Synaptic Transmission

Q.

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

1. The presynaptic membrane is depolarized.

2. Voltage gated calcium channels open

3. Release of synaptic Vesicles

4. Calcium enters the synaptic knob

5. The neurotransmitter diffuses across the synaptic cleft and binds to the receptor proteins on the postsynaptic membrane.

1. 2, 1, 4, 3

2. 3, 2, 4, 1

3. 1, 2, 3, 4

4. 4, 1, 3, 2

Q. Question 21
Which of the following statements about transmission of nerve impulse is incorrect?

(a) Nerve impulse travels from dendritic end towards axonal end.
(b) At the dendritic end electrical impulses bring about the release of some chemicals which generate an electrical impulse at the axonal end of another neuron.
(c) The chemicals released from the axonal end of one neuron cross the synapse and generate a similar electrical impulse in a dendrite of another neuron.
(d) A neuron transmits electrical impulses not only to another neuron but also to muscle and gland cells.

Q.

What is the correct order of nerve impulse conduction through nerve fibre?

1. [repolarisation] => [resting] => [depolarisation]

2. [resting] => [repolarisation] => [depolarisation]

3. [repolarisation] => [depolarisation]

4. [resting] => [depolarisation] => [repolarisation]

Q.

Which structure in a neuron helps to conduct a nerve impulses towards the cell body and away from the cell body

Q.

Unidirectional transmission of a nerve impulse through neuron is due to the fact that

1. The neuron is insulated by a medullary sheath

2. Sodium pump starts operating only at the cyton and then continues into the nerve fibre

3. Neurotransmitters are released by dendrites and not by axon endings

4. Neurotransmitters are released by the axon endings and not by dendrites.

Q.

The nerve impulse in nerve fibre is conducted when permeability increases mainly of

1. Chloride ions

2. Potassium ions

3. Sodium ions

4. Calcium ions

Q.

Question 25
What is the correct direction of flow of electrical impulses?

Q.

Gap present between the terminal branches of axon of one neuron and the dendrites of the next neuron.

Enter 2 words or less.

Q. Impulses travels rapidly in ____________ neurons.
[Review question: Pg. No: 227]

1. Myelinated neurons
2. Non myelinated nephrons
3. Non myelinated neurons
4. All the above

Q.

Nerve impulse travel at about $100m/s.$ If a woman $1.8m$ tall steps on a drawing pin.
a) Roughly how long is it before she knows about it?
b) If she is walking along at a speed of $2m/s$ , how far will she have traveled in this time?

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 - cholinesterase, Q - $C{a}^{2+}$

4. P - GABA, Q - $N{a}^{+}$

Q. How does action potential propagate in neuron?

Q. Transmission of impulse across synapse takes place by

1. electrical impulse
2. neurotransmitter
3. mechanical means
4. high jump

Q.

During the propagation of a nerve impulse, the action potential results from the movement of ______.

1. K+ ions from intracellular fluid to extra cellular fluid

2. Na+ ions from extra cellular fluid to intra cellular fluid

3. Na+ ions from intra cellular fluid to extra cellular fluid

4. K+ ion from extra cellular fluid to intra cellular fluid

Q.

Note the relationship between the first two words and suggest as word for the fourth place.

Cones:iodopsin::rods:_______

Q. Read the following statements about the transmission of nerve impulse and select the correct ones.
(i) In a neuron, nerve impulse travels from the axonal
end to the dendritic end as:
Axonal end ->Axon-> Cell body-> Dendritic end
(ii) The chemicals released from the axonal end of one neuron cross the synapse and generate a similar electrical impulse in the dendrite of another neuron.
(iii) A neuron transmits the nerve impulses not only to another neuron but also to the muscle cells and gland cells.
(iv) The neurotransmitter released at the post-synaptic membrane, diffuses across the synapse and comes into contact with the chemoreceptor sites in the pre-synaptic membrane.

1. (ii) and (iii) only
2. (i) and (iv) only
3. (iii) and (iv) only
4. (i) and (ii) only

Q.

Impulses travel much more rapidly along the myelinated nerve.

1. True
2. False

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. In which direction the nerve impulse is carried in a nerve cell?

Q.

what is the importance of a synapse?

why does cyton lack a centrosome?

Q. Assertion :The chemicals stored in the synaptic vesicles are termed as neurotransmitters. Reason: Synaptic vesicles release these chemicals in the synaptic cleft.

1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion.
2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion.
3. Assertion is correct but Reason is incorrect.
4. Assertion is incorrect but Reason is correct.

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. Anaphylactic shock is caused due to the release of which of the following hormone?

1. Adrenalin
2. Histamine
3. Glucagon
4. Somatostatin

Q. Which of the following releases neurotransmitters to cross the synapse?

1. Dendrites
2. Axons
3. Cell bodies
4. All of the above
5. None of the above

Q. How does cocaine act as a neuronal stimulant?

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

Q. How does cocaine act as a neuronal stimulant?

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

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

Q.

Fill in the correct sequence for generation of Action potential in a neuron

Stimulus ⟶ Inflow of $N{a}^{+}$ ions ⟶ (i) ⟶ Repolarisation ⟶ (ii)

1. Inflow of Na+ ions Transmission of Na+

2. Transmission of Na+ Inflow of Na+ ions

3. Transmission of Na+ & K+ Hyperpolarization & RMP

4. Hyperpolarization Inflow of Na+ ions