Pathology & the Dentist

Question 1

What are the 2 types of cell death?

Answer 1

Reversible and irreversible

Question 2

What 2 things happens in reversible cell death?

Answer 2

Cellular swelling which is hydrophobic change causing excess watery fluid due to impaired function of Na+ cell membrane pump

Fatty change due to impaired function of normal enzymes that normally metabolise fat, causing fat to accumulate

Question 3

What happens in irreversible cell death?

Answer 3

Impaired Ca2+/ATPase pump leading to a build up in CALCIUM IONS in the cell

Ca2+ stimulates DEGRATATIVE ENZYMES
▪ Causes destruction of organelle membranes
▪ Eventually leads to cell losing its phospholipid membrane and causing CELL DEATH

Question 4

What are the advantages and disadvantages of cell death?

Answer 4

➢ Advantages: Development, kills cancer cells

➢ Disadvantages: Tissue destruction, atrophy

Question 5

What is necrosis? What are the 3 types?

Answer 5

CATASTROPHIC cell death following INJURY accompanied by RELEASE of POTENT
MEDIATORS of INFLAMMATION

COAGULATIVE, COLLIQUATIVE and CASEOUS NECROSIS

Question 6

What is apoptosis?

Answer 6

o GENETICALLY PROGRAMMED cell death

o Does NOT evoke an INFLAMMATORY RESPONSE

Question 7

What is acute inflammation?

Answer 7

• TRANSIENT series of TISSUE REACTIONS to injury
• Attempt to REDUCE the IMPACT of the insult and RESTORE NORMAL STRUCTURE and FUNCTION
• < 48 HOURS

Question 8

What are the signs of inflammation?

Answer 8

➢ REDNESS (RUBOR)
➢ WARM (CALOR) 
➢ PAIN (DOLOR) 
➢ SWELLING (TUMOR) 
➢ LOSS OF FUNCTION

Question 9

What is chronic inflammation?

Answer 9

• PROLONGED tissue reaction
• TISSUE DESTRUCTION by OFFENDING AGENT or the process itself
• MACROPHAGES, LYMPHOCYTES, PLASMA CELLS
• > 48 HOURS

Question 10

What are the two types of chronic inflammation?

Answer 10

➢ Non-specific chronic inflammation
▪ No specific cause and causes a generalised

➢ Specific chronic inflammation
▪ GRANULOMATOUS INFLAMMATION
▪ REPAIR by GRANULATION TISSUE – new connective tissue that forms on surface during
wound healing
▪ FIBROSIS results from PROGRESSIVE changes in the granulation tissue

Question 11

What is healing?

Answer 11

• Resolution, regeneration, repair, reconstitution

* Humans cannot reconstitute – Eg. Lizards regrowing their tail

Question 12

What is ischemia?

Answer 12

• Caused by an OCLCUSION in BLOOD VESSELS leading to IMPAIRED BLOOD FLOW or PERFUSION in an
organ/tissues
• May be REVERSIBLE depending on the DURATION of the ischaemia and the METABOLIC NEEDS of the
organ/tissue

Question 13

What is a thrombus?

Answer 13

▪ A SOLID MASS of BLOOD CONSTITUENTS formed WITHIN THE VASCULAR SYSTEM during
life
▪ Formed by successive DEPOSITION OF PLATELETS (pale) and FIBRIN (dark) layers called the
LINES OF ZAHN
▪ PROPAGATION occurs when the thrombus increases in size/length

Question 14

What are the 4 fates of a thrombus?

Answer 14

• Resolution
• Embolization into the lungs
• Organised and incorporated into the wall
• Organised and recanalized

Question 15

What is an embolism?
What is a thromboembolism?
Wat is the most common type of embolism?

Answer 15

▪ An abnormal mass of material that can MOVE IN THE VASCULAR SYSTEM and
become LODGED in a VESSEL and BLOCKING ITS LUMEN
▪ Thromboembolism is an embolus breaking off from a THROMBUS
▪ PULMONARY EMBOLUS is the most common type and is a result/complication from Deep
vein thrombus

Question 16

What is metaplasia?

Answer 16

Is when a differentiated cell of a certain type is REPLACED BY ANOTHER CELL TYPE, which may
be less differentiated

Question 17

What is aplasia?

Answer 17

Is POOR CELLULAR DIFFERENTIATION causing failure of an organ/tissue to develop and function
normally

Question 18

What is atrophy?

Answer 18

Decrease in cell size

Question 19

What is hypoplasia?

Answer 19

Decrease in the number of cells

Question 20

What is hypertrophy?

Answer 20

Increase in cell size

Question 21

What is hyperplasia?

Answer 21

Increase in the number of cells

Question 22

What is a hamartoma?

Answer 22

➢ BENIGN, FOCAL MALFORMATION that resembles as neoplasm
➢ Grows in a DISORGANISED MANNER
➢ Grows at the SAME RATE as surrounding tissues and composed of tissues normally found at that
site

Question 23

What is a neoplasm?

What are the 3 types?

Answer 23

➢ Abnormal mass of tissue with UNCOORDINATED GROWTH that PERSISTS in the same excessive
manner after STIMULUS which evoked the change is REMOVED
➢ Occurs when GENETIC ALTERATIONS ALTERS CELL GROWTH

➢ Types:
▪ In Situ
o ABSENCE OF INVASION of tumour cells INTO SURROUNDING TISSUE
o No penetration through the BASEMENT MEMBRANE
▪ Benign
▪ Malignant

Question 24

Compare and contrast benign vs malignant (5 points)

Answer 24

Benign Tumour 
• Slow growing
• Encapsulated
• Non-invasive 
• Do not metastasize
• Well differentiated

Malignant
• Fast growing 
• Not capsulated 
• Invasive and infiltrative 
• Metastasizes 
• Poorly differentiated

Question 25

What is diagnosis?

Answer 25

HISTORY + CLINICAL EXAMINATION + SPECIAL INVESTIGATION

Question 26

What 5 ways can aid in making a diagnosis?

Answer 26

• An explicit diagnosis from a colleague, e.g., by a referral letter
• A direct verbal indication of a diagnosis by the patient or a relative
• An indirect indication via description of symptoms, signs or drug therapy
• The detection of typical clinical changes of the disease in the head & neck,
  face, mouth, hands
• The indirect detection of typical changes via a report on laboratory findings