Structure of the Carotid Sinus of the Dromedary Camel (Camelus dromedarius)

The morphology of the terminal segment of the common carotid artery of the camel was studied. It was found that this artery terminated by giving off a patent internal carotid artery and continuing as the external carotid artery. A presumptive carotid sinus was present at the region of origin of the internal carotid. Similar to that of other mammals, the carotid sinus of the camel was characterized by a comparatively thin vascular wall rich in elastic fibres. With the electron microscope, free (non-encapsulated) afferent endings, efferent endings, encapsulated axons and bundles of unmyelinated and myelinated nerve fibres were found in the wall of the presumptive carotid sinus. The free afferent endings closely resembled baroreceptor endings of the carotid sinus of other mammalian species in their mitochondrial content and the presence of abnormal organelles such as lamellar bodies, vesicular mitochondria and dense bodies. They were regarded as slowly adapting baroreceptors. The presumptive efferent endings were considered adrenergic whereas the encapsulated axons were thought to be the proximal parts of encapsulated sensory nerve endings.     

Prenatal Development of the Eye Tunics in the Dromedary Camel (Camelus dromedarius)

Studies of ocular development in the dromedary camel (Camelus dromedarius) have not been reported previously. The aim of the present investigation was therefore to document the major landmarks and the time course in the prenatal development of the eye tunics in dromedary camel and its accommodation with the surrounding hard environment of the desert. Serial histological sections of dromedary camel embryos and foetuses were used. Age estimation was made on the basis of gestational size, crown vertebral‐rump length (CVRL), which ranged 1.2–110 cm. The eye of the dromedary camel developed in a similar manner to that of the human and domestic animals eyes; the principal differences were in the time of occurrence of certain developmental events, pigmented peripheral cornea near the limbus, a remarkably thickened Descemet's membrane and pigmentation in the corneo‐scleral junction, which represent an adaptive modification in relation to a severe environment.     

Ultrastructure of Camel (Camelus dromedarius) Spermatozoa

Spermatozoa collected from the caudae epididymidis of six camels were examined by phase contrast, scanning electron and transmission electron microscopy. A comparison of the morphology of the camel spermatozoa with that of other domestic animals is presented.     

The Poll Glands of the Dromedary (Camelus dromedarius): Ultrastructural Characteristics

The poll glands of the camel are tubuloalveolar glands. They consist of lobules separated by interlobular connective tissue. Adrenergic axons and blood vessels including fenestrated capillaries are present in the intralobular connective tissue in close proximity to the secretory cells. The prominent features of the secretory cell cytoplasm are many mitochondria, smooth endoplasmic reticulum, and many vesicles in various secretory stages.
It is concluded that the secretory cells have apocrine as well as merocrine modes of secretion. The glands may have the ability to uptake hormones and concentrate them. Additional work is needed before considering these glands as steroid-secreting glands.     

Anatomic Study of the Veins and the Arteries of the Penis of the Camel (Camelus dromedarius)

A neoprene latex and gelatin injection corrosion study of the arteries and veins of the camel penis was conducted utilizing three intact male camels and ten excised penises. The gross anatomic distribution of arteries and veins supplying the penis is described and compared with that of other ruminants and with the horse.     

Ultramicroscopical Study on Thyrocalcitonin Cells in the Camel (Camelus dromedarius)

Thyrocalcitonin cells (C cells) were predominantly demonstrated in the ultimobranchial (UB) structures of the thyroid gland of one‐humped camels. The UB population was observed as clear cells, either singly distributed or as groups of cells between the component cellular elements lining the UB structures. They displayed various shapes: oval, pear‐like, rounded, cubical, columnar and or ellipsoid. Those populating the cell nests or solid cellular masses were almost polygonal or ovoid in shape. The cytoplasm contained well‐developed golgi complexes, several mitochondria and characteristically presented rounded or oval membrane‐bound electron dense granules of different sizes. The latter granules were irregularly distributed within the cytoplasm especially at the vascular pole. The nucleus of C cells was relatively large, indented, occupying a more or less central position in the cytoplasm. It presented various chromatin contents; the heterochromatin variety was predominantly demonstrated at the marginal zone. However, the euchromatin occupied a more central position within the nucleus.     

Specialised Vascular Structures in the Pododerma of the Camel Footpad (Camelus dromedarius)

Transversal, horizontal and sagittal sections of the brain were stained by the ancient but efficient Mulligan method, a procedure that establishes a clear macroscopic difference between the white and grey substances. Different structures of each section were studied and most of the details were identified and named according to the NAV. All sections were projected onto the whole brain. By means of this easy and basic procedure the students increase their understanding of (1) the size and/or the form and/or the topography of several prominent structures of the brain, (2) the general distribution of the substancia alba and grisea, and they begin to understand the complexity of the brain.     

Contribution to the Paranasal Sinuses of the One Humped Camel (Camelus dromedarius)

A gross anatomic and radiological examination of the paranasal sinuses of the camel is described. Radiological examination was enhanced through the use of a barium sulphate paste.     

