pathology 1 intro

Question 0

Explain the term, pathogenesis?

Answer 0

mechanism of disease development, all the events following exposure to the agent/event. from the initial stimulus to the expression of the disease.

Question 1

3 roles of pathology?

Answer 1

post mortem
clinical practice - diagnosis and treatment
surgical biopsy

Question 2

explain morphological diagnosis?

Answer 2

predominant lesions - structural changes seen in cells/tissues relating to the disease.

Question 3

aetiological diagnosis?

Answer 3

cause of the disease - what agent caused it? it identifies the aetiology

Question 4

what is the ratio of formalin tissues need to be fixed in?

Answer 4

10-20 times the mass of the tissue. if not then will result in autolysis of the tissue

Question 5

what occurs in the event of inadequate fixation?

Answer 5

formalin may only penetrate so far in and tissues in the centre of the specimen will undergoe autolysis. lysosomal enzymes are responsible for this.

Question 6

what is the stain most routinely used when staining tissues?

Answer 6

H&E - heamatoxylin and eosin. but does not stain certain tissues/cells.

Question 7

which stain do you use for fat?

Answer 7

oil red o

Question 8

which stain is used for fibrous tissue?

Answer 8

masson’s trichrome (turns green)

Question 9

which stain is used for haemosiderin (iron breakdown)

Answer 9

perl’s prussian blue

Question 10

which stain used for immunohistochemistry?

Answer 10

GFAP. - look for viruses which are antigen specific

Question 11

which stain is used for basement membranes?

Answer 11

jone’s/silver stain - e.g. look for integrity of BM (liver)

Question 12

define;

hypoplasia? hyperplasia? aplasia? agenesis? metaplasia? dysplasia?

Answer 12

hypo - decreased number of cells
hyperplasia - increased number
aplasia - defective development/absence
agenesis - absence or failed development
metaplasia - one adult type of cell replaced by another
dysplasia - altered size, shape or organisation

Question 13

what is hydropic degeneration?

Answer 13

cell swelling due to hypoxia (reduced ATP) therefore anaerobic respiration and lactate accumulates - membrane pumps inhibited and NA AND H2O move into cell.

Question 14

what happens in ballooning degeneration? if dont stain with h&e then what could it be?

Answer 14

vacuolated cytoplasm and may be irreversible. contain water fat or glycogen. - may lead to oncotic necrosis - cell death.

Question 15

what happens in apoptosis?

Answer 15

cell shrinkage and death - controlled cell death.

Question 16

5 types on oncotic necrosis? what are the characteristics of each? cclgf.

Answer 16

1. coagulative - caused by ischaemia (lack of O2) blocked proteolysis, eg. renal infarct.
2. caseous - friable cheese appearance,often white, may lead to calcification, eg. TB in lymph node and lungs.
3. liquefactive - cavities filled with liquid debris, eg. abcesses due to pyogenic bacteria.
4. gangrenous - follows from coaguative, moist dry or gas. eg. saprphytes or mummification
5. fat - pancreatic /traumatic in areas of fat.

Question 17

pyknosis?

Answer 17

small shrunken, densley staining nucleus - no chromatin

Question 18

karyorrhexis - ?

Answer 18

nucleus split up

Question 19

karyolysis?

Answer 19

nucleus lysed - wont take up h&e.

Question 20

when do you see pinker cells?

Answer 20

when they are necrosed - take up more eosin

Question 21

apoptosis?

Answer 21

condensed chromatin, fragmented cytoplasm, NO INFLAMMATION!

Question 22

LIPIDOSIS?

Answer 22

eg. in liver. lipid accumulates inside cells. eg. excess FFAS in diet/adipose breakdown.
or. toxic damage affecting fat metabolism

Question 23

fatty infiltration?

Answer 23

replacement of cells by adipocytes eg. old age/obese.

Question 24

glycongen seen inside cells? - vacuoles that dont stain?

Answer 24

significant in liver. hepatic. diabetes mellitus. glycogen storage disease.

Question 25

2 types of calcification in pathology?

Answer 25

1. dystrophic - serum ca2 levels are normal but deposited in dead or dying tissues
2. metastatic - hypercalcaemia. - kidneys cant excrete, hypercalcaemia (malignancy) or vit.D toxicity.

Question 26

inflammatory cells? name as many as possible and what do they look like?http://images.wisegeek.com/types-of-white-blood-cells.jpg

Answer 26

neutrophil - multinuclei and no granules
eosinophil - big granulated cytoplasm
lymphocytes - small round and densely staining nucleus
plasma cells - blue and have a halo - produce immunoglobin
mast cells - large and much cytoplasm
macrophages- large and much cytoplasm - phagocytose
firboblasts - long
giant macro - eg. in TB.

Question 27

which cells would you find in pyogranulomatous?

Answer 27

area of neutrophils and macrophages. (bacterial/foreign body)

Question 28

what can you use to stain bacteria inside a cell?

Answer 28

ZN stain (very pink/red)

Question 29

4 types of fluid in inflammation?sfsm

Answer 29

suppurative/purulent - neutrophils and dead host cells (abcess if walled off) eg. empyema - pus filled guttoral pouch.

2. fibrinous - thin eosinophillic meshwork - increased vascular permeability and fibrinogen escapes (yellow tinge)
3. serous - eg. blister. albumen and plasma proteins.
4. mucous/cattarhal - eg. resp or GI tract where mucous cells can contribute.

Question 30

what stain do you use for glycogen?

Answer 30

PAS - periodic acid schiff