Motor Neurons Location Structure and Function

being the most basic units of the human

nervous system neurons play a vital role

in sensing and responding to different

external as well as internal stimuli a

motor neuron is one of the three types

of neurons involved in this process read

about the structure and function of a

motor neuron with reference to a neatly

labeled diagram in this Buzzle post

motor neuron disease MND a motor neuron

disease affects the normal functioning

of motor neurons resulting in their

degeneration and death this leads to

muscle weakness and atrophy to such an

extent that basic voluntary muscle

activity like speaking swallowing and

breathing is largely affected let's

begin with the definition of a motor

neuron a motor neuron is basically a

nerve cell whose function is to respond

to sensory stimulation by producing the

required muscular movement motor neurons

are located in the spinal cord and their

axon protrudes outside to the muscle

fibers the functions of motor neurons

are linked to the cerebral cortex of the

brain however in case of reflexes it is

the spinal cord that ensures quick and

responsive motor functioning for

instance when one places his or her hand

over a flame the sensory neurons carry

the stimulus of pain to the motor

neurons via the neural network

interneurons if this stimulus was to go

to the brain and then returned with an

analyzed response the person's hand

would keep burning till the motor neuron

functioned therefore situations which

require an immediate response like

quickly withdrawing the hand as in the

previous example the motor functioning

is coordinated by the spinal cord as of

now you should have got the basic idea

of what exactly a motor neuron is let's

dive a bit deeper into the functioning

of motor neurons as we refer to a neatly

labeled diagram

structure function and location of motor

neurons structure all motor neurons are

multi polar neurons a multipolar neuron

has only one axon and densely branched

dendrites the axon in most cases is

usually long especially in case of motor

neurons as their terminals need to

extend to the muscle fibers to function

correctly as motor neurons are the

fundamental units of our body's response

mechanism they need to be very sensitive

to incoming neural messages this is the

reason that these neurons are multipolar

there several extending dendrites sense

even the weakest signal transmitted and

coordinate muscle movement accordingly

function their functions classify them

into three types somatic motor neurons

general visceral motor neurons and

special visceral motor neurons let's

discuss the respective functions of each

of the three the somatic neurons stem

from the central nervous and are

connected to the skeletal muscles which

are responsible for locomotion or

movement some skeletal muscles include

intercostal muscles thigh and limb

muscles are muscles and several others

which help in the movement of bones and

support the skeleton visceral neurons

are specifically designed to stimulate

organ related muscles the special

visceral neurons control the bronchial

marek muscles bronchial marek muscles

are basically muscles of the face and

neck the general visceral neurons

stimulate cardiac muscles smooth

visceral muscles and also certain gland

cells now take a look at the diagrams

given below neural response mechanism

reflexes above Illustrated is the basic

functioning of the three different types

of neurons to produce a response when

the body receives the stimulation the

receptor slash sensory neurons in the

affected area are innervated they

transmit the impulse to the motor

neurons in order to trigger a response

sensory and motor neurons are connected

by several into neurons once the impulse

reaches the lower motor neurons via

interneurons the lower motor neurons as

per the type of stimulation would either

transmit the impulse further to upper

motor neurons or directly communicate

with the affected muscle fibers the

latter is more evident in case an urgent

response is required reflexes when you

are pricked by a thorn your body would

in normal circumstances follow this

process resulting in withdrawal of the

affected portion arm in this case


motor neurons also foster several basic

voluntary functions like walking

swallowing speaking breathing etcetera

location motor neurons according to

location can be classified into two main

types upper motor neurons and lower

motor neurons both function and unison

to carry out motor operations the upper

motor neurons are either located in the

cerebral cortex of the brain or the

brainstem whereas the lower motor

neurons are located in the spinal cord

and their terminals extend all the way

to the muscle fibers and tendons

when complex motor operations are

required the lower motor neurons consult

the upper motor neurons and both work in

union to provide a meaningful response

upper motor neurons are often consulted

in case of voluntary motor responses

this is because voluntary actions are

backed by thoughts for instance you

don't walk just because you have to you

walk in the direction you wish to go

hence the motor neurons of the brain

have to be consulted in order to acquire

coordination between thought and action

in case of reflexes the nervous system

has an automatic response mechanism

hence the responses in this case are

quicker than the former as there is no

involvement of upper neurons our body is

conditioned in such a way that in case a

part of our body is affected or harmed

we tend to pull it or contract it away

from the threat for example when a boxer

hits his opponent in the abdominal area

the affected area is automatically

contracted or pulled inward to avoid

more harm to put the whole thing in a

nutshell we can say that motor neuron

located in the cerebral cortex and

spinal cord are the output of the

stimulus response mechanism as they are

the ones which initiate muscular

movement as per the received sensory