نموذج لأحد الامتحانات واجابتها

*Complete The Following Statements (10 Marks)*

1- Mechanisms of NAC in treatment of acetaminophen toxicity 

Are:  1- Enhancing the synthesis of additional glutathione.

        2- Acting intracellular as glutathione substitute.

        3- Enhance the non toxic sulphation pathway.

        4- Acting as antioxidant to modify the 2ry effect of theInflammatory response after the initial direct toxic injury.

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2- Indication of multiple dose activated charcoals: 

       1- Very large dose of toxin.

       2- Life threatening toxins.

       3- Substances that form a large lump.

       4- Toxins that slow gut function.

       5- Toxins that are released slowly into gut lumen.

       6- Substances that have a large enterohepatic or enteroenteric circulation.

(N.B. Only 3 Items are requested)

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3- Death from drowning in fresh water occurs within (3-5 minute) due to  (pulmonary edema and electrolyte disturbance) while in sea wateroccurs within (8-12 minute) due to (heart failure).

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4- Diagnosis of sudden death:

     1- Circumstantial evidence.

     2- Exclusion of other causes.

     3- Analysis of toxicological & forensic  Samples.

 *Choose The Correct Answer (10 Marks)*

           1      (b)

           2      (d)

           3      (b)

           4      (b)

           5      (e)

           6      (b)

           7      (a)

           8      (c)

           9      (a)

           10    (c)

 *Forensic Case*

1} *Identify the age 16 in male by doing x-ray:

         - On elbow joint to see union of epiphysis of:

a-Upper end of ulna.

b-Lateral epicondyle with the lower end of humorous.

         -On pelvis to see union of lesser trochanter of the femur. 

     *Medicolegal importance of age 16:

             1] The age of getting identity card.

             2] The legal age of marriage in female.

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2} *The possible injuries of the skull due to this blow are:

    A] Linear (fissured) fracture:

These are straight or curved fracture lines. Often of Considerable length. They either radiate out from depressed zone or arise under or at a distance from an impact area. They usually involve both table of the skullwithout displacement of the fragments, but they rarely involve the inner table only. Small fracture can be detected only by x-ray. They may occur any where of the skull, but are especially common in weak unsupported plates.

   B] Depressed fractures:

•  Focal impact causes the outer table to be driven inwards and, unless absorbed in the dipoloe, the inner table will also be intruded into the cranial cavity causing all the dangers of direct damage to the intracranial contents.

•  The deepest of the depression will indicate where the weapon first struck the skull and the probable position of the assailant and his victim at the time of the attack.

   C] Comminuted fractures:

-  These are induced by a blow from heavy blunt instrument with a wide striking surface.

-  When sever local impact causes focal and general deformation, a combination of depressed fracture and fissured fracture lines radiating from it will occur, forming "spider's –web or mosaic" pattern.

-  The comminuted fracture may show minimal or no displacement of the fragment.

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3}* Mechanisms of skull fracture expected are:

   {a} Fracture due to direct local impact:

-  When the skull receives a focal impact there is a momentary distortion of the shape of the cranium.

-  The area under the point of impact bends inward and, as the content of the skull are incompressible there must be a compensatory bulging of other areas surrounding an impact area – the well known 'struck hoop'. Both these intruded and extruded areas can be the site of fracturing if the distortion of the bone exceeds the limits of its elasticity.

-  At the site of impact, the bone is indented in the form of a shallow cone. Compression occurs on the concavity of the curved bone and tension 'tearing' forces on the convexity.  Thus the inner table will be fracture where the skull is indented and the outer table will fracture at the margins of the deformed area.

-  In more common circumstances of a wider impact from blunt injury, the deformation of the skull is less localized but fracture can still occur from the same mechanism of exceeding elastic limit.

 

-  The fracture may be:

     {1} remote from the area of impact, following lines of structural weakness.

     {2} or may extend from the area of impact.

     {3} or even commence at a distance and run back to the impact site.

{b} Fractures according  to the mobility of the skull:

{1} If the head is free and unsupported, the principle effect are likely to be due to shearing or swirling movement imparted to the brain, causing bruising and even laceration of the cortex rather than a fracture.

{2} If the head is fixed and supported, the skull is flattened at these two supported points and bulges mostly at the poles of the perpendicular direction hence the fracture at these two poles may take place and known as "polar fracture".

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4}  The difference between the clinical picture of the first Unconsciousness and late one:

   {a} the first unconsciousness is due to "concussion"

*Def.: A transient paralytic state due to head injury, it does not show any evidence of structural cerebral damage and is always followed by amnesia from the actual moment of accident. 

* Clinical picture:

{1} Sudden transient loss of consciousness for second or minute.

{2} Retrograde amnesia is almost inevitable, though like concussion it self, it may be so transient as to escape notice. The memory of events immediately before the incidence is rarely returns.

{3} Rapid weak pulse, rapid shallow respiration, low blood pressure, subnormal temperature and pale moist skin with clammy sweat.

{4} Loss of reflexes and general muscular flaccidity.

{5} Equal pupils (may be normal in mild case or dilated in sever case).

{6} Vomiting.

{7} No sign of lateralization.

{8} There is often diffuse change in the EEG.

 

{b} the late unconsciousness is due to "compression"

* Def.:  It is a condition of increased intracranial pressure, induced by bone fragments, intracranial hemorrhage and brain abscess or tumor.

* Clinical picture:

{1} Loss of consciousness.

{2} Projectile effortless vomiting.

{3} Slow full pulse and high blood pressure due tostimulation of vagal and vasomotor centers.

{4} Stertorous respiration.

{5} Fever due to derangement and paralysis of the heatregulating center.

{6} Papilledema.

{7} Sign of lateralization (focal neurological signs):

(a) Unequal pupils: contracted on the affected side, then on the contra lateral side .Pupillary contraction occur during the early stage of irritation, while the late stage of cerebralparalysis lead to pupillary dilatation. 

(b) Exaggerated reflexes on contra lateral side in early stage of brain irritation, then muscular paralysis occur in paralytic stage.

(c) Conjugate deviation of both eyes towards the side of the lesion.