Carnegie stage 18

Introduction

Facts

Week 7, 44 - 48 days, 13 - 17 mm

Events

Ectoderm: sensory placodes, lens pit, otocyst,nasal pits moved ventrally, fourth ventricle of brain

Mesoderm: heart prominence

Head: 1st, 2nd and 3rd pharyngeal arch, forebrain, eye, auricular hillocks

Body: heart, liver, umbilical cord

Limb: upper and lower limb buds, foot plate, wrist, hand plate with digital rays

Features

Development indices: number of semicircular ducts (1-3) and length of the paramesonephric duct.

Identify: pigmented eye, eyelid, nasolacrimal groove, external acoustic meatus, heart, digital rays, liver prominance, thigh, ankle, foot plate, umbilical cord

Carnegie Stages: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | About Stages | Timeline

Bright Field


Embryo in gestational sac	Embryo open sac

Embryo with placentation (ectopic)	Embryo in amniotic sac

Stage 18 Links: Embryo in gestational sac | Embryo open sac | Embryo 2 and gestational sac | Embryo 2 | Carnegie stage 18

Kyoto Collection

View: This is a dorsolateral view of embryo. Amniotic membrane removed.

Image source: Embryology page Created: 19.03.1999

Image source: The Kyoto Collection images are reproduced with the permission of Prof. Kohei Shiota and Prof. Shigehito Yamada, Anatomy and Developmental Biology, Kyoto University Graduate School of Medicine, Kyoto, Japan for educational purposes only and cannot be reproduced electronically or in writing without permission.