Question

Multiple sclerosis is a debilitating autoimmune disease that results in the loss of the insulation around neuron axons. What cell type is the immune system attacking, and how does this disrupt the transfer of messages by the nervous system?

a) Immune system attacks Schwann cells; disrupts saltatory conduction
b) Immune system attacks oligodendrocytes; disrupts the myelin sheath
c) Immune system attacks microglia; disrupts neurotransmitter release
d) Immune system attacks astrocytes; disrupts electrical impulses

Answer 1

Multiple sclerosis involves the immune system attacking oligodendrocytes, which produce the myelin sheath insulating neuron axons, thereby disrupting signal transmission in the nervous system.

Step-by-step explanation:

In multiple sclerosis (MS), the immune system attacks a specific type of cell in the central nervous system (CNS), known as oligodendrocytes. These cells are responsible for the creation and maintenance of the myelin sheath, which insulates the axons of neurons. The destruction of myelin impedes the efficient transmission of nerve impulses, leading to the various symptoms of MS, such as muscle weakness, coordination issues, and sensory disturbances. It predominantly affects the CNS, which includes the brain and spinal cord. Signal transmission is disrupted because without proper myelination, electrical impulses cannot travel rapidly and efficiently along nerve fibers, resulting in a slowdown or blockage of communication between neurons, manifesting in the neurological symptoms of MS.