What Is a Sensory Neuron?

1. Sensory neurons:

1. Sensory neurons:

Sensory neurons are neurons that can receive stimuli inside or outside the body and transmit excitement to the central nervous system. They are called sensory neurons. This name is based on the function of neurons. Pseudounipolar or bipolar neurons mostly belong to this category, such as sensory cells of the retina and inner ear, and ganglion cells of the brain and spinal cord are sensory neurons.

2. Neurons:

Neurons, or nerve cells, are the most basic structural and functional units of the nervous system. It is divided into two parts: cell body and protrusion. The cell body consists of the nucleus, the cell membrane, and the cytoplasm. It has the function of contacting and integrating input information and transmitting information. There are two types of processes: dendrites and axons. The dendrites are short and multi-branched. They directly expand and protrude from the cell body to form a dendrite. Its role is to receive impulses from other neuron axons and pass them to the cell body. The axons are long and have few branches. They are slender protrusions of uniform thickness. They often occur in the axillary mounds, and their role is to receive external stimuli, which are then transmitted by the cell body. In addition to the lateral branches, the axons form dendritic nerve endings. The terminals are distributed in certain tissues and organs, forming various nerve terminal devices. Sensory nerve endings form various receptors; motor nerve endings are distributed in skeletal muscles, forming the ultimate motor. Neurons can be divided into pseudounipolar, bipolar and multipolar neurons according to the number of protrusions. According to its functional characteristics, it can be divided into afferent neurons (also known as sensory neurons), intermediate neurons (also called contact neurons) and efferent neurons (also called motor neurons). Excitation or suppression is divided into excitatory neurons or inhibitory neurons.

Chinese name

Sensory neuron

nickname

Receptor neuron

Features

Nutritional effect

System

Closed loop system

Sensory neurons physiological functions:

Sensory neurons are also known as "afferent neurons" and "receiver neurons." Neurons that transmit nerve stimuli from the receptor or sensory organs to the central nervous system. Afferent neurons are connected to specific intermediate neurons. In terms of morphology, unipolar neurons are predominant. Among them, part of the sensory neurons are transmitted through synapses and can transmit the received information from the skin receptors to the spinal cord and the brain, activating the corresponding brain area to cause sensation; the other part can only transmit information and not cause sensation.

Sensory neurons morphologically include pseudounipolar neurons and bipolar neurons, and their role is to transmit various information of the internal and external environment from the surrounding to the center. Its peripheral processes terminate at the receptors of various parts of the body. The receptors receive various stimuli and convert the stimuli into nerve impulses, which are transmitted to the cell along the peripheral process and continue to be introduced into the center through the central process. Therefore it is also called afferent neuron.

Sensory neuron and sensory neuron related diseases:

1. Paraneoplastic sensory neuron disease:

Paraneoplastic sensory neuron disease is a rare peripheral nerve disease. The main part of the lesion is the posterior root ganglion of the spinal cord. The pathology is the most severe lesion in the posterior root ganglion of the spinal cord. The posterior cord is degenerated. The anterior cord is less affected. A large number of monocyte infiltration around the vein, with Na-geotle nodular hyperplasia, gastrocnemius muscle biopsy may have peripheral axons loss, myelin breakdown and fibrosis. The disease is more common in the elderly, with subacute or chronic onset. It is believed that the pathogenesis of PSN is related to autoimmunity, that T cell-mediated cytotoxicity is involved in the occurrence of PSN, and it is speculated that antigen-stimulators other than the central nervous system produce antibodies that affect the posterior root ganglia to produce PSN, which is prominently caused by deep sensory disorders Sensory ataxia may also have shallow sensory disturbances, such as distal to proximal extremities. Electrophysiological examination: sensory conduction speed is slowed down, action potential amplitude is reduced, latency period is prolonged, and H response is as follows, motor nerve conduction speed is normal or slightly slowed.

2. Neuron degeneration:

Neuron degeneration is a neuronal cell body degeneration and necrosis secondary to axonal degeneration and myelin destruction. The lesions are similar to axonal degeneration, but neuron necrosis makes axonal degeneration and disintegration in a short period of time. It is called neuron disease ( neuronopathy). Sensory neuron lesions in the posterior root ganglia such as cancerous sensory neuron disease, organic mercury poisoning, etc., and motor neuron lesions such as acute polio and motor neuron disease.