Final answer:
A nerve impulse is an electrical signal transmitted through the nervous system by neurons. The myelin sheath enables faster transmission of these impulses. An ECG displays the heart's electrical activity, providing health insights.
Step-by-step explanation:
A nerve impulse is an electrical signal that flows through the nervous system. The nervous system comprises a vast network of nerves that coordinates all of the body's voluntary and involuntary activities. Neurons, the cells that transmit electrical signals throughout the body, are crucial for nerve conduction.
Process of Signal Transmission Along a Neuron
Neurons send signals, known as nerve impulses, as a result of the difference in electrical charge across the neuron's plasma membrane. This is due to the movement of ions. An electrical nerve impulse can travel very quickly along an axon – a long projection of the neuron that directs the impulse toward specific target cells. The myelin sheath, created by glial cells, insulates the axon, allowing these nerve impulses to travel more rapidly.
Effects of Myelin Sheaths
The myelin sheath enhances the speed at which a nerve impulse propagates. It acts as an insulator and ensures that the electrical impulse can jump across the small gaps along the axon, known as nodes of Ranvier, in a process known as saltatory conduction.
Understanding ECG Signals
An electrocardiogram (ECG) measures the signals associated with the contractions of the heart. It shows the timing and strength of electrical signals as they pass through each part of the heart, which can be used to assess the health and rhythm of the heart.