Question 9 (Head & Neck)

Question: You are a qualified trauma surgeon traveling in your car on a highway having your  well-equipped kit with you. At the scene of accident you find an unconscious driver. After clearing his airway your next step of management would be?

a. Have an IV line

b. Do tracheostomy

c. Pass endotracheal tube

d. Secure cervical spine

e. Manage shock

Answer: d

Explanation: 

Lets dissect the answers one by one.

Have an IV line: there is no use having an IV line right there at the road side. You might say that the first things are always Airway  (which this surgeon, that is you) have cleared, Breathing, Circulation. Now you might argue that passing an IV line is included in Circulation. There are two things there. First, there is no mention of a cardiac arrest (which can compromise circulation), second even if the patient is in cardiac arrest  (which he is not), then your priority should be chest compressions to maintain the circulation and not an IV line.

Do tracheostomy: Haven’t you been clearly told that he has cleared the airway? A tracheostomy is required only if the upper air way is blocked and cannot be cleared. So there is no need of tracheostomy in this situation

Pass endotracheal tube: Since the airway is clear and there is no mention about the patient NOT BREATHING (which requires ventilation) so there is not need to pass endotracheal tube.

Manage shock: Shock?? Where is shock in this question? No where. So if something is not mentioned, don’t bother cooking it up. (Although some FCPS-1 questions are absurd enough that to answer then you have to cook the missing bits of questions (a problem with CPSP) up and then answer it)

Secure cervical spine: Ah…here comes our correct answer. Now whenever you find an unconscious trauma patient (like in this question), after clearing off the airway and making sure he is breathing and not dead, stabilise his cervical spine and DO NOT manipulate the neck of the patient in any case. Even when securing the airway you have to very careful about cervical spine. Because if you don’t secure the cervical spine first, instead of saving the patient’s life, you might actually kill him or get him quadriplegic for life if the cervical vertebrae were damaged in the accident and you put further insult to injury and break his cervical spine. So secure it first!

In short the management might include  all of the above options, but the emphasis is about priorities, that is which step should be done first.

Securing the spine

Securing the spine

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Question 8 (Abdomen)

Question: A patient comes to you with portal hypertension and dilated abdominal veins, which vessel is involved?

a. Hepatic Vein

b. Inferior vena cava

c. Portal vein

d. Hepatic artery

e. Superior mesenteric artery

Answer: c

Explanation:

This is the kind of MCQ in which the answer lies in the question, look at the phrase “portal hypertension” in the question, well the best guess (that is if you are clueless about what portal hypertension actually is!) would be portal vein even without knowing the anatomy. But since we are here to become good doctors so its better to leave the wild guessing game aside and learn some basic things about the portal anatomy.

The portal system

The portal system

In simplest of words, the portal vein receives all the blood from the gut and takes it to the liver where nutrients are processed and blood detoxified by the liver and the blood is then dumped into the inferior vena cave which takes it to the heart. Since the blood from the gut does not directly go to the heart (instead goes first to another organ, i.e, liver), it is therefore called the portal (carrier) system.

The portal vein blood gets into the liver sinusoids and from here the hepatic vein drains it  and enters the inferior vena cava. This the normal pathway. If the liver sinusoids are distorted like in cirrhosis of liver, the blood from portal vein has trouble passing through the liver. Now the pressure in the portal vein rises as the forward resistance is high due to distorted sinusoids. This is the portal hypertension.

The blood from the gut however still has to get back to the heart no matter what. So the collaterals between gut veins and other veins which drain directly into the inferior vena cava, open up. This way most of the blood from gut can bypass the portal system/liver and reach the heart directly. This results in the collaterals to enlarge. Three important areas where this shunting of blood from portal system to systemic veins (bypassing the liver) occurs are:

At the lower end of oesophagus (causing esophageal varices)

At the rectum

Over the anterior abdominal wall (like in this question, where abdominal walls are dilated)

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Question 7 (Thorax)

Question: During exhaustion, a person uses the accessory muscles of inspiration. The muscle which primarily increases the anteroposterior diameter of thoracic cage is?

a. Sternocleidomastoid

b. Scalene Anterior

c. Internal Intercostal

d. External Intercostal

e. Diaphragm

 

Answer: d

Explanation:

Its important to know about muscles of respiration as questions often come up in exam about them.

During quiet breathing, the predominant muscle of respiration is the diaphragm. Expiration during quiet breathing is predominantly a passive phenomenon, as the respiratory muscles are relaxed and the elastic lung and chest wall return passively to their resting volume, the functional residual capacity.

However, during exercise or exhaustion like in this question, many other muscles become important to respiration. During inspiration, the external intercostals raise the lower ribs up and out, increasing the lateral and anteroposterior dimensions of the thorax. The scalene muscles and sternomastoids also become involved, serving to raise and push out the upper ribs and the sternum.

During active expiration, the most important muscles are those of the abdominal wall (including the rectus abdominus, internal and external obliques, and transversus abdominus), which drive intra-abdominal pressure up when they contract, and thus push up the diaphragm.

