Synapse, also called neuronal junction, the site of transmission of electric nerve impulses between two nerve cells (neurons) or between a neuron and a gland or muscle cell (effector). A synaptic connection between a neuron and a muscle cell is called a neuromuscular junction.

Synapse is the answer bcoz small gap between two neurons where nerve impulse passes from one neuron to other in one direction is called synapse
Hope u will undersrand then upvote my answer

**Synapse: The Junction Between Two Neurons**

The correct answer is option 'D', synapse. Let's delve into the details to understand why this is the correct answer.

**What is a Synapse?**

A synapse is a specialized junction or connection between two neurons. It is the point where information is transmitted from one neuron to another. It allows for communication and signal transmission in the nervous system.

**Structure of a Synapse:**

A synapse consists of three main components:

1. **Presynaptic Neuron:** This is the neuron that sends the signal or message.

2. **Postsynaptic Neuron:** This is the neuron that receives the signal or message.

3. **Synaptic Cleft:** This is the small gap or space between the presynaptic and postsynaptic neurons.

**Working of a Synapse:**

When an electrical signal, known as an action potential, reaches the end of a presynaptic neuron, it triggers the release of neurotransmitters. Neurotransmitters are chemical messengers that carry the signal across the synapse.

The neurotransmitters are released into the synaptic cleft and travel across the gap. They then bind to specific receptors on the postsynaptic neuron. This binding process allows the signal to be transmitted from the presynaptic neuron to the postsynaptic neuron.

Once the signal is transmitted, the neurotransmitters are either broken down by enzymes or reabsorbed by the presynaptic neuron for future use.

**Importance of Synapses:**

Synapses play a crucial role in the functioning of the nervous system. They allow for the transmission of signals between neurons, enabling communication and coordination within the body. Without synapses, the nervous system would not be able to function properly.

**Other Options Explained:**

- Option 'A': Cell junction is a general term used to describe connections between cells, but it does not specifically refer to the junction between two neurons.

- Option 'B': Neuro muscular junction is a specialized synapse between a motor neuron and a muscle fiber. It is not the term used to describe the junction between two neurons.

- Option 'C': Neural joint is not a commonly used term in neuroscience and does not accurately describe the junction between two neurons.

Therefore, the correct answer is option 'D', synapse, as it specifically refers to the junction or connection between two neurons.