In anatomy, the head of an animal is the rostral part (from anatomical position) that usually comprises the brain, eyes, ears, nose and mouth (all of which aid in various sensory functions, such as sight, hearing, smell, and taste). Some very simple animals may not have a head, but many bilaterally symmetric forms do. Heads develop in animals by an evolutionary trend known as cephalization. In bilaterally symmetrical animals, nerve tissues concentrate at the anterior region, forming structures responsible for information processing. Through biological evolution, sense organs and feeding structures also concentrate into the anterior region, which collectively form the head.
Read more about Head: Human Head
Famous quotes containing the word head:
“All men are partially buried in the grave of custom, and of some we see only the crown of the head above ground. Better are the physically dead, for they more lively rot. Even virtue is no longer such if it be stagnant. A man’s life should be constantly as fresh as this river. It should be the same channel, but a new water every instant.”
—Henry David Thoreau (1817–1862)
“It’s sort of a shock to see your head detached that way.”
—Crane Wilbur (1889–1973)
“Don’t want no money from you Ethan, no money, Marty. Just a roof over old Mose head and a rocking chair by the fire, my own rocking chair by the fire.”
—Frank S. Nugent (1908–1965)