Definitions

Question 1

Abscess

Answer 1

Cavity lined by granulation tissue containing pus (alive & dead bacteria, alive & dead neutrophils, tissue debris, serum)

Question 2

Pus

Answer 2

alive & dead bacteria, alive & dead neutrophils, tissue debris, serum

Question 3

Cyst

Answer 3

collection of fluid in a sac lined by endothelium or epithelium which usually secretes the fluid.
• True cysts are lined by endo- or epithelium.
• False cysts are the result of exudation or degeneration, e.g.
pseudocyst of pancreas, cystic degeneration in a tumour.

Question 4

Classification of cysts

Answer 4

True: lined by endo/epithelium
False: from exudation/degeneration- eg pancreatic pseudocyst, cystic degeneration of tumour

Congenital: dermoid cyst, branchial cyst, hyatidid of Morgagni

Acquired: sebacous, thyroid/ovarian, parasitic, pseudocysts

Question 5

Sinus

Answer 5

blind epithelial track, lined by granulation tissue which extends from a free surface into the tissues, e.g. pilonidal sinus.

Question 6

Fistula

Answer 6

abnormal communication between two epithelial
surfaces. It is lined by granulation tissue and colonized by bacteria, e.g. fistula-in-ano, pancreaticocutaneous, colovesical, vesicovaginal.

Question 7

Ulcer

Answer 7

breach in an epithelial surface.

Question 8

Diverticulum

Answer 8

Outpouching of a hollow viscous (true = includes all tissue layers), false= only mucosa & muscularis mucosae
eg bowel, bladder, oesophagus

Question 9

Atherosclerosis

Answer 9

Degenerative disease of large and medium-sized arteries characterized by lipid deposition and fibrosis.

Question 10

Thrombus

Answer 10

solid mass of blood constituents formed within the vascular system.

Question 11

Embolism

Answer 11

mobile mass of material in the vascular system capable of blocking its lumen.

Question 12

Clot

Answer 12

Solid collection of blood cells in a fibrin network

Question 13

Ischaemia

Answer 13

Tissue effect from insufficient oxygen

Question 14

Infarction

Answer 14

Tissue death from insufficient oxygen

Question 15

Gangrene

Answer 15

Ischaemic tissue necrosis with desiccation (dry) or putrefaction (wet)

Can be secondary to thrombosis (eg appendicular artery)/ embolism eg in PVD/extrinsic compression eg in facture or tourniquet use

Question 16

Metaplasia

Answer 16

Reversible transformation of one type of terminally differentiated cell into another fully differentiated cell type.
Eg Baratt’s oesophagus (squamous to columnar)

Adaptive response of a tissue to environmental stress. It is mediated by changes in expression of genes involved in cellular differ- entiation. It does not progress to malignancy: if the environmental changes persist, dysplasia may result and progress to malignancy

Question 17

Dysplasia

Answer 17

Potentially premalignant condition characterized
by increased cell growth, atypical morphology, and altered differentiation.

May be a response to chronic inflam- mation or exposure to carcinogens. Early forms may be reversible: severe dysplasia has a high risk of progression to malignancy,

Question 18

Neoplasia

Answer 18

Autonomous abnormal growth of cells which persists

after the initiating stimulus has been removed.

Question 19

Inflammation

Answer 19

local physiological response to tissue injury. It can be acute or chronic.

Question 20

Granuloma

Answer 20

Aggregate of epitheloid histiocytes to isolate infection or foreign body

Question 21

Necrosis

Answer 21

Abnormal tissue death with inflammatory changes- not energy depedant

Question 22

Apoptosis

Answer 22

Physiological process
Cell degradation via intracellular enzyme activation
Energy dependant with no inflammatory response

Question 23

Coagulative necrosis

Answer 23

Preserved tissue architecture
Coagulation of proteins to preserve architecture eg kidney/heart/spleen
Eg when tissue placed in boiling water

Question 24

Colliquative necrosis

Answer 24

Liquefactive necrosis occurring in lipid-rich tissue

Lysosomal enzymes active to break down fat to denature it resulting in liquefaction eg in brain

Question 25

Caseous necrosis

Answer 25

Unstructured necrosis where tissue architecture cannot be identified secondary to necrosis eg in TB Contains amorphous proteins and degenerate lipids

Question 26

Wet gangrene

Answer 26

From venous & arterial occlusion | Necrosis and putrefaction by gram negative bacteria- bacterioides & clostridia

Question 27

Dry gangrene

Answer 27

Tissue desiccation with no infection and often autoamputates eg in diabetic foot

Question 28

Gas gangrene

Answer 28

infection with gas-forming anaerobic bacteria resulting in surgical emphysema & crepitus