Histology (Chap 5)

  1. Histology
    the study of tissues and how they are arranged into organs

    also called microscopic anatomy
  2. tissue
    a group of similar cells and cell products that arise from the same region of the embryo and work together to perform specific structural or physiological role in an organ
  3. four primary tissue types?
    • 1. epithelial
    • 2. connective
    • 3. nervous
    • 4. muscle
  4. matrix
    • -surrounds the cell
    • -composed of fibrous proteins and clean gel called: ground substance, tissue fluid, or extracellular fluid

    also called extracellular material
  5. epithelial tissue
    • -composed of layers of closely spaced cells
    • -cover organ surfaces
    • -form glands
    • - serve for protection
    • -secretion
    • -absorption

    • Examples:
    • -epidermis
    • -inner lining of the GI tract
    • -liver
    • -glands
  6. connective tissue
    • -usually more matric than cells
    • -often specialized to support, bind and protect organs

    • Examples:
    • -tendons
    • -ligaments
    • -cartilage
    • -blood
  7. nervous tissue
    containing excitable cells specialized for rapid transmission of coded information to other cells.

    • Examples:
    • -nerves
    • -brain
    • -spinal chord
  8. muscular tissue
    composed of elongated, excitable muscles cells specialized for contraction

    • Examples:
    • -skeletal muscle
    • -heart (cardiac muscle)
    • -walls of viscera (smooth muscle)
  9. embryonic tissue
    • tissue of the embryo divided into three primary germ layers:
    • -ectoderm
    • -mesioderm
    • -endoderm
  10. ectoderm
    outer layer that gives rise to the epidermis and nervous system
  11. mesioderm
    • between the endoderm and ectoderm
    • eventually turns into mesenchyme which gives rise to muscle, bone, ect.
  12. endoderm
    innermost layer of the embryo and gives rise to the mucous membranes of the digestive and respiratory tracts
  13. histological section
    • thin slices of tissue mounted on microscope slides.
    • fixatives are added to prevent decay and stain to enhance detail
  14. longitudinal section (l.s)
    a tissue cut on its long axis
  15. transverse section (t.s) or corss section (x.s)
    a tissue cut perpendicular to its long axis
  16. oblique section
    a section of tissue cut on a slant between a longitudinal and cross section.
  17. smear
    a slide prepared by smearing or spreading tissue across the slide.
  18. spread
    tissue is laid out on the slide
  19. basement membrane
    • -located between the epithelium and the underlying connective tissue
    • -contains collagen, glycoproteins, and other protein-carbohydrate complexes
    • -anchors the epithelium to the connective tissue
  20. basal surface
    surface of the epithelial cell that faces the basement membrane
  21. apical surface
    surface of an epithelial cell that faces the lumen
  22. simple epithelium
    one layer, every cell touches the basement
  23. stratified epithelium
    multiple layers of cells, not every cell touches the basement membrane
  24. pseudostratified columnar epithelium
    • -has tall, narrow cells
    • -all cells touch basement membrane, but not all cells reach the apical surface
  25. simple squamous epithelium
    • -one layer of flat and scaly cells
    • -found in tissue for fast diffusion such as capillaries.
  26. simple cuboidal epithelium
    • -spherical or cube shaped
    • -with is the same as height
    • -one layer
    • -found in tissue that is secretory or absorption like glands
  27. simple columnar epithelium
    one layer of tall narrow cells
  28. goblet cells
    • -shaped like wine glass or goblet
    • -found in columnar tissue
    • -produce protective mucous coating over the mucous membranes
  29. stratified squamous epithelium
    many layers of squamous cells and cuboidal cells. Basement membrane has cuboidal cells that become squamous as it get more apical.
  30. stratified cuboidal epithelium
    two layers of cuboidal cells found in glands usually
  31. transitional epithelium
    mix of squamous and cuboidal cells, not in layers but in clusters
  32. exfoliation
    the process by which dead squamous cells push toward the apical surface, die, and flake off

