ATI TEAS (Test of Essential Academic Skills) Version 7ScienceEasy
A scientist is investigating the electrical impulses that allow for rapid communication between different parts of the body. Which of the following cell structures is primarily responsible for transmitting these signals over long distances?
- ADendrite
- BAxon
- CCell body (soma)
- DMyelin sheath
Show answer & explanationAnswer & explanation
Correct answer: B. Axon
The axon is the primary structure of a neuron responsible for transmitting electrical signals, known as action potentials, away from the cell body over long distances to other neurons or target cells. Dendrites receive signals, the cell body contains the nucleus, and the myelin sheath insulates the axon but does not transmit the signal itself.
Why the other options are wrong
- A. Dendrites receive incoming signals from other neurons.
- C. The cell body contains the nucleus and is involved in signal integration, but not long-distance transmission.
- D. The myelin sheath insulates the axon and increases the speed of signal transmission, but it is not the transmitting structure.
Axon
The long, slender projection of a nerve cell, or neuron, that conducts electrical impulses away from the neuron's cell body.
- Transmits action potentials.
- Can be very long, extending to distant parts of the body.
- Often insulated by a myelin sheath.
Memory trick: Neurons 'axon' to send signals 'far on'.