Patterns of innervation of the lacrimal gland with clinical application.

Parasympathetic stimulation of the lacrimal gland is responsible for tear production, and this innervation originates from fibers conveyed in the facial nerve. After synapse in the pterygopalatine ganglion, postsynaptic parasympathetic fibers travel within the zygomatic and zygomaticotemporal nerves (ZTN) into the orbit. As described in most anatomy texts, ZTN communicates with the lacrimal nerve (LN) posterior to the gland and then secretomotor fibers enter the gland. This study was performed to gain a better understanding of the innervation of the lacrimal gland. Seventeen cadaver heads were bisected for a total of 34 sides, which then underwent dissection of the superolateral orbital region to observe the course for the LN and ZTN. Three variations of the course of the LN and ZTN were found. In 20 (60.6%) dissections it was documented that the ZTN entered directly into the lacrimal gland with no communication with the LN. In 12 (36.4%) of the bisected heads, ZTN had both a direct connection into the gland and a communicating branch with the LN. In only one (3.0%) bisected head, ZTN communicated with the LN before entering the gland as it is commonly described in anatomy texts. Our study reveals that the ZTN usually takes a different course than is classically described in most anatomy textbooks. A greater understanding of the typical course these nerves take may help surgeons identify them more easily and avoid damaging them.

The effect of degenerated neuron density of petrosal ganglion on the development of blood pressure variabilities after subarachnoid hemorrhage in a rabbit model: an experimental study.

AIM: The aim of this study was to determine the relationship between ischemic neurodegeneration, of the petrosal ganglion of the glossopharyngeal nerve, and BP fluctuations, after subarachnoid hemorrhage (SAH). MATERIAL AND METHODS: Twenty-four rabbits had their blood pressure and heart rhythms studied daily over 20 days. Then, the histopathology of the petrosal ganglion was examined in all animals. Normal and apoptotic neuron density of the petrosal ganglion and blood pressure values were compared statistically. RESULTS: Mean total volume of the petrosal ganglia was calculated as 0.9 ± 0.34/mm3. BP level of control group was 96.1 ± 2.1 mmHg; 116.5 ± 4 mmHg of mild hypertension (HT) group and 128.1 ± 3.6mmHg in the severe HT group. When the groups were compared to each other they were significantly different. The level of normal-apoptotic neuron in control group was 11,240 ± 802/mm³ -40 ± 6.3/mm³; 9730 ± 148.7/mm³ - 1560 ± 256.2/mm³ in the mild HT group and 6870 ± 378.8/mm³-4240 ± 628.2/mm³ in the severe HT group. When the groups were compared to each other there was significantly difference. CONCLUSION: Blood pressure variability observed in this study may be explained by ischemic neurodegeneration of petrosal ganglia caused by SAH. The results of this study suggest that petrosal ganglion ischemia has potential implications for the development of hypertension. These findings suggest that new treatment strategies should be considered for the treatment of SAH.

Parasympathetic innervation of the initial segments of the large intestine in cats.

The locations and morphometric characteristics of efferent parasympathetic neurons in the dorsal motor nucleus of the vagus nerve and the cruciform parasympathetic nucleus of the spinal cord, innervating the area of the ileocecal sphincter and the ascending and transverse segments of the colon, were studied. Horseradish peroxidase solution was injected beneath the serous membranes of these parts of the intestine in urethane-anesthetized cats. After 48 h, animals were subjected to transcardiac perfusion with a fixative mixture and sections of the medulla oblongata and spinal cord were prepared and processed by the Mesulam method. The results showed that all these parts of the large intestine received parasympathetic innervation from neurons in the ventrolateral part of the dorsal motor nucleus, which were uniform in terms of their morphometric characteristics. The number of neurons of this group sending axons to the ileocecal area was greater than the number of neurons innervating the ascending colon. A second group of neurons, which were smaller cells, was located in the same part of the nucleus and innervated the transverse colon. The transverse colon also received innervation from neurons in the cruciform parasympathetic nucleus of the spinal cord.

Anatomía del sistema linfático del miembro inferior / Anatomy of the lower limb lymphatic system

Desde el punto de vista anátomo funcional, el sistema linfático se divide en: corrientes linfáticas, ganglios linfáticos y linfa. A nivel del miembro inferior, al igual que ocurre en las venas, se diferencian dos corrientes linfáticas: superficiales y profundas. Un tercer sistema, el de los vasos linfáticos perforantes, comunicaría ambas corrientes. Los grupos ganglionares principales de la extremidad inferior están representados por los ganglios poplíteos y los ganglios inguinales; existiendo además ganglios secundarios tales como los tibiales anteriores, peroneos, tibiales posteriores, femorales e iliopélvicos. El sistema linfático del abdomen esta formado por los troncos linfáticos, los ganglios parietales (de la pared abdominal anterolateral y los retroperitoneales) y los ganglios viscerales. La linfa procedente de los miembros inferiores y de todo el plexo retroperitoneal es recogida por los troncos lumbares, que son el origen principal del conducto torácico (AU)

From the anatomical functional point of view, the lymphatic system is divided into: the lymphatic currents, lymphatic nodes and lymph. At the lower limb level, as happens in the veins, are differentiated two lymphatic currents: the superficial and the deep. A third system, of the perforant lymphatic vessels, links both currents. The principal node groups of the lower extremities are represented by the popliteal nodes and the inguinal nodes; there also exist secondary nodes such as the anterior tibial nodes, peroneal nodes, posterior tibial nodes, femoral nodes and iliopelvic nodes. The lymphatic system of the abdomen is formed by the lymphatic trunks, the parietal nodes (of the anteriolateral abdominal wall and the retroperitoneals) and the visceral nodes. The lymph proceeding from the entire retroperitoneal plexus is collected by the lumbar trunks, which are the principal origin of the thoracic duct (AU)

Cerebral vasodilatation induced by stimulation of the pterygopalatine ganglion and greater petrosal nerve in anesthetized monkeys.

Although brain cell viability depends largely on cerebral circulation, mechanisms of blood flow control, such as autoregulation, or of the pathogenesis of functionally impaired blood supply to brain regions, such as in cerebral vasospasm after subarachnoid hemorrhage, have not been clearly defined. Our recent studies support the hypothesis that nitric oxide, released from nitrergic nerves, plays a crucial role as a neurotransmitter in vasodilating cerebral arteries from primate and subprimate mammals. In the present study, we demonstrated, by using arterial angiography, that electrical stimulation of the pterygopalatine ganglion produced vasodilatation of ipsilateral cerebral arteries of anesthetized Japanese monkeys. The response was abolished by intravenous injections of N(G)-nitro-L-arginine, a nitric oxide synthase inhibitor. Denervation of the ganglion elicited cerebral vasoconstriction, indicating that vasodilator nerves from the vasomotor center were tonically active. Stimulation of the greater petrosal nerve, upstream of the pterygopalatine ganglion, also elicited cerebral vasodilatation, which was abolished by treatment with the nitric oxide synthase inhibitor and with hexamethonium, indicating that the nerve is in connection via synapses with the nitrergic nerve innervating cerebral arteries. Endogenous nitric oxide released from the nerve may contribute to the maintenance of blood flow in major cerebral arteries necessary to supply blood to the different brain regions. Without this influence, cerebral arteries might be constricted to the extent that blood flow is impeded. This is the first direct evidence indicating an important role of nitric oxide liberated by pre- and postganglionic nerve stimulation in the control of cerebral arterial tone in primates.