The Joseph cells extend from the caudal end of the anterior vesicle ( or cerebral vesicle ) to the boundary between myomeres 3 and 4, where the Hesse organs begin and continue nearly to the tail.
22.
A mammary crest usually stops growing at 8 weeks and its length is regressed starting at the caudal end and extending cranially, so that what remains is a round, ectodermic placode where the axilla develops.
23.
There is a long retractor muscle from the vesicle, and its stem is fixed internally to the back of the slug in the median line ( midline of the body ) near the caudal end ( tail end ) of the body.
24.
In the central part of the caudal end of the body, behind the ovary, there is likewise a glandular substance, of a reddish colour, folliculated and apparently branched, in connexion with the branches of the hepatic canals within the skin.
25.
This small group of neural cells is located between S1 and S2 or S2 and S3 and although Onuf s nucleus is located primarily in S2, it can extend to the caudal end of the first sacral segment or to the middle part of the third sacral segment.
26.
This, the amniotic fold, first makes its appearance at the cephalic extremity, and subsequently at the caudal end and sides of the embryo, and gradually rising more and more, its different parts meet and fuse over the dorsal aspect of the embryo, and enclose a cavity, the amniotic cavity.
27.
The cephalic part of the tube becomes the larynx, and its next succeeding part the trachea, while from its caudal end two lateral outgrowths, the right and left lung buds, arise, that branch into main ( primary ), lobar ( secondary ), segmental ( tertiary ), and subsegmental bronchi and lead to development of the lungs . The Hox complex, FGF-10 ( fibroblast growth factor ), BMP-4 ( bone morphogenetic protein ), N-myc ( a proto-oncogene ), syndecan ( a proteglycan ), tenascin ( an extracellular matrix protein ) and epimorphin ( a protein ) appear to play a role in development of the respiratory system.
