Afferent vs. Efferent neurons both connect the central nervous system, so a signal transmission pathway can be produced to coordinate function in the body. The central nervous system consists of the brain and spinal cord. The main difference between afferent and efferent neurons is that afferent neurons carry signals from a sensory perception of the Central Nervous system, while efferent neurons carry signals from the central nervous system to the effector organs.
Let’s take a closer look at efferent versus afferent
| Known As | Afferent is known as sensory neurons, while efferent as motor neurons |
| Receptor | Afferent has receptor while efferent does not |
| Axon | Efferent has longer axon than afferent |
| Dendrons | Efferent has a larger number of dendrons |
Table of Contents
What Is Afferent?
If we look at the afferent meaning, it refers to the neurons which carry the signals toward the central nervous system. The main function of the afferent neurons is to convert the external stimuli into the internal electric impulse, which travels along with the afferent nerve fiber until it reaches the central nervous system. Sensory perception, like smell, taste, light, hearing and touch, comes from the nose, tongue, eyes, ears and skin and provides the information to afferent neurons. For example, in the case of light, the sensory signals are gathered from the cone cells and rod of the eye’s retina, and then these nerve impulses are carried by the efferent neurons of the eyes to the brain. On the other hand, the afferent neurons of the nose are stimulated by smell, and they carry the nerve impulse to the brain.
What Is Efferent?
If we look at the efferent meaning, it refers to the neurons which carry away signals from the central nervous system towards the effector organs. This action of efferent neurons facilitates substance secretion from glands and muscle contraction. Efferent neurons only consist of one large axon, which makes a neuromuscular junction with the effector organs. Efferent neurons are divided further into different types, like general visceral efferent neurons, special visceral efferent neurons and somatic efferent neurons. There are further types of somatic neurons, alpha motor neurons and beta motor neurons. All these neurons help in carrying signals to the organs. For example, if a person is walking on the road and sees a bike coming towards him, he will suddenly jump on the side or make a side immediately. That is because efferent neurons immediately carry signals from the brain to the leg muscles to move out of the way.
6 Key Differences Between Afferent and Efferent Neurons
| Components | Afferent | Efferent |
|---|---|---|
| Definition | Afferent are neurons which carry the signals toward the central nervous system. These neurons convert the external stimuli into internal electric impulses, which travel along with the afferent nerve fiber until it reaches the central nervous system. | Efferent refers to the neurons which carry away signals from the central nervous system towards the effector organs. This action of efferent neurons facilitates substance secretion from glands and muscle contraction. |
| Contain | Afferents contain multiple short axons and receptors with a long dendron | Efferent neurons contain only one long axon, with numerous short dendrons |
| Location | Afferent neurons are present outside of the central nervous system | Efferent neurons are present inside the central nervous system |
| Cell Body | The cell body of afferent neurons is of smooth and round shape; it is situated in the dorsal root ganglion of the spinal cord. | The efferent cell body has a satellite-like shape and is situated in the ventral root ganglion of the spinal cord. |
| Main Function | The main function of afferent neurons is to carry signals from different body organs to the Central nervous system. | The main function of efferent neurons is to transfer the signals from the brain to different body organs. |
| Present In | These are present in the nose, tongue, ear and skin | These are present in muscles and glands |
Afferent vs. Efferent Similarities
- Whether it’s afferent or efferent neurons, both belong to the peripheral nervous system.
- Both of these neurons consist of dendrons, cell bodies and dendrites.
Afferent vs. Efferent Examples
Afferent Examples
- In light: the sensory signals are gathered from the cone cells and rod of the eye’s retina, and then these nerve impulses are carried by the efferent neurons of the eyes to the brain.
- In smell: afferent neurons of the nose are stimulated by smell, and they carry the nerve impulse to the brain.
Efferent Examples
- If a person is walking on the road and sees a bike coming towards him, he will suddenly jump on the side or make a side immediately. It is because of efferent neurons
- If a person accidentally puts his hand on the stove and immediately removes it or turns off the stove, that is because his efferent neurons send signals to his hand.
Afferent vs. Efferent Pros and Cons
Afferent Pros and Cons
Pros of Afferent
- Afferent neurons are responsible for carrying all the sensory signals from the outside world to the brain
- These neurons are responsible for our senses, like smell, taste, touch and hearing, to work properly.
Cons of Afferent
- Dysfunction of afferent neurons can result in dysfunctional organs due to the loss of sensory impulses transmission from those organs.
- If afferent neurons get damaged, it can interfere with the ability of the brain to communicate with other muscles and organs, resulting in a loss of sensory and motor function.
Efferent Pros and Cons
Pros of Efferent
- Efferent neurons are responsible for initiating the action or telling the body when to perform certainly.
- Efferent neurons are the one which helps the organs to prevent from getting damaged in serious condition like removing a hand from a burning pan.
Cons of Efferent
- In efferent dysfunction, the organs cannot move properly as the signals won’t be transmitted to those.
- If efferent neurons are not working properly, the brain won’t get notifications from sensory organs.
Comparison Chart
Comparison Video
Conclusion
Afferent and efferent are two of the main components of the peripheral nervous system. Both of these carry signals with them. If we look at afferent vs efferent differences, both are different in structure, size and function. The afferent neurons carry signals from organs to the brain while efferent from the brain to the different organs. Moreover, if we talk about afferent versus efferent components, the afferent has numerous short axons with tendons, while the efferent has one long axon with various short tendons.