    also called desquamation
  33. cytology
    the study of exfoliated cells
  34. keratinized (cornified) epithelium
    • -found in epidermis
    • -cells packed with durable protein keratin and coated with water repellant glycolipid.
    • -skin surface dry
    • -resists retards water loss from body and penetration form disease.
  35. nonkeratinized epithelium
    • -lacks surface layer of dead cells
    • -surface is resistant to absorption
    • -moist and slippery
    • -found in cheek cells and vagina
  36. umbrella cells
    • -found in the urinary ladder
    • -change shape as bladder expands to prevent leakage
    • -domed surface has thicker phospholipid layer to protect the cell from urine.
  37. connective tissue
    • -most abundant tissue type
    • -fibrous, adipose, cartilage, bone, and blood tissue
    • -cells occupy less space than the matrix
  38. functions of connective tissue?
    • -binding to organs
    • -support
    • -physical protection
    • -immune protection
    • -movement
    • -storage
    • -heat production
    • -transport
  39. fibroblast
    • -large fibrous connective tissue cell
    • -stellate
    • -produce fibers and ground substances that for matrix
  40. macrophages
    • -large phagocytes
    • -fibrous connective tissue
    • -engulf and destroy bacteria
    • -arise from monocytes
  41. leukocyte
    • -white blood cell (WBC)
    • -travel briefly in blood
  42. plasma cell
    • -lymphocytes turn into plasma cells when they detect foreign agents
    • -synthesis of disease fighting antibodies
  43. mast cell
    • -found alongside blood vessels
    • -secrete heparin that inhibits blood clotting
    • -secrete histamine that increased blood flow
  44. adipocytes
    • -fat cells
    • -small clusters
    • -adipose tissue
  45. collagenous fibers
    • -made of collagen, tough and flexible
    • -glistening white appearance
    • -make tendons, ligaments, and dermis
  46. reticular fibers
    • -thin collagen fibers coated with glycoprotein
    • -sponge like framework for organs like spleen and lymph nodes
  47. elastic fibers
    • -thinner collagen fibers
    • -branch and rejoin
    • -made of elastin protein
  48. loose connective tissue
    -much space occupied by ground substance
  49. dense connective tissue
    fibers occupy more space than ground substance
  50. areolar tissue
    • -loose connective tissue
    • -fibrous
    • -fibers run in random directions
    • -mostly collagen, but also elastic and reticular
  51. reticular tissue
    -mesh of reticular fibers and fibroblaasts
  52. dense regular connective tissue
    • 1) collagen fibers are closely packed with little open pages
    • 2) fibers are parallel
    • -found in tendons and ligaments
  53. elastic tissue
    type of dense regular connective found in vocal chords and spinal ligaments
  54. dense irregular connective tissue
    • -thick bundles of collagen fibers and little room for cell and ground substances.
    • -bundles run in random directions
  55. adipose tissue
    • -adipocytes are the dominant cell type
    • -space between adipocytes is occupied by areolar tissue, reticular tissue and blood capillaries
  56. white fat
    • -most abundant fat
    • -cells are 70 to 120 micrometers
    • -provide thermal insulation, anchors, cushion
  57. brown fat
    • found mainly in fetuses, infants, and children
    • -6% of infant weight
    • -stores lipid in multiple globules rather than one
  58. cartilage
    • -stiff connective tissue with flexible rubbery matrix.
    • -avascular
    • -forms external ear, tip of nose, ect
    • -nutrients through diffusion
    • -cell metabolism is slow and healing takes a long time
  59. chondroblasts
    • -immature cartilage cells
    • -surround themselves with the matrix in cavities called lacunae
  60. chondrocytes
    • -mature cartilage cells
    • -fully surrounded by lacunae
  61. hyaline cartilage
    • -clear, glassy appearance from fine collagen fibers
    • -collagen fibers not usually visible
    • -chondrocytes in lacunae in clusters of three or four
    • -eases joint movement, holds airway open, -moves vocal chords during speech
    • -found in trachea, at the ends of bones
    • -usually covered by perichondrium
  62. elastic cartilage
    • -lots of elastic fibers in web-like mesh
    • -always covered by perichondrium
    • -flexible, elastic support
    • -found in external ear epiglottis
  63. fibrocartilage
    • -parallel collagen fibers similar to tendon
    • -rows of chondrocytes in lacunae between collagen fibers
    • -never has perichondrium
    • -found in intervertebral discs, shock absorbing cartilage
    • -resists compression, transitional tissue
  64. perichondrium
    a sheath of dense irregular connective tissue that covers cartilage
  65. osseous tissue
    • -bone tissue (different than a bone)
    • -hard calcified connective tissue
  66. spongey bone
    • -fills the head of long bones
    • -fills middle layer of flat, irregular bones
    • -delicate slivers and planes
  67. dense (compact) bone
    • -denser osseous tissue with no spaces visible to the naked eye
    • -always covers spongey bone
  68. central osteonic canals
    • -run longitudinally through shafts of long bones
    • -filled with blood vessels and nerves
  69. concentric lamellae
    • -bone matrix deposited in this
    • -onionlike layers around each central canal
  70. osteon
    central canal and its surrounding lamellae
  71. osteocytes
    tiny lacunae between the lamellae are occupied by bone cells
  72. canaliculi
    -radiate from each lacunae to other lacunae and allow cell communication
  73. periosteum
    tough connective tissue that covers bone
  74. blood
    • -fluid connective tissue that travels through blood vessels
    • -transport cells and dissolved matter from place to place
    • -more ground substance(plasma) than formed elements(cells)
  75. blood plasma
    ground substance of blood
  76. erythrocytes
    • -red blood cells (RBCs)
    • -most abundant
    • -transport carbon dioxide
  77. leukocytes
