Tissue Types

1. Tissue Types

2. Tissue Types • Tissue – group of cells performing the same function Cells Tissue • 4 types of tissue 1. 2. 3. 4.

3. 1. Epithelium -- Qualities A. Epithelial cells cover all exposed surfaces of the body • Skin • Lining of mouth and GI system • Lining of blood vessels • Lining of the uterus • Lining of respiratory airways

4. 1. Epithelium -- Qualities • Epithelial cells have polarity • Epithelial cells have apical and basal surfaces. • Apical surface is the exposed surface • Basal surface comes in contact with underlying cells

5. These cells resemble the cells that line the inside of your cheek or oral cavity.

6. 1. Epithelium -- Qualities C. Epithelial cells are avascular (without blood or blood vessels). • How do epithelial cells receive nutrients?

7. 1. Epithelium -- Qualities • Epithelial cells have high capacity to regenerate. • Cells at exposed surfaces (skin and lining of stomach) are easily damaged and die and can be replaced. • Now…..why do you think epithelium is avascular? • And, why do you think regeneration is an important quality of epithelial cells?

8. 1. Epithelium -- Functions • Protection • Physical • Chemical • Biological • Secretion • All glands of the body are epithelial in origin. • Sweat and oil glands • Mammary glands • Enzyme secretion • Sensory detection • Contain nerve ending that can detect many sensations such as touch, pressure, temperature, light, taste, smell, hearing and equilibrium

9. 1. Epithelium -- Classification • Many types of epithelial cells • Many different functions of epithelial cells • How do we classify the various types? • Cell shape (3) • # of cell layers (2)

10. Cell Shape (3) • Squamous (flat) • Cuboidal • Columnar

11. Squamous Epithelium These cells resemble the cells that line the inside of your cheek or oral cavity.

12. Cuboidal Epithelium

13. Columnar Epithelium

14. 1. Epithelium -- Classification • Many types of epithelial cells • Many different functions of epithelial cells • How do we classify the various types? • Cell shape (3) • # of cell layers (2)

15. # of layers • Simple – single layer of epithelial cells • Stratified – more than one layer of epithelial cells

16. Simple Squamous Epithelium • Single layer of flat cells with an exposed surface

17. Stratified Squamous Epithelium • Multiple layers of flat cells with an exposed surface • Skin is great example

18. Ciliated Epithelium • Found on apical surface of epithelial cells in respiratory and reproductive organs • Moves surface objects in one direction • What objects are we talking about?

19. Glands • All glands with ducts are epithelial in origin.

20. 4 Tissue Types • Epithelium • Connective • Muscle • Nervous

21. 2. Connective Tissue (CT) • Designed to support, protect and bind organs as well as stores fat and transports gases, nutrients, hormones and wastes • It is the glue and packing material of the body

22. Composition of CT • Specialized cells • Ground substance – produced by the CT cells and can either be semisolid (cartilage) or solid (bone) • Extracellular protein fibers – collagen, elastin • Matrix -- #2 plus #3

23. Components of CT 1. 2. 3. 4.

24. Classification of CT X

25. Classification of CT • Connective Tissue Proper • Loose CT • Dense CT • Supporting CT • Cartilage • Bone

26. Classification of CT Proper • Loose CT – can be distorted without damage, an open framework, the packing material of the body

27. Loose CT • Adipose (fat) CT • What does adipose CTconnect to what?

28. Classification of CT Proper • Dense CT – densely packed, cannot be stressed too much without damage • Ligaments – attach bone to bone • Tendons – attach muscle to bone

29. Dense CT

30. Classification of CT • Connective Tissue Proper • Loose CT • Dense CT • Supporting CT • Cartilage • Bone

31. Classification of Supporting CT • Cartilage – firm, gel-like matrix, semi-flexible. • 3 types • Hyaline – articular cartilage, nose • Fibrocartilage – intervertebral disk, pubic symphysis, cartilage of knee joint • Elastic – external ear

32. 1. Hyaline • Chondrocyte – specialized cell of cartilage • Lacuna – spaces within matrix that cells occupy

33. 2. Fibrocartilage • Resists compression • Absorbs shock

34. 3. Elastic • Provides good flexibility

35. Classification of Supporting CT • Bone – more solid than cartilage and provides more support but is also more brittle

36. 4 Tissue Types • Epithelium • Connective • Muscle • Nervous

37. 3. Muscle • 3 types of muscle • Smooth – walls of blood vessels, gut and respiratory tree, reproductive tract….involuntary • Cardiac – walls of the heart….involuntary • Skeletal – muscles attached to skeleton, majority of muscles in the body….voluntary

38. 1. Smooth muscle

39. 2. Cardiac muscle

40. 3. Skeletal muscle

41. Function of Muscle • Contraction (shortening) • Result is movement • Smooth – movement of blood, food, sperm • Cardiac – movement of blood • Skeletal – movement of skeleton 2. Heat generation – ATP breaks down to give off energy in form of work and heat

42. 4 Tissue Types • Epithelium • Connective • Muscle • Nervous

43. 4. Nervous • Composition • Neurons – nerve cells • Neuroglia – support cells for the neurons • Function • Generate and conduct electrical impulses to other cells – activation of functions of organs

44. Neuron A cell that communicates with many other cells