1. Chapter 5 Tissues (Histology) Here We Go! Histology of the Ovary meets Van Gogh

2. 2 1 : a branch of anatomy that deals with the minute structure of animal and plant tissues as discernible with the microscope 2 : tissue structure or organization

3. 3 Cells are arranged in tissues that provide specific functions for the body. Cells are arranged in tissues that provide specific functions for the body. The tissues of the human body include four major types: The tissues of the human body include four major types: epithelial, connective, muscle and nervous.

4. 4 Epithelial Tissues: Epithelial tissue is widespread throughout the body, covers organs, and lines body surfaces. Epithelial tissue- - made up of tightly packed cells - made up of tightly packed cells - generally lack blood vessels - generally lack blood vessels - replaced frequently - replaced frequently

5. 5 Epithelial Tissue Overview Cell Shapes squamous squamous cuboidal cuboidal columnar columnar Cell Arrangements Simple – one layer Simple – one layer Pseudostratified – looks layered Pseudostratified – looks layered Stratified – true layers Stratified – true layers flat, pancake like flat, pancake like cube shaped cube shaped cylindrical cylindrical Side view Top view

6. 6 Simple Squamous Epithelium Simple squamous epithelium is made up of a single layer of thin, flattened cells. Simple squamous epithelium is made up of a single layer of thin, flattened cells. FUNCTION: FUNCTION: exchange of gases in the lungs The JayDoc HistoWebThe JayDoc HistoWeb click epithelia

7. 7 Simple Cuboidal Epithelium Simple cuboidal epithelium consists of a single layer of cube-shaped cells with centrally located nuclei. Simple cuboidal epithelium consists of a single layer of cube-shaped cells with centrally located nuclei. FUNCTION: secretion and absorption in the kidneys and glands The JayDoc HistoWebThe JayDoc HistoWeb click epithelia

8. 8 Simple Columnar Epithelium Simple columnar epithelium  a row of elongated cells It may be ciliated. LOCATION: lines the uterus, stomach, and intestines FUNCTION: protects underlying tissues, secretes digestive fluids, and absorbs nutrients FUNCTION: protects underlying tissues, secretes digestive fluids, and absorbs nutrients The JayDoc HistoWebThe JayDoc HistoWeb click epithelia

9. 9 In the intestine, these cells possess microvilli that increase the surface area available for absorption.

10. 10 Pseudostratified Columnar Epithelium These cells appear layered due to the varying positions of their nuclei within the row of cells, but are not truly layered. Cilia may be present, along with mucus- secreting globlet cells, that line and sweep debris from respiratory tubes.

11. 11 Stratified Squamous Epithelium This type of tissue is made up of layers of flattened cells that are designed to protect underlying layers. Location: outer layer of skin, and lines the mouth, throat, vagina, and anal canal The JayDoc HistoWebThe JayDoc HistoWeb click epithelia

12. 12 Stratified Squamous Epithelium mature cells young basal cells basement membrane Stratified = true layers only mature cells on free surface have mature shape only mature cells on free surface have mature shape basal cells look cuboidal or even columnar

13. 13 Stratified Cuboidal Epithelium This tissue consists of two to three layers of cuboidal cells. This tissue consists of two to three layers of cuboidal cells. The JayDoc HistoWebThe JayDoc HistoWeb click epithelia

14. 14 Stratified Columnar Epithelium This tissue consists of several layers of cells and is found in the vas deferens, part of the male urethra, and parts of the pharynx. This tissue consists of several layers of cells and is found in the vas deferens, part of the male urethra, and parts of the pharynx. The JayDoc HistoWebThe JayDoc HistoWeb click epithelia

15. 15 Transitional Epithelium Transitional epithelium is designed to distend and return to its normal size, as it does in the lining of the urinary bladder. The JayDoc HistoWebThe JayDoc HistoWeb click epithelia

16. 16 Glandular Epithelium Cells secrete substances into ducts or body fluids; 1 or more of these cells makes a gland Cells secrete substances into ducts or body fluids; 1 or more of these cells makes a gland Exocrine – secrete into ducts open to internal or external surfaces Exocrine – secrete into ducts open to internal or external surfaces Merocrine – release water, protein-rich fluids by exocytosis Merocrine – release water, protein-rich fluids by exocytosis Apocrine – lose small part of their cell bodies during secretion Apocrine – lose small part of their cell bodies during secretion Holocrine – entire cell lyses during secretion Holocrine – entire cell lyses during secretion

17. 17 Endocrine – secret products into tissue fluid or blood Endocrine – secret products into tissue fluid or blood

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20. 20 Stratified Cuboidal Simple Columnar

21. 21 Pseudostratified Colulumnar Transitional

22. 22 Simple Squamous Stratified Squamous

23. 23 Connective Tissues: General Characteristics Connective tissues bind, support, protect, serve as frameworks, fill spaces, store fat, produce blood cells, protect against infection, and repair tissue damage. Unlike epithelial tissues, connective tissues have abundant matrix, or intercellular material, throughout, and have good blood supplies (except cartilage).

