1. 12/17/20151 Laboratory Two Histology

2. 12/17/20152 Histology Study of structure and function of tissues – Groups of cells that are structurally and functionally the same –A combination of living and non-living material Go over each microscope –Illustrate and write anatomical details –Touch only the fine focus knob –Pointer helps you locate the assigned structures

3. 12/17/20153 Four Primary Tissue Types 1.Epithelial - lines & covers surfaces 2.Connective - protects, supports, & binds 3.Muscular - contracts & produces movement 4.Nervous – generates & conducts nerve impulses

4. 12/17/20154 1. Epithelial Tissue (E.T.) Lines, covers surfaces both inside & out Consists of many cells, tightly packed together Usually arranged in layers (except glands) –Simple (1 layer) or stratified (2 or more layers) Secured to deeper tissue by basement membrane A free surface is found opposite basement membrane

5. 12/17/20155 Specific Types of Epithelial Tissues are Characterized by: Number of layers: –Simple (1 layer) - secretion, absorption, filtration –Stratified (>2 layers) – wear & tear Cell shape –Squamous – flat from side, like fried egg from top (yolk: nucleous) –Cuboidal - as wide as tall as deep, nucleous in center –Columnar – tall & thin, nucleous elongated

6. 12/17/20156 Simple Squamous Epithelial Tissue Tissue: simple squamous E. T. Cell: squamous epithelial cell ID: flattened cells, mosaic shape Location: alveoli of lungs Function: diffusion

7. 12/17/20157 Tissue: simple cuboidal E.T. Cell: cuboidal epithelial cell ID: round centrally located nucleous Location: salivary glands Function: secretion Simple Cuboidal Epithelial Tissue

8. 12/17/20158 Simple Columnar Epithelial Tissue Tissue: simple columnar E. T. Cell: columnar epithelial cell ID: elongated nuclei, closer to BM, one layer Location: small intestine Function: secretion of digestive enzymes, absorption of nutrients Higher magnification (showing goblet cells)

9. 12/17/20159 Pseudostratified Ciliated Columnar E. T. Higher magnification (showing cilia and goblet cell) Tissue: P. C. C. E.T. Cell: columnar epithelial cell with their elongated nuclei appear in multi- layer (cells with different dimension are arranged in one layer) ID: ciliated Location: trachea Function: protection (cilia moves mucous along with unwanted substances in air upwards

10. 12/17/201510 Stratified Squamous Epithelial Tissue Tissue: S. S. E.T. Surface cells: Squamous E. C. ID: multiple layer, squamous cells at free surface (As cells mature, they change shape) Location: esophagus Function: protection against wear & tear Lower magnification (see abrupt change in tissue type at BM)

11. 12/17/201511 Transitional Epithelial Tissue Relaxed urinary bladder Tissue: T. E.T. ID: stratified with cuboidal EC Location: urinary bladder (distended) Function: accommodates fluctuation in the volume of fluid, protects against caustic effect of urine

12. 12/17/201512 E.T. Assignment View each assigned E.T. through microscopes or as micrographs Complete your histology worksheet in your handout –Illustrate the specific tissue –Label the assigned structures on your illustration –Record & learn one location and one function for each tissue

13. 12/17/201513 2. Connective Tissue (C.T.) Protects, supports, binds Consists of relatively few cells scattered in non-living matrix Matrix varies –Fluid (e.g. plasma of blood C.T.) –Semi-solid matrix of cartilage –Solid (e.g. bone) –May contain various types of protein fibers arranged in various ways and with a range of densities Cells vary too –RBCs carry oxygen and WBCs & macrophages are protective –Chondrocytes secrete the matrix in cartilage C.T. –Osteocytes secrete bony matrix in osseous C.T. –Fibroblasts secrete fibers –Adipose cells store fat

14. 12/17/201514 Osseous Connective Tissue Osteocytes inside lacunae (magnified) Tissue: Osseous C. T. Cell: Osteocytes ID: Cells arranged circularly around central canal, deposit the matrix in layers call lamella, nucleous (dark dots) Location: skeleton Function: support, protection

15. 12/17/201515 Hyaline Cartilage Connective Tissue Chondrocytes inside lacunae (magnified) Tissue: Hyaline cartilage C. T. Cell: Chondrocytes ID: Cells with clear periphery embedded in a semi-fluid matrix, nucleous (dark dots) Location: Capping the end of bones Function: support, protection, cushion Chondrocytes inside lacunae (magnified) Tissue: Hyaline cartilage C. T. Cell: Chondrocytes ID: Cells with clear periphery embedded in a semi-fluid matrix, nucleous (dark dots) Location: Capping the end of bones Function: support, protection, cushion

16. Fibrocartilage Connective Tissue Tissue: Fibrocartilage C. T. Cell: Chondrocytes ID: Cells (dark dots) embedded in a matrix with blue collagen fibers Location: Disks between the vertebrae of spinal column Function: cushion

17. 12/17/201517 Dense Fibrous Connective Tissue Tissue: Dense fibrous C. T. Cell: Fibroblasts ID: Parallel collagen fibers packed tightly, nuclei of fibroblasts (dark dots) Location: tendon (muscle to bone) and ligament (bone to bone) Function: attachment

18. 12/17/201518 Areolar Connective Tissue Tissue: Areolar C. T. Cell: Fibroblast (most common) ID: Irregularly & loosely arranged collagen and elastic fibers, dots are nuclei of fibroblasts Location: Under the skin Function: Attachment, support

19. 12/17/201519 Tissue: Adipose C. T. Cell: Adipocyte, signet ring cells, or fat cells ID: Large clear cells with nuclei pushed to the sides by fat vacuoles Location: Breasts, hips Function: Energy storage, cushioning, insulation Adipose Connective Tissue

20. Reticular Connective Tissue Tissue: Reticular CT Cells: Reticular cells, blood cells ID: network of reticular fibers embedded in cells Location: spleen Function: framework to support free blood cells

21. 12/17/201521 Blood Connective Tissue Tissue: Blood C. T. Cell: RBC & WBC ID: RBC – look like life saver, no nucleous, high in number WBC – different shapes, have a nucleous, low in number Location: blood vessels Function: gas & nutrients transport, protection against infection

22. 12/17/201522 C.T. Assignment View each assigned C.T. Complete illustrations in your worksheet

23. 12/17/201523 3. Muscle Tissue ( Contracts producing movement ) Muscles cells are called fibers Cells vary in their number of nuclei and shape, and whether or not they are banded

24. Tissue: Smooth Muscle Cell: smooth muscle cell ID: many nuclei crammed in, no striation Location: stomach Function: movement of substances Tissue: Cardiac Muscle Cell: cardiac muscle cell ID: intercalated disks, striated uninucleated Location: heart Function: heart pump Tissue: Skeletal Muscle Cell: Muscle fiber ID: Striated with multiple nuclei Location: arm Function: movement of body

25. 12/17/201525 4. Nervous Tissue Tissue: Nervous tissue Cell: Multipolar neuron ID: Cell body with processes Location: Nervous system Function: Conduction of nerve impulses

26. 12/17/201526 Integumentary System (Skin) This organ system consists of 2 layers: –Epidermis: Stratified squamous E.T. –Dermis (papillary and reticular layers): Sebaceous & sweat glands Hair folicle Arrector pilli muscle Meissner corpuscles (sense receptors for light touch) –Hypodermis (not part of skin): Adipose C. T. Pacinian corpuscles (sense receptors for pressure) Learn locations of all four primary tissue types, and the assigned layers and structures on the skin model