Mhmkrrkslallaooaoaoakuusla
Answer:
The sodium channel have refractory period.
Explanation:
Action potential are generated at axon hillock of neuron and travel across the neuron in response to stimuli. For the the generation of action potential the steps are stimulus, depolarization, repolarization, hyperpolarization and resting state.
So the first step for action potential after stimulus is depolarization. Depolarization requires the opening of sodium channels to make the inside of neuronal membrane positive. These sodium channels have refractory period. They cannot open immediately after activation. So the sodium channels of one direction in neuron (upstream) become refractory and it is convenent to open the sodium channels of other direction (downstream) of neuron. That why action potential is transmitted in one direction.
It is like the gunpowder placed at a line the fire cannot go back in burnt gun powder direction.
Answer: The Central Nervous System and The Peripheral Nervous System
Answer;
REM sleep
Xander is probably experiencing REM sleep.
Explanation;
-REM sleep is a stage of sleep that is characterized by low muscle tone, rapid eye movements and dreams. It is present in all mammals and has unique physiologic properties that distinguish it from non-REM sleep.
-It is believed that the chemical and electrical activity that regulate this sleep phase originate in the brain stem, and this is most notably characterized by a combination of an abundance of acetylcholine (a neurotransmitter), and the almost complete absence of serotonin, histamine, and norepinephrine.
