In Depth: Organs and Circulatory
The human head is home to all the body’s major sensory organs, and the most important of these is the brain.
Although the nose, ears, tongue, nerves, and others parts are important, without a healthy brain, they’d all be useless.
Encased in the skull, the brain is the body’s centralized conveyor of all information. Much of its job involves receiving information from the rest of the body, interpreting that information, and then guiding the body's response to it.
Input the brain interprets includes odor, light, sound, and pain, and these are gathered from organs located in the head. Major sensory organs located in the head include:
- Ears: The outer, middle, and inner ear are responsible for collecting auditory information. Sound waves travel through the ears and vibrate membranes and tiny bones. Those signals are sent to the brain via the vestibulocochlear nerve. Other than hearing, your inner ears also help you keep your balance.
- Eyes: Light rays pass through the eye and refract through the vitreous humor, or liquid part of the eye. This stimulates the optic nerve, which sends the information to the brain.
- Tongue: Thanks to taste buds, the food you eat is vibrant with flavor. Whether food is sweet, salty, sour, or bitter, a normal tongue can taste it all. The taste buds collected the tastes, and three nerves (facial, glossopharyngeal, and vagus) send the information to the brain where it is interpreted. The tongue also helps you speak; its movement inside the mouth helps form sounds that become words.
- Nose: Olfactory nerves in your upper nasal cavity send messages to your brain to help you distinguish an infinite number of smells. The sense of smell also aids your sense taste.
- Nerves: Nerves all over the body help you sense heat, cold, pain, pressure, and texture. The touch receptors, called tactile corpuscles, are mostly located in the dermis layer of the skin around hair follicles.
Your senses constantly send information to your brain, but it doesn’t always instruct the body to respond.
For example, your eyes always see your nose, but your brain blocks out the information for better vision, as your nose is stationary and unchanging.
You can test this: close one eye and see how your nose magically appears.