Nutrient arteries of the human sciatic nerve.

The sources of blood supply of the human sciatic nerve were investigated in 32 nerves from 28 cadavers (16 men and 12 women). It was shown that the sciatic nerve is supplied by 4-8 nutrient arteries arising from inferior gluteal, medial circumflex femoral, perforating and popliteal arteries.

Structure of the intramedullary vascular net of the spinal cord in Wistar rats.

The number, diameter and structure of the capillary vessels differ in particular parts of the spinal cord. Density of the vascular net is much greater within the gray substance. Also the density differs in particular parts of the gray substance at the same spinal level.

Arterial blood supply of the thoracic and lumbosacral parts of the spinal cord in Wistar rats.

The thoracic and lumbosacral parts of the rat's spinal cord are supplied by 1) ventral and dorsal radicular arteries which contribute to vascular trunk passing along the spinal cord, and 2) ventral and 2) dorsolateral spinal arteries. The dorsal radicular arteries in the thoracic part arise bilaterally at the same level and are more numerous and of lesser diameter than corresponding ventral radicular arteries. In the lumbar part the dorsal radicular arteries are also more numerous than ventral ones which were mainly found at the levels of L1, L2 and L3. The sacral radicular arteries are present sporadically at the S1.

External veins of the spinal cord it the Wistar rats.

In 54 Wistar rats the number, diameter, and topography of veins on the ventral and dorsal surfaces of the spinal cord were investigated. The spinal cord in rats possesses well developed venous net forming meningeal venous system. The veins pass independently of arteries and they consists of single trunks with intervals passing on the ventral and dorsal surfaces of the spinal cord as well as dorsal and ventral radicular veins draining to the epimeningeal venous plexus.

Changes in the peripheral nerves in rats induced by vibration.

Effects of long-term low frequency vibrations on the structure of the sciatic and plantar nerves were examined in Wistar strain rats. Decrease in total number of nerve fibers was noted. This was associated with altered distribution of myelinated fiber diameters, disturbances in axon structure and with fiber demyelination. The extend of lesions depended upon duration of exposure and distance from the source of vibrations.

Sources of blood supply and angioarchitecture of nerves in limbs of the white rat.

Sources of blood supply and structure of vascular network were described in nerves of forelimbs and hindlimbs of 30 Wistar strain rats. The vessels were injected through the left ventricle of the heart with aqueous solution of gelatin, stained with black ink. Following fixation in formaldehyde samples were taken at various points of the median, ulnar, radial, musculocutaneous, femoral, nerves and their terminal branches. The preparations were made translucent in methyl benzoate. The observations point to constant sources of regional vessels supplying nerves of forelimbs and hindlimbs and to a similar angioarchitecture of studied nerve trunks at their entire length. Branches of regional vessels which enter the nerves form a fine mesh network in epineurium. Within nerve fascicles capillary network forms a uniform cord of vessels, the structure of which resembles that of human sciatic nerve.

Studies on density of capillary network in the course of nerves in the white rat.

Density of capillary network was examined in the course of nerves of frontal and rear extremities in the white rat, in various portions of the nerves. At the same levels, number of nervous fibers per mm2 of the area was scored as well as diameters of myelinated fibers was recorded in proximal and distal fragments of chosen nerves. Decreased density of capillary network was detected in peripheral portions of the nerves, which was paralleled by an increase in number of myelinated fibers and a decrease in their diameter.

Blood vessels of epineurium of ischaidic nerve in the man.

Blood vessels were examined within epineurium of 38 ischiadic nerves from corpses of men and women aging 26 to 65 years. The studies demonstrated that large eyeholed and fine meshed vascular plexuses are formed in both components of ischiadic nerve. The plexus maintain communication with axial arterial and venous vessels which run in the outer layer of epineurium and with interfascicular vessels located in connective tissue of interfascicular epineurium.

Ganglia of the cervical part of the sympathetic trunk in the white rat. Sources of blood supply and angioarchitectonics.

Each ganglion of the cervical part of the sympathetic trunk in white rat is supplied by several arteries of diameter of 15--30 micrometers. The arteries arise from three sources: 1) large vessels adjacent to the ganglia, 2) vascular net of connective and muscular tissues surrounding the ganglion, 3) vessels of nerves and interganglionic rami. The vascular network of the cervical sympathetic ganglia was connected with the vascular plexus of the vagus nerve and cervical as well as brachial plexuses.

Sources and variations of the arteries supplying the cervical part of the spinal cord in white rat.

Investigations were performed in 36 rats of Wistar strain. In 50% of cases the accessory arteries originating from the vertebral artery and connections of the ventral spinal artery with the first radicular arteries were found. The dorsal spinal arteries always originated from the intracranial part of the vertebral artery, and in many instances their discontinuity at the level of C4--C6 was observed. Besides the spinal arteries the cervical part of the spinal cord is supplied by radicular arteries which are more frequent in rats than in human.