Carnegie Stage 11

Introduction

Stage 11 embryos have a greatest length of 1.4 to 5 mm and an estimated postfertilization age of 28 to 30 days. There are 13 to 20 pairs of somites or body segments along the body axis. Sclerotomes are forming in the ventromedial part of the somites as the somite remnants move dorsolatterally. The rostral neuropore closes and the optic vesicle forms at the outer part of the optic sulcus in the wall of the diencephalon. The otic placode or pit is present as thickened ectoderm lateral to the rhombencephalon.

New structures include adenohypophysis, ectodermal ring, hypoglossal neural crest, maxillary prominence, pericardioperitoneal canal, primary head vein, vagal neural crest (CN X).

Also on EHD: Hand Movement

Embryo

Features