Correct Option: B. Dendrite Explanation of the Correct Answer Neurons are specialized cells in the nervous system that transmit information throughout the body. They consist of several key parts, each with distinct functions. The part of the neuron that is primarily responsible for receiving signals from other neurons is the dendrite.

1. Structure of Dendrites: Dendrites are tree-like extensions that branch out from the cell body of the neuron. They have many synaptic receptors on their surface, which are designed to receive neurotransmitters released by other neurons. This structure increases the surface area available for receiving signals, allowing a neuron to connect with multiple other neurons.
2. Function of Dendrites: When a neurotransmitter binds to a receptor on a dendrite, it can cause a change in the electrical state of the neuron. This change is known as a postsynaptic potential. If the signal is strong enough, it can lead to the generation of an action potential, which is an electrical impulse that travels down the axon to communicate with other neurons or muscles.
3. Signal Integration: Dendrites play a crucial role in integrating signals from various sources. A single neuron can receive inputs from thousands of other neurons through its dendrites, allowing it to process complex information and respond appropriately.

Why the Other Options are Incorrect

• A. Axon: The axon is the long, slender projection of a neuron that conducts electrical impulses away from the cell body to other neurons or muscles. While the axon is essential for transmitting signals, it is not involved in receiving signals. Instead, it is responsible for sending the action potential generated in the neuron to its target.
• C. Cell Body: The cell body (or soma) contains the nucleus and organelles of the neuron. It is responsible for maintaining the cell's health and processing the information received from the dendrites. However, it does not directly receive signals from other neurons; that function is primarily performed by the dendrites.
• D. Synapse: The synapse is the junction between two neurons where communication occurs. It is the site where neurotransmitters are released from the axon terminal of one neuron and bind to the receptors on the dendrites of another neuron. While the synapse is crucial for signal transmission, it is not a part of the neuron that receives signals; rather, it is the location where the signal transfer occurs.

Summary of Key Points

• Dendrites are the primary structures responsible for receiving signals from other neurons.
• They have a large surface area and numerous receptors to facilitate the reception of neurotransmitters.
• The axon transmits signals away from the neuron, while the cell body processes information and maintains cell health.
• The synapse is the site of communication between neurons but does not receive signals itself.

Revision Summary

• Dendrites are the parts of neurons that receive signals from other neurons.
• They have many receptors for neurotransmitters, allowing for effective signal reception.
• Axons transmit signals away from the neuron, while cell bodies process information.
• Synapses are the junctions where signal transmission occurs, not where signals are received.