Carnegie stage 21
Introduction
Facts
Week 8, 53 - 54 days, 22 - 24 mm
Events
Ectoderm: sensory placodes, nasal pits moved ventrally, fourth ventricle of brain
Mesoderm: heart prominence, ossification continues
Head: nose, eye, external acoustic meatus
Body:straightening of trunk, heart, liver, umbilical cord
Limb: upper limbs longer and bent at elbow, foot plate with digital rays begin to separate, wrist, hand plate with webbed digits
Features
scalp vascular plexus, eylid, eye, nose, auricle of external ear, arm, elbow, wrist, knee, notch between digital rays, umbilical cord
Identify: straightening of trunk, pigmented eye, eyelid, nose, external acoustic meatus, scalp vascular plexus, webbed digits, liver prominance, thigh, ankle, foot plate, umbilical cord
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Kyoto Collection
View: This is a dorsolateral view of embryo. Amniotic membrane removed.
Image source: Embryology page Created: 19.03.1999
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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.
Cite this page: Hill, M.A. (2024, April 23) Embryology Carnegie stage 21. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Carnegie_stage_21
- © Dr Mark Hill 2024, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G