Added: 17th October 2014
The Smell Alone
Many of us will find ourselves more awake from there mere smell of a cup of coffee. Many researchers believe that this aroma will signal to the brain that caffeine is not far off; thus the mind will become more alert even before the first sip is taken. Additionally, the psychological association with beginning one’s day will cue the brain into stirring from sleepiness. This may be one of the reasons why those who are suffering from a cold (and cannot smell normally) do not feel as energised before a cup in the morning.
Within the Brain Itself
Without delving into overly technical terms, it is just as critical to appreciate the role of caffeine within the brain. When we are drowsy, a chemical known as adenosine binds to the receptors of the nerves within our brains. In turn, this brings on the urge to sleep. In simplest terms, adenosine slows down the activity of our nerves. Caffeine appears much like adenosine to the average nerve cell and it will bind to the same sites that would normally be occupied by adenosine. Interestingly enough, caffeine does not slow down the activity between cells. If enough caffeine binds to these receptor sites, adenosine will not be able to make us feel drowsy and thus, higher levels of alertness are produced.
Constriction of Blood Vessels
Adenosine also has the effect of dilating the blood vessels within the brain. This is thought to allow more oxygen to the neurons during sleep. When caffeine is present, this dilation will not occur. This is significant because it is thought that many headaches are caused from this very same expansion. So, it is not uncommon to see caffeine listed within the ingredients of many headache medications.
Fooling the Pituitary Gland
As we have seen earlier, caffeine increases the levels of neural communication within the brain. This is interpreted by the pituitary gland as an unexpected event or an emergency. So, “fight-or-flight” hormones are released that include adrenaline and epinephrine. These are the main chemicals that produce the “buzz” often associated with an intake of caffeine.
This can result in:
- Pupil dilation
- Increased alertness
- Faster heart rate
- An expansion of the bronchial tubes
- A rise in blood pressure
- Increased blood flow to the muscles
Of course, like anything, too much coffee will overdo these effects and may then cause irritability in some, so it’s important to never go over the top in consumption. Nonetheless, it is now clear to appreciate why millions of individuals from all walks of life choose a piping hot cup of coffee to start their day or to get a pick me up.