Prelims Flashcards
(106 cards)
1
Q
first and most critical step in tissue processing
A
fixation
2
Q
stop the metabolic processes that continue to alter the state of the tissue being examined
A
killing
3
Q
renders the tissue firmer for proper grossing and easy cutting of thin sections for processing
A
hardening
4
Q
primary goal:
A
to preserve the mophologic and chemical integrity of the cell in as life-like manner as possible
5
Q
what does fixation prevents?
A
degeneration, decomposition, putrefaction, distortion of tissues
6
Q
secondary goal:
A
harden and protect the tissue from the trauma of further handling, for easier cutting and process for microscopy
7
Q
practical purpose:
A
aims to prevent or arrest the degenerative processes
8
Q
results from tissue digestion by intracellular enzymes
A
autolysis
9
Q
brought about by microorganisms which may already be present in the specimen
A
putrefaction
10
Q
objectives of fixation
A
preserve the tissye, prevent breakdown of cellular elements, to coagulate protoplasmic substances
11
Q
preserves the tissue by stopping all cellular activities
A
to preserve the tissue
12
Q
prevents autolysis by inactivating the lysosomal enzymes
A
to prevent breakdown of cellular elements
13
Q
renders insoluble certain tissue components
A
to coagulate protoplasmic substances
14
Q
methods of fixation:
A
physical & chemical
15
Q
under physical method:
A
heat, microwave, cryo-preservation
16
Q
under the chemical method:
A
immersion & perfusion
17
Q
application being confined to smears of microorganisms
A
heat fixation
18
Q
can be regarded as heat fixation, works as physical agent similar in mechanism to vacuum
A
microwave fixation
19
Q
also known as freeze drying
A
cryo-preservation
20
Q
has some applications in histochemistry but not usually applied to diagnostic tissue specimens
A
cryo-preservation
21
Q
usually achieved by immersing the specimen in the fixative solution
A
immersion fixation
22
Q
injecting the vascular system with fixative
A
perfusion
23
Q
two basic mechanisms involved in fixation
A
additive & non-additive
24
Q
chemical constituent becomes part of the tissue by forming cross-links or molecular complexes
A
additive
25
not incorporated but alters the composition of tissues
non-additive
26
how long before specimen should be transferred to fixative?
less than 1 hour after surgery
27
why does it need to be transferred less than 1 hour after surgery?
deterioration will commence with the loss of blood supply
28
general ratio in fixative:
20:1 or at least 10:1
29
main factors involved in fixation:
volume, hydrogen ion concentration, temperature, thickness of section, osmolality,concentration, duration of fixation, interval
30
volume
10-20:1, fixative to specimen
31
hydrogen ion concentration
best carried out close to neutral pH, in the range of 6-8
32
common buffers:
phosphate, bicarbonate, cacodylate, veronal
33
temperature of regular tissue processing:
40 degrees C
34
temperature for electron microscopy:
0-4 degrees C
35
formalin is heated to ______ is sometimes used for the rapid fixation of very urgent biopsy specimens
60 degrees C
36
recommended size of tissue
2 cm squared, and no more than 4mm. thick
37
thickness for electron microscopy
1 to 2 mm squared
38
thickness for light microscopy
2 cm squared wide
39
commonly quoted rate of penetration for aldehyde fixative:
2-3 mm per hour
40
recommended fixative
normal phosphate buffered saline based fixative
41
types of fixative:
according to composition and according to action
42
only one component substance
simple fixative
43
two or more fixatives
compound fixative
44
examples of simple fixative
aldehyde, metallic fixative, picric, acetic, acetone, alcohol, osmium tetroxide
45
according to action:
microanatomical fixative and cytological fixative
46
permit the general microscopic study of tissue structures
microanatomical fixative
47
preserve the specific parts and particular microscopic elements of the cell itself
cytological fixative
48
preserve the nuclear structures in particular
nuclear fixative
49
preserve cytoplasmic structures
cytoplasmic fixative
50
preserve the chemical constituents of cells and tissues
histochemical fixative
51
gas produced by the oxidation of methyl alcohol
formaldehyde
52
made with formaldehyde but the percentage denotes a different formaldehyde
formalin
53
most widely used fixative:
10% neutral buffered formalin
54
fixation of 10% neutral buffered formalin
24 hours
55
most common metallic fixative
mercuric chloride
56
combination of histology and pathology
histopathology
57
also called anatomic pathology
histopathology
58
a highly specialized physician who identify diseases by studying cells and tissues under a microscope
pathologist
59
Is a branch of biology that deals with the
microscopic anatomy of cells, tissues and
organs in relation to their function.
