1 / 50

Chapter 4

Chapter 4. Histology: The Study of Tissues. Tissues and Histology. Tissues are collections of similar cells and the substances that surround them. Tissue Level of Organization Epithelial Connective Muscle Nervous Histology : Microscopic Study of Tissues. Epithelium Characteristics.

axelle
Download Presentation

Chapter 4

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chapter 4 Histology: The Study of Tissues

  2. Tissues and Histology • Tissues are collections of similar cells and the substances that surround them. • Tissue Level of Organization • Epithelial • Connective • Muscle • Nervous • Histology: Microscopic Study of Tissues

  3. Epithelium Characteristics • Consists almost entirely of cells • Covers body surfaces and forms glands • Has free and basal surface • Specialized cell contacts • Avascular • Undergoes mitosis

  4. Functions of Epithelia • Protecting underlying structures • Acting as barriers • Permitting the passage of substances • Secreting substances • Absorbing substances

  5. Classification of Epithelium • Simple • Squamous, cuboidal, columnar • Stratified • Squamous, cuboidal, columnar • Pseudostratified • columnar • Transitional • Cuboidal to columnar when not stretched and squamouslike when stretched

  6. Types of Epithelium

  7. Types of Epithelium

  8. Types of Epithelium

  9. Types of Epithelium

  10. Types of Epithelium

  11. Types of Epithelium

  12. Types of Epithelium

  13. Types of Epithelium

  14. Functional Characteristics • Cell layers and shapes • Diffusion, Filtration, Secretion, Absorption, Protection • Cell surfaces • Microvilli: Increase surface area absorption or secretion • Cilia: Move materials across cell surface • Cell connections • Desmosomes, tight, gap • Glands • Exocrine: Have ducts • Endocrine: Have no ducts

  15. Cell Connections • Functions • Bind cells together • Form permeability layer • Intercellular communication • Types • Desmosomes • Tight • Gap

  16. Exocrine Glands • Unicellular • Goblet cells

  17. Multicellular Exocrine Glands

  18. Exocrine Glands and Secretion Types • Merocrine • Sweat glands • Apocrine • Mammary glands • Holocrine • Sebaceous glands

  19. Connective Tissue • Abundant • Consists of cell separated by extracellular matrix • Diverse • Performs variety of important functions

  20. Functions of Connective Tissue • Enclosing and separating as capsules around organs • Connecting tissues to one another as tendons and ligaments • Supporting and moving as bones • Storing as fat • Cushioning and insulating as fat • Transporting as blood • Protecting as cells of the immune system

  21. Connective Tissue Cells • Specialized cells produce the extracellular matrix • Suffixes • -blasts: create the matrix • -cytes: maintain the matrix • -clasts: break the matrix down for remodeling • Adipose or fat cells • Mast cells that contain heparin and histamine • White blood cells that respond to injury or infection • Macrophages that phagocytize or provide protection • Stem cells

  22. Extracellular Matrix • Components • Protein fibers • Collagen which is most common protein in body • Reticular fill spaces between tissues and organs • Elastic returns to its original shape after distension or compression • Ground substance • Shapeless background • Fluid

  23. Connective Tissue Categories • Embryonic or mesenchyme • Adult • Loose • Dense • Connective tissue with special properties • Cartilage • Bone • Blood

  24. Loose Connective Tissue • Also known as areolar tissue • Loose packing material of most organs and tissues • Attaches skin to underlying tissues • Contains collagen, reticular, elastic fibers and variety of cells

  25. Dense Connective Tissue • Dense regular • Has abundant collagen fibers • Tendons: Connect muscles to bones • Ligaments: Connect bones to bones • Dense regular elastic • Ligaments in vocal folds • Dense irregular • Scars • Dense irregular collagenous • Forms most of skin dermis • Dense irregular elastic • In walls of elastic arteries

  26. Dense Regular Connective Tissue

  27. Dense Irregular Connective Tissue

  28. Connective Tissue with Special Properties • Adipose tissue • Consists of adipocytes • Types • Yellow (white) • most abundant, white at birth and yellows with age • Brown • found only in specific areas of body as axillae, neck and near kidneys • Reticular tissue • Forms framework of lymphatic tissue • Characterized by network of fibers and cells

  29. Adipose Tissue

  30. Reticular Tissue

  31. Cartilage • Composed of chondrocytes located in spaces called lacunae • Next to bone firmest structure in body • Types of cartilage • Hyaline • Fibrocartilage • Elastic

  32. Hyaline Cartilage • Found in areas for strong support and some flexibility • Rib cage and cartilage in trachea and bronchi • Forms most of skeleton before replaced by bone in embryo • Involved in growth that increases bone length

  33. Fibrocartilage • Slightly compressible and very tough • Found in areas of body where a great deal of pressure is applied to joints • Knee, jaw, between vertebrae

  34. Elastic Cartilage • Rigid but elastic properties • External ears, epiglottis

  35. Bone • Hard connective tissue that consists of living cells and mineralized matrix • Organic and inorganic • Types • Cancellous or spongy bone • Compact bone

  36. Bone

  37. Blood • Matrix between the cells is liquid • Hemopoietic tissue • Forms blood cells • Found in bone marrow • Yellow • Red

  38. Bone Marrow

  39. Muscle Tissue • Characteristics • Contracts or shortens with force • Moves entire body and pumps blood • Types • Skeletal • Striated and voluntary • Cardiac • Striated and involuntary • Smooth • Nonstriated and involuntary

  40. Skeletal Muscle

  41. Cardiac Muscle

  42. Smooth Muscle

  43. Nervous Tissue • Found in brain, spinal cord and nerves • Ability to produce action potentials • Cells • Nerve cells or neurons • Consist of dendrites, cell body, axons • Consist of multipolar, bipolar, unipolar • Neuroglia or support cells

  44. Neurons

  45. Neuroglia

  46. Membranes • Mucous • Line cavities that open to the outside of body • Secrete mucus • Serous • Line cavities not open to exterior • Pericardial, pleural, peritoneal • Synovial • Line freely movable joints • Produce fluid rich in hyaluronic acid

  47. Inflammation • Response when tissues damaged or with an immune response • Manifestations • Redness, heat, swelling, pain, disturbance of function • Mediators • Include histamine, kinins, prostaglandins, leukotrienes • Stimulate pain receptor and increase blood vessel permeability

  48. Tissue Repair • Substitution of viable cells fordead cells • Skin repair • Primary union: Edges of wound close together • Wound fills with blood • Clot forms • Scab • Pus • Granulation tissue • Scar • Secondary union: Edges of wound not close • Clot may not close gap • Inflammatory response greater • Wound contraction occurs leading to greater scarring

  49. Tissue Repair

  50. Tissues and Aging • Cells divide more slowly in older than younger people • Tendons and ligaments become less flexible and more fragile • Arterial walls become less elastic • Rate of blood cell synthesis declines in elderly • Injuries are harder to heal in elderly

More Related