Carnegie stage 20

Introduction

Facts

Week 8, 51 - 53 days, 18 - 22 mm

Events

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

Mesoderm: heart prominence, ossification continues

Head: forebrain, eye, external acoustic meatus

Features

scalp vascular plexus, eylid, eye, nose, external acoustic meatus, auricle of external ear, arm, elbow, wrist, liver prominence, digital rays

Identify: straightening of trunk, pigmented eye, eyelid, nose, external acoustic meatus, scalp vascular plexus, 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

Kyoto Collection

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

Image source: Embryology page Created: 19.03.1999

Additional Images

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  Stage 20-23 limbs

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  Human embryonic shoulder girdle

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

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.

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Cite this page: Hill, M.A. (2024, June 9) Embryology Carnegie stage 20. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Carnegie_stage_20

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© Dr Mark Hill 2024, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G