Prenatal development of the adrenal gland in the one-humped camel (Camelus dromedarius).

UNLABELLED: With 14 figures and 3 tables SUMMARY: Each adrenal gland consisted of cortex and medulla that developed from different embryological origins and presented different cellular organization. One hundred male or female camel embryos or fetuses with crown vertebral rump lengths (CVRL) that ranged from 0.8 to 117 cm were examined. The adrenal cortex, which is derived from intermediate mesoderm, was first observed in the 0.8-cm CVRL camel embryo. The adrenal cortex initially was combined with the gonad as a thickened region of proliferating cells derived from splanchnic intermediate mesoderm. Adrenocortical tissue was first separated from the gonadal tissue in the 2-cm CVRL camel fetus and was observed as a separate dorso-medial mass of cells. At 2.5-cm CVRL, the adrenocortical tissue was surrounded by a capsule of undifferentiated mesenchymal cells, except at its proximal pole, where an invagination was located through which chromaffinoblast cells entered the cortex. The chromaffinoblast cells migrated from the neural crest to form the medulla of the developing adrenal gland. In the 3.5-cm CVRL camel fetus, the adrenocortical cells differentiated into two layers: the inner fetal cortex and the outer definitive cortex. As development proceeded, the fetal cortex degenerated and the definitive cortex formed the zona glomerulosa and zona fasciculata. The zona reticularis did not form until the end of gestation. During prenatal life, the adrenal medulla was much thicker than the cortex.

Innervation of the pelvic limb of the adult ostrich (Struthio camelus).

The pelvic limb of the ostrich is innervated by the lumbar and sacral plexuses. The lumbar plexus gave rise to several nerves (N.s) including, N. coxalis cranialis, lateral and cranial femoral cutaneous N.s, N. femoralis, cranial, caudal and medial crural cutaneous N.s, and N. obturatorius. The remaining nerves emanated from the sacral plexus. The N. iliotibial, N. ischiofemoralis, N. iliofibularis, and N. coxae caudalis were distributed in the thigh, while the N. ischiadica, which terminated as the tibial and fibular N.s that innervated the leg and foot. The tibial N. gave rise to the parafibular N. then divided to form the Nn. suralis medialis and lateralis. The N. suralis medialis continued as the N. metatarsalis plantaris medialis. The parafibular N. continued as the N. plantaris lateralis, which terminated as the R. digitalis of the fourth digit. The fibular N. terminated as the superficial and deep fibular N.s. The superficial fibular N. continued as the N. metatarsalis dorsalis lateralis and divided into two digital N.s to the third and fourth digits. The deep fibular N. crossed the ankle joint and continued as the N. metatarsalis dorsalis medialis that continued as the R. digitalis of the third digit. In general, the innervation of the pelvic limb of the ostrich was similar to the pelvic limbs of several different species of domesticated birds, including the chicken. We discuss the few differences as well as appropriate sites to perform nerve blocks for the lateral and medial dorsal and the lateral plantar N.s.

The arterial supply of the pelvic limb of the adult ostrich (Struthio camelus).

Blood to the pelvic limb of the ostrich is provided by the external iliac and ischiatic arteries that arise from the descending aorta. The external iliac artery (a.) gave rise to the pubic a. that supplied the obturator muscles and continued as the femoral a. The femoral a. gave off three branches: (1) cranial coxal a. to muscles above the pre-acetabular ilium; (2) cranial femoral a. to muscles cranial to the femur, the gastrocnemius muscle, hip and stifle joints and (3) medial femoral a. to muscles caudal and medial to the femur. The ischiatic a. gave rise to the caudal coxal a. that supplied muscles caudal to the femur, muscular branches to the iliotibialis lateralis muscle and to the deep femoral a. that supplied the iliofibularis muscle, cutanea femoralis caudalis and lateralis aa., and branches to the flexors of the leg and knee joint, then terminated as the sural and popliteal arteries. The sural a. supplied most of the flexors of the foot. The popliteal a. supplied the knee joint and flexors of the leg, and then terminated as the cranial and caudal tibial arteries. The caudal tibial a. supplied flexors of the foot. The cranial tibial a. provided four branches to the knee and ankle joints and to the leg. The cranial tibial a. continued into the foot as the common dorsal metatarsal a., which gave off seven different branches to the ankle and foot. With few exceptions, the arteries of the ostrich pelvic limb are similar to those of domestic fowl.