What would happen if there were no Schwann cells?
A) Muscles would not be able to contract and the body would be paralyzed.
B) An increase in cerebrospinal fluid (CSF) within the spinal cord and brain would result in death.
C) Bacteria and viruses would accumulate in the brain and would slowly cause neural destruction.
D) The heart would beat too rapidly, exceeding 180 beats per minute (normal is 80 beats per minute).
The Correct Answer and Explanation is :
Correct Answer:
A) Muscles would not be able to contract and the body would be paralyzed.
Explanation:
Schwann cells are a type of glial cell that play a crucial role in the peripheral nervous system (PNS). Their primary function is to form the myelin sheath, a fatty layer that wraps around axons, providing insulation and speeding up nerve signal transmission. This process is known as saltatory conduction, which allows electrical impulses to jump from one node (Node of Ranvier) to the next, ensuring fast and efficient communication between the brain, spinal cord, and muscles.
If Schwann cells were absent, myelination would not occur, leading to significantly slower nerve signal transmission or complete failure of impulse conduction. Without proper nerve signals reaching the muscles, the body would be unable to contract muscles efficiently, resulting in muscle weakness, paralysis, or severe motor dysfunction. This condition is observed in demyelinating diseases such as Guillain-Barré syndrome and Charcot-Marie-Tooth disease, where Schwann cell dysfunction leads to loss of motor control.
Additionally, Schwann cells play a role in nerve regeneration. When peripheral nerves are damaged, Schwann cells help by guiding regrowth. Without them, nerve injuries would not heal, leading to permanent nerve damage and loss of function.
Other answer choices are incorrect:
- B (CSF accumulation) is related to conditions like hydrocephalus, not Schwann cell dysfunction.
- C (Bacterial/Viral accumulation) is associated with the role of the blood-brain barrier and microglial cells, not Schwann cells.
- D (Rapid heart rate) is regulated by the autonomic nervous system, mainly through the vagus nerve and cardiac pacemaker cells, not Schwann cells.
Thus, Schwann cell absence would directly impact motor function, causing paralysis due to nerve signal failure.
Here is the generated scientific illustration showing the role of Schwann cells in the nervous system. It compares a normal myelinated neuron with a neuron lacking Schwann cells, highlighting the impact on nerve signal transmission. Let me know if you need any modifications or further explanations!