Question

A neuron has three main parts: dendrites, cell body, and axon. A neuron may send signals to other neuron or other tissues (effectors). Describe the physiology of how the signal moves from one point to the other and the other organ or tissue responds.

Answer 1

✓Dendrites (from Greek means "tree"), also dendrons, are branched protoplasmic extensions of a nerve cell that propagate the electrochemical stimulation received from other neural cells to the cell body, or soma, of the neuron from which the dendrites project.

✓The cell body is the spherical part of the neuron that contains the nucleus and connects to the dendrites, which bring information into the neuron, and the axon, which sends information to other neurons. The job of the cell body is to control all of the functions of the cell.

✓the long threadlike part of a nerve cell along which impulses are conducted from the cell body to other cells.

Signals neuron to another neuron :

The place where the axon of one neuron meets the dendrite of another is called a synapse. ... Neurotransmitters travel across the synapse between the axon and the dendrite of the next neuron. Neurotransmitters bind to the membrane of the dendrite. The binding allows the nerve impulse to travel through the receiving neuron.

When neurons communicate, an electrical impulse triggers the release of neurotransmitters
from the axon into the synapse. The neurotransmitters cross the synapse and bind to special molecules on the other side, called receptors. Receptors are located on the dendrites. Receptors receive and process the message.

What’s particularly interesting about neurotransmission is that each neurotransmitter
can bind only to a very specific matching receptor. A neurotransmitter binds to a receptor in much the same way a key fits into a lock. After transmission has occurred, the neurotransmitter is either broken down by an enzyme (a chemical that speeds up some of
the body’s processes) or is reabsorbed into the neuron that released it. The reabsorbed neurotransmitters can be reused at a later time.

Signals one point to another point : organ, tissue

Your brain is a hotbed of electrochemical activity. About 100 billion neurons are each firing off 5-50 messages (action potentials) per second. This activity allows you to process your environment, move your muscles, and even keep your balance! If you touch something slimy, that information goes from your fingertips to your brain, and then your brain says “eww, no!” and sends information to your fingertips telling them to move away. The same thing happens when you trip and you’re about to fall, or a bright light flashes in your eyes. Your brain receives information about where you are in space, or the brightness of the light, and responds accordingly. And it’s in our best interests that this action-reaction process goes quickly – so that we can catch ourselves as we fall, or shut our eyes tight. The process of sending these signals takes place in two steps: along the cell (action potential) and between cells (neurotransmitters).