Carnegie Stage 22

Introduction

Stage 22 embryos have a greatest length of 23.4 to 27.5 mm and an estimated postfertilization age of 52 to 55 days. At this stage the eyelids cover approximately half of the exposed part of the eye. The fingers approach those on the other side and sometimes touch and overlap. Many nuclei, fiber tracts and commissures are evident in the brain. All of the vertebral segments have formed and ossification has begun in the clavicle and long bones. All of the joints of the extremities can be identified.

New structures include cortical plate, greater trochanter of femur, internal thoracic artery, nucleus cuneatus, nucleus gracilis, talus, urinary bladder trigone.

Also on EHD: Eyes and Eyelids

Surface

There are no published figures for this stage.