Neuronal Communication | OCR A-Level Biology A (H420)

Neuronal Communication

56 questions
5 subtopics
Module 5: Communication, homeostasis and energy
Component 01 and Component 03

Neuronal communication is the third section of Module 5.

It covers how a sensory receptor turns a stimulus into a generator potential, the types of neurone and why myelination speeds transmission, the resting and action potentials, and how an impulse crosses a synapse.

Sample questions from Neuronal Communication

Answer each one closed book first, then open the answer.

Sensory receptors and the Pacinian corpuscle

Describe the structure of a Pacinian corpuscle.

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It consists of a sensory nerve ending surrounded by layers of connective tissue called lamellae, which are separated by gel.
Sensory receptors and the Pacinian corpuscle

What type of ion channels open when the lamellae press on the nerve ending in a Pacinian corpuscle?

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Stretch-mediated sodium channels open.
Types of neurone and myelination

Describe the structural features of relay neurones.

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Relay neurones have short axons and many dendrites.
Types of neurone and myelination

What structures form the myelin sheath in myelinated neurones, and what are the gaps between them called?

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The myelin sheath is formed by Schwann cells wrapped around the axon, with gaps called nodes of Ranvier.
Resting potential and the action potential

What happens to voltage-gated Na⁺ channels when threshold is reached?

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Voltage-gated Na⁺ channels open.
Resting potential and the action potential

What is the effect of K⁺ leaving the axon during repolarisation?

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The membrane potential returns towards the resting level.
Transmission across a cholinergic synapse

What is the first event at the presynaptic knob when an impulse arrives at a cholinergic synapse?

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An action potential arrives at the presynaptic knob.
Transmission across a cholinergic synapse

What happens when acetylcholine binds to receptors on the postsynaptic membrane?

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Acetylcholine diffuses across the synaptic cleft and binds to specific receptors, causing ligand-gated sodium channels to open.

The 5 subtopics

One subtopic is one session. Work down the list.

Subtopic	What it covers	Questions
Sensory receptors and the Pacinian corpuscle	How a receptor converts one form of energy into another, and the lamellae, stretch-mediated sodium channels and generator potential of a Pacinian corpuscle.	8
Types of neurone and myelination	Sensory, relay and motor neurones and how each is built, the Schwann cells and nodes of Ranvier of a myelinated neurone, and saltatory conduction.	9
Resting potential and the action potential	The sodium-potassium pump and membrane permeability at rest, depolarisation, repolarisation and hyperpolarisation, the refractory period, and the all-or-nothing rule.	17
Transmission across a cholinergic synapse	Calcium entry at the presynaptic knob, the release and binding of acetylcholine, the sodium entry that follows, and the acetylcholinesterase that ends it.	12
Summation and inhibitory synapses	Spatial and temporal summation, the difference between excitatory and inhibitory synapses, and how a postsynaptic neurone decides whether to fire.	10

Neuronal Communication is 56 of the 1,833 questions in the guide.Get the guide, £8

How the guide is worked

Answering a question from memory stores it far better than reading the answer again. The guide runs that as a fixed procedure on one subtopic at a time, about twenty minutes a session.

Step 1 · Closed book
Cover the answers. Work through one subtopic and write down what you can. Leave blanks where you have nothing.
Step 2 · Open book
Go back to the top. Read each printed answer and write it out in full, including the ones you had right.
Step 3 · Closed book again
Same questions, same order, from memory. The gap between pass one and pass three is the session result.

Read the full method, the return schedule and the research behind it.