1. Histology: The Study of Tissues Mrs. Hartley Anatomy and Physiology

2. Types of Tissues Epithelial Tissue – Covering and Lining Epithelial Tissue – Covering and Lining Connective Tissue – Support and Manufacture Connective Tissue – Support and Manufacture Muscle Tissue – Movement Muscle Tissue – Movement Nerve Tissue – Signaling and Support Nerve Tissue – Signaling and Support

3. Epithelial Tissue Cells closely joined together with little or no intercellular material between cells Cells closely joined together with little or no intercellular material between cells Blood vessels cannot penetrate between them therefore they are avascular Blood vessels cannot penetrate between them therefore they are avascular Covers body surfaces, lines body cavities and organs and forms glands Covers body surfaces, lines body cavities and organs and forms glands May perform secretion, absorption, and serve as protection in certain areas May perform secretion, absorption, and serve as protection in certain areas

4. Covering & Lining Epithelium Cover external body surfaces and lines inner walls of cavities and organs Cover external body surfaces and lines inner walls of cavities and organs Cells are stationary and anchored by their basal surfaces Cells are stationary and anchored by their basal surfaces 3 general shapes can are recognized 3 general shapes can are recognized –Squamous = flat –Cuboidal = cube-shaped (= in height & width) –Columnar = cylindrical (greater in height) Two cell arrangements simple = single layer stratified = multiple layers

5. Simple Squamous Simple = one layer Simple = one layer Squamous = flat Squamous = flat Flattened cells arranged in a single layer Flattened cells arranged in a single layer Centrally located nucleus Centrally located nucleus Found where layers must be thin to permit diffusion of materials Found where layers must be thin to permit diffusion of materials Lines the walls of blood vessels, forms walls of capillaries, forms walls of air sacs in lungs, linings of the body cavities Lines the walls of blood vessels, forms walls of capillaries, forms walls of air sacs in lungs, linings of the body cavities Outermost section of frog skin viewed from the top Outermost section of frog skin viewed from the top

6. Simple Cuboidal Single layer of cube- shaped cells Single layer of cube- shaped cells Centrally located nucleus Centrally located nucleus Often contain cilia and/or microvilli along their free border Often contain cilia and/or microvilli along their free border Forms the walls of small tubes, or ducts, that carry secretions from one part of the body to another Forms the walls of small tubes, or ducts, that carry secretions from one part of the body to another i.e. kidneys, liver, and many glands i.e. kidneys, liver, and many glands

7. Simple Columnar Epithelium Single layer of elongated, cylindrical cells Single layer of elongated, cylindrical cells Nuclei lie near basement membrane Nuclei lie near basement membrane Frequently secrete a product (abundance of ER and Golgi) Frequently secrete a product (abundance of ER and Golgi) Lining the walls of the uterus and digestive organs such as the stomach and small intestine Lining the walls of the uterus and digestive organs such as the stomach and small intestine Small intestine = microvilli Small intestine = microvilli

9. Pseudostratified Columnar Appears multi-layered but is not Appears multi-layered but is not Uniformity among cell shapes and locations of nuclei Uniformity among cell shapes and locations of nuclei Long cilia that create currents for the movement of mucus Long cilia that create currents for the movement of mucus Lines parts of the respiratory tract such as the trachea and bronchi Lines parts of the respiratory tract such as the trachea and bronchi

11. Transitional Epithelium Multiple-layered arrangement of cells of cubelike or irregular shape Multiple-layered arrangement of cells of cubelike or irregular shape Have the capacity to expand in size and recoil giving the tissue the ability to stretch (elasticity) Have the capacity to expand in size and recoil giving the tissue the ability to stretch (elasticity) Lines the insides of organs that require elasticity and extensibility for normal function Lines the insides of organs that require elasticity and extensibility for normal function Urinary bladder and the ureters (tubes that travel from the kidneys to the bladder) Urinary bladder and the ureters (tubes that travel from the kidneys to the bladder)

12. Left: Empty Bladder Right: Full Bladder

13. Glandular Epithelium Closely packed cells highly specialized to manufacture and secrete products Closely packed cells highly specialized to manufacture and secrete products Particular type = gland Particular type = gland Exocrine glands: empty their products into ducts which transport the product onto the body surface or into a cavity where it will provide some benefit (sweat, oil, salivary) Exocrine glands: empty their products into ducts which transport the product onto the body surface or into a cavity where it will provide some benefit (sweat, oil, salivary) Endocrine glands: secrete their products into the extracellular space and into the bloodstream where it is distributed throughout the body (pituitary, thyroid, adrenal, the endocrine system) Endocrine glands: secrete their products into the extracellular space and into the bloodstream where it is distributed throughout the body (pituitary, thyroid, adrenal, the endocrine system)

14. Exocrine Glands Left: Salivary Glands Right: Sweat Glands

15. Endocrine Glands Left: Pituitary Right Bottom: Adrenal Glands

16. Stratified Squamous Multi-layered arrangement of flat cells Multi-layered arrangement of flat cells Covers areas of the body that take constant wear and tear and must resist that wear and tear Covers areas of the body that take constant wear and tear and must resist that wear and tear Surface layer is squamous, deepest layers may have cuboidal or columnar cells that have become flattened Surface layer is squamous, deepest layers may have cuboidal or columnar cells that have become flattened Outer layer of skin to protect from abrasions Outer layer of skin to protect from abrasions

18. Your Assignment Create a picture atlas of tissues. Create a picture atlas of tissues. You will be able to use this atlas on the test! So make it good! You will be able to use this atlas on the test! So make it good! Each page will have the tissue name, the function, location, and a picture. Each page will have the tissue name, the function, location, and a picture. You may use the text or this slideshow which is found on my website. You may use the text or this slideshow which is found on my website. You will be graded by test and by completion of the atlas…do not get behind! You will be graded by test and by completion of the atlas…do not get behind!