I know there's already a forum for sore and tender scalps but naturally, I can't find it! I needed to register before posting...so it's GONE. For about a year my scalp has been so sore and so tender that it hurts 24 hrs a day. At first I thought perhaps I was allergic to my shampoo so I changed brands. No improvement. Next I wondered if my shower was too hot.
Although small in size, the eye is a very complex organ. The eye is approximately 1 inch (2.54 cm) wide, 1 inch deep and 0.9 inches (2.3 cm) tall. The tough, outermost layer of the eye is called the sclera. It maintains the shape of the eye.
From head to tail, human sperm cells measure about 50 micrometers (0.05 millimeter, or roughly 0.002 inch). The tiniest object you can see with your unaided eyes is about 0.1 mm--so forget about seeing sperm without a microscope. A human egg is about 30 times bigger--large enough to be seen with the naked eye.