In 4 or 5 sentences, describe the anatomy of the basic unit of the nervous system, the neuron. Include each part of the neuron and a general overview of electrical impulse conduction, the pathway it travels, and the net result at the termination of the impulse. Be specific and provide examples.

 

Neurons (neurones or nerve cells) are the fundamental units of the brain and the nervous system

which are responsible for receiving sensory input, sending motor commands to muscles, and

transforming and relaying the electrical signals over long distances within the body (Camprodon

& Roffman, 2016). A basic analogy of a neuron is to compare it to a tree. With three main parts:

dendrites, an axon, and a cell body or soma which may be represented as the branches, roots and

trunk of a tree, respectfully. Dendrites are responsible for receiving input from other cells, the

spines that branch out of a dendrite are the postsynaptic contact site, the axon is the transmitting

part of the neuron which action potentials are generated (Camprodon & Roffman, 2016). A

general electrical impulse is typically generated in the axon which sends active signals to

neurons. A nerve impulse travels along the neuron to the axon which causes the release of

neurotransmitters into the synapse, this release allows the neurons in each cell to communicate

(Camprodon & Roffman, 2016). For example, during an electrical impulse from the heart

muscle (myocardium) an electrical impulse begins in the sinoatrial (SA) node located at the top

of the right atrium, to the atrioventricular node (AV node) where impulses travel down the

conduction pathway via the bundle of His into the ventricles where the bundles of His divides

into two (right and left) pathways called the bundle branches to stimulate both ventricles

(National Heart, Lung, and Blood Institute (NIH), n.d.). Each contraction of the ventricles

represents one heartbeat.

2. Answer the following (listing is acceptable for these questions):

1. What are the major components that make up the subcortical structures?

Diencephalon, pituitary gland, limbic structures, and basal ganglia (Sonne,

2020).

2. Which component plays a role in learning, memory, and addiction?

Dopamine