Fundamentals of Histology, Fresh tissue exam, Autopsy

• Simple Squamous


  Bowman’s capsule

  Endothelium of blood vessels

  Loop of Henle

  Alveoli of lungs
• Simple Cuboidal


  In walls of thyroid follicles and ducts of glands

  Renal Collecting Tubules

  Thyroid Follicles

  Mesothelium Covering in the Ovary
• Simple Columnar

  • Gallbladder (Non ciliated)

  • Uterine tube (Ciliated)

  Renal Collecting Duct

  Oviduct Lining with secretory and ciliated Cells

  Lining of the Gallbladder
• Stratified Squamous

  -Epidermis of the skin (keratinized)

  -Vagina (Non-keratinized)

  -Esophagus (Non-keratinized)

  -Cervix (Non-keratinized) ‘
• Stratified Cuboidal

  Sweat gland ducts

  Urothelium
• Stratified Columnar

  -Male urethra
• Transitional


  Urinary tract
• Pseudostratified


  Much of female reproductive

  Tract (Non-ciliated)

  Trachea (Ciliated)
• Necrosis


  “accidental” and unregulated form of cell death
• Cellular Swelling


  hydropic change / vacuolar degeneration

  First manifestation of almost all forms of injury to cells
• Ultrastructural changes of reversible cell injury

  Plasma membrane alterations

  Mitochondrial changes

  Dilation of the ER, with detachment of polysomes

  Nuclear alterations
• APOPTOSIS

  Programmed cell death

  It is a form of cell death that is generally triggered by the normal healthy processes in the body.
• NECROSIS


  Is a cell death that is triggered by external factors or disease, such as trauma or infection

  is always abnormal and harmful
• COAGULATIVE NECROSIS


  This is brought by intercellular enzyme that were set free on the death of cell.

  a firm texture

  eosinophilic and anucleate cell may persist for a days or weeks.

  seen most often in the heart after an infarction, as well as in kidneys and in adrenal gland

  Examples: Ischemia
• LIQUEFACTIVE NECROSIS


  fairly rapid total enzymatic dissolution of the cells with complete destruction of the entire cells

  Seen in focal bacteria/ and fungal infections

  Appearance: creamy yellow in color – dead leukocytes (pus)

  Example: Hypoxic death of cells within the CNS
• GANGRENOUS NECROSIS


  Non- specific form of necrosis

  massive death of the tissue caused by a combination of ischemia and superimposed by bacterial infection.
• Coagulative 


  Arterial occlusion

  Dry Gangrene
• Liquefactive


  Venous occlusion

  “Wet Gangrene”
• CASEOUS NECROSIS

  Encountered most often in foci of tuberculous infection.

  “Caseous” – “cheese- like”- showed white appearance

  Microscopic exam: structureless collection of fragmented or lysed cell and amorphous granular debris that are enclosed with a distinctive inflammatory border.
• FAT NECROSIS


  Not specific pattern of necrosis.

  Fatty acid and calcium ion can be seen and chalky white areas can be observed because of the fat saponification.

  Histologic exam: foci of shadowy outlines of necrotic fat cells, with basophilic calcium deposits, surrounded by an inflammatory reaction
• GASEOUS NECROSIS


  combination of liquefactive and coagulative necrosis is caused by dead cells that are not completely digested by microphages; they leave a granular residue that impedes circulation.

  Caused by Fungal and mycobacterial infections, such as TB.
• FIBRINOID NECROSIS


  Occurs when the complexes of the antigen and antibody are deposited in the walls of the arteries.
• AVASCULAR NECROSIS


  When the blood supply is limited to the tissue the demise of the bone tissue happens
• Fine needle aspiration


  simplest, least invasive test and uses the smallest needle to simply remove cells from the area of abnormality

  not always adequate to obtain a diagnosis
• core needle biopsy


  removes not only cells, but also a small amount of the surrounding tissue

  provides additional information to assist in the examination of the lesion
• incisional biopsy


  takes out some of the abnormality, but not all, slice into the lesion and remove only a portion of it
• excisional biopsy


  removes the entire area in question
• Punch biopsy


  primary technique for obtaining diagnostic full-thickness skin specimens.
• Shave biopsy


  small fragments of tissue are “shaved” from a surface
• Curettings


  tissue is scooped or spooned to remove tissue or growths from body cavity such as endometrium or cervical canal.
• Teasing or Dissociation


  selected tissue specimen is immersed in isotonic salt solution, carefully dissected with a needle and separated by direct or zigzag spread using an applicator stick

  advantage of permitting the cells to be examined in the living state
• Squash Preparation (Crushing)


  small pieces of tissue (not more than one mm. in diameter) are placed in a microscopic slide and forcibly compressed with another slide or with a cover glass
• Streaking


  attempting to obtain a relatively uniform distribution of secretion
• Spreading


  advantage of maintaining cellular interrelationships of the material to be examined

  recommended for smear preparations of fresh sputum and bronchial aspirates, and also for thick mucoid secretions.
• Pull-Apart


  done by placing a drop of secretion or sediment upon one slide and facing it to another clean slide.
• Touch Preparation (Impression Smear)


  advantage in that the cells may be examined without destroying their intercellular relationship.
• Frozen Section


  a rapid diagnosis of a pathologic process

  intra-operative pathology to help the surgeon in choosing his next plan of action
• fresh tissue

  C02 , or on a cryostat

  cold chamber - atmospheric temperature of -10° to -20° C
• non-fatty unfixed tissues

  sectioned well at temperatures between -10 oC and -25°C
• Cryostat


  consists of an insulated microtome housed in an electrically driven refrigerated chamber and maintained at temperatures near -20°C

  optimum working temperature of cryostat is -18 to -20°C