Our bodies are amazing instruments: extremely intricate, adaptable, and above all resilient. We grow up studying our body, learning its limits, and exploring its infinite possibilities. But it isn’t until we take an anatomy & physiology class that we really begin to discover its true potential - and some of its strangest secrets.

1. Your tongue actually has no one receptor for one taste.

Many people think that because we have four primary tastes (sour, sweet, bitter, and salty) that we have specific taste buds that have one receptor for that particular taste. On the contrary, 90% of taste receptors are stimulated by more than one primary taste. This means that one taste bud can sense most of the different types of tastes, and the idea that one side of our tongue tastes a certain taste better than another part is false. Deciding which taste we are perceiving depends on smell and which taste is being picked up the most in multiple neurons.

2. The areas for speech understanding and speech ability are actually separate parts of the brain.

Our brain is an amazing organ with many intricate facets and parts that work cooperatively to make us functional human beings. An example of these separate parts that work together is our ability to speak. Broca’s area is a place in the brain where speech formation takes place, while Wernike’s area is a place where language comprehension takes place. They are completely different areas of the brain itself, but they work together to enable us to understand what someone is saying to us and respond. When one of these parts of the brain is damaged, a condition called aphasia develops. It manifests in one of two ways; either the person can hear and understand what is being said to them, but they cannot reply or they cannot understand what they are hearing and formulate a response, but they do retain the ability to speak.

3. Birth control works by tricking your body into thinking it’s pregnant.

The female body initiates menstruation after a drop in estrogen and progesterone levels caused by the deterioration of the corpus luteum, or the surrounding of the egg before it’s released. When a female becomes pregnant, these levels of the hormones remain elevated and prevent the release of another egg. Birth control actually contains estrogen and progesterone, which tricks our body into thinking it’s pregnant. This prevents the release of subsequent eggs and stops an actual fertilization from taking place.

4. Your heart actually pumps itself.

Most of the muscles in the body require innervation for movement to occur. They are innervated by neurons, which deliver action potentials and allow contraction to take place. However, our hearts are not innervated by any neurons. The heart has a unique conduction system to allow for increased or decreased rate and strength of contraction of the heart as needed. This means that even if the brain was incapacitated if the flow of calcium and energy to the heart is kept constant, the heart will continue to beat on its own even outside of the body.

5. Quiet breathing normally requires 3% of total energy expenditure.

Normal, relaxed breathing only takes about 3% of total energy at any given time! When airway resistance, compliance, and elasticity are changed, this percentage can change to increase or decrease the work of breathing and enable us to get oxygen to our tissues in greater or lesser amounts.