1. Tissues Groups of cells similar in structure and function
The four types of tissues
Epithelial
Covers and lines body cavities both inside and outside of the body.
Connective
Protects and insulates vital organs and fills body cavity spaces. Connects different type of tissues to each other.
Muscle
Functions in locomotion, digestive and cardiovascular functions.
Nerve
Communicate electrical impulses which facilitates the action of both muscles and glands.

2. Epithelial Tissue Covers the entire surface of the body
Skin and reproductive tracts
Barriers between what is in and out of the body.
Lining of the lung, digestive and urinary tracts
controls what substances enter/exit the body and what substances stay in/out of the body
Specialized type types of epithelial tissue include:
exocrine glands
secrete substances outside of the body
(sweat, salivary)
endocrine glands
secrete substances (hormones) into the blood
(insulin, growth hormone)

3. Epithelial Membranes
Serous – moist membranes that line internal organs.

4. Epithelial Membranes

5. Classification of Epithelial Tissues
Epithelial tissue is classified based on 2 criteria:
Shape and number of layers
Cell shape
squamous (flattened cells)
cell width is larger than cell height
cuboidal (cube-like cells)
cell width is equal to cell height
columnar (column-like cells)
cell height is larger than cell width

6. Classification of Epithelial Tissues
Number of layers of epithelial cells
Simple
Thin layer allows for exchange of substances into or out of the body
Stratified
Multiple layers protects act as a natural barrier to prevent abrasion, puncture.

7. Epithelia: Simple Squamous
Figure 4.2a

8. Epithelia: Simple Cuboidal
Single layer of cubelike cells with large, spherical central nuclei
Function in secretion and absorption
Present in kidney tubules, ducts and secretory portions of small glands, and ovary surface
Figure 4.2b

9. Epithelia: Simple Columnar
Figure 4.2c

10. Epithelia: Pseudostratified Columnar
Single layer of cells with different heights; some do not reach the free surface
Nuclei are seen at different layers
Function in secretion and propulsion of mucus
Present in the male sperm-carrying ducts (nonciliated) and trachea (ciliated)
Figure 4.2d

11. Epithelia: Stratified Squamous
Thick membrane composed of several layers of cells
Function in protection of underlying areas subjected to abrasion
Forms the external part of the skin’s epidermis (keratinized cells), and linings of the esophagus, mouth, and vagina (nonkeratinized cells)
Figure 4.2e

12. Epithelia: Transitional
Several cell layers, basal cells are cuboidal, surface cells are dome shaped
Stretches to permit the distension of the urinary bladder
Lines the urinary bladder, ureters, and part of the urethra
Figure 4.2f

13. Connective Tissue
Widely spaced cells separated by fibers and ground substance. Most abundant and variable tissue type
Connective tissue proper
Dense
Regular and Irregular
Loose
Areolar, Adipose, Reticular.
Cartilage
Hyaline, Elastic, Fibrocartilage
Bone
Spongy, Compact
Blood
Fluid connective tissue (plasma ) red blood cells, white blood cells, platelets
Functions
connects organs
gives support and protection (physical and immune)
stores energy and produces heat
movement and transport of materials

14. Connective Tissue
Figure 4.5

15. Structural Elements of Connective Tissue

16. Cells of Connective Tissue
Fibroblasts produce fibers and ground substance
Adipocytes store triglycerides
Chondroblasts – produce cartilage
Osteoblasts – build bone
Hematopoietic stem cells – blood
White blood cells, plasma cells, macrophages, and mast cells

17. Fibers of Connective Tissue
Collagen fibers (white fibers)
tough, stretch resistant, yet flexible
tendons, ligaments and deep layer of the skin
Reticular fibers
thin, collagen fibers coated with glycoprotein
framework in spleen and lymph nodes
Elastic fibers (yellow fibers)
thin branching fibers of elastin protein
stretch and recoil like rubberband (elasticity)
skin, lungs and arteries stretch and recoil

18. Connective Tissue Ground Substance
Gelatinous material between cells
absorbs compressive forces
attract sodium and hold water

19. Ground Substance: Proteoglycan Structure
Figure 4.6b

20. Fibrous Connective Tissue Types
Loose connective tissue
gel-like ground substance between cells
types
areolar
reticular
adipose
Dense connective tissue
fibers fill spaces between cells
types vary in fiber orientation
dense regular connective tissue
dense irregular connective tissue

21. Loose Connective Tissue Proper: Areolar

22. Areolar Connective Tissue
Figure 4.8b

23. Connective Tissue: Embryonic
Figure 4.8a

24. Adipose Connective Tissue

25. Reticular Connective Tissue
Figure 4.8d

26. Connective Tissue: Dense Regular
Figure 4.8e

27. Connective Tissue : Dense Irregular
Figure 4.8f

28. Connective Tissue: Hyaline Cartilage
Figure 4.8g

29. Connective Tissue: Elastic Cartilage
Similar to hyaline cartilage but with more elastic fibers
Maintains shape and structure while allowing flexibility
Supports external ear (pinna) and the epiglottis
Figure 4.8h

30. Connective Tissue: Fibrocartilage Cartilage
Matrix similar to hyaline cartilage but less firm with thick collagen fibers
Provides tensile strength and absorbs compression shock
Found in intervertebral discs, the pubic symphysis, and in discs of the knee joint
Figure 4.8i

31. Connective Tissue: Bone
Figure 4.8j

32. Connective Tissue: Blood
Figure 4.8k

33. Nervous Tissue
Figure 4.10

34. Muscle Tissue: Skeletal
Long, cylindrical, multinucleate cells with obvious striations
Initiates and controls voluntary movement
Found in skeletal muscles that attach to bones or skin
Figure 4.11a

35. Muscle Tissue: Cardiac
Branching, striated, uninucleate cells interdigitating at intercalated discs
Propels blood into the circulation
Found in the walls of the heart
Figure 4.11b

36. Muscle Tissue: Smooth
Figure 4.11c

37. Tissue Shrinkage and Death
Atrophy = loss of cell size or number
disuse atrophy from lack of use (leg in a cast)
Necrosis = pathological death of tissue
gangrene - insufficient blood supply
Diabetic complications.
infarction - death of tissue from lack of blood
Heart attack or cerebral vascular accident ( stroke)
decubitus ulcer - bed sore or pressure sore
Pressure cuts off blood supply to a specific part of body.

38. Diabetic Ulcer Bedsores