Pathological morphology - tissue processing, staining Flashcards
what solutions are used for decalcification of dense cortical bone
Strong mineral acids such as nitric and hydrochloric acids
what solutions are used for decalcification of bone marrow
Organic acids such as acetic and formic acid
what is the best all-around decalcifier
Formic acid in a 10% concentration
define sample clearing
Tissue clearing refers to a collection of techniques that render biological samples transparent.
Is a process of replacing dehydrant with a substance which is miscible (capable of being mixed) with embedding medium or paraffin wax.
how does acetic acid affect protein and fat?
Protein droplets will dissolve in acetic acid
and fat droplets will not change.
potassium acetate - Has a similar effect.
What are KOH & NaOH caustic soda 1…3% aqueous solutions used for?
KOH (Potassium hydroxide), NaOH (Sodium hydroxide aka lye)
These solutions are used for studying myeloid, fat, elastic connective tissue, bone tissue, pigments and microbes.
What is Alcohol-ether for?
for dissolving fat
What are hydrochloric acid HCl and sulphuric acid H2SO4 used to identify?
to identify calcium salts in tissues.
What is Lugol’s solution used for in histology?
Used for diagnosing amyloid mutations.
Lugol’s solution makes the amyloid mutated patches on the surface of the organ dark purple. The borders of the cell become more defined and clear.
It is also used in parasitology.
define amyloid
are aggregates of proteins characterised by a fibrillar morphology
The build-up of amyloid proteins (deposits) can make it difficult for the organs and tissues to work properly = amyloidosis
name 2 simple fixatives
ethyl alcohol aka ethanol C2H5OH
formalin
name 3 complex fixatives
Zenker’s fixative (Helly’s fluid)
Carnoy’s fluid
Bouin’s fluid
name 3 embedding materials
- celloidin embedding
- paraffin embedding
- gelatin embedding
name an alkaline stain
hematoxyline
name 2 acidic stains
eosin
picro fuchsin
define nosology
is the branch of medical science that deals with the classification of diseases
what is the difference between general- & special pathology?
General pathology – processes that are common to several organs and diseases.
Special pathology – the changes that occur in the organs; characteristic of a disease.
what is the difference between pathomorphology & anatomical pathology?
pathomorphology = morphologic changes caused by a pathological condition
anatomical pathology = concerned with the diagnosis of disease based on the examination of organs and tissues
define dysergia
lack of muscular coordination due to a defect in innervation.
define hyperergic & hypergia
hyperergic = characterized by or exhibiting a greater than normal sensitivity to an allergen
hypergia = Obsolete term for allergic hypersensitivity.
define inanition death
inanition (undernutrition or starvation, inanitio)
starvation (inanitio totalis)
undernutrition (inanitio partialis)
define Algor Mortis
refers to the rate at which a body cools after death. It is the most useful single indicator of the time of death during the first 24 hours postmortem
Livor Mortis
or Postmortem lividity/ Postmortem suggilation/ Hypostasis/ Vibices/
refers to discolouration or staining of the skin and organs after death due to accumulation of fluid blood in the dependent parts of the body
The color of lividity is usual reddish purple or violet
Autolysis
Rise of enzyme levels in the tissue cells after death
Softening and liquefying of the body tissue
Starts 3-4 hours after death and continues for 2-3 days
Organs that have higher enzymes value (liver, pancreas) undergo autolysis faster
Putrefaction
Involves bacteria (aerobic, anaerobic) and fermentation
Depends on:
Environment
Body condition prior to death
difference between autolysis and putrefaction processes
Putrefaction involves the action of bacteria on the tissues of the body.
