Test 39  (pathology)

1. In ionizing radiation:

a. cells in G1 phase of the cell cycle are most sensitive

b. mitosis does not occur in irradiated cells

c. cells experiencing hypoxia are vulnerable to radiation 
    damage

d. granulation tissue formation is delayed in wounds which 
     have been radiated

e. undifferentiated tumours are usually more sensitive to 
    radiation than differentiated tumours

Answera. F   b.F   c.F   d.T   e.T
Cells are most vulnerable during mitosis whereas in G1 phase, cells are relatively resistant to radiation.
Mitosis can still occur with radiation.
Hypoxia appears to confer protection against radiation. The centre of a malignant tumour is protected by hypoxia.

2. The following are true with regard to an incision held together by 
    monofilament nylon suture:

a. early suture removal does not affect the granulomatous response

b. monocytes clean the debris left by phagocytes

c. the epidermal and dermal epithelia grow downwards along 
    the suture track

d. fibroblasts have a contractile function which helps to 
    produce a small scar

e. the wound site becomes more vascular as time passes.

Answera.F   b.T   c.T   d.T   e.F
The extent of granulation decreases if the suture is removed early.
The wound site becomes less vascular as time passes

3. The following are true:

a. gangrene refers to tissue necrosis with or without infection

b. acute inflammation usually occurs around necrotic tissues

c. apoptosis does not usually cause inflammation

d. autolytic changes in the nucleus are pathognomonic of 
    necrosis

e. the blood vessels surrounding an acutely inflamed site 
    usually show progressive vasodilatation from the time of 
    injury

Answera. F   b.T   c.T   d.T   e.F
Gangrene refers to tissue necrosis with infection.
The blood vessels surrounding an acutely inflamed site initially undergo vasoconstriction before vasodilatation.

4. The following are true with regard to cell growth:

a. ionizing radiation can cause atrophy

b. hypocalcaemia can lead to enlargement of the parathyroid 
    gland

c. the main stimulus for hypertrophy is hormonal

d. in metaplasia, there is a change of a type of differentiated 
    cell to a type of undifferentiated cell

e. achondroplasia does not affect membranous bone

Answera.T   b.T   c.F   d.F   e.T
The main stimulus for hypertrophy is usually mechanical.
In metaplasia, there is a change from one type of differentiated cell to another type of differentiated cells.

5. During wound healing:

a. the inflammation is greater for catgut than nylon

b. with absorbable suture, the wound strength decreases from 
    the time of suturing.

c. in scurvy the wound is weak due to increased activity of 
    collagenase

d. in infected wound collagen lysis is increase

e. during collagen synthesis, lysine and proline are directly 
     incooperated into the collagen molecules

Answera.T   b.T   c.F   d.T   e.F
In scurvy, the synthesis of collagen is reduced because ascorbic acid is needed for protocollagen hydroxylase.
During collagen synthesis, lysine and proline are incooperated into the protocollagen molecules which are then acted on by protocollagen hydroxylase.