yolk (yok, yolk)

1. One of the types of nutritive material stored in the ovum for the nutrition of the embryo; y. is particularly abundant and conspicuous in the eggs of birds.vitellus; 2. Fatty material found in the wool of sheep; when extracted and purified, it becomes lanolin. [A.S. geolca; geolu, yellow]
white y. y. consisting of much finer particles than those of yellow y.; thin layers of it lie between the zones of yellow y. and form the latebra.
yellow y. the chief constituent of the y. in a bird's egg; it consists of relatively coarse particles of stored food materials and is laid down in concentric zones with interposed thin layers of white y.


Browse Medical References:

[A] [B] [C] [D] [E] [F] [G] [H] [I] [J] [K] [L] [M]
[N] [O] [P] [Q] [R] [S] [T] [U] [V] [W] [X] [Y] [Z]