Autolysis is the breakdown of the body by endogenous substances.
acanthosis
A benign abnormal thickening of the stratum spinosum, or prickle cell, layer of the epidermis.
parakeratosis definition
Parakeratosis refers to incomplete maturation of epidermal keratinocytes, resulting in abnormal retention of nuclei in the stratum corneum
ante mortem
Having been inflicted or having occurred before death
conditions caused by lack of vitamins are called
avitaminoses
latin for constipation
koprostasis
infolding of one part within another part of a structure
intussusception
difference between a wound (vulnus) and an ulcer (ulcus)
a wound is caused by a mechanical injury with some
object, but an ulcer is caused by damage to tissues by a disease process, e.g an inflammation.
another term for Severe dislocation
luxation (luxatio)
endogenic toxicosis
(autointoxicatio) is self-poisoning, resulting from toxins produced
within the body.
The condition caused by overheating of the body is called
thermoplegia
is synonymous with “heat stroke” in English. defines it as the most acute version of it, which could result in body temperature exceeding 40C and an “extremely high” death rate.
sun stroke
(insolatio) should be mentioned, as it is caused by direct effect of sun rays on the head, not
the general overheating of the whole body, as it is wrongly assumed sometimes.
another term for blistering
vesication
According to their origin, diseases are divided into three groups:
hereditary,
congenital and acquired.
According to their duration, diseases are classified as
acute, sub-acute and
chronic.
Acute diseases (morbi acuti) last from
a couple of hours to 2-3 weeks.
Sub-acute diseases (morbi subacuti) last for approximately
3-6 weeks.
Chronic diseases (morbi chronici) last for
weeks, months or even years.
An exostosis is
an extra growth of bone that extends outward from an existing bone. Common types of exostoses include bone spurs, which are bony growths also known as osteophytes.
differnce between bacteremia, pyemia & septicemia
bacteremia = when bacteria and microbes are present in bloodstream
pyemia = a form of septicemia due to the presence of pus-forming organisms in the blood, manifested by formation of multiple abscesses of a metastatic nature.
septicemia or sepsis is the clinical name for blood poisoning by bacteria. It is the body’s most extreme response to an infection.
Full recovery (restitutio ad integrum) can also be called
entelechy.
what is the purpose of xylene?
used as a solvent , removes paraffin
What is the importance of embedding in histopathology?
The principle of the embedding station is to accurately and precisely orientate a histological specimen into a block of paraffin wax; this will allow the support and firm hold of the tissue sample so that fine cutting of thin sections for histological diagnostic purposes can ensue.
What is the use of Canada balsam in histopathology?
Canada balsam is a commonly used mounting medium to prepare permanent slides for microscopy. It is produced from the resin of the balsam fir tree and can be combined with xylene-containing specimens.
benefits to celloidin embedding?
It is a much longer process than paraffin but causes much less shrinkage and distortion. It is used especially in examination of the eye and brain.
what pH are nulcear stains?
alkaline
e.g. hematoxyline
what pH are cytoplasmic stains?
acidic
e.g. eosin
what is celloidin exactly?
a clear, concentrated, semisolid solution of pyroxylin used in microscopy for embedding specimens that are to be cut into thin cross sections.
the stain used in routine staining is typically
hematoxylin and eosin
a stain often used for connective tissue & collagen is
Van Gieson
or
Masson trichrome stain
a stain often used to stain lipids is
Oil red 0 (cryosections)
a stain often used to stain carbohydrates is
PAS (Periodic acid-Schiff reaction),
a staining method used to detect polysaccharides such as glycogen
the stain, Best’s carmine, may also be used for glycogen
a stain often used to stain amyloid is
Congo red
crystalviolet may also be utilized
what is Brown-Brenn stani used to detect
bacteria
What is Von Kossa stain used to detect?
calcium salts
What is Luxol fast blue stain used to detect?
myelin
What is Toluidine blue stain used to detect?
granulation tissue
What is cryosectioning?
“Frozen section procedure”
is a pathological laboratory procedure to perform rapid microscopic analysis of a specimen.
It is used most often in oncological surgery. The technical name for this procedure is cryosection. The microtome device that cold cuts thin blocks of frozen tissue is called a cryotome. -20 to -30*C inside
What is in situ hybridization?
is a laboratory technique used to localize a sequence of DNA or RNA in a biological sample.
