The common carotid artery (CCA) bifurcation is of clinical importance due to its vascular access site for intravascular intervention. Additionally, it is also one of the most common sites of atherosclerotic plaque formation. There are numerous studies on the diameters of CCA, internal carotid artery (ICA), and external carotid artery (ECA) in adults, but few studies on newborns. Cadaver and angiographic studies have shown dimensional variations in the carotid arteries within/between individuals and also between different sexes. It is well known that the initial lesions of atherosclerosis begin very early in fetal life. Therefore, it is important to know the anatomical details of the CCA and its branches. In the present study, the neck regions of 20 (11 males and 9 females) fixed newborn cadavers were dissected. The CCAs were cut below the bulb of the carotid bifurcation further; ICA and ECA were cut above the bulb of the carotid bifurcation. The internal diameters of the CCA, ICA, and ECA were measured using a light microscopy. ECA/CCA, ICA/CCA, ICA/ECA ratios, and outflow to inflow area ratio were calculated. The mean outflow to inflow area ratio was 1.14+/-0.28. Our results highly correlated with the defined optimal ratio (1.15). The ECA/CCA, ICA/CCA, and ICA/ECA ratios were 0.78+/-0.12, 0.71+/-0.13, and 0.93+/-0.16, respectively. There were no statistically significant differences between male and female and also between right and left sides. These findings are of importance in understanding the anatomy of carotid artery during newborn period.
The celiac trunk is the widest ventral branch of the abdominal aorta. The unusual embryological development of the ventral splanchnic arteries can lead to considerable variations. During the dissection of a 54-year-old male cadaver as a rare variation, a celiacomesenteric trunk was observed. The rare occurrence of this variation is stated to be 1%-2.7%. As in the other case, the celiac trunk and the superior mesenteric arteries arose from a common trunk at the level of L1. This case of celiacomesenteric trunk is described in detail, which can be of value in the operative procedures of the upper abdomen.
The stimulation or ablation of cerebellar structures has produced a variety of visceral responses, indicating a cerebellar role in visceral functions. Studies using anterograde and retrograde tracing methods have revealed connections between the hypothalamus and cerebellar structures. The aim of this study is to investigate the cerebellar connections of the dorsomedial (DMH) and posterior hypothalamic nuclei using retrograde axonal transport of horseradish peroxidase (HRP). In the present study, micro‐injection of HRP restricted within the borders of the DMH showed that the projections of this nucleus are not uniform throughout its extent. The posterior DMH receives projections from the cerebellum, whereas the anterior DMH does not. These projections were from the (greatest to least concentration) lateral (dentate), anterior interposed (emboliform), and medial (fastigial) cerebellar nuclei. In addition, both the anterior and posterior DMH receive projections from various areas of the brainstem which confirms earlier studies and provides detailed descriptions. This study also demonstrates the distribution of labelled neurons to cerebellar and brainstem nuclei following HRP injection into the posterior hypothalamic nucleus. It provides clear evidence for a direct cerebellar nuclei‐posterior DMH and cerebellar nuclei‐posterior hypothalamic nucleus connections. We suggest that the brainstem reticular nuclei and other connections, such as the solitary, trigeminal and vestibular nuclei, of both DMH and posterior hypothalamus may contribute to the indirect cerebellohypothalamic connections. These observations offer a new perspective on the question of how the cerebellum may influence autonomic activity.
The posterior hypothalamic nucleus has been implicated as an area controlling autonomic activity. The afferent input to the nucleus will provide evidence as to its role in autonomic function. In the present study, we aimed to identify the detailed anatomical projections to the posterior hypothalamic nucleus from cortical, subcortical and brainstem structures, using the horseradish peroxidase (HRP) retrograde axonal transport technique in the rat. Subsequent to the injection of HRP into the posterior hypothalamic nucleus, extensive cell labelling was observed bilaterally in various areas of the cerebral cortex including the cingulate, frontal, parietal and insular cortices. At subcortical levels, labelled cells were observed in the medial and lateral septal nuclei, the bed nucleus of stria terminalis, and various thalamic and amygdaloid nuclei. Also axons of the vertical and horizontal limbs of the diagonal band were labelled and labelled cells were localised at the CA1 and CA3 fields of the hippocampus and the dentate gyrus. The brainstem projections were from the medial, lateral and parasolitary nuclei, the intercalated nucleus of the medulla, the sensory nuclei of the trigeminal nerve, and various reticular, vestibular, raphe and central grey nuclei. The posterior hypothalamic nucleus also received projections from the lateral and medial cerebellar nuclei and from upper cervical spinal levels. The results are discussed in relation to the involvement of the posterior hypothalamic nucleus in autonomic function and allows a better understanding of how the brain controls visceral function.
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