Fetal Dog Research Articles

Histological Studies on the Innervation of Clitoris in the Latter Fetal Stage of Dog

In the fetal stage of a bitch, the corpus clitoridis already extends longitudinally along the median line of the ventral wall of the sinus urogenitalis, but unlike that in adult dog which is formed of fat tissue in its proximal half, is composed of closely packed connective tissue cells. The glans clitoridis hangs down to the ventral in the distal half of the sinus urogenitalis, but as in the latter fetal stage, the praeputium and the glans clitoridis are continued by a common epithelium, the fossa clitoridis found in adult dog is not yet formed. This common epithelium is powerfully developed and throws out many large petal-like epithelial processes toward the praeputium. The corpus clitoridis is already well formed.The n. dorsalis clitoridis on either side runs alongside the a. dorsalis clitoridis on the lateral of the v. dorsalis clitoridis running along the median line in the proximal part of the corpus clitoridis, but more distalwards, the dorsal vein diverges to the lateral and runs into the midst of the bundles of the n. dorsalis clitoridis together with the a. dorsalis. In this course, the n. dorsalis sends out small branches into the immature tunica albuginea. These nerves and blood vessels, upon reaching the base of the glans clitoridis, turn further lateralwards, the blood vessels coming into close connection with the corpus cavernosum clitoridis and the n. dorsalis clitoridis, sending out some rami into the praeputium clitoridis and branching out further, run up further in the glans. The n. dorsalis upon reaching the middle height of the glans, divides up into many fine branches on either side of the corpus glandis, which radiate toward the superficial layer of the glans.As in adult dog but unlike in the case of man, no PACINIan body was found throughout the running course of the n. dorsalis clitoridis in fetal dog.Unbranched and simple branched terminations may be seen in the tunica albuginea in dog's fetus, but no genital nerve body type III as observed in adult dog is yet formed in fetal stage. This is in agreement with what YAMADA has found in human fetus.The development of sensory terminations in the haired skin of the outer plate of the praeputium clitoridis is yet very poor. The distribution and the terminal mode of sensory fibres in the inner plate of the praeputium are about the same as that in the glans clitoridis. In this fetal stage, to speak nothing of the genital nerve bodies Types I and II, no any complex branched terminations are ever formed in the glans clitoridis. The sensory terminations in this part, as was in the case of human fetus, consist only in unbranched and simple branched terminations, except some intraepithelial terminations in the common epithelium above. The latter comprise to Types, the I, like those in human fetus, consisting of complex ansal terminations and the II, unlike those in human fetus, of long-drawn unbranched terminations. In this latter fetal stage, the degeneration of such intraepithelial fibres is considerably advanced, so that the number of such fibres in active service is rather low.

On Innervation, Especially, Sensory Innervation of Rectum and Anus in Canine Fetus

