Final answer:
Sleep pressure is influenced by the accumulation of adenosine, a neurotransmitter that promotes sleep and is countered by the stimulating effects of caffeine.
Step-by-step explanation:
Sleep pressure is influenced by the accumulation of adenosine. This neurotransmitter builds up in the brain during wakefulness and promotes sleep. Caffeine, a well-known stimulant found in coffee and energy drinks, works by being an adenosine antagonist. It inhibits the adenosine receptors in the brain, which leads to a decreased feeling of sleepiness and an increase in wakefulness. Sleep pressure is influenced by the accumulation of adenosine, a neurotransmitter that promotes sleep and is countered by the stimulating effects of caffeine.