Problem 9 Describe the events that occur a... [FREE SOLUTION] (2024)

Short Answer

Neural Impulse

A neural impulse, also known as an action potential, is the way nerve cells communicate. It is a brief electrical charge that travels down the axon of a neuron. This process begins when the neuron receives a sufficient stimulus, causing a change in electrical charge across its membrane.
Neurons maintain a resting membrane potential due to differences in ion concentrations inside and outside the cell. When an action potential happens, there is a rapid depolarization of the membrane.
The change in electrical charge along the neuron helps transmit signals quickly along the nervous system. When this impulse reaches the end of the neuron, it causes various events in the synaptic terminal, leading to neurotransmitter release.

Synaptic Terminal

The synaptic terminal is the endpoint of a neuron where the communication with another cell occurs. It's packed with synaptic vesicles, which are tiny sacs containing neurotransmitters—the chemicals responsible for transmitting signals across the synapse.
When a neural impulse reaches the synaptic terminal, it plays a crucial role in converting the electrical signal into a chemical signal. This conversion is essential for the communication between neurons and between neurons and other types of cells.
The presynaptic membrane of the synaptic terminal is responsible for the release of neurotransmitters into the synaptic cleft, a small gap separating the presynaptic neuron from the postsynaptic cell.

Neurotransmitter Release

Neurotransmitter release is a key event that occurs after a neural impulse arrives at the synaptic terminal. The arrival of the action potential causes depolarization of the presynaptic membrane, leading to the opening of voltage-gated calcium channels.
Calcium ions (Ca²⁺) flow into the presynaptic cell, which is the driving force behind the synaptic vesicles merging with the membrane. This process, known as vesicle fusion, releases neurotransmitters into the synaptic cleft.
Released neurotransmitters then diffuse across the synaptic cleft and bind to receptors on the membrane of the postsynaptic cell, triggering further cellular responses.

Calcium Channels