How does the motor neuron work?

Motor neurons play a critical role in our body’s ability to move. They carry messages from the brain and spinal cord to muscles throughout the body, telling them when and how to contract. But how do these fascinating cells work? And what happens when they don’t function correctly? Buckle up, folks – we’re about to dive into the world of motor neurons!

The Basics: What Are Motor Neurons?

Let’s start with some definitions (yawn). Motor neurons are a type of nerve cell that reside in our central nervous system (that fancy part of your body containing your brain and spinal cord). Their primary function is to send signals (or impulses) that instruct muscle fibers on when and how much to contract or relax.

Sounds simple enough, right? Well, it gets even more complicated (oh boy!). There are actually two types of motor neurons: upper motor neurons and lower motor neurons. Upper motor neurons come from the cerebral cortex in our brains while lower ones originate from either the anterior horn cells within our spine or brainstem nuclei.

It All Starts with Electrical Signals

So, let’s get technical for a minute. Have you ever heard of an action potential? Yeah… me neither until I did some research for this article (wink wink). An action potential is essentially an electrical signal that travels along a neuron (including those lovely little motor ones we’re talking about).

When an action potential reaches a junction called synapse between one neuron and another (the say what?!), it triggers tiny vesicles (“tiny” referring purely relative here) full of neurotransmitters contained by motor neuron terminal/s which release their goods across tiny gaps known as gap junctions onto other nerves’ dendrites — thereby generating another electrical impulse….aaaaand exhale.

Never Heard Of Neurotransmitters Before?

Here’s where it gets even more fun (not sarcasm, I swear). Neurotransmitters are small chemicals that act as messengers between neurons. When an action potential reaches the motor neuron terminal, it signals for the release of neurotransmitters (like dopamine or serotonin) into the gap junctions.

And this is where things get really cool (finally!). Depending on which neurotransmitter is released and which muscle it’s targeting, a different response will occur. For example, if your motor neuron releases acetylcholine (remember THAT for trivia night), your muscles will contract… but if it releases something like norepinephrine instead (what?!) then they’ll relax instead!

Why Do We Even Need Motor Neurons?

Well folks (drum roll please) without them we’d be statues — unable to move an inch. Simple body movements such as walking, running or waving to someone couldn’t happen without our motor neurons operating as they should.

Each time we initiate movement by making the conscious decision in our brain – “let’s go dancing!”, somehow your nerves carry out what seems like magic compelling muscles throughout your legs and arms.. all by sending electrical patterns through bunches of cells called neurons with long tubes sticking out from them known as dendrites until finally reaching down towards motor neuronal cell bodies found in you guessed it—the anterior horn-of spinal cord/places within nuclei of certain glands).

It all comes full circle when motor-neuron-axons, those nerve fibers extending from lower motor neuronal cell bodies connect directly via synapses onto nearby muscle fibers; stimulating their simultaneous contractions signaling a particular movement/action/sensation/response/disturbance/ result…

The Pathway To Movement: Upper & Lower Motor Neurons

How does this whole process start? Well my friend (patting on shoulder), when you decide to wiggle those toes inside your shoes there’s quite a bit going on underneath the hood (aka in your central nervous system). It starts with upper motor neurons, located in the cortex of our brains:

  1. The Cortex sends a signal down to…
  2. Lower motor neuron cell bodies
  3. Upper Motor neurons could also possibly send signals towards the brainstem nuclei connecting directly onto alpha-motor-neurons
  4. Alpha-motor-neuronal axons extend out from anterior horn cells and terminates on muscle fibers triggering contractions.

Note that there are several steps involved and all must occur for movement to take place!

Muscle Atrophy

So what happens when this process doesn’t work? Answer: muscle atrophy! “Oh no not atrophying muscles” – I hear you cry (sympathy please).

Muscles will start wasting away if their corresponding lower motor neurons fail to receive or respond appropriately to those electrical impulses traveling down from higher levels within spinal cord beginning its journey up elsewhere such as via corticospinal tract.

In some instances (such as spinal injuries), one’s ability may be compromised likely resulting in reduced functionality unless they undergo serious therapeutic measures designed specifically to enhance neuromuscular pathways so folks can continue working through life’s movements without difficulty ranging across subtle neurocomplexities…

Let’s Wrap Things Up

Whew, glad we made it! As we’ve seen today (sip water) , motor neurons play an integral role in everything from our everyday movements (throws arms dramatically around )to more complex actions like playing music or holding a tool steady while fixing something (seriously impressive stuff).

By sending electrical impulses down specific pathways between nerves, neurotransmitters released into synapses — all while communicating with your muscles by contracting/relaxing as necessary– these incredible little cells accomplish feats most of us could only dream about doing ourselves every day right within your own body.(applauds)

So, if someone ever asks you how motor neurons work, just smile, take a deep breath and begin recounting this article – from action potentials and neurotransmitters to atrophy-inducing impulses. Because who doesn’t love impressing people with their scientific knowledge (and let’s not forget humor) (winks)!

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