Question

35yr old female was watching TV for long hours with hands under her head. She complains of tingling sensation over her arm. Which type of nerve fibers is most likely to be affected?

• A. Fibers
• B. B - fibers
• C. C - Fibers
• D. Sympathetic nerve fibers

Answer 1

The Correct Option is A

To determine which type of nerve fibers are most likely affected, we need to consider the scenario where a 35-year-old female experiences a tingling sensation in her arm after keeping her hands under her head while watching TV. This position likely compresses the nerve pathways and primarily affects the sensory pathways.

In the nervous system, different types of nerve fibers carry various functions such as motor, sensory, and autonomic functions. The main types of sensory fibers, arranged by diameter and conduction velocity, are:

• A fibers: Further divided into A-alpha, A-beta, A-gamma, and A-delta fibers. A-beta and A-gamma fibers are involved in motor functions while A-delta fibers carry pain and temperature sensations.
• B fibers: These are preganglionic autonomic fibers, primarily involved in the autonomic nervous system.
• C fibers: Unmyelinated fibers carrying pain and temperature sensations. They have slow conduction velocities.

Since the symptom is a tingling sensation, it's associated with the sensory fibers responsible for proprioception, touch, and pressure - typically the larger-diameter A-beta fibers. The conventional categorization in this context, referring to large fibers, includes more specific types such as those present in peripheral nerves. They are responsible for fine touch and pressure sensations.

Type	Function
A-beta fibers	Sensory - related to touch and pressure
A-delta fibers	Sensory - related to pain and temperature
B fibers	Autonomic nervous system
C fibers	Sensory - related to pain and temperature

Based on this information, the correct answer referring to sensory fibers specifically associated with certain sensations such as tingling and pressure is most aptly described as simply "Fibers" in the context provided, likely referring to the larger sensory fibers such as A-beta.