The director and regulator of all the body activities whether small or big is nervous system. The main and major functions of nervous system are control and communication. The nervous system is built from two main cells which are named as neuron and neuroglia. The neuron is considered to be the structural and functional unit of the nervous system. These cells are specialized to respond to chemical and physical stimuli and to carry and transfer messages all over the body. Normally a human brain can direct more than 10 billion neurons at all the times. Each neuron has three portions; namely, a cell body, an axon, and numerous dendrites. Axon and dendrites are collectively called as processes of a neuron. Based on the different shapes and functions of the neurons, there are three categories of neurons; namely, afferent neurons, interneurons, and efferent neurons. These three types have various characteristic features and functions.
The task of afferent neurons is to transfer sensory information such as nerve impulse towards the brain from the periphery of the human body. Sensory neurons also known as afferent neurons are the special cells that allow carrying nerve impulse to the central nervous system from all the parts of the body. These types of sensory neurons are activated by physical modalities such as light, sound, temperature etc. These kinds of cells consists sensory receptors located on their cell membrane and are capable of transforming stimuli into electronic nerve impulses. These neurons are generally pseudo unipolar neurons that consist of a single long dendrite and a short axon. The body structure of the cell are smooth, round shaped and are present in the peripheral nervous system. Their axons travel from ganglion, to ganglion and lead back to the spinal cord. Single long myelinated dendrite is same as an axon and is responsible for conducting sensory information or nerve impulse from sensory receptors to its cell body.
These type of neurons are also known as motor neurons and they are found inside the central nervous systems (in the grey matter of spinal cord and medulla oblongata) the function of these neurons is to receive information from other neurons and transmitting nerve impulse to the periphery of the body such as muscles, glands etc. the structure of the cell in satellite in shape and it is connected to a long axon and few shorter dendrites. The axon forms a neuromuscular junction with the effectors. The impulse enters via dendrites and leaves it through the single axon to the other end.
What is the difference between Afferent and Efferent Neuron?
- The function of afferent neurons is to receive and transmit messages to the central nervous system from all parts of the body. While on the other hand the function of efferent neurons is to receive and transmit the information from the central nervous system to all parts of the body.
- Afferent neurons are also known as sensory neurons while efferent neurons are called as motor neurons.
- Afferent neurons begins with a receptor efferent ends with effector.
- Efferent neurons has short dendrite and long axon while afferent has long dendrite and short axon .
- Afferent neurons cell body is at the side of the while efferent cells are the end.