Log out Go to App
Go to App

Learning Materials

Features

Discover

Chapter 13: Problem 5

Explain transmission of a nerve signal across a synapse. (page \(281)\)

Short Answer

Expert verified
Nerve signal transmission across a synapse involves the following steps: an action potential travels along the presynaptic neuron and triggers the opening of voltage-gated calcium channels at the synaptic terminal. Calcium ions enter, causing vesicles to release neurotransmitters into the synaptic cleft. Neurotransmitters bind to specific receptors on the postsynaptic neuron, opening ion channels and generating an excitatory or inhibitory postsynaptic potential. If the threshold value is reached, an action potential is triggered in the postsynaptic neuron. Finally, neurotransmitters are removed from the synaptic cleft to terminate the signal transmission.

Step by step solution

01

Introduction to Nerve Signal Transmission

Nerve signal transmission is the process through which electrical signals are transmitted between nerve cells to facilitate communication within the nervous system. This involves a specialized junction called a synapse, which allows a signal to cross from one nerve cell to another.
02

Propagation of an Action Potential

When a nerve signal is initiated, an electrical charge called an action potential travels along the neuron's axon. The action potential is a result of depolarization and repolarization of the neuron's membrane due to the movement of ions (mainly sodium and potassium) through specialized protein channels.
03

Arrival at the Synaptic Terminal

Once the action potential reaches the synaptic terminal (axon terminal) of the presynaptic neuron, it triggers the opening of voltage-gated calcium channels. This allows calcium ions to enter the neuron.
04

Release of Neurotransmitters

The influx of calcium ions inside the synaptic terminal causes vesicles containing neurotransmitters (chemical messengers that transmit signals) to fuse with the plasma membrane. This results in the release of neurotransmitters from the presynaptic neuron into the synaptic cleft, a tiny gap between the two neurons.
05

Binding to Receptors

Neurotransmitters released into the synaptic cleft diffuse across the gap and bind to specific receptors on the postsynaptic neuron's dendrites. This binding generates a response in the postsynaptic neuron, either leading to excitation (depolarization) or inhibition (hyperpolarization) depending on the type of receptor and neurotransmitter involved.
06

Generation of a Postsynaptic Potential

Once neurotransmitters bind to their receptors, this opens ion channels on the postsynaptic neuron's membrane. The flow of ions generates either an excitatory postsynaptic potential (EPSP) or an inhibitory postsynaptic potential (IPSP), depending on whether the neuron is depolarized or hyperpolarized.
07

Integration and Propagation of the New Signal

If the postsynaptic neuron receives enough EPSPs to overcome the inhibitory effects of IPSPs, it will reach the threshold value that triggers an action potential in this neuron. This new action potential will then be propagated along the postsynaptic neuron, effectively allowing the nerve signal to cross the synapse and continue transmitting the signal to the next neuron or target cell.
08

Termination of the Signal at the Synapse

To terminate the signal transmission, the neurotransmitter molecules are removed from the synaptic cleft. This can be achieved through reuptake by the presynaptic neuron, degradation by enzymes, or diffusion away from the synapse. This process ensures that the signal does not continue to stimulate the postsynaptic neuron and helps maintain the sensitivity of synaptic connections. By understanding these steps, students will have a clear and comprehensive overview of how a nerve signal is transmitted across a synapse in the nervous system.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Start your free trial

Over 30 million students worldwide already upgrade their learning with Vaia!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

The neuroglial cells that form myelin sheaths in the PNS are a. oligodendrocytes. b. ganglionic cells. c. Schwann cells. d. astrocytes. e. microglia.

Which of these are the first and last elements in a spinal reflex? a. axon and dendrite b. sensory receptor and muscle effector c. ventral horn and dorsal horn d. brain and skeletal muscle e. motor neuron and sensory neuron

What type of neuron lies completely in the CNS? a. motor neuron b. interneuron c. sensory neuron

What types of nerves make up the PNS? How many of each type are there, and what areas of the body do each serve? \((\text { pages } 290-91)\)

Transmission of the nerve signal across a synapse is accomplished by the a. movement of \(\mathrm{Na}^{+}\) and \(\mathrm{K}^{+}\). b. release of a neurotransmitter by a dendrite. c. release of a neurotransmitter by an axon. d. release of a neurotransmitter by a cell body. e. All of these are correct.
See all solutions

Recommended explanations on Biology Textbooks

Ecological Levels

Read Explanation

Cell Communication

Read Explanation

Energy Transfers

Read Explanation

Cell Cycle

Read Explanation

Plant Biology

Read Explanation

Ecosystems

Read Explanation
View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.

Sign-up for free