Action potential is unique to neurons and muscle cells. Other body cells do not use this process T True F False Question 21
The Correct Answer and Explanation is:
The correct answer is True.
Explanation:
Action potentials are electrical signals that play a crucial role in communication within the nervous system and muscle contraction. These signals are unique to neurons and muscle cells (i.e., skeletal, smooth, and cardiac muscle cells), and they allow these cells to transmit information rapidly across long distances.
An action potential occurs when a cell’s membrane potential rapidly changes, leading to a transient reversal of the cell’s voltage. This rapid depolarization is followed by repolarization, which restores the membrane to its resting state. This process is mediated by ion channels, primarily sodium (Na+) and potassium (K+), that open and close in response to changes in voltage.
Here’s how it works in different cells:
- Neurons: Neurons generate action potentials to carry signals from the brain and spinal cord to various parts of the body. When a neuron receives a stimulus that depolarizes it to a certain threshold, voltage-gated sodium channels open, and sodium ions rush into the cell, causing the membrane potential to become positive. The action potential then travels down the axon to transmit information.
- Muscle Cells: In muscle cells, action potentials trigger muscle contraction. In skeletal muscles, the action potential travels along the sarcolemma (muscle cell membrane) and into the T-tubules. This activates the release of calcium ions from the sarcoplasmic reticulum, initiating muscle contraction. In cardiac muscle cells, action potentials help synchronize the contractions of the heart.
Unlike neurons and muscle cells, other body cells do not generate action potentials. These cells may undergo other forms of electrical signaling or maintain stable resting potentials, but they do not experience the rapid, large-scale changes in membrane potential that characterize action potentials.
Thus, the unique nature of action potentials is central to the functionality of neurons and muscle cells.
