raphe

1. Anatomy. A seamlike line or ridge between two similar parts of a body organ, as in the scrotum.
2. Botany. The portion of the funiculus that is united to the ovule wall, commonly visible as a line or ridge on the seed coat.
3. The median groove of a diatom valve.

[New Latin, from Greek rhaphē, seam, suture, from rhaptein, to sew.]

(pl raphae) a crease or ridge that divides an organ in half.

A line, ridge, or furrow in a tissue or organ.

A seam; line of union of the halves of various symmetrical parts.

• abdominal r. — linea alba.
• r. nuclei — small group of serotenergic cells in the midline of the brainstem; may be involved in the initiation of sleep.