Which type of neuron secretes myelin in the central nervous system:
A Oligodendroctye B Schwann cell C Bipolar neuron D Multipolar neuron
The correct answer and explanation is:
The correct answer is A. Oligodendrocyte.
Oligodendrocytes are specialized glial cells found in the central nervous system (CNS), and they play a crucial role in the formation of myelin sheaths around neurons. These cells are responsible for providing insulation to axons, which is essential for efficient signal transmission. The myelin sheaths created by oligodendrocytes allow nerve impulses to travel much faster and more efficiently, as the electrical signals jump between gaps called nodes of Ranvier. This process is called saltatory conduction.
Unlike oligodendrocytes in the CNS, Schwann cells (answer B) are responsible for myelination in the peripheral nervous system (PNS). They wrap around the axons of peripheral neurons to form myelin sheaths, but they do not function in the CNS.
Bipolar neurons (answer C) are a type of sensory neuron typically found in the retina of the eye or the olfactory system. They do not secrete myelin and are primarily involved in transmitting sensory information rather than providing myelination.
Multipolar neurons (answer D) are the most common type of neuron in the CNS. These neurons have multiple dendrites and a single axon, but they do not produce myelin themselves. Instead, their axons may be myelinated by oligodendrocytes.
In summary, oligodendrocytes are responsible for myelinating axons in the central nervous system, which is a critical function for maintaining rapid and coordinated communication between different regions of the brain and spinal cord. Without this myelination, the efficiency of neural signaling would significantly decrease, leading to various neurological issues.