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:
“Every head should be cultivated.”
—Abraham Lincoln (1809–1865)
“His eyelids droop, his head falls low,
His old eyes cloud with dreams;
The sun upon all things that grow
Falls in sleepy streams.”
—William Butler Yeats (1865–1939)
“I feared
The belly-cold, the grave-clout, that betrayed
Me dithering in the drift of cordial seas;
Ten years are time enough to be dismayed
By mummy Christ, head crammed between his knees.”
—Allen Tate (1899–1979)