Brain of Embryo
The brain of a human embryo in the fifth week. A, Brain as seen in profile. B, Mesial section through the same brain. Labels: M, mammillary eminence, Tc, tuber cinereum; Hp, Hypophysis (pituitary diverticulum from buccal cavity); Opt, optic stalk; TH, optic thalamus; Tg, tegmental part of mesencephalon; Ps, pars subtalamica; Cs, corpus striatum; FM, foramen of Monro; L, lamina terminalis; RO, recessus opticus; RI, recessus infundibuli.