Essentials of Human Anatomy Body Tissues

1. Essentials of Human AnatomyBody Tissues

2. Tissue Level of Organization • Group of similar cells • common embryonic origin • common function • Histology • study of tissues

3. 4 Basic Tissues (1) • Epithelial Tissue • covers surfaces because cells are in contact • lines hollow organs, cavities and ducts • forms glands when cells sink under the surface • Connective Tissue • supports and binds structures together • stores energy as fat • provides immunity to disease

4. 4 Basic Tissues (2) • Muscle Tissue • cells shorten in length producing movement • Nerve Tissue • cells that conduct electrical signals • detects changes inside and outside the body • responds with nerve impulses

5. Biopsy • Removal of living tissue for microscopic examination • Useful for diagnosis, especially cancer • Tissue preserved, sectioned and stained before microscopic viewing

6. Epithelial Tissue Functions Protection Sensory functions Secretion Absorption Excretion

7. Epithelial Tissues General characteristics - • cover organs and the body • line body cavities • line hollow organs • have a free ( apical ) surface • have a basement membrane • avascular • cells readily divide • cells tightly packed • cells often have desmosomes • classified according to cell shape and number of cell layers

8. Types of Epithelium • Covering and lining epithelium • epidermis of skin • lining of blood vessels and ducts • lining respiratory, reproductive, urinary & GI tract • Glandular epithelium • secreting portion of glands • thyroid, adrenal, and sweat glands

9. Cell Shapes Squamous Cuboidal Collumnar Arrangement Simple Stratified Pseudostratified Classification

10. Simple Epithelial Tissues • Simple Squamous • Simple cuboidal • Simple columnar • Pseudostratified columnar

11. Epithelial Tissues • Simple Squamous • single layer of flat cells • substances pass easily through • line air sacs • line blood vessels • line lymphatic vessels

12. Simple Squamous

13. Epithelial Tissues • Simple cuboidal • single layer of cube-shaped cells • line kidney tubules • cover ovaries • line ducts of some glands

14. Simple Cuboidal

15. Epithelial Tissues • Simple columnar • single layer of elongated cells • nuclei usually near the basement membrane at same level • sometimes possess cilia • sometimes possess microvilli • often have goblet cells • line uterus, stomach, intestines

16. Simple Columnar Epithelium

17. Simple Columnar Epitheliumwith cilia

18. Epithelial Tissues • Pseudostratified columnar • single layer of elongated cells • nuclei at two or more levels • appear striated • often have cilia • often have goblet cells • line respiratory passageways

19. Pseudostratified Columnar Epithelium

20. Stratified Epithelial Tissues • Stratified squamous • Stratified cuboidal • Stratified columnar

21. Epithelial Tissues • Stratified Squamous • many cell layers • top cells are flat • can accumulate keratin • outer layer of skin • line oral cavity, vagina, and anal canal

22. Stratified Squamous Epithelium

23. Epithelial Tissues • Stratified cuboidal • 2-3 layers • cube-shaped cells • line ducts of mammary glands, sweat glands, salivary glands, and the pancreas

24. Stratified Cuboidal Epithelium

25. Epithelial Tissues • Stratified columnar – • top layer of elongated cells • cube-shaped cells in deeper layers • line part of male urethra and part of pharynx

26. Stratified Columnar Epithelium

27. Epithelial Tissues • Transitional • many cell layers • cube-shaped and elongated cells • line urinary bladder, ureters, and part of urethra

28. Transitional Epithelium

29. Glandular Epithelium Composed of cells that are specialized to produce and secrete substances

30. Endocrine Glands • Lack ducts and secrete their products directly into the interstitial fluid and bloodstream. • Hormones act as chemical messengers to influence cell activities elsewhere in the body.

31. Exocrine Glands • Usually maintain their contact with the epithelial surface by means of a duct. • Duct secretes materials onto the surface of the skin or onto an epithelial surface lining an internal passageway.