    • -white blood dells (WBCs)
    • -defense against infection
  78. platelets
    • -small cell fragments scattered amid blood cells
    • -involved n clotting
  79. excitable tissue
    nervous and muscle tissue
  80. membrane potential
    • -occurs across the plasma membrane
    • -changes result in membrane potential lead to rapid changes in the cell
  81. nervous tissue
    • -specialized for communication (electrical and chemical signals)
    • -composed of neurons
  82. neuron
    -nerve cell
  83. neuroglia
    • -glial cells
    • -protect and assist neurons
  84. neurosoma
    • -cell body of a neuron
    • -houses the nucleus
    • -usually round, ovoid, or stellate
  85. dendrites
    • -branching off of the neurosoma
    • -receive signals from other cells and conduct messages to the neurosoma
  86. axon
    • -long nerve fiber that send out signals to other cells
    • -some are more than a meter long
  87. muscular tissue
    • -specialized to contract when stimulated, exerting physical force on other tissue
    • -involved in movement
  88. types of muscle tissue?
    • skeletal
    • smooth
    • cardiac
  89. skeletal muscle
    • -composed of muscle fibers
    • -most is attached to bone
    • -each muscle cell (fiber) has many nuclei because multiple cells have fused together
    • -have striations, created by overlapping cytoplasmic proteins that cause contraction
  90. cardiac muscle
    • -only found in the heart
    • -striated
    • -muscle fibers are shorter and called myocytes or myocardiocytes
    • -myocytes branch off
    • -contain intercalated discs which carry electrical impulses quickly form cell to cell.
  91. smooth muscle
    • -myocytes are fusiform in shape
    • -not striated
    • -only have one central nucleus
    • -found in visceral muscle
  92. cell junction
    connections between cells
  93. tight junction
    • -completely encircle an epithelial cell near its apical surface and joins neighboring cells together
    • -stomach and intestines have these to prevent leakage
  94. desmosomes
    • -a patch that holds cells together like a snap
    • -can't prevent leakage
    • -keep cells from pulling apart and resist mechanical stress
    • -J shaped proteins
  95. gap junction
    • -formed by a connexon
    • -allow substances to pass from cell to cell
  96. gland
    a cell or organ that secrets a substance for use elsewhere in the body
  97. secretion
    used in the body
  98. excretion
    expel out of the body
  99. exocrine glands
    • -have a duct
    • -sweat, mammary, and tear glands
  100. endocrine glands
    • -have lose contact with the surface
    • -have no ducts
    • -secrete directly into blood
  101. unicellular glands
    • -secretory cells in epithelial tissue
    • -can be exocrine or endocrine
  102. capsule
    • -encapsulates multicellular glands
    • -gives off extensions called septa or trabeculae
  103. parenchyma
    cells that perform the tasks of synthesis and secretion
  104. simple gland
    single unbranched duct
  105. compound gland
    branching duct
  106. tubular duct
    duct and secretory portion are uniform diameter
  107. ancinar duct
    if the secretory cells form a dilated sac
  108. tubuloancinar gland
    secretory cells in both tubular and ancinar portions
  109. serous gland
    produce relatively thin watery fluids
  110. mucous glands
    secrete a glycoprotein called mucin
  111. mixed glands
    have serous and mucous gland cells
  112. cytogenic gland
    releases whole cells
  113. merocrine glands
    • -also called ecctine gland
    • -release product by exocytosis
  114. apocrine secretion
    lipids coalesce from the cytosol into droplets that bud off from cell surface
  115. holocrine glands
    cell accumulate a product and the cell bursts to dispense it
  116. cutaneous membrane
    the skin
  117. mucous membrane (mucosa)
    lines passageways that are open to the environment
  118. lamina propria
    areolar connective tissue
  119. musularis mucosa
    smooth muscle layer found in mucous membrane
  120. serous membrane
    • -simple squamous epithelium resting on thin layer of areolar connective tissue
    • -line body cavities
    • -produce serous fluid
  121. mesothelium
    epithelial compound of serous membrane
  122. endothelium
    simple squamous epithelium that lines the circulatory system
  123. hyperplasia
    tissue growth through cell multiplication
  124. hypertrophy
    enlargement of preexisting cells
  125. neoplasia
    the development of a tumor
  126. differentiation
    development of a specialized form or function
  127. metaplasia
    change from one type of mature tissue to another
  128. stem cells
    undifferentiated cells that are not yet performing any specialized function
  129. developmental plasticity
    diversity of mature cell types which stem cells can give rise
  130. embryonic stem cells
    • -early human embryo
    • -called totipotent because they an become anything
  131. pluripotent
    stem cells that can become any cell in the embryo but not accessory organs of pregnancy
  132. adult stem cells
    • -occur in small numbers in mature organs and tissue
    • -divide mitotically
    • -one daughter cell remains stem and the other differentiates
  133. multipotent
    stem cells that can differentiate into two or more different types of cells
  134. unpotent
    stems cells that can only differentiate into one cell type
  135. regeneration
    replacement of dead or damaged cells by the same type of cells
  136. fibrosis
    the replacement of damages tissue with scar tissue
  137. atrophy
    shrinkage of tissue through loss of cell size
  138. necrosis
    premature, pathological tissue death
  139. infarction
    sudden tissue death
  140. Gangrene
    tissue death because of insufficient blood supply
  141. tissue engineering
    artificial production of tissues and organs in the lab for implantation into the human body
  142. apoptosis
    programed cell death
Card Set
Histology (Chap 5)
Vocab from Anatomy & Physiology by Saladin. Histology Chapter 5