Lecture 1 - Introduction to Histology and Microscopy Flashcards
what are the 5 levels of organization within the body?
- cell
- tissue
- organ
- organ system
- organism
what are the 4 basic tissue types?
- epithelial
- connective
- muscle
- nervous
def: microscopic study of tissue structure
histology
def: microscopic study of tissue in regards to medical pathology
histopathology
def: microscopic study of cells
cytology
def: application of cytology in the clinical sense
cytopatholgy
what are the 3 types of microscopes?
- light microscope
- transmission electron microscope
- scanning electron microscope
what’s the difference between a single lens microscope and a compound lens microscope?
compound uses combination of lenses and single uses just one
def: uses an ultraviolet light source to capture images of fluorescently labelled samples
fluorescence microscope
def: increase resolution and contrast by using a pinhole to block out of focus light in image formation
confocal microscope
the majority of conventional histology is ________ ________
bright field
def: uses a beam of accelerated electrons as a light source
electron microscopy
def: produces 3d images of the surface of a specimen, resolution is high but no information about internal structures
scanning EM
def: more analogous to optical microscopy, in that the beam of electrons must pass through specimens to form an image, this results in 2D image of the plane in section
transmission EM
EM takes advantage of _______ ________ of electrons to achieve higher spatial resolution
short wavelength
objects smaller or thinner than 0.2 µm ________________
cannot be distinguished under LM
why can’t be see objects smaller than 200 nm using a light microscope?
because any object less than half of the wavelengths of the microscopes illumination source is not visible, light is 400 nm therefore we cannot see less than 200 nm
what is the resolution of TEM?
0.1 nm or 1000x greater than light microscope
differential contrast is produced by electron permeability, therefore what terms do we use when describing EM imaging?
dark = electron dense
light = electron lucent
def: dark blue or violet stain that is basic/positive. binds to basophilic tissue components like acids and some polysaccharides, THINGS THAT ARE NEGATIVELY CHARGED
hematoxylin
def: pink or red stain that is acidic/negative. it binds to acidophilic tissue components such as positively charged amino acid side chains, many proteins are basic THINGS THAT ARE POSITIVELY CHARGED
eosin
structures that appear pink/red are described as ________
eosinophilic
structures that appear blue/violet are described as _________-
basophilic
def: loosely packed, actively transcribing
euchromatic
def: densely packed, black on EM, purple on LM, cells are not transcribing
heterochromatic
def: tissue cut along he longest direction of an organ
longitudinal section
def: tissue cut perpendicular to the length of an organ
cross-section
def: tissue cut at an angle between a cross and longitudinal section
oblique section