In a canine fetus of the later fetal stage, the anal mucous part, containing the zonae intermedia and columnaris, is much smaller in area than that in human fetus. Tne intermediate zone is lined with a bladder-like tsratified epithelium poorer in development than in human fetus. No papillae are formed out of the propria into this epithelium, as little in fetal as in adult dogs. The propria in this as well as in the columnar zone is composed of a connective tissue containing abundant spindle-formed connective tissue cells, and no longitudinal muscle fibres extending down from the muscularis mucosae of the rectum is yet formed between the propria and the submucosa of a similar tissue, as was in the case of the human anus.In the zona columnaris, the columnae are lined with a 3-4-rowed cylindrical or a flat epithelium, and the sinus with a tall cylindrical epithelium. Unlike that in human fetus, papillae are found in formation out of the propria into these epithelia, even rather markedly in the part nearer the rectum. Anal canals are formed beginning in the epithelium of the zona columnaris and running down along the subepithelial layer before ending in blind sacs, but in number, these are much smaller than in human fetus. The epithelium here is of stratified cylindrical type.The proctal glands are already in formation. These are found, beside within the mucosa and the tunica muscularis of the anus, also not rarely extending into the rectal mucous membrane. But in fetal dog, they are as yet not nearly full-grown, their end parts being mere epithelial cords and the ducts being indicated by a 2-3-rowed cylindrical epithelium, no sign of their specific structure being yet apparent.The muscularis of the rectum is composed of an inner circular and an outer longitudinal layers extending down as far as the intermediate zone of the anus, the former layer thence passing over into the m. sphinter ani internus. On the other hand, the outer longitudinal layer partly reaches down along the outside of the m. sphincter ani externus, and gaining in strength, finally arrives at the inside of the coxal bone to end there. I wish to call this the m. dilatator ani.The ganglia in the AUERBACH's plexus are formed, beside between the two muscle layers above, often enough inside the muscle layers as well and in a small number in the m. dilatator ani too. Smaller ganglia are formed also in the MEISSNER's plexus. Such ganglia are found in the anus as well, but in development these are much poorer than those in the rectum. The ganglion cells are still very ill developed and their multipolarity is as yet sufficiently manifest, so that they are seen as more apolar round cells.The nerve fibres coming into the distal part of the rectum run via the AUERBACH's plexus into the MEISSNER's plexus and come into closest relation with these plexuses. Beside the very fine vegetative fibres, a small number of thick sensory fibres are also found among them. The terminations of the vegetative fibres are already well developed into full-grown STOHR's terminal reticula.The sensory fibres, in company with the vegetative fibres, run also via the AUERBACH's plexus into the MFISSNER's plexus, and thence, parting from the vegetative fibres in most cases, into the subepithelial connective tissue layer to form their terminations there. Since in the dog fetus, the formation of the muscularis mucosae in the rectum is as yet not clearly defined, it is often undefinable in which layer a sensory fibre ends, but it seems that most of them end at the plane where the boundary between the submucosa and the muscularis mucosae is to be formed, except a comparatively few that penetrate further into the propria and attain the vicinity of the intestinal crypts. Their terminal mode is much simpler than those in adult dogs, unbranched terminations occupying the largest majority, and only a few bifurcated terminations representing the branched terminations found here.

The ponderal growth of the ovaries and uterus in the fetal dog.

The Anatomical RecordVolume 125, Issue 4 p. 731-744 Article The ponderal growth of the ovaries and uterus in the fetal dog Homer B. Latimer, Homer B. Latimer Departments of Anatomy, University of Kansas and University of MissouriSearch for more papers by this author Homer B. Latimer, Homer B. Latimer Departments of Anatomy, University of Kansas and University of MissouriSearch for more papers by this author First published: August 1956 https://doi.org/10.1002/ar.1091250407Citations: 4AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Citing Literature Volume125, Issue4August 1956Pages 731-744 RelatedInformation

Growth of the hypophysis, thyroid and suprarenals in the fetal dog.

The Anatomical RecordVolume 120, Issue 2 p. 495-514 Article Growth of the hypophysis, thyroid and suprarenals in the fetal dog Homer B. Latimer, Homer B. Latimer Department of Anatomy, University of KansasSearch for more papers by this author Homer B. Latimer, Homer B. Latimer Department of Anatomy, University of KansasSearch for more papers by this author First published: October 1954 https://doi.org/10.1002/ar.1091200209Citations: 3AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume120, Issue2October 1954Pages 495-514 RelatedInformation

The growth of the kidneys and the bladder in the fetal dog.

The growth of the kidneys and the bladder in the fetal dog.

Peptone Shock in Fetal Dogs and its Significance in the Metabolism of Histamine

It has previously been shown1, 2 that “peptone” shock in dogs, which is produced by the intravenous injection of proteoses, is accompanied by and due to the liberation of histamine from the tissues of the injected animals. The source of, and the reasons for, the storage of histamine in the tissues are only incompletely understood. It seemed, therefore, of interest to determine whether histamine is present in the tissues of fetal animals, and if it is present, to determine whether it can readily be liberated with resulting shock reactions such as occur in adult animals. The studies of Code3 indicate that the traces of histamine which are normally present in the blood of dogs occur in the cellular elements and not in the plasma. This would imply that the histamine normally circulating in the blood of a pregnant dog would not be accessible to the fetus. As there is no opportunity for the formation of histamine within the fetus by bacterial decomposition of histidine in the fetal intestine, it may be presumed...