A reminder of the anatomy of the recurrent artery of heubner.

Previous accounts of the recurrent artery of Heubner show serious inconsistencies concerning the origins, dimensions and numbers of the artery. In the present study, based on 54 (38 male, 16 female) human autopsy brains the common type of the recurrent artery of Heubner was present bilaterally in 46 cases (85.2%), while in 6 (11.1%) cases it was present only on one side (4 on the right, 2 on the left). Unilateral vessels were seen only in the male autopsy brains. The recurrent artery of Heubner could not be identified in 2 brains (3.7%). Multiple Heubner arteries were not observed in the present study. No gender differences were observed regarding the origin and dimensions of the recurrent artery of Heubner. 76 recurrent arteries of Heubner arising from the junction of the anterior cerebral artery (ACA) and anterior communicating artery (ACoA) (79.2%) had a mean diameter of 0.66+/-0.11 mm. In 14 arteries the artery derived from the A2 segment of the ACA (14.6%) and the mean diameter was 0.66+/-0.17 mm; in 6 arteries it originated from the A1 segment of the ACA (6.2%) and the mean diameter was 0.47+/-0.15 mm. The average diameter was calculated as 0.67+/-0.12 mm and ranged between 0.40 and 0.90 mm, irrespective of sex or side. A detailed anatomical knowledge of the recurrent artery of Heubner is important when considering vascular surgery in this area.

Changing diameters of cerebral vessels with age in human autopsy specimens: possible relationships to atherosclerotic changes.

AIMS/OBJECTIVES: It has been previously recognized that the anatomy of arterial bifurcations influences blood flow and has a significant role in the development of vascular disease. MATERIAL AND METHODS: In the present study, we measured the average diameters of the internal carotid (ICA), anterior cerebral (ACA), and middle cerebral arteries (MCA) in autopsy cases. We also calculated the outflow to inflow area ratios for four distinct age groups and for each gender, using 33 adult autopsies and 7 fetuses. RESULTS: The area ratios decreased with age in both male and female samples. The decrease in the male (30%, p<0.05) was greater than the decrease for the female (17%, p > 0.05). The average diameter of the ACA, MCA and ICA of both female and male cases increased up to the 25-44 age group, decreased for the 45-64 age group, with a second increase above the age of 65. CONCLUSIONS: The decrease in the area ratios and the pattern of changes of the dimensions of the cerebral vessels with age are useful to examine the causal relationships of these pathologic conditions and raises novel questions about age and gender differences in the structure of the intracranial vessels.

Morphometric measurements of the caudal cranial nerves in the petroclival region.

OBJECTIVE: The dural zone of entry or exit of the caudal cranial nerves in the petroclival region does not have a constant localization. The present study aimed to measure the clival length, the distances between cranial nerve dural openings and the distance of cranial nerves from the mid-clival line in 30 human autopsy cases. MATERIAL AND METHODS: Thirty autopsy specimens (8 female, 22 male) from persons aged between 20-76 years (mean age 38.9 years) were studied. Autopsies with intracranial lesions were not included in the study. RESULTS: The average distances between the right and left dural openings of caudal cranial nerves in the petroclival region were as follows (mean+/-sd): trigeminal, 32.17+/-5.41 mm; abducent, 20.04+/-3.23 mm; facial and vestibulocochlear, 50.97+/-5.86 mm; glossopharyngeal, vagus, accessory, 41.59+/-6.46 mm and hypoglossal 26.8+/-4.33 mm. The measurements of the distances of the cranial nerve exits to the mid-clival line showed considerable asymmetries for the left and right trigeminal nerves. Furthermore, the distances between the trigeminal and the abducent nerves on the right and left differed significantly (