Synaptic Transmission

Q.

Explain how transmission of nerve impulse takes place.

Q. Assertion: Impulse transmission across an electrical synapse is always faster than that across a chemical synapse.
Reason: The synaptic cleft in electrical synapsis is only 0.2 nm

1. Assertion is true but the reason is false
2. Reason is true but the assertion is false
3. Both the assertion and reason are true and the reason is the correct explanation for the assertion
4. Both the assertion and reason are true but the reason is not the correct explanation for the assertion

Q.

The electrical impulse travels in a neuron from

1. Dendrite → axon → axonal end → cell body

2. Cell body → dendrite → axon → axonal end

3. Dendrite → cell body → axon → axonal end

4. Axonal end → axon → cell body → dendrite

Q.

Give a brief account of:

(a) Mechanism of synaptic transmission

(b) Mechanism of vision

(c) Mechanism of hearing

Q. Impulse transmission across an electrical synapse compared to chemical synapse is always:

1. Faster
2. Slower
3. Intermittent
4. Continuous

Q. Describe the major events occurring during the transmission of nerve impulse

Q. Impulse transmission across chemical synapse is _________ across an electrical synapse.

1. faster than that
2. equal to that
3. none of the above
4. slower than that

Q.

Into what does the neuron release its neurotransmitter at the neuromuscular junction?

1. cisternae

2. motor end plate

3. cytoplasm of the muscle cell

4. synaptic cleft

Q.

Where do Axons transmit nerve impulses to?

Q.

Give a brief account of :

(a) Mechanism of synaptic transmission

(b) Mechanism of vision

(c) Mechanism of hearing

Q. Which of the following is incorrect about electrical synapses?

1. The synaptic cleft is only 0.2 nm.
2. Electrical synapses are abundant in our system.
3. Impulse transmission through an electrical synapse is faster than chemical synapses.
4. All of the above are correct

Q. Explain the process of the transport and release of a neurotransmitter with the help of a labelled diagram showing a complete neuron, axon terminal and synapse.

Q.

Explain the following:

(a) Role of Na⁺ in the generation of action potential.

(b) Mechanism of generation of light-induced impulse in the retina.

(c) Mechanism through which a sound produces a nerve impulse in the

inner ear.

Q. A diagram showing axon terminal and synapse is given. Identify correctly at least two of A-D.

1. A-Receptor; C-Synaptic vesicles
2. B-Synaptic connection; $D-K^{+}$
3. A-Neurotransmitter; B-Synaptic cleft
4. C-Neurotransmitter; $D-C{a}^{++}$

Q. A diagram showing the axon terminal and synapse is given. Identify correctly at least two of A - D.

1. C - Neurotransmitter; D - $C{a}^{++}$
2. B - Synaptic connection; D - $K^{+}$
3. A - Receptor; C - Synaptic vesicles
4. A - Neurotransmitter; B- Synaptic cleft

Q.

What are brain waves?

Q. The figure below shows events of nerve impulse conduction. Select the option giving correct identification together what it represents?

1. Figure [A] – Site (a) is showing repolarisation
2. Figure [B] – Site (c) is showing hyper polarisation
3. Figure [A] & [B] – Site (a) is showing depolarization
4. Figure [B] – Site (a) is in refractory period

Q. Which of the following is not matched correctly?

1. Auditory canal - directs sound wave to ear drum
2. Eardrum - vibrates and tranmits sound waves
3. Cochlea - helps in body balance
4. Ear ossicles - amplify sound waves

Q.

What is the difference between electrical transmission and chemical transmission?

Q. The junction of an axon and dendrite is called______.

1. Synapse
2. Relay
3. Conduction zone
4. Cyton

Q. How does cocaine act as a neuronal stimulant?

1. Cocaine binds to the neurotransmitter receptor and causes stimulation of the postsynaptic membrane.
2. Cocaine binds to the neurotransmitter and makes it a stimulant
3. Cocaine stops the release of dopamine and therefore neurons release a different stimulant.
4. Cocaine prevents reuptake of dopamine, increasing the dopamine activity in the synaptic cleft.

Q.

Briefly describe the structure of the following:

1. Brain (b) Eye (c) Ear

Q. A diagram showing axon terminal and synapse is given. Identify correctly at least two of A-D.

1. B-Synaptic connection; $D-K^{+}$
2. C-Neurotransmitter; $D-C{a}^{++}$
3. A-Receptor; C-Synaptic vesicles
4. A-Neurotransmitter; B-Synaptic cleft

Q.

Which one of the following is the correct sequence of events that follows in a synaptic transmission of nerve impulse?

1. Calcium enters the synaptic knob.
2. The neurotransmitter binds to the receptor proteins on the postsynaptic membrane.
3. Release of synaptic vesicles.
4. The presynaptic membrane is depolarized.
5. The neurotransmitter diffuses across the synaptic cleft.
6. Voltage gated calcium channels open.

1. 2$\to$ 1 $\to$ 4 $\to$ 3 $\to$6 $\to$ 5

2. 5 $\to$ 6 $\to$ 3 $\to$ 2 $\to$4 $\to$ 1

3. 1 $\to$ 2 $\to$ 3 $\to$ 4 $\to$ 5 $\to$ 6

4. 4 $\to$ 6 $\to$ 3 $\to$ 1 $\to$ 5 $\to$ 2

Q. Mineral forming $90$% of the cations of blood plasma is

1. $Mg$
2. $K$
3. $Ca$
4. $Na$

Q.
Transmission of a nerve impulse is unidirectional. Give reasons.

Q. Describe in detail the mechanism of hearing.

Q. During synaptic transmission of nerve impulse, a neurotransmitter (P) is released from synaptic vesicles by the action of ions (Q). Choose the correct P and Q

1. P - acetylcholine, Q - $C{a}^{2+}$
2. P - acetylcholine, Q - $N{a}^{+}$
3. P - GABA, Q - $N{a}^{+}$
4. P - cholinesterase, Q - $C{a}^{2+}$

Q. Cocaine interferes with transportation of which of the following neurotransmitter?

1. Serotonin
2. Dopamine
3. Acetylchotine
4. Epiniphrine

Q. Cocaine interferes with transportation of neurotransmitter _________.

1. Serotonin
2. Dopamine
3. Epinephrine
4. Acetylchotine