Manual of general, descriptive, and pathological anatomy (Volume 3).

  • Meckel, J. F. (Johann Friedrich), 1781-1833.
Date:
1832
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Licence: Public Domain Mark

Credit: Manual of general, descriptive, and pathological anatomy (Volume 3). Source: Wellcome Collection.

Provider: This material has been provided by the National Library of Medicine (U.S.), through the Medical Heritage Library. The original may be consulted at the National Library of Medicine (U.S.)

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    foramina. These branches are distributed to the posterior part of the muscles of the back, to the gluteus rnaximua and the skin which covers them. The posterior branches, the dorsal or lumbar (R. postici, s. dorsales, s. lumbales), of the lumbar nNyes diminish considerably in volume from the first to the last, so that t!._ 'ast two rarely extend to the skin, but are distributed only in the comay. belly of the sacro-lumbalis and multifidus spinse muscles. From the first sacral nerve to the fourth, the posterior branches again enlarge much. That of the fourth is the largest; the fifth is smaller, while the sixth is much more minute. § 1814. The anterior or abdominal branches (R. antici, s. abdomi- nales) of the lumbar nerves pass behind the psoas magnus muscle, unite not only with each other, but beside the first with the anterior branch of the last dorsal, the last with the anterior branch of the first sacral, to form the lumbar plexus, the lumbar ganglion of the ganglionnary nerve, and produce the nerves we are about to describe. The anterior branches of the sacral nerves, principally the first, second, third, and fourth, concur in the same manner to form the sacral plexus to which the fifth contributes least, and the sixth takes no part when it exists. Some ramifications arise from the anterior twigs after their union, some of which, the smaller ones, are usually formed by the filaments of a single nerve, while others which are larger, arise from the union of fasciculi from several nerves. The first are principally the external pudic nerve, several branches for the muscles in the lumbar region, the skin of this region and the common integuments of the inguinal region, the gluteal nerves and the inferior and middle hemorrhoidal nerves. The second are the three nerves of the lower extremities, the obtu- rator, the crural, and the gluteal nerve. A. SMALL NERVES WHICH ARISE FROM THE ANTERIOR BRANCHES OF THE LUMBAR AND SACRAL NERVES. § 1815. First and second lumbar nerve. From the first and second lumbar nerve, especially from the inferior extremity of the plexus be- tween them, arises the external pudic or the genitocrural nerve (JV. pudendus extemus, s. spermalicus extemus, s. inguinalis, s. genito-cru- ralis), which passes between the superior digitations of the psoas mus- cle, arives at the anterior face of this muscle, on which it goesfrom behind forward and from above downward, and divides within the pelvis into branches which all emerge from the inguinal ring. Among these, the most considerable which are always the continuation of the trunk, arrive at the spermatic vessels, and are distributed in the male in the cremaster muscle and its coats, and in the female in the round liga- ment of the uterus, and anastomosing with the inferior pudic nerves, terminate in the glands and integuments of the inguinal region. The external passes under the crural arch, penetrates the aponeurosis, is dis- Vol. III. 3