Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1984-6-20
pubmed:abstractText
Serial sections of 105 human embryos (including 20 silver preparations) from stage 11 (24 days) to stage 22 (54 days) were studied, and 23 graphic reconstructions were prepared. The hypoglossal nucleus is evident at stage 12 and becomes isolated from other efferent nuclei at stage 14. The first hypoglossal nerve fibers appear at stage 12. The roots unite at stage 14 and the main trunk arrives in the tongue at stage 15. Four occipital somites can be identified during stage 13, and the sclerotomic material forms two bilateral masses. The fourth sclerotome separates in stage 14 and develops like a vertebra. This and the remaining sclerotomic material form the basioccipital and exoccipital parts of the chondrocranium , which are the first to appear. Four occipital myotomes develop and grow towards the tongue as the "hypoglossal cord", which arrives prior to the hypoglossal nerve. The developmental similarity in the hypoglossal region between birds and mammals, combined with experimental studies in birds, renders it extremely likely that the hypoglossal musculature in mammals also is derived from occipital somites. The present study is the first in which this conclusion is adequately supported in the human. This investigation aids in the interpretation and timing of origin of variations (e.g., bipartite hypoglossal canal) and anomalies (e.g., persistent hypoglossal artery).
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0002-9106
pubmed:author
pubmed:issnType
Print
pubmed:volume
169
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
237-57
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1984
pubmed:articleTitle
The early development of the hypoglossal nerve and occipital somites in staged human embryos.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.