Written Examination - The Essay Question

Why Essays

The ability to communicate ideas logically in a coherent and organised manner is an important aspect of learning. Writing an essay on a theme is an exercise devoted to this aspect. The knowledge tested in an essay can be assessed by short answer questions as well; and in some cases even by MCQs. But these types of questions tend to be highly focussed. In an essay you have more freedom of expression and organisation. This also means that two equally good answers do not have to be identical - in fact if they are one would suspect... you know what.

In the final examination for the unit there will one essay question. You will have a choice of one topic from three. An essay topic may have greater emphasis on one of the strands of the unit, but they all will reflect integration.

The essay question in this examination does not set a limit to the length of your essay in terms of number of words. Such a limit may distract you from writing freely. Since the entire theory paper is a 'write-on' paper, the essay also needs to be written in the space provided. It is expected that your essay does not exceed one side of an A4 paper with average handwriting. However, given that the size of handwriting does vary, if you need additional space, you may use the reverse side of the page.

It is the content and its organisation that matters more than the length. If you wish and if time permits you may illustrate your essay with a diagram. But a diagram cannot be accepted as a total substitute for a written answer!

Make sure you understand what the question seeks.
Decide what you are going to write.
See that it presented as a logical sequence rather than a haphazard collection of facts. The essay should lead into the topic and have a conclusion.
Avoid writing irrelevant material. Your introduction to the topic should not begin with the origin of life on the earth!

Let us take two examples (For more essays and links to answers, go to the list of topics - see link at the top of this page) :

1. Correlate the general histological plan of the hollow organs of the digestive system with its function.
What this question seek?
General plan - structural details of individual organs are not required. In any case we have not studied these in this unit.
Histological - we therefore need to know the tissues that take part in the organisation of the structures of the GI Tract.
Correlate structure with function - what does each of these tissues do in the overall function of the hollow organs?

So, we need to know what the hollow organs of the GI tract do - except the oesophagus, they are all involved in either digestion or absorption or both, of the contents.
Being hollow organs, they need to be lined with an epithelium. The epithelium must have its own supporting connective tissue.
They need to move their contents forward (distally) - they need muscle for this. Except for a part of the oesophagus, this muscle is smooth and arranged in two layers : circular and longitudinal.
The activities need to be controlled by nerves.
The muscular and epithelial layers are joined together by a layer of connective tissue - this tissue also has the function of carrying the blood vessels and the nerves.

We now only need to give names to these layers and organise our material. Remember that you have freedom to organise your material the way you wish. There is no single best way of doing this! A possible answer may run as follows :

The hollow organs of the digestive system are involved in digestion or absorption. Being hollow, they are lined by an epithelium.The epithelium best suited for secretion of enzymes and absorption is simple columnar. In may places it specialises as glands. The epithelium is supported by a layer of loose connective tissue called lamina propria. The entire functional unit is the mucosa and has its own thin layer of muscle.
The organs have a wall of smooth muscle for movement of their contents. The smooth muscle is organised in two layers. The rhythmic, involuntary contractions of the muscle coat create peristaltic waves along the length of the digestive tube.
The mucosa and the muscular layer are joined by the main connective tissue layer called submucosa. Blood vessels of the organs form an extensive network (plexus) in this layer. From this plexus branches go towards the muscular layer and the mucosa. The submucosa also has a network of autonomic nerves.
The overall plan of the oesophagus follows the same principles. However, since it is subject to friction and is not involved in digestion or absorption, the epithelium of the oesophagus is stratified squamous, non-keratinised.
Thus we see that all four primary tissues contribute to the functioning of the digestive system organs.

Remember that the focus here is on the organisation and function of digestive organs - this is not an essay on the detailed structure of say, stratified squamous epithelium or smooth muscle. If, for example, you go about explaining how the structure of smooth muscle differs from that of cardiac muscle or skeletal muscle, you are wasting your time and straying from the theme!
Also bear in mind that the 'answer' given above covers the essential, key points. In an essay you are free to elaborate on any of these provided you retain your sense of timing and relevance.

Let us take another example :

2. Compare the structure and function of a synchondrosis and symphysis.

I would say that this is a classic example of integration between histology and gross anatomy!
To begin with, think of what a synchondrosis is and what a symphysis is! This is an exercise in the descriptive anatomy of joints.
How does white fibrocartilage differ from hyaline cartilage in structure?
What are the functional implications of this?
Where do we find synchondroses and symphyses?
You may end up with commenting on whether a synchondrosis is a 'joint' at all...

A possible answer :

A synchondrosis is a type of joint where bones are connected by a plate of hyaline cartilage. In a symphysis, bones are covered by a thin layer of hyaline cartilage, but the principle structure uniting the bones is white fibrocartilage.
Hyaline cartilage more rigid and resists compression to a great extent, even though it is not hard and mineralised like bone. White fibrocartilage has a matrix largely made of collagen bundles. It is therefore more like a firm but slightly deformable pad.
Deformability of white fibrocartilage allows a small degree of movement between the bones it joins. The movement mey be due to compression, stretching or even twisting (torsion) of the cartilage. This movement is in no way comparable to the more freely movable synovial joint.
In the vertebral column the bodies of the vertebrae are joined by white fibrocartilage discs (intervertebral discs). This allows only a small degree of movement between adjacent vertebrae. This has a functional advantage as the vertebral column encloses the delicate spinal cord. These small movements can, however, be added up over the length of the vertebral column.
In contrast a synchondrosis is a growth mechanism. Hyaline cartilage provides a mechanism for growth by the interstitial and appositional modes and is continuously replaced by bone during growth period of a bone. At the end of the growth period the cartilage stops growing and the last of it is replaced by bone. The two bones or parts of a bone thus are continuous with each other - this is called synostosis.

Notice that this essay links topics like the vertebral column, classification of joints, histology and function of cartilage and bone. Though it may not be off the mark to mention that the intervertebral disc has a notochordal remnant as the nucleus pulposus, one need not pay too much attention to this - this is not a feature of other symphyses.

In the pages that follow many more essay topics are discussed.