cells are rounded and give a scalloped appearance.

29. Transitional Epithelium

30. Let’s Review Name the Types of Epithelial Tissues

31. Simple Squamous • Simple Columnar • Simple Cuboidal • Pseudostratified Columnar (Ciliated) • Stratified Squamous • Stratified • Transitional

32. Connective Tissue Found in all parts of the body Characteristics Most are well vascularized (except tendons, ligaments, and cartilages) Composed of many types of cells Cells separated

33. Matrix composed of 1. ground substance Glycoproteins that determine nature of connective tissue 2. fibers • Support for matrix • collagenic (white) fibers • elastic (yellow) fibers • reticular fibers (fine collagenic)

34. Functions • Binding and support • Protection • Insulation • Transportation • Storage

35. Dense Connective Tissue • Collagen is the main matrix • Forms strong ropelike structures: ligaments and tendonsLigaments; connect bones to bones • Tendons: bones to muscles • DCT is also the lower part of dermis. • There is Dense Regular and Dense Irregular

36. LOOSE CONNECTIVE TISSUES • Areolar • Reticular • Blood • Adipose

37. Where Can We Find Areolar Tissue? • Areolar is found throughout the body, underlying the muscus membranes . We call the LAMINA PROPIA. It cushions us. Edema: When excess fluids are not absorbed by lymph vessels, the areolar tissue has room and takes up fluid….swells! See picture.

38. Areolar Connective Tissue Light packaging material found throughout body

39. EDEMA

40. Reticular Connective Tissue Network of reticular fibers in loose matrix Forms soft internal skeleton to support other cell types

41. Where Can We Find Reticular Connective Tissue? • The Stroma, that is the network that lines the lymph nodes and of lymphatic system such as the SPLEEN.

42. Blood Transports respiratory gases, nutrients and wastes

43. Matrix for blood: Plasma

44. Adipose Tissue Storage, insulation, protection

45. Bone Supports and protects, stores calcium, acts as levers for muscles

46. Hyaline Cartilage Forms most of embryonic skeleton, covers ends of bones, costal cartilages, cartilage of nose, trachea, larynx

47. Fibrocartilage • Forms the cushionlike disks between vertebrae • Highly compressible

48. Elastic Cartilage • Found where elasticity is desired • Supports the Ear

49. Muscle Tissue Specialized to contract Skeletal muscle--attached to bones Cardiac muscle--wall of heart Smooth

50. Skeletal Muscle Striated, voluntary muscle