1. Distinguish different types of connective and muscular tissues.
Tissues Chapter 5
Objectives:
List and describe the four major tissue types, and provide examples of where each occurs in the body.
Name the types of epithelium, and identify an organ in which each is found.
Distinguish different types of connective and muscular tissues.

2. Tissue:
Def.: a group of similar cells that performs a specialized function
4 major types of tissues:

3. A. Epithelial Tissues Forms linings throughout the body
Anchored to underlying connective tissue by a nonliving layer called basement membrane
1. Simple Squamous Epithelium - a single layer of thin, flattened cells
Fit together tightly
Broad, thin nuclei
Substances pass through easily; easily damaged
Found in lung air sacs, capillary walls, and membranes lining body cavities
???
Why would substances pass through easily? Why would the tissue be easily damaged?
Why would this type of tissue be useful in lung air sacs and capillary walls?

5. Epithelial Tissues (cont.)
2. Simple Cuboidal Epithelium – single layer of cube-shaped cells
Centrally located, spherical nuclei
Ovaries, kidney tubules, ducts of some glands
Adds in secretion and absorption

7. Epithelial Tissues (cont.)
3. Simple Columnar Epithelium – longer than they are wide (elongated, like columns)
Thicker
Nuclei located near the basement membrane
Ciliated – found in female reproductive tubes
Nonciliated – lining of uterus, stomach, intestines

9. Epithelial Tissues (cont.)
4. Pseudostratified Columnar Epithelium – appear to be stratified (layered), but are not
Why? Nuclei are found at different levels in the cells, instead of only near the basement membrane.
Many are ciliated.
Found lining respiratory passages

11. Epithelial Tissues (cont.)
5. Stratified Squamous Epithelium
Many layers = thick (for protection) ???
Outer layer of skin (“epidermis”)
Lining of mouth, throat, vagina, and anal canal
6. Stratified Cuboidal Epithelium
2-3 layers of cuboidal cells lining a lumen
Lines large ducts of glands (mammary, sweat, salivary, pancreas) and of ovarian follicles and seminiferous tubules
7. Stratified Columnar Epithelium
Top layer elongated; base layer cube-shaped
Found in male urethra, vas deferens, and pharynx
5. Why would these areas need thick, layered epithelium?

14. Why do you think the bottom layer is more cuboidal than elongated?
???

15. Epithelial Tissues (cont.)
8. Transitional Epithelium – changes in response to tension
Found lining the bladder, ureters, and part of the urethra
Contracted – thicker; many layers **
Relaxed – stretches and appears thinner
See Table 5.3, p. 99!!
Contracted =thicker in muscle, too.

17. B. Connective Tissues Made up of: Major cell types:
Cells, which are further apart than epithelial cells
Fibers
Matrix: intercellular material
Major cell types:
Fibroblasts – large, fixed, star-shaped cell that secretes fibers
Macrophages – wandering scavenger cells that defend against infection
Mast cells – large cells, located near blood vessels, that secrete heparin and histamine

18. Fibroblast

19. Macrophage & Mast Cell

20. Connective Tissues (cont.)
Connective tissue fibers:
Strong, collagenous fiber (white fiber), made of the protein collagen; adds strength
Stretchy, elastic fiber (yellow fiber), made of the protein elastin; adds ____________.
Reticular fibers – thin collagenous fibers that form supportive networks in tissue
flexibility

21. Connective Tissues (cont.)
Loose Connective Tissue (“areolar tissue”)
Cells are some distance apart; separated by gel-like matrix
Forms delicate, thin membranes
Binds skin to underlying organs, fills space between muscles

22. Connective Tissues (cont.)
2. Adipose Tissue – fat
Large fat droplets in cells push nuclei close to the cell membranes.
Beneath the skin, between muscles, around kidneys, behind eyeballs, on heart, around joints

23. Connective Tissues (cont.)
3. Dense Connective Tissue – closely packed, thick collagenous fibers + elastic fibers
Strong!
Binds organs together
Found in tendons, ligaments, deep skin layers

24. Connective Tissues (cont.)
4. Cartilage – a rigid connective tissue
Chondrocyte: cartilage cell
Perichondrium: around cartilage; membrane surrounding cartilage; contains blood vessels to supply nutrients
Three types of cartilage, distinguished by intercellular (???) matrix:
Hyaline cartilage
Elastic cartilage
Fibrocartilage
What does intercellular mean?

25. Connective Tissue (cont.)
Hyaline cartilage
Very fine collagenous fibers in matrix
White glass appearance
Ends of bones in joints, soft part of nose
Elastic Cartilage
Dense network of elastic fibers = more flexible
Framework for external ears and parts of larynx
Fibrocartilage
Very tough; many collagenous fibers
Forms intervertebral discs and pads between bones in knees and pelvic girdle

26. Hyaline cartilage cells
Insert Pics!!!
Elastic cartilage cells

27. Fibrocartilage http://www.bartleby.com/107/Images/small/image295.jpg

28. Connective Tissue (cont.)
5. Bone – the most rigid connective tissue
Matrix made of mineral salts and collagen fibers
Osteocyte: bone cell
6. Blood
See Table 5.4, p.105!!!

29. ???
What does bone resemble?

30. C. Muscle Tissues Skeletal muscle tissue (“voluntary”)
Long, threadlike cells
Striations: alternating light and dark cross-markings
Each cell has many nuclei just beneath the cell membrane.

31. Muscle Tissues (cont.) 2. Smooth muscle tissue (“involuntary”)
No striations
Cells are shorter than skeletal muscle, spindle-shaped, and have one, centrally located nucleus.
Line walls of internal organs

32. Muscle Tissues (cont.) 3. Cardiac muscle tissue – heart
Striated and joined end-to-end
Each cell has only one nucleus ???
How would you be able to differentiate b/t skeletal and cardiac muscle tissue, since both are striated?

33. D. Nervous Tissue Nervous tissue is See Table 5.5, p.107!!!
found in the brain, spinal cord, and nerves.
made up of:
Neurons: nerve cells
Neuroglial cells: helper cells
“glia” = glue
Support and bind components of nervous tissue to each other and to blood vessels
See Table 5.5, p.107!!!