Why do our fingers wrinkle in water..?

…and all those other nagging questions about your body answered.
  • Why does your brain ‘freeze’ when you eat something cold?

The sudden sharp pain that you get in your head within a few seconds of eating or drinking something cold occurs because the abrupt change in the temperature of your mouth causes blood vessels to dilate quickly in order to warm the area. This dilation triggers pain receptor cells and the area becomes temporarily inflamed. Although the pain originates in the mouth, the brain interprets the pain signals as coming from the forehead. This is known as ‘referred pain’.

  • Why is yawning contagious?

While you might typically associate yawning with tiredness, researchers have suggested that it is actually an involuntary action designed to help you stay awake. Yawning could be triggered by a subconscious, protective mechanism to make your group or ‘herd’ more vigilant against external dangers. The idea is that contagious yawning offers a subtle and silent communication with those around you. 

  • Why do we blush when we are embarrassed?

The curse of every pale-skinned lady, blushing is an unfortunate, uncontrollable reflex that is caused by the nerve system, which controls the muscles of the blood vessels in your face. In embarrassing situations, your body will automatically release the hormone adrenaline, which triggers the blood vessels to dilate and subsequently, the increased blood flow to your cheeks makes your face appear red or flushed.

  • Why do we hiccup?

The medical condition ‘singultus’, more commonly known as hiccupping, is another uncontrollable reflex action. It occurs when the diaphragm suddenly and involuntarily contracts, resulting in an abrupt sound being produced at the top of the windpipe. Short-term hiccups may occur due to heavy consumption of alcohol, eating or drinking too quickly or even a sudden change in room temperature, but they remain something of a mystery. 

  • Why do fingers wrinkle in water?

While it may be a bothersome side effect of staying too long in the bath, the shrivelling of skin under water may actually have been crucial to the survival of our human ancestors. Wrinkly fingertips help to improve grip and our ancient predecessors could have used them to great effect to gather food underwater or in wet conditions.

  • Why do we get goosebumps?

Humans get goosebumps when they are cold or frightened. Many other animals experience the same phenomenon, for example when a hedgehog raises its quills. The rising of hair follicles traps air between the hairs and the skin. This not only creates insulation for the animal but also makes it appear larger in order to scare potential predators away. 

  • Why do we sneeze with our eyes closed?

A sneeze helps to clear the nose and sinus regions and injects oxygen into the body’s cells. However, despite its benefits, a sneeze places tremendous pressure on the body due to the stimulation of various nerve endings and our eyes are particularly vulnerable because of the considerable additional air pressure. Although the pressure is not strong enough to cause serious damage, scientists suggest that the reason we close our eyes is to protect them from possible discomfort.

  • Why do our eyelids twitch?

The eyelids twitch because of an involuntary muscle spasm in the upper eyelid, which causes a strange, fluttery sensation. Although the exact cause of it isn’t known, scientists believe that fatigue, stress, eye-strain and caffeine can all contribute to eye twitches. You may also observe that people’s eyelids twitch while they are asleep. This is because, during the deepest phase of sleep, known as ‘REM’, the body’s muscles twitch and spasm in reaction to the events that are taking place in their dreams. 

  • Why do we have wisdom teeth?

Wisdom teeth are an extra set of molar teeth that early humans needed to cope with their diet. This contained coarse, uncooked food, such as nuts, roots and leaves, which needed greater effort to chew and caused the teeth to wear excessively. As human diets changed, and with the advent of forks, spoons and knives, our jaws grew proportionately smaller. Evolutionary biologists now classify wisdom teeth as vestigial organs, or body parts that have become redundant due to evolution.

  • Why do we laugh when we are tickled?

Laughing when you are tickled is a reflex reaction much like the involuntary knee-jerk. However, studies suggest that this reaction is not explicitly mirthful, but is instead a panic response, possibly related to the subconscious fear of harmful creatures, such as spiders. The fear that you experience when someone is tickling you, causes you to laugh uneasily and struggle against the possible source of danger. This explains why it is impossible to tickle yourself, as the brain is completely prepared and therefore doesn’t respond in a state of panic.