Test Flashcards
Four types of tissue
Epithelial, connective, muscular, nervous
Define: tissue
2 or more different types of cells that function together
Most human cells are how big?
7-20 microns
Human red blood cells are how big?
7-8 microns
A micron is:
1/1,000 of a millimeter or 1×10−6
Specimens are usually preserved in ___ to prevent decay and make tissue more firm
Aldehyde
How does aldehyde fix tissues?
Forms stable bridges in proteins between adjacent AAs, making them unaffected by enzymes. These proteins are “denatured”
What does processing refer to in histotechnology?
Replacing all water in the tissue with wax.
1) water to alcohol (graded concentration).
2) Alcohol removed with solvents
3) solvents replaced with liquid wax
What does grossing refer to in histotechnology?
Gross processing refers to cutting specimens into small pieces to facilitate chemical penetration or mark specimens
List the steps of histotechnology.
Grossing and Fixation Processing Embedding Sectioning Staining Coverslipping Diagnosis
Name the machine that cuts wax specimens into thin sections (~4-5 microns)
Microtome
The “gold standard” for reference stains.
Hematoxylin and eosin (H&E).
Hematoxylin:
cell nuclei - blue/purple
Eosin:
cytoplasm/connective tissue - pink/orange
RBC - bright red
Which microscopy produces true color images?
Light microscopy
What’s the magnification of light microscopy? What is it used to examine?
1000x.
Used to examine cells + larger organelles (e.g. Nuclei, mitochondria)
Electron microscopes produce images using high energy electrons that are either transmitted through the specimen (______) or reflected off the surface of the specimen (_____).
Transmitted through specimen: transmission electron microscopy
Reflected off the surface: scanning electron microscopy
Stains for electron microscopy must be able to block electrons. Why?
Creates contrast in greyscale.
Plane of section:
Cut along the longest direction of a structure
Longitudinal section
Plane of section: cut perpendicular to the length of a structure
Cross section
Plane of section:
Cut at an angle between cross and longitudinal section
Oblique section
What is ground substance?
Ground substance is the material between cells in addition to water and fibrous proteins
E.g. Liquid (plasma) Rubbery (cartilage) Stony (bone) Elastic (tendon)
Epithelia are named on what criteria?
Number of layers,
Shape,
Surface modifications
Four shapes of epithelium
Squamous
Cuboidal
Columnar
Transitional
Three types of muscle tissue
Skeletal,
Smooth,
Cardiac
Definition:
The changing of unspecialized tissue into specialized mature tissue
Differentiation
Definition:
A normal or abnormal change in tissue
Metaplasia
Definition:
Enlargement of pre existing cells
Hypertrophy
Definition: abnormal increase in the number of cells in an organ or tissue
Hyperplasia
Definition:
Growth of abnormal tissue into a tumor
Neoplasia