Observations on the Clinical Examination of the Camel (Camelus dromedarius) in the Field

Camels usually inhabit remote areas, where diagnostic facilities and laboratories are very scarce. The species differences between the camel and other domestic animals necessitate some specific examination techniques. The objective of this study was to describe the clinical examination methods and sources of common errors that require special consideration in the camel. Young camels are examined in the standing position, while adults require restraint. Restraining procedures, both standing and in sternal recumbency, are described. New equipment and a crush were designed. The body temperature of the camels examined fluctuated from 35.7 to 38.9 degrees C, being lowest in the morning and highest in the afternoon; high temperature in the morning is indicative of fever, while high afternoon temperatures could be hyperthermia. It was difficult to take the pulse rate for routine procedures. The heart rate ranged from 35 to 50 per min; there was no difference between the heart rate in the morning and in the afternoon. The mean respiratory rate was 11 per min and respiration was of thoracol-lumbar type. The mucous membranes of the eye were an important site for appreciating signs of discoloration, while those of the mouth, rectum and vagina were unsuitable. The left flank was the best site for determining the rate of rumen contractions, which was 3+/-1.2 every 5 min, as determined by auscultation; counting the contractions by the application of the fist was difficult. The palpable external lymph nodes were the parotid, maxillary, prescapular, inferior cervical, thoracic, cubital, ilial and popiteal; they are large and can be seen on inspection in healthy animals, so that was not indicative of disease. A list of diagnostic indicators for the rapid diagnosis of ten endemic camel diseases was generated from the empirical signs.     

Coronary arterial anatomy of the one-humped camel (Camelus dromedarius)

The detailed coronary arterial anatomy of seven camels was studied and compared with that of horses and cattle. In camels, there is a bilateral coronary supply, the right coronary artery being the larger. The left coronary artery follows the same pattern as that in horses. The ramus collateralis proximalis in camels separates off some distance away from the origin of the ramus interventricularis paraconalis, as in horses, whereas it separates off very quickly in cattle. The ramus collateralis distalis has two branches in camels, whereas the left distal ventriculi ramus does not branch. The ramus angularis is also absent but the left distal atrii ramus is present.Abbreviations LCR left ramus circumflexus - RCR right circumflexus ramus - RIS ramus interventricularis subsinosus - RIVP ramus interventricularis paraconalis     

Observations on the Fine Structure of the Liver in the Camel (Camelus dromedarius)

The structure of macroscopically inconspicuous livers in 23 adult camels (Camelus dromedarius) was studied by light and transmission electron microscopy. A well-developed connective tissue characterizes the camel liver. Thick trabeculae divide the liver parenchyma into lobules. Portal tracts and central veins are surrounded by a variable amount of fibrous tissue. In the perisinusoidal space (DISSE), collagen fibres form a dense three-dimensional network around the sinusoids. A mild to moderate fatty infiltration is present in hepatocytes of all animals. In the epithelial cells of the bile ducts, small to medium sized lipid inclusions are a common feature. The ultrastructure of hepatocytes in the camel liver corresponds to that of other domestic mammalian species. The endothelial cells lining the sinusoids show a multiple fenestration and are surrounded by a discontinuous basal lamina. Fat-storing cells are numerous and contain lipid droplets varying in size, number and electron density from one cell to another.     

Some Aspects of Macroscopic Studies of the Placentation in the Camel (Camelus dromedarius)

The paper presents some salient aspects of a study on the placentation of camel at gross, light and electron microscopic levels. The study involved factors analysis on five pregnant uteri from camel slaughter house in Yazd, Iran.
The experimental observations confirmed that unlike other animals, in camel, the fetus only developed in the left horn of the uterus. Based on the distribution type of the chorionic villi, in camel, similar to horse, the placenta was found to be in diffused form. At light microscopic level, the results revealed six layers between the fetal and maternal blood. From this it inferred that camel's placenta was also of epitheliochorial form.
The detailed examination further showed that similar to cow and sheep umbilical cord in camel was also limited to the amniotic sac but it contained two arteries, two veins and one urachus. Little amount of elastic fibers were also observed in the histological and electron microscopical sections. At the electron microscopic level, both binucleated and mononucleated cells in trophoblastic layer were confirmed.     

Dynamics of Follicular Fluid in One‐humped Camel (Camelus dromedarius)

In the present study, ovarian follicular fluid and serum biochemical, hormonal, electrolytes and amino acids profiles in female dromedary camel (Camelus dromedarius), were investigated. Fluid from small (2–6 mm) and large follicles (7–20 mm) and blood samples were collected from 25 clinically healthy adult female camels. The concentrations of glucose, cholesterol, triglycerides, high‐density lipoproteins, urea, total proteins, albumin, globulin, fibrinogen, alanine aminotransferase, aspartate aminotransferase and tri‐iodothyronine were lower (p ≤ 0.05) in large follicles when compared with the small follicles. However, the concentrations of low‐density lipoproteins, uric acid, creatinine, alkaline phosphatase and acid phosphatase in small and large follicles did not differ. The concentrations of oestradiol 17‐β and progesterone were higher (p ≤ 0.05) in large follicles. The serum concentrations of these hormones were many folds lower (p ≤ 0.05) than those of follicular fluid. Among electrolytes, the concentration of phosphorus was higher (p ≤ 0.05) in the large follicles, while that of potassium and chloride were lower (p ≤ 0.05) in the small follicles. Serum concentrations of sodium, chloride, calcium and phosphorous were higher (p ≤ 0.05), while that of potassium lower (p ≤ 0.05) than corresponding concentrations in the follicular fluid. The concentrations of leucine and arginine were higher (p ≤ 0.05) in follicular fluid when compared with serum concentrations, while the reverse was true for other amino acids. In conclusion, this study is indicative of either low or high concentrations of certain biochemical metabolites, hormones, electrolytes and amino acids in small and large follicles for the individual roles that they play in the growth and development of follicles in the one‐humped she‐camel.     

Camel (Camelus dromedarius) contagious ecthyma in the Sudan. A case report.

The clinical and pathological features of the contagious ecthyma in camel calves in the Sudan were investigated. The animals were inappetant, emaciated and slightly anaemic. The disease was characterized by skin lesions around the lips and nostrils with occasional involvement of mucocutaneous junctions. The pathology includes vaculoar changes of the epithelial layers. Affected areas were ulcerated, haemorrhagic and with frequent secondary bacterial surinfection. Negative contrast electron microscopy has proven to be an extremely useful procedure for quick differential diagnosis.