A Neurophysiologist Is Investigating Reflexes in Two Different Animals: a Crab

question 7

Multiple Choice

A neurophysiologist is investigating reflexes in two different animals: a crab and a fish. Action potentials are found to pass more rapidly along the fish's neurons. What is a likely explanation?

• A) The fish's axons are smaller in diameter than the axons in the crab.
• B) The fish's axons are myelinated. The crab's axons are not myelinated.
• C) The fish's axons are not myelinated. The crab's axons are myelinated.
• D) There is a higher percentage of ion channels in the axons of the crab compared with the percentage of ion channels in fish axons.

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Definitions:

Split-Brain Patient

An individual whose corpus callosum has been surgically severed, separating the brain's two hemispheres to treat severe epilepsy.

Visual Field

The total area in which objects can be seen in the peripheral vision while the eyes are focused on a central point.

Association Area

Regions of the brain that combine and process information from various other parts of the brain to carry out complex functions.

Cerebral Cortex

The outer layer of brain tissue, crucial for complex cognitive functions such as thought, memory, consciousness, and language.