32. Connective Tissues General characteristics - • most abundant tissue type • many functions • bind structures • provide support and protection • serve as frameworks • fill spaces • store fat • produce blood cells • protect against infections • help repair tissue damage • have a extra-cellular matrix • have varying degrees of vascularity • have cells that usually divide

33. Extra-Cellular Matrix • Cells rarely touch due to extracellular matrix • Matrix(fibers & ground substance secreted by cells • Consistency varies from liquid, gel to solid

34. Connective Tissue Major Cell Types • Macrophages • wandering cell • phagocytic • important in injury • or infection • Fibroblasts • fixed cell • most common cell • large, star-shaped • produce fibers • Mast cells • fixed cell • release heparin • release histamine

35. Connective Tissue Fibers • Collagenous fibers • thick • composed of collagen • great tensile strength • abundant in dense CT • hold structures together • tendons, ligaments • Elastic fibers • bundles of microfibrils embedded in elastin • fibers branch • elastic • vocal cords, air passages • Reticular fibers • very thin collagenous fibers • highly branched • form supportive networks

36. Connective Tissues • Connective tissue proper • loose connective tissue • adipose tissue • reticular connective tissue • dense connective tissue • elastic connective tissue • Specialized connective tissue • cartilage • bone • blood

37. Connective Tissues • Loose connective tissue • mainly fibroblasts • fluid to gel-like matrix • collagenous fibers • elastic fibers • bind skin to structures • beneath most epithelia • blood vessels nourish • nearby epithelial cells • between muscles • Adipose tissue • adipocytes • cushions • insulates • store fats • beneath skin • behind eyeballs • around kidneys and heart

38. Connective Tissues • Dense connective tissue • packed collagenous fibers • elastic fibers • few fibroblasts • bind body parts together • tendons, ligaments, dermis • poor blood supply • Reticular connective tissue • composed of reticular fibers • supports internal organ walls • walls of liver, spleen, lymphatic organs

39. Connective Tissues • Elastic connective tissue • abundant in elastic fibers • some collagenous fibers • fibroblasts • attachments between bones • walls of large arteries, airways, heart • Bone (Osseous Tissue) • solid matrix • supports • protects • forms blood cells • attachment for muscles • skeleton • osteocytes in lacunae

40. Cartilage Connective Tissue Characteristics: • Weaker than bone • More flexible than bone • Cells in an abundant matrix. • Cell Types • Chondroblasts • Chondrocytes in lacunae • Avascular

41. 3 Major Functions of Cartilage • Supporting soft tissues. • Providing a gliding surface at articulations (joints) • Providing a model for the formation of most of the bones in the body.

42. Types of Cartilage • Three types of cartilage: • Hyaline cartilage • Most abundant kind • Has a perichondrium (membrane) • Associated with synovial joints • Most bones first modeled in hyaline cartilage • Fibrocartilage • Has collagen fibers • Intervertebral discs, pubic symphysis • Elastic cartilage • Has elastic fibers • Ear, respiratory tubing

44. Muscle Tissues • Skeletal muscle • attached to bones • striated • voluntary • General characteristics • muscle cells called muscle fibers • contractile • three types • skeletal • smooth • cardiac • Smooth muscle • walls of organs • skin • walls of blood vessels • involuntary • not striated • Cardiac muscle • heart wall • involuntary • striated • intercalated discs

45. Muscle Tissues Skeletal Muscle Smooth Muscle Cardiac Muscle

46. Nervous Tissue • Sometimes termed neural tissue. • Found in brain, spinal cord, and peripheral nerves • Consists of neurons, or nerve cells, and glial cells that support, protect, and provide a framework for neurons.

47. Neurons • Detect stimuli, process information quickly, and rapidly transmit electrical impulses from one region of the body to another. • Prominent cell body functions in control; information processing, storage, and retrieval; internal communication.

48. Neurons • Processes extend from the nerve cell body. • Dendrite • Axon

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