Tissues

1. Tissues Mr. Hill Anatomy

2. Contents Tissues Epithelial Tissues Epithelial Tissue - Simple Epithelial Tissue - Stratified Epithelial Tissue - Glandular Connective Tissue Connective Tissue – Cell Types Connective Tissue - Fibers Connective Tissue - Types Muscle Tissue Nervous Tissue

3. Tissues • Cells are organized into tissues. Cells within a tissue are similar. • Usually, tissue cells are separated by nonliving, intercellular materials - solid, semi-solid, or liquid. • The human body has 4 major types of tissues: • epithelial • connective • muscle • nervous

4. Epithelial Tissue • Widespread throughout the body. • Covers organs, forms inner lining of body cavities, and lines hollow organs. • Epithelial tissue is anchored to underlying connective tissue by a thin basement membrane. • Usually lacks blood vessels (nutrients diffuse via the basement membrane). • Protective barrier, secretion, absorption, excretion. • Classified by shape and number of layers of cells. Single layer: simple. Two or more layers: stratified. Shapes: squamous (flat), cuboidal (cube), columnar (elongated).

5. Epithelial TissueSimple Squamous • Single layer of flattened cells. • Substances pass easily through simple squamous epithelium – common at sites of diffusion and filtration. • Lines alveoli (in lungs), walls of capillaries, lines inside of blood and lymph vessels, lines body cavities. • Easily damaged.

6. Epithelial TissueSimple Cuboidal • Single layer of cube-shaped cells. • Centrally located, spherical nuclei. • Covers the ovaries, lines the kidney tubules and ducts of the salivary glands, pancreas, and liver. • Secretion and absorption.

7. Epithelial TissueSimple Columnar • Single layer of elongated cells. Thick and protects underlying cells. SCE also secretes digestive fluids and absorbs nutrients. • SCE lines the uterus and digestive tract. • Ciliated or nonciliated. • May have microvilli to increase surface area for absorption. • Often glandular cells (goblet cells) are scattered among SCE. These cells secrete a protective fluid called mucus

8. Epithelial TissuePseudostratified Columnar • PCE appears stratified (layered), but is not. The cells vary in shape and all cells reach the basement membrane. • Cells are often fringed with cilia. Goblet cells are scattered in this tissue. • PCE lines the passages of the respiratory system.

9. Epithelial TissueStratified Squamous • Many layers (thick). Cells at the surface are flattened (squamous). Deeper cells are cuboidal or columnar. • Outermost layer of the skin (epidermis). SSE also lines the oral cavity, throat, vagina, and anal canal.

10. Epithelial TissueStratified Cuboidal • Two or three layers of cuboidal cells. (More protection than one layer). • SCE lines the larger ducts of the mammary glands, sweat glands, salivary glands, and pancreas. • Lines the developing ovarian follicles and seminiferous tubules.

11. Epithelial TissueStratified Columnar • Several layers of cells. • SCE is in the vas deferens and parts of the pharynx.

12. Epithelial TissueTransitional • Specialized to change in response to increased tension. From many layers to only a few layers when the organ is distended. • Lines the urinary bladder, the ureters, and part of the urethra.

13. Epithelial TissueGlandular • GE is composed of cells that are specialized to produce and secrete substances into ducts or into body fluids. • Glands that secrete into tissue fluid or blood are called endocrine glands. • Single cells, simple or compound.

14. Epithelial TissueGlandular

15. Connective Tissue • Comprise much of the body and are the most abundant type of tissue. • Bind structures, provide support and protection, fill spaces, store fat, produce blood cells, protect against infection, and help repair tissue damage. • Cells are not adjacent but have a matrix between them. Matrix consists of fibers and a ground substance which binds, supports, and provides a medium. • Can be rigid or flexible. CT has a variety of cell types.

16. Connective TissueCell Types • The fibroblast is the most common kind of fixed cell in CT. Produce fibers by secreting protein. • Macrophages originate as white blood cells. Usually attached to fibers, can detach and move. Scavenger cells. • Mast cells are large and widely distributed. Located near blood vessels. Release heparin to prevent blood clotting and histamine to promote reactions to asthma and hay fever.

17. Connective TissueFibers • Collagenous fibers are thick strands of collagen, which is the major structural protein of the body. Appear white. • Long, parallel bundles, flexible, slightly elastic. Great tensile strength. Elastic fibers are bundles of microfibrils embedded in elastin (a protein). Appear yellow. • Fibers branch. Weaker than collagenous fibers but more elastic. • Found in vocal cords and air passages. (Where elasticity is needed). • Reticular fibers are thin collagenous fibers. Highly branched. Form delicate supporting networks.