The internal intercostals assist with active expiration by pulling the ribs down and in, thus decreasing thoracic volume

 

intercostal_muscles

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Question 6 (Lower Limb)

Question: A mass along the lateral wall of the pelvis results in the paralysis of the medial muscles of the thigh. Involvement of which of the following structures is most likely cause of this paralysis?

a. Exteranl iliac artery

b. Femoral Nerve

c. Obturator Nerve

d. Sciatic Nerve

e. Superior gluteal nerve

Answer: c

Explanation:

The key to solve any MCQ is to reach the root question quickly. In this question the plain simple thing being asked is about the innervation of medial thigh muscles, in a twisted way though!

So lets jump to the answer now. First, which are the medial muscles? The adductors obviously cause they lie medially so they can pull the thigh medially (adduct it). Next which nerve supplies the adductor of hip (or medial muscles of thigh)? Its the obturator nerve. From the question we can see that there is mention of a mass running along the lateral pelvic wall. Obturator nerve runs along the lateral wall of the lesser pelvis to enter the thigh later. So a mass along lateral wall of pelvis can damage the obturator nerve.

Can you name the medial thigh muscles (the adductors)?

These are:

Adductor brevis

Adductor longus

Adductor minimus

Adductor brevis

Pectinues

Gracilis

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Obturator Nerve

 

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Question 5 (Upper Limb)

Question: A person can’t abduct his arm after fall on the out-streched hand; however he is able to abduct it after the initial 90 degrees of passive abduction of his arm. The most likely muscle involved is?

a. Trapezius

b. Deltoid

c. Pectoralis major

d. Supraspinatus

e. Teres Major

Answer: b

Explanation:

Remember that in  normal subjects the supraspinatus initiates the first 15 degrees of abduction along the vertical plane. The deltoid functions from 15 to 90 degrees, while synergistic actions of the trapezius and serratus anterior abduct from 90 to 180 degrees by rotating the scapula laterally.

So our patient in this question is unable to abduct this arm till 90 degrees only (indicating a paralysed deltoid), and then from 90 degrees onwards his trapezius and serratus anterior muscles take over and perform the rest of abduction.

A little bit of more information about the Deltoid which is a favourite muscle in medical exams:

Deltoid is supplied by the Axillary Nerve (C5, C6)

I like to think of deltoid as the epaulet (the shoulder ornament you see on soldier uniforms, picture follows).

The deltoid muscles.

The deltoid muscles.

epaulet

The epaulet that overlie the deltoids.

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Question 4 (Histology)

Question: A medical student is examining a slide under the microscope but he is unable to differentiate the gallbladder different from the colon; the point which will help him in differentiating the gallbladder from colon histologically will be?

a. Muscular layer arranged in 3 layers in the gallbladder wall

b. Columnar epithelium in gallbladder wall

c. Peyer’s patches in the gallbladder wall

d. No submucosa in the gallbladder wall

e. No serosa in the gallbaldder wall

Answer: d

Explanation:

Of all the things, gallbladder does not have a well defined submucosa or muscularis mucosae.

Almost all the GI tract from stomach to large intestine is lined with columnar epithelium. So you will find columnar epithelium in the gallbaldder as well as the colon, can’t differentiate them using this feature.

Gall baldder’s muscular layer isn’t arranged into layers. The classic three layered muscular layer is the feature of stomach

Peyer’s patches are organised lymphoid tissue in the gut wall found only in the small intestine, mostly the ileum. So Peyer’s patches are neither the feature of the colon nor the gall bladder. 

Serosa is a distintive feature of both gallbaldder and the colon so you can’t use this feature for differentiation either. 

Then all we are left with is the submucosa which is absent in gallbaldder and present in colon.

Just Mucusa, Muscularis and Serosa in the gall baldder wall. NO submucosa.

Just Mucusa, Muscularis and Serosa in the gall baldder wall. NO submucosa.

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Question 3 (Pathology)

Question: A 60 year old man develeoped shock. AFter recovery he was found to have focal neurologial signs. The most likely change expected to be seen in brain biopsy would be:

a. Coagulative Necrosis
b. Liquefactive Necrosis
c. Acute hemorrhagic change
d. granulomatous change
e. Lacunar infarcts

Answer b

Always remember whenever there will be necrosis in brain it will be liquefactive necrosis. The reason why is exactly not clear but lets make up our own reasons. Have you eaten brain (siri/paye)….not of human off course…but lets say…of goat. And you must have eaten meat of goat as well. Now do you remember how soft the former one is? and the meat required a bit chewing before it can be taken down? Thats it…the brain is so soft naturally if it gets necrosed it will get liquified. Also most of brain is made up of fats…..heat the fat and it melts! Heat the proteins (meat) and it solidifies (coagulates). Simple isn’t it?
Another place where you can find liquefactive necrosis is the lung (may be cause of loose connective tissue rather than dense).
Ok now how did this man go into brain necrosis? He had shock–>; low brain perfusion–>;ischemia–>;sustained ischemia–>;tissue death–>;necrosis.

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