Top definition. Musk. Though technically the name for the secretion of the male musk deer, musk is most often used as the name for the scent of arousal in both men and women, as actual musk is used in perfumes and colognes. Generally causes arousal for both genders, as it is a secondary sex characteristic.
These photoreceptors are called the rods and cones. Rods are called rods because under the microscope, they are shaped like, of all things, a rod. Finally, those pesky scientists named a structure for what it actually looks like as opposed to someone's unpronounceable last name!
The eye's inner layer is composed of the retina: thin tissue that contains blood vessels and light-sensitive photoreceptor cells called rods and cones. Every human eye contains about 120 million rods and 7 million cones. The rods are very sensitive to low-level light, but they cannot distinguish color.he eye's inner layer is composed of the retina: thin tissue that contains blood vessels and light-sensitive photoreceptor cells called rods and cones. Every human eye contains about 120 million rods and 7 million cones. The rods are very sensitive to low-level light, but they cannot distinguish color.