In 1921, Sanger founded the American Birth Control League, which later became the Planned Parenthood Federation of America. In New York City, she organized the first birth control clinic staffed by all-female doctors, as well as a clinic in Harlem with an entirely African-American staff.
Cephalization is considered an evolutionary trend, whereby nervous tissue, over many generations, becomes concentrated toward one end of an organism. This process eventually produces a head region with sensory organs.Cephalization is intrinsically connected with a change in symmetry.It accompanied the move to bilateral symmetry made in flatworms, with ocelli and pinnae placed in the head region.his process eventually produces a head region with sensory organs. Cephalization is intrinsically connected with a change in symmetry. It accompanied the move to bilateral symmetry made in flatworms, with ocelli and pinnae placed in the head region.
From Wikipedia, the free encyclopedia. The cephalocaudal trend, or cephalocaudal gradient of growth, refers to the pattern of changing spatial proportions over time during growth. One example of this is the gradual change in head size relative to body size during human growth. During prenatal growth, from conception to 5 months, the head grows more than the body. In humans, the head comprises almost 50% of total body length at approximately the third month of intrauterine development.