1. …pass the tissues please…
Histology
…pass the tissues please…

2. I. Intro to Histology
Tissue definition: A group of similar cells working towards one unifying goal
Tissues components
Similar cells
Extracellular Matrix
- water, NaCl, ions, calcium, fibers, nutrients, etc..

3. I. Intro to Histology The 4 types of tissues
Epithelial         * covers body surfaces         * lines hollow organs         * lines body cavities and ducts         * forms glands and secretions
Connective         * protection and support         * binding together (like glue)         * energy storage
Muscle
* movement and force (including peristalsis)
Nervous
* coordinates body activities

4. I. Critical Thinking Question?
What tissue type does blood belong to?
A. Epithelial
B. Connective
C. Muscle
D. Nerve
E. Blood isn’t a tissue

5. II. Epithelial Anatomy Location Covers external surfaces
Lines internal surfaces such as cheeks, blood vessels, organs etc…
Glands

6. II. Epithelial Anatomy Basic Anatomy Cells bound tightly together
Classified by shape of cells and number of layers
Avascular
Contain Stem cells
Has an exposed surface (Apical membrane)
Has a surface bound to connective tisuuse (basal membrane)
Apical Surface
Basal
(basement)
Connective
tissue

7. III. Epithelia Physiology
Function
Provides protection internally and externally
Controls permeability
Provides for touch/stimuli
Produces secretions:
exocrine – released onto surfaces
digestive enzymes, sweat
endocrine – releases into tissue fluid and blood
Hormones (chemical messengers) from pancreas, thyroid, pituitary, etc

8. II. Epithelial Anatomy Basic Anatomy
Apical Surface may contain specialized structures
Cilia for movement
Microvilli for increased absorption (Brush Borders)

9. II. Epithelial Anatomy
The Brush Border

10. II. Epithelial Anatomy Basic Anatomy Basal Membrane: “Basement”
Provides strength to epithelium
Creates barriers to prevent molecules from entering connective tissue

11. II. Epithelial Anatomy Classification Systems By Layers Shape
Simple: single
Stratified: multiple
Pseudostratified: appears multiple, but really simple
Shape
Squamous: Flat
Cubodial: cube-like
Columnar: column-like
Transitional: changes
Example. Simple cubodial = 1 cell thick of cube shaped cells

12. IV. Epithelial Tissues: Simple Squamous
Anatomy
Lining of body cavities, organs, blood vessels, alveoli lung surface
Serous Membranes
Physiology
Diffusion
Secretions

13. IV. Epithelial Tissues: Simple Squamous

14. IV. Epithelial Tissues: Simple Squamous

15. IV Epithelial Tissues: Simple Cuboidal
Anatomy
Digestive tract, Kidney tubules, glands
Physiology
Absorption and Secretions

16. IV Epithelial Tissues: Simple Cuboidal

17. IV Epithelial Tissues: Simple Columnar
Anatomy
Lining of digestive tract
Modified by presence of cilia
Contains “Goblet cells”
Physiology
Help move surface material
Absorption

18. IV Epithelial Tissues: Simple Columnar

19. IV Epithelial Tissues: Simple Cuboidal
Simple Columnar

20. IV Epithelial Tissues: Simple Columnar

21. IV Epithelial Tissues: Stratified Squamous
Anatomy
Outer most layer- squamous cells
Inner- cuboidal or columnar
Lining of mouth, esophagus, skin
Can be keratinized
Physiology
Protection
Secretion
Moistens membranes

22. IV Epithelial Tissues: Stratified Squamous
Stratified Squamous – non keratinized

23. IV Epithelial Tissues: Stratified Squamous
Keratinized Stratified Squamous
Keratin: Waxy protective coverings
Waterproofs

24. IV Epithelial Tissues: Pseudostratified Columnar
Anatomy
One layer
All attach to the basal membrane
Appears stratified
Upper respiratory tract
Physiology
Move material

25. IV Epithelial Tissues: Pseudostratified Columnar

26. V. Connective Tissue Abundant extracellular material
Matrix (dominant part) or ground substance
Fiber, cells in liquid, gel, or solid matrix
Never exposed to “outside environment”
If exposed, causes a response for “damage control” (ie. Bleeding)
Functions
Bind and/or support other tissue
Energy storage
Defense of the body

27. V. Connective Tissue
Classification is based on the composition of matrix…
1. Connective Tissue Proper – loose and dense. subcutaneous, fat, tendons and ligaments
2. Fluid connective tissue
3. Supporting connective tissue

28. V. Connective Tissue Connective Tissue Tissue Proper Fluid Supporting
Blood
Lymph
Loose
Dense
Cartilage
Bone
Dense Regular
Dense Irregular

29. VI. Connective Tissue Proper
- Either loose or dense
- Examples: subcutaneous, fat, tendons and ligaments
Tissue Proper is composed of …
Fibroblasts – homeostasis of tissue
Macrophages – engulf waste
Fat cells – permanent residents
Mast cells – near blood vessels, release chemicals to elicit injury response

30. VI. Connective Tissue Proper
3 Fibers
Collagen - long and straight, most common fibers, strong but flexible
Elastic – branched and wavy, contains elastin, are elastic
Reticular – less common, thin, branching, interwoven framework of fibers

31. VI. Connective Tissue Proper
Loose or areolar
Fewer fibers but all kinds
Cushioning and support
Deep to skin, between muscles, around vessels
Dense Fibrous
abundant, organized collagen fibers
Tendons and ligaments
Dense Regular or Dense irregular

32. VI. Connective Tissue Proper
Dense Regular
collagen runs parallel, packed tightly, aligned with forces
Tendons and ligaments
Provides attachements
Dense Irregular
with collagen to provide support and strength
Gives skin its strength

33. VII. Adipose Adipose Connective Tissue Loose connective
Store large droplets of fat
Large “marshmellow” looking cells
Nuclei squished to one side

34. VIII. Fluid Connective Tissue
Blood
Plasma: Liquid matrix
RBC’s
WBC’s
Lymphatic System
Lymph: fluid portion
Part of your immune system

35. IX. Supporting Connective
Cartilage Connective Tissue
Rubbery consistency (matrix)
Avascular

36. IX. Supporting Connective
Types of Cartilage
Hyaline – most common
Joints, rib cage, respiratory tract
Elastic
Mostly elastic fibers, Very flexible
Outer ear, nose, epiglottis
Fibrocartilage
Mostly collagen fibers, durable, strong, tough
Backbone (resist compression, absorb shock…)

38. IX. Supporting Connective
Bone
Osteocytes: bone cells
Hardest connective tissue
Spongy bone
Ends of long bones
Compact
Shafts of long bones
Tightly organized

39. Bone Connective Tissue

40. X: Muscle Functions: Three types 1. Skeletal 2. Smooth 3. Cardiac
Cells have ability to contract
Locomotion
Support
Other body movement

41. X: Muscle: Skeletal Voluntary movement
Long and cylindrical (up to 25 cm)
Transverse striation
multi-nucleated

42. X: Muscle: Smooth Involuntary movement Long, spindle shape
Single nucleus
Internal organs

43. X: Muscle: Cardiac Striations Involuntary One nucleus
Intercalated disks
Heart muscle

44. XI: Nervous Cells very high ability to Two types of cells
Respond to stimuli
Transmit impulses
Two types of cells
Neurons – conduct nerve impulses
Neuroglia – provide physical support, maintain chemical composition of tissue fluids, nutrients…

45. XI: Nervous Cell Body(3) Dendrites (5) Axon(1) Very LONG cells
Can’t be replaced
Very LONG cells
Create the human “electrical system”