Trillions of microbes, including bacteria, live in the human body. In fact, the number of bacterial cells in the stomach alone may outnumber human cells in the body.
Each person has a distinct tongue print, similar to fingerprints. Every person has a unique arrangement of taste buds and other features on their tongue.
The corpus callosum is a bundle of nerve fibers connecting the left and right hemispheres of the brain. It plays a crucial role in communication between the two halves of the brain.
The spinal cord doesn't extend the full length of the vertebral column. It typically ends around the first or second lumbar vertebra, and the rest is made up of nerve roots.
The "lub-dub" sound of a heartbeat is not the sound of the heart contracting. It's actually the sound of the heart valves closing.
Hiccups in fetuses have been observed in ultrasounds, suggesting that humans begin hiccupping even before birth.
The human nostrils have a nasal cycle, where one nostril is more open than the other at any given time. This alternates throughout the day, helping with airflow and filtering.
The longest nerve in the human body is the sciatic nerve, which can extend from the lower back down to the foot. It can cause pain when irritated, leading to a condition known as sciatica.
While most people know the spleen is involved in filtering blood and removing damaged blood cells, it also stores platelets and plays a role in the immune system.
Newborns have a reflex known as the palmar grasp reflex, where they instinctively grab onto objects placed in their palm. This reflex disappears after a few months.