As it binds to adenosine receptors, it slows down our nerve cell activity, which then causes drowsiness. A nerve cell mistakes caffeine for adenosine. Therefore, caffeine binds with the adenosine receptor, but rather than slowing down the cell's activity, the nerve cells speed up. While adenosine opens up blood vessels, allowing for more oxygen intake, caffeine constricts these blood vessels.
windshield - transparent screen (as of glass) to protect occupants of a vehicle. windscreen. aeroplane, airplane, plane - an aircraft that has a fixed wing and is powered by propellers or jets; the flight was delayed due to trouble with the airplane.
Windshield wipers typically consist of a lower wiper arm that protrudes up from the vehicle and the wiper blade assembly that attaches to that arm; the blade assembly includes a long strip of rubber or silicone that wipes the glass.