NEET-Pattern Practice Questions

How to Use This Set

These 40 questions cover the whole of Neural Control and Coordination, in roughly the proportion the chapter itself gives each topic. Seven of them are coordination and the divisions of the neural system; seven are the neuron, its parts, its types and its two kinds of axon; five are the resting potential; six are the action potential and its conduction; six are the synapse; and nine - the largest single block - are the brain and its parts. That weighting follows the chapter. Three mechanisms and one address grid carry this chapter between them, and a student who can walk the resting potential, the action potential and the crossing of a chemical synapse as ordered lists, and read off which part of the brain controls what, has already earned most of what this chapter is worth.

Sit the whole set in one go, and look nothing up. Answer every question in order, and mark every question where you were choosing between two options rather than certain. Those marked questions, not only the wrong ones, are your revision list afterwards. Check the answers only at the end, and when you check, go back to the step list or the control-centre table rather than to the option - the fix for a wrong answer here is almost always a step you had put in the wrong place in the sequence, or a function you had filed under the neighbouring part of the brain.

The marking is +4 for a correct answer and -1 for a wrong one, and it is worth doing that arithmetic once. With four options and one of them right, a blind guess wins 4 marks once in every four attempts and loses 1 mark on the other three, so four blind guesses are worth about +1 mark between them - almost nothing, for four questions' worth of time. Cut the options down to two and the same four attempts are worth about +6. So the rule is not "never guess". It is never guess blind, and never spend time on a guess. On this chapter you can usually strike out at least one option at sight, because the wrong options are the other real parts of the chapter - the neighbouring part of the brain, the other real ion, the other real permeability state - and one of them will belong to a completely different division. When you can strike one out, take the guess, and take it quickly. If two brain parts still look alike after fifteen seconds, leave it blank and keep the minute.

These are exam-pattern practice questions built on the chapter's recurring core facts. They are not authenticated year-tagged previous-year papers.

Before You Start

Give yourself 40 minutes for the 40 questions.

Strip this chapter down and it is three ordered mechanisms and one address grid. The mechanisms are the resting potential, the action potential with its conduction, and the crossing of a chemical synapse. The address grid is the brain - which part controls what. Almost every item in this set is one step of a mechanism or one row of that grid, and the two halves reward completely different habits. The mechanism items reward knowing the sequence - what comes immediately before and immediately after the event named in the stem. The brain items reward knowing the address - which part, in which division, doing which job.

That has a direct consequence for pacing: most items should take 15 to 25 seconds, and anything that has not come in fifteen seconds is not coming by staring at it. A step you learnt in order arrives at once. Mark it, move, and come back only if minutes are left over. The exceptions are the sequence-ordering items and the match-the-column items, and those are worth a full minute each, because they can be worked out rather than recalled - fix one pairing you are sure of, strike out every option that disagrees with it, and the answer usually falls out from two pairings rather than four.

For an impulse item, walk the sequence and stop at the step the stem names. Do not scan the four options first. Start at the resting membrane and go forward - more permeable to $\mathrm{K^+}$ and nearly impermeable to $\mathrm{Na^+}$, gradients held by the pump at 3 $\mathrm{Na^+}$ out for 2 $\mathrm{K^+}$ in, outer surface positive, stimulus at site 'A', membrane freely permeable to $\mathrm{Na^+}$, rapid influx, polarity reversed, action potential, current inside from 'A' to 'B' and outside from 'B' to 'A', action potential at 'B', sodium permeability short-lived, potassium permeability rises, $\mathrm{K^+}$ out, resting potential restored - and take the step that fits. Each event happens once and in one place, so the first fit is the only fit.

For a synapse item, walk the six events of the chemical synapse in order. Impulse arrives at the axon terminal, vesicles move towards the membrane, vesicles fuse with the plasma membrane, neurotransmitters are released into the synaptic cleft, neurotransmitters bind to their specific receptors on the post-synaptic membrane, the binding opens ion channels and the entry of ions generates a new potential - and that new potential may be either excitatory or inhibitory. The binding comes before the channels open, and that ordering is exactly what a sequence item tests.

For a brain item, say the division before you say the part.

• Forebrain - cerebrum, thalamus, hypothalamus (and the limbic system in the inner parts of the hemispheres, with the amygdala and hippocampus).
• Midbrain - cerebral aqueduct, corpora quadrigemina (four round swellings).
• Hindbrain - pons, cerebellum, medulla.
• Brain stem - midbrain + pons + medulla oblongata, three regions, and the cerebellum is not one of them.

Two pairs break more answers than anything else in this chapter. Thalamus is the coordinating centre for sensory and motor signalling; hypothalamus holds the centres for body temperature, eating and drinking and the neurosecretory cells. Cerebellum handles balance and the semicircular-canal input; medulla holds respiration, cardiovascular reflexes and gastric secretions. A student who has those two pairs the right way round answers half the brain block without thinking.

Three more habits carry this set. 1. For a direction question, say the direction out loud before you look at the options - afferent is tissues to CNS, dendrites carry towards the cell body, axons carry away from it, and the paper will offer you the reverse of each. 2. For a count question, say what is being counted before you look at the number - 12 pairs is cranial nerves, 31 pairs is spinal nerves, 3 is the meninges, 4 is the corpora quadrigemina, and the paper will offer you all four in the same list.

3. For a comparison question, say the odd row first - an electrical synapse is ALWAYS faster than a chemical one and yet is RARE in our system, and that single row settles most of the synapse items on its own.