File:Human embryonic shoulder girdle 02.jpg

Human Embryonic Shoulder Girdle

Semi-schematic drawing of semi-coronal section of right clavicle of an 18 mm. embryo.

All the parts shown save the subclavius muscle were shown in the section drawn, but the subelavitus was added from its appearance in several sections.

Notice how the sternal segment overrides the acromial segment of the clavicle.

Legend

• A.p - acromion process
• B.1 - bone of sternal segment
• B.2 - bone of acromial segment
• Ct.b. - pre- cartilaginous bridge unossified and connecting acromial and sternal segments
• C. Cl. Lig. - coraco-clavicular ligament
• C - coracoid process
• Cl.M. - cleido-mastoidmuscle
• C.Cl.L. - costo- clavicular ligament
• R.1 - first rib
• S. M. - subclavius muscle

Original file name: FIG.4. Semi-schematic drawing of semi-coronal section of right clavicle of an 18 nm. embryo. (figure scaled and background cleared, above text modified from figure legend)

18mm CRL (Robinson) embryo

• difficult to estimate the amount of shrinkage in this historic material.
• Week 7 Stage 19 CRL 16 - 18 (Somites 48 - 51)

Reference

Fawcett The Development and Ossification of the Human Clavicle. J Anat Physiol: 1913, 47(Pt 2);225-34 PMID 17232952 | PMC1289013

J Anat Physiol. 1913 Jan;47(Pt 2):225-34. The Development and Ossification of the Human Clavicle. Fawcett. University of Bristol.

<pubmed>17232952</pubmed>