We all know what yawning is – that contagious reflex that seems to happen when we’re tired, bored, or just plain old relaxed. But there’s a lot more to this seemingly simple act than meets the eye. For instance, did you know that yawning is actually a complex, coordinated effort involving the entire body? Or that it’s believed to play an important role in cooling the brain?
Here are 5 things you probably didn’t know about yawning:
1. Yawning is a reflex that’s triggered by the brain
When we yawn, it’s actually our brain that’s responsible for initiating the reflex. More specifically, it’s the hypothalamus – the region of the brain that regulates things like body temperature, hunger, and thirst.
The exact mechanism by which the brain triggers a yawn is still not fully understood. But it’s thought to involve a complex interplay of neurotransmitters (chemicals that transmit signals between nerve cells).
2. Yawning is a whole-body effort
Yawning is not just about opening our mouths wide and taking a deep breath in. It’s actually a coordinated effort involving many different muscle groups throughout the body.
For instance, when we yawn, the muscles that open our jaw (the masseter and temporalis muscles) work together with the muscles of the neck and throat (the sternocleidomastoid and scalenes) to open our mouths wide. At the same time, the diaphragm – the muscle that helps us breathe – contracts, and the chest and abdominal muscles relax. All of this results in a deep inhalation of air.
3. Yawning is contagious
Have you ever noticed that yawning is often contagious? If you see someone else yawn, there’s a good chance you’ll start yawning too.
This phenomenon is thought to be due to a combination of imitation and empathy. When we see someone else yawn, we automatically imitate the action (this is known as the “mirror neuron system”). And when we see someone yawning, we can’t help but feel empathy for them – after all, we know how it feels to be tired or bored.
4. Yawning is a sign of fatigue
One of the most common reasons why people yawn is because they’re tired. When we’re sleep-deprived, our bodies release a hormone called adenosine. This hormone builds up in the brain and is thought to cause fatigue.
It’s also believed that yawning helps to increase alertness by increasing the oxygen levels in the blood and cooling the brain.
5. Yawning is not just for humans
Yawning is not just something that humans do – it’s a behavior that’s been observed in many different animals, from dogs and cats to chimpanzees and even rats.
So why do animals yawn? It’s thought that yawning may serve a similar purpose in animals as it does in humans – to increase alertness and help regulate body temperature.