Question

1. Which of the following statements concerning axoplasmic transport is correct?

A. Large membranous organelles are transported by slow axonal     

transport

B. Cytosolic proteins are transported by fast transport

C. Retrograde transport is generally limited to a fixed rate of movement of particles

D. Anterograde transport is dependent upon microtubules

(Please note: you should give the reason of why you made the choice.)

2. A 65-year-old man is diagnosed with a form of a peripheral neuropathy. This individual will likely display

A. A loss in motor function, but sensory functions will remain largely intact

B. A reduction in conduction velocity of the affected nerve

C. An increase in the number of Ranvier’s nodes

D. Degeneration of myelin but the axon will typically remain intact

E. Signs of an upper motor neuron (UMN) paralysis

(Please note: you should give the reason of why you made the choice.)

Answer 1

1) answer should be D) anterograde transport is dependent upon microtubules.

Axonal transport is of four types - fast transport, slow transport, anterograde transport and retrograde transport.

Fast transport is used by vesicular cargoes or cytoskeletal elements.

Slow transport is used by cytosolic proteins.

All the transport types is dependent upon microtubules which is present along the axon. The proteins present along the length of axon moves the elements in anterograde or retrograde fashion.

2) answer should be B) a reduction in conduction vocity of the affected nerve.

Nerve conduction velocity is defined as the speed at which electric impulse travels along the neuron.

A decrease in nerve conduction velocity signifies an abnormal nerve or nerve compression.

Peripheral neuropathy affects peripheral nerves that are nerves outside the brain and spinal cord, so both motor and sensory functions are affected. Hence option a is incorrect

There is loss of myelin sheath in the peripheral neuropathy with loss of axonal functions as well.

Upper neuron motor paralysis will be seen in pyramidal and extrapyramidal pathways.