18. Connective TissueCategories • Loose connective tissue (areolar) forms delicate, thin membranes throughout the body. • Cells are mainly widely scattered fibroblasts and are separated by a gel-like ground substance that contains many collagenous and elastic fibers. • Binds skin to underlying organs and fills spaces between muscles. Also beneath epithelium.

19. Connective TissueCategories • Adipose (fat) tissue Certain cells within CT store fat within their cytoplasm. • Lies beneath the skin, between muscles, around the kidneys, in the abdomen, and around the heart. • Cushions joints and some organs. Insulates beneath the skin.

20. Connective TissueCategories • Reticular CT is composed of thin, collagenous fibers. • Supports the walls of the liver, spleen, and lymphatic organs.

21. Connective TissueCategories • Dense CT consists of closely packed, thick, collagenous fibers, a network of elastic fibers, and a few fibroblasts. • Regular dense CT has strong collagenous fibers to withstand pulling forces. Tendons, ligaments. Blood supply poor. • Irregular dense CT is randomly organized. Can withstand tension from many directions. Dermis.

22. Connective TissueCategories • Elastic CT consists mainly of yellow, elastic fibers. • Between these fibers are collagenous fibers and fibroblasts. • Found in attachments between vertebrae and within the walls of the heart, larger arteries, and the larger airways.

23. Ch. 5 Categories of Connective Tissue 2.1 Atoms, Ions, and Molecules Sponge: Set up Cornell Notes on pg. 51 Topic: Ch. 5 Categories of Connective Tissue Essential Question: • Explain why injured bone heals more rapidly than does injured cartilage? • What are the major components of blood? Don’t forget to add it to your T.O.Contents! • Explain why injured bone heals more rapidly than does injured cartilage? • What are the major components of blood?

24. Connective TissueCategories • Cartilage is a rigid connective tissue. Largely composed of collagenous fibers in a gel-like ground substance. • Support, framework, attachments, protects underlying tissue, forms structural models for many developing bones. • Cartilage lacks a direct blood supply so healing is slow!

25. Connective TissueCategories • Hyaline cartilage is the most common type of cartilage. • Ends of bones, in the nose, and in respiratory passages. • An embryo’s skeleton begin as hyaline cartilage “models” that bone replaces.

27. Hyaline Cartilage Connective Tissue

28. Connective TissueCategories • Elastic cartilage is very flexible. Contains many elastic fibers. • Ears and parts of the larynx.

29. Figure 05.24b

30. Figure 05.24a Elastic Cartilage Connective Tissue

31. Connective TissueCategories • Fibrocartilage is very tough. Contains many collagenous fibers. Acts as a shock absorber. • Intervertebral disks (spine).

33. Figure 05.25a Fibrocartilage Connective Tissue

34. Connective TissueCategories • Bone is the most rigid connective tissue. Hardness is due to mineral salts (calcium phosphate and calcium carbonate). Also contains a large amount of collagen for toughness. • Bone supports, forms blood cells, and protects • Every bone cell is close to a blood supply, injured bone heals rapidly

37. Bone Tissue

38. Connective TissueCategories • Blood is composed of cells suspended in a fluid called blood plasma. • Cells are: red blood cells, white blood cells, and cellular fragments called platelets. • RBCs transport gases. WBCs fight infection. Platelets are involved in blood clotting.

39. Figure 05.27b

40. Blood Tissue

41. Muscle TissueSkeletal • Muscle tissues are contractile. Muscle fibers can shorten and thicken. • Skeletal muscle tissue forms muscles that we control by conscious effort. (Voluntary). • Can be long (to 40 mm) and narrow (0.1 mm). Have alternating light and dark cross markings called striations. • Each cell has many nuclei.

42. Muscle TissueSmooth • Smooth muscle tissue lacks striations. Cells are shorter and have one nucleus. • Involuntary. • In walls of hollow internal organs. (Stomach, intestines, urinary bladder, blood vessels.

43. Muscle TissueCardiac • Cardiac muscle tissue is only in the heart. Striated cells are branched and form complex networks. Single nucleus. • Where cells join forms an intercalated disk. • Involuntary. Can function without nerve impulses.

44. Nervous Tissue • Nervous tissues are found in the brain, spinal cord, and peripheral nerves. • Cells are called neurons. Specialized. Also includes neuroglia, which support and bind the components of nervous tissue. • Sense changes in the environment and respond by transmitting nerve impulses. • Coordinate, regulate, and integrate many body functions.