INTRO Flashcards
fixation to tissue ratio
10:1
duration of fixation
3-5mm for 6-48 hours
STUDY OF TISSUES COMPRISING OF THEIR CELLULAR STRUCTURE AND FUNCTION
histology
introduction of pathology in Germany
1800s
study of disease
pathology
branch of histology concerned with the effects of diseases on microscopic structure of tissues
histopathology
has diagnostic and research purpose
pathology department
father of histopathology
Johannes Mueller
discovered formalin
Blum (1892)
founder of pathology
Malphigi
interprets microscopically surgical and autopsy tissues
anatomic pathologist
skills and knowledge on the methods used to prepare and process tissue samples for study
histotechniques
prepares and stains tissues in prep for microscopic analysis
histotechnician
step-by-step procedure in preparing tissues for microscopy
tissue processing
2 main samples being processed
- surgical material
- autopsy material
2 types of tissue examination
- preserved tissue examination
- fresh tissue examination
simplest and least invasive test
fine needle aspiration
uses small needle to remove cells from affected areas of abnormality
fine needle aspiration
removes not only cells, but also small amount of the surrounding tissue
core needle biopsy
the lesion will be sliced and a portion will be removed
incisional biopsy
removal of the entire area in question
excisional biopsy
primary technique for obtaining diagnostic full-thickness skin sample
punch biopsy
what mm of cylindrical core of tissue sample is collected for punch biopsy
3-4 mm
small fragments of tissues are shaved from a surface
shave biopsy
tissue samples are scooped or spooned from a cavity
curettings
apparatus for uterine curettage
vaginal speculum
tissues are immersed in isotonic salt solution in a petri dish or watch glass
teasing or dissociation
tissue is dissected with a needle and is separated direct or zigzag using an applicator stick
teasing
tissue sample is placed between 2 slides and forcibly compressed and must not be more than 1mm in diameter
squash prep
supravital stain is dropped at the junction via capillary action
squash prep
used mainly for cancer diagnosis and cytological smear preparation
smear prep
utilized for preparing thick secretions and may be made permanent by fixing while wet
smear prep
categories of smear prep
a. streaking
b. spreading
c. pull-apart
moderate thick film is created by teasing the mucus membrane strands
spreading
spreading is recommended for what type of secretions
- fresh sputum
- bronchial spirates
- mucoid secretions
a drop of secretion is placed between two slides then pulled apart with a single uninterrupted motion
pull apart
the surface of a freshly cut piece of tissue is brought into contact and pressed onto the surface of a glass slide
impression smear
cells are transferred directly and preserve anatomic structure of tissue
touch prep/ impression smear
rapid pathologic diagnosis during surgery and is for diagnostic and research enzyme histochemistry
frozen section
diagnostic and research demonstration of soluble substances such as lipids and carbohydrates
frozen section
immunofluorescent and immunohistochemical staining
frozen section
some specialized silver stains, particularly in neuropathology
frozen sections
equipment in frozen section wherein tissue is placed on a platform, CO2 gas is used to freeze the tissue. once frozen the microtome blade slices the tissue
microtome with CO2
thickness of tissue for microtome with CO2
5-10 um
a microtome mounted inside a cold chamber
cryostat
allows for cutting thin tissue sections at low temperature
cryostat
temp recommended for cryostat
-10 to -20
freezing agents
- liquid nitrogen
- CO2
- isopentane
- aerosol spray (cryowik)
most rapid of the commonly available agent however, soft tissues may crack and may snap frozen
isopentane
cooled by liquid nitrogen and it is an excellent freezing agent for muscle tissue
isopentane
approx. temp of isopentane
-170C
used in small pieces of tissue except for muscles
aerosol spray
term used to describe the initial anoxic changes a tissue suffers when blood supply is cut off
warm ischemia
lack of o2 once the tissue sample is removed from the patient’s body and before all metabolic processes are stopped by fixation
cold ischemia
