Question

When you stick your hand in a bucket of ice, it grows numb after a while. Based on what you know regarding neuronal signaling, explain how the sensation of touch is blocked from signaling to the brain.; Lidocaine is a local anesthetic that works by blocking voltage-gated sodium channels. Explain how blocking voltage-gated sodium channels would cause numbness and pain.

Answer 1

When you stick your hand in a bucket of ice, the sensation of touch is blocked from signaling to the brain due to neuronal signaling.

Step-by-step explanation:

The sensation of touch is blocked from signaling to the brain when you stick your hand in a bucket of ice due to neuronal signaling. Neuron signaling occurs through the transmission of electrical signals called action potentials. When the skin comes into contact with ice, the thermoreceptors in the skin detect the cold temperature and generate graded potentials.

If the stimulus is strong enough, it can generate an action potential which travels along the axon of the sensory neuron to the brain, resulting in the sensation of touch. Lidocaine is a local anesthetic that works by blocking voltage-gated sodium channels.

These sodium channels are responsible for the generation and propagation of action potentials. By blocking these channels, lidocaine prevents the generation of action potentials in the sensory neurons that transmit touch signals from the skin to the brain. Blocking voltage-gated sodium channels with lidocaine also prevents the generation of action potentials in the pain pathway.