Final answer:
Nerve and muscle cells can change their membrane potential to produce an electrical signal known as an action potential, which is crucial for communication and muscle contraction.
Step-by-step explanation:
Cells that can change their membrane potential to produce a signal include nerve cells and muscle cells. The resting membrane potential is typically around -70 mV due to the presence of negatively charged ions inside the cell and positively charged sodium (Na+) ions outside.
When a nerve cell is stimulated, Na+ ions are allowed to flow into the cell, generating a positive membrane potential known as an action potential.
This shift is fundamental for the communication between nerves and other cells like muscle cells. The action potential is a rapid rise and subsequent fall in voltage that propagates along the membrane of the neuron.
This electrical event leads to the release of neurotransmitters such as acetylcholine (ACh) from synaptic terminals, which cross the synaptic cleft to bind with receptors on the motor end plate.
The binding of neurotransmitters to the receptors—which are sodium channels—triggers further entry of Na+ ions into the muscle cell, generating a muscle contraction.
Another type of potential related to the neuronal function is a graded potential. Graded potentials are local changes in membrane potential that occur in response to a stimulus and are essential for initiating an action potential when they reach a threshold level.
They can lead to either depolarization or hyperpolarization, depending on the type of stimulus and the specific ion channels that are activated.