24. 24 Major Cell Types 1. The fibroblast is the most common cell type, and is a fixed, star-shaped cell that secretes fibers. 2. Wandering macrophages function defend against infection, carry on phagocytosis. 3. Mast cells are fixed cells located near blood vessels where they release heparin (anticoagulant) and histamine (promotes inflammation). (promotes inflammation).

25. 25 Connective Tissue Fibers Strong collagenous fibers (white fibers), made of collagen, add strength for holding body parts together. (ligaments and tendons) Elastic fibers (yellow fibers), made of elastin, are stretchy; add flexibility to connective tissues. (vocal cords)

26. 26 Reticular fibers are thin collagenous fibers that form supportive networks in a variety of tissues.

27. 27 Loose Connective (areolar) Tissue - forms thin membranes that bind body parts together, ex.- skin and underlying organs. - forms thin membranes that bind body parts together, ex.- skin and underlying organs. The JayDoc HistoWebThe JayDoc HistoWeb click connective

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29. 29 Adipose Tissue Adipose tissue is loose connective tissue designed to store fat. (cells - adipocytes) Found beneath the skin, around joints, padding the kidneys and other internal organs, and in certain abdominal membranes.

30. 30 AverageAdult 40 to 50 billion

31. 31 Dense Connective Tissue 1.This tissue consists of densely packed collagenous fibers and is very strong but lacks a good blood supply. 1.This tissue consists of densely packed collagenous fibers and is very strong but lacks a good blood supply. 2.It is found as part of tendons and ligaments. 2.It is found as part of tendons and ligaments.

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33. 33 Tendons of the Hand

34. 34 Cartilage - rigid; provides a supportive framework for various structures; lacks a vascular system and so heals slowly. - cells (chondrocytes) lie within lacunae in the gel-like fluid matrix. - cells (chondrocytes) lie within lacunae in the gel-like fluid matrix.

35. 35 Hyaline - most common, white with abundant fine collagen fibers, found at the ends of bones, supports respiratory passages.

36. 36 Elastic - elastic fibers, provides a framework for the external ears and parts of the larynx. Fibrocartilage – many collagenous fibers, is tough, provides a shock-absorbing function in intervertebral disks and in the knees and pelvic girdle.

37. 37 Hyaline Cartilage Hyaline Cartilage Fibrocartilage Elastic Cartilage

38. 38Bone - the most rigid connective tissue. - Bone internally supports the body, protects, forms muscle attachments, and is the site for blood cell formation. - cells, called osteocytes, lie within lacunae and are arranged in concentric circles (osteons) around osteonic canals interconnected by canaliculi, has a good blood supply

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40. Blood Transport materials between interior body cells and those that exchange substances with the external environment Blood is composed of formed elements (red and white cells and platelets) suspended in a liquid matrix called plasma. Maintains a stable internal environment

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43. 43 Blood Bone

44. 44 Hyaline Cartilage Dense Connective Tissue

45. 45 Adipose Tissue

46. 46 Muscle Tissues: Muscle cells, or fibers, can contract and consist of three major types. 40% - skeletal 10% - smooth and cardiac

47. 47 Skeletal Muscle Tissue - attached to bone and is voluntary - muscle fibers are long and cylindrical, striated, have many nuclei, and contract from nervous impulse.

48. 48 Smooth Muscle Tissue - lacks striations - involuntary - found in the walls of internal organs, and in the digestive tract, blood vessels, and urinary bladder.

49. 49 Cardiac Muscle Tissue - found only in the heart - consists of branching fibers that are connected to each other with intercalated disks. - involuntary muscle has a single nucleus in each cell - appears striated

50. 50 Skeletal Muscle Smooth Muscle

51. 51 Cardiac Muscle

52. 52 Nervous Tissues: - found in the brain, spinal cord and nerves. - Neurons conduct nervous impulses while helper cells, or neuroglia, support and nourish the neurons - respond to environmental changes

53. 53 Neuron (nerve cell) Spinal Cord