Tissues

1. Tissues Histology – the study of tissues *A group of specialized cells with specialized functions

2. 4 Major Tissue Types: Function – Location • Epithelial : protects, secretes, senses, absorbs, excretes – • covers body surfaces composes glands • Connective : Binds, supports, protects, fills space, • stores fat, produces blood cells – through out • the body • Muscle : allows movement – attached to bones, in • the walls of hollow internal organs, heart • Nervous : transmits impulses for coordination, • regulation, integration, and sensory reception- • brain, spinal cord, nerves

3. I. Epithelial Tissue • Covers all body surfaces, lines most internal organs and • are the major tissues of glands • Always has a free surface • Underside of tissue is always anchored to connective • tissue by a thin non cellular layer called the basement • membrane • Lacks blood vessels and is replaced continuously

4. Use your text and web site to describe the • structure, function, and location of each type • of epithelial tissue • Simple squamous epithelium • Simple cuboidal epithelium • Simple columnar epithelium • Pseudostratified columnar epithelium • Stratified squamous epithelium • Transitional epithelium • Glandular epithelium

5. 1. Simple squamous epithelium

6. 2. Simple cuboidal epithelium

7. 3. Simple columnar epithelium

8. 4. Pseudostratified columnar epithelium

9. 5. Stratified Squamous Epithelium

10. 6. Transitional Epithelium Distended

11. 7. Glandular Epithelium – found in glands and contain cells that function in secreting and producing substances. Exocrine gland – gland that secretes into ducts or onto a body surface (internal or external). Endocrine gland – gland that secretes hormones directly into the blood or body fluids *thyroid gland, pituitary and adrenal glands, islet cells of the pancreas Table 5-2 p133

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13. Types of Exocrine glands • Merocrine gland – release fluids without a loss of • cytoplasm • *sweat glands, salivary glands

15. Types of Exocrine glands • Apocrine gland – lose small amts of their cell bodies • during secretion • *mammary glands; milk contains molecular components

17. Types of Exocrine glands • Holocrine gland – release entire cells with secretory • products…”self destruct” • *sebaceous, some sweat glands (pubic and breast)

18. Happy Halloween

19. http://faculty.une.edu/com/abell/histo/histolab2.htm

20. II. Connective Tissues -A tissue that is abundant throughout the body, it includes bone, cartilage, and various fibrous tissues. Function : bind, support, fill spaces, store fat, produce blood cells, and helps repair damaged tissue

21. Characteristics of Connective Tissue: -Most are well vascularized -Extracellular matrix (liquid, solid, or semisolid) exp: Adipose is mostly cellular vs bone is mostly matrix - 2 cell types -3 types of fibers

22. 2 Cell types 1.Resident Cells - present in stable #’s a) fibroblasts - lg star shaped cell that secretes protein to produce fibers b) mastcells - lg cells found near blood vessel, they release heparin and histamine 2. Wandering Cells - present in tissues usually in response to injury and infection; includes white blood cells a) macrophage - carry out phagocytosis, function in the defense of foreign bodies from tissues http://www.meddean.luc.edu/lumen/MedEd/Histo/frames/h_frame4.html

24. 3 Types of Connective Tissue Fibers 1. Collagenous - thick, strong, threadlike white fibers that are composed of collagen. *tendons 2. Elastic - yellow, elastic fibers that are common in parts that are often stretched. *vocal cords 3. Reticular - thin, fine fibers composed of collagen *various tissues (lymph nodes, bone marrow, spleen)

25. Types of Connective Tissue • -defined by fiber type and number of fibers in the matrix • 1. Bone : provides structure, support, protection and • serves as attachment, it also functions in forming • blood cells • contains mineral salts and collagen fibers

26. The lamellae forms the layers of the matrix (rings) Also called the osteonic / central canals

28. Types of Connective Tissue • 2. Cartilage : rigid and flexible, provides support, • framework for attachment, protects and forms • structure for developing bones • Chondrocyte - cartilage cell • lacks blood vessels but is surrounded by them, relies • on diffusion to obtain nutrients (heals slowly) • * most cartilage cells occupy a small chamber called • lacunae

29. Types of Cartilagep140-141 Fig 5-21 – Fig 5-23 A.Hyaline - moderate amts of collagen in matrix giving a shiny/glass like appearance. Most prevalent. *end of nose, ribs, ends of bones, fetal skeleton B.Elastic - flexible, contains elastic fibers, highly flexible *framework of ear and larynx C.Fibrocartilage - tough, densely packed collagen fibers, provide shock absorption *intervertebral disks, cushions bones in the knee

30. Hyaline cartilage Fibrocartilage Elastic cartilage

31. Types of Connective Tissue • 3.Fibrous-dense, tightly packed collagenous fibers with • few cells and fibroblasts • Functions in binding body parts together and found • in tendons and ligaments or skin, outer walls of kidneys • and spleen • P139 Fig 5-17, and 5-18 • Dense fibrous regular & • Dense fibrous irregular

32. Types of Connective Tissue • 4. Loose / Areolar - mainly composed of fibroblasts • this tissue forms the thin membrane between • organs. Gel/fluid matrix with multiple types of • fibers and cells. • It can be found beneath the skin and between muscles.

33. Types of Connective Tissue 5. Adipose - a form of loose connective tissue that stores fat in its cell cytoplasm * found beneath skin, beneath muscles, around the kidneys, behind the eyeballs, in some abdominal membranes, around certain joints and on the surface of the heart.

34. Types of Connective Tissue 6. Reticular - phagocytic: ingest and destroy foreign particles. Defend the body against infection or invasion (macrophages). *Found in lymphatic organs - lymph nodes, spleen, blood, and bone marrow

35. Other Types of Connective Tissue 7. Blood - transports substances, maintains homeostasis Fluid matrix - Blood Plasma a) red blood cells (erthrocytes) b) white blood cells (leukocytes) c) platelets - cellular fragments (thrombocytes) *blood cells are formed in the hollow parts of certain bones Hematopoietic tissue also called red bone marrow.

38. III. Muscle Tissue - contractile tissue that moves parts that are attached to it. 3 Different Types 1.Skeletal - found in muscles and usually attached to bones that can be controlled by a conscious effort (voluntary muscle tissue). Cells are long and thread like with striations and have more than 1 nuclei per cell.

40. 2. Smooth - lacks striations, found in the walls of hollow internal organs (stomach, bladder, uterus, blood vessels). Usually controlled by involuntary muscle tissue, uninucleate.

42. 3. Cardiac - found only in the heart. Its cells are striated and each cell has a single nucleus. Its cells are joined by intercalculated disks (controlled involuntarily)

43. http://www.histology-world.com/videos/video.htm

44. IV. NervousTissue - makes up the brain, spinal cord and peripheral nerves neurons - nerve cells that are sensitive to changes in their surroundings and respond by sending impulses to other neurons or to muscles or glands. Function: coordinate, communicate and regulate body function neuroglial cells - support, connect, insulate and protect nervous tissue, but do not conduct like neurons.

45. Nerve cell Neuroglial cells

47. Some things to look at before the test: *Read over Box 5-1 – 5-4. Emphasis on the terminology used in Box 5-3!!!!! *Hint – you might see some of those bold faced words again! *Know difference between parietal membranes and visceral membranes Fig 5-32 on p148 helps in identifying.