The cleanest part of the human body is often considered to be the eye because of its abilities to clean itself. The eyelid opens and shuts several times every minute in order to keep the eye clean and moist.Know More
The eye also protects itself through the production of tears. Tears are secreted from the lacrimal gland on each eye and helps to wash away dirt, germs or other foreign particles, such as dust. The lacrimal gland can be found above the outer corner of each eye.
The eyelids also have good reflex control so they are able to help prevent damage to the eye. An example of the eye's reflex control is when eyelids shut automatically whenever the eye is exposed to bright light from dim light or when an object comes to close to the eye. Eyelashes also help to keep eyes clean by keeping dirt away.
The eye has many parts that make it possible to detect light allowing humans to see. The sensitive tissue lining around the inner surface of the eye is known as the retina. There are cone cells in the retina that help to detect color and rod cells that help to detect low light contrasts. The central opening of the eye around the pupil is the iris and it controls the size of the pupil. The iris is also the colored part of the eye and is where a person will have brown, blue, green or hazel eyes.Learn more about Human Anatomy
Food is needed by the human body for energy, to repair and build cells and to prevent sickness and heal from it. While it is possible to obtain nutrients in a scientifically controlled manner, common food is the most efficient way of obtaining energy and nutrients.Full Answer >
Meiosis occurs in the reproductive organs of the human body. Meiosis is the process of cell division that is used to make sperm or egg cells, also known as gametes. In meiosis, cells divide twice.Full Answer >
Photos of the human body are available on websites like National Geographic and Healthline. Science Kids offers less graphic, detailed illustrations and photos that are suitable for children learning about biology. Interactive and narrative videos are also available on some websites.Full Answer >
The two largest veins in the human body are the superior and inferior vena cavae. These veins, which are roughly the same size, are the final conduits for deoxygenated blood before it is returned to the heart.Full Answer >