histology
60
the scientific study of the nature of the disease
and its causes, processes, development, and
consequences.
pathology
61
is the art and science performed by the histotechnologist to produce a tissue section of good quality
that will enable the pathologist to diagnose the presence or absence of disease
histotechnology
62
divisions of pathology
gross pathology and microscopic pathology, anatomic pathology, clinical pathology
63
the recognition of disease based on macroscopic examination of surgical specimens
gross pathology
64
The recognition of disease based on microscopic examination of surgical specimens generated
microscopic pathology
65
The study of changes in the function, structure, or appearance of organs or tissues, including
postmortem examinations and the study of biopsy specimens.
anatomic pathology
66
kinds of anatomic pathology:
surgical, autopsy, exfoliative cytology
67
The pathology of disease processes that are surgically accessible for diagnosis or treatment.
surgical pathology
68
The pathology of disease processes that are surgically accessible for diagnosis
autopsy pathology
69
A branch of General Cytology which deals with the microscopic study of cells that have been
desquamated from the epithelial surfaces
exfoliative cytology
70
The branch of general pathology directed to the diagnosis and monitoring of diseases through the
examination of blood, body fluids, secretions, and tissue biopsy specimens for chemical,
morphological, microbiological, and immunological abnormalities.
clinical pathology
71
kinds of clinical pathology:
cc, hema, bb, microbiology, clinical immunology and serology
72
father of modern histology
marie francois xavier bichat
73
father of histopathology and cellular pathology
johannes peter muller
74
proposed the use of formaldehyde as fixative
ferdinand blum
75
the simplest, least invasive test and uses the smallest needle
fine needle aspiration
76
removes not only cells, but also a small amount of the surrounding tissue
core needly biopsy
77
takes out even more surrounding tissue
incisional biopsy
78
generally removes the entire area in question
excisional biopsy
79
also called a wide local incision
excisional biopsy
80
considered the primary technique for obtaining diagnostic full-thickness skin
specimens.
punch biopsy
81
where small fragments of tissue are “shaved” from a surface (usually skin).
shave biopsy
82
where tissue is scooped or spooned to remove tissue or growths from body cavity such as
endometrium or cervical canal.
curettings
83
carefully dissected with a needle and
separated by direct or zigzag spread using an applicator stick.
teasing
84
is a process whereby 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.
squash preparation
85
This technique is especially useful in cytological examinations, particularly for cancer diagnosis
smear preparation
86
With an applicator stick or a platinum loop, the material is rapidly and gently applied in a
direct or zigzag line throughout the slide,
streaking
87
-A selected portion of the material is transferred to a clean
slide and gently spread into a moderately thick film by teasing the
mucous strands apart with an applicator stick
spreading
88
two slides are then pulled apart with a single uninterrupted motion
pull-apart
89
surface of a freshly cut
piece of tissue is brought into contact and pressed on to the surface of a
clean glass slide
touch preparation
90
Normally utilized when a rapid diagnosis of the tissue in question is required
frozen section
91
Very thin slices (________ micra) are cut from fresh tissue frozen on a microtome with CO 2 or on a Cryostat
and then transferred to a slide, and processed for light microscopic studies
10-15
92
a cold chamber kept at an atmospheric temperature
cryostat
93
temperature of cryostat
-10 to -20 C
94
Used in histochemistry and during intraoperative procedures and is the
most rapid of the commonly available freezing agents.
liquid nitrogen
95
excellent method for freezing muscle tissue.
isopentane
96
Tissue blocks can be frozen by adapting a conventional freezing
microtome gas supply of carbon dioxide gas from a C0 2 cylinder, or by
using a specially made piece of equipment known as cryostat.
carbon dioxide gas
97
Adequate for freezing small pieces of tissue except muscle
aerosol sprays
98
temperature for knife
-40 to -60
99
temperature for tissue
-5 to -10
100
temperature for environment
0 to -10
101
This method makes use of the Cryostat, an apparatus used in fresh tissue microtomy.
cryostat procedure
102
optimum working temperature of cryostat
-18 to -20
103
Preserves tissues by rapid freezing (quenching)
freeze-drying
104
A process of dehydration, performed at temperatures low enough to avoid the formation of ice
crystals and to circumvent the damaging effects observed after ambient-temperature
dehydration
freeze-substitution
105
difference of freeze subsitituon and drying
instead of being subjected to dehydration in an expensive vacuum drying apparatus, is fixed in
Rossman's formula or in 1% Acetone and dehydrated in absolute alcohol
106
advantage of freeze-substitution
more economical and less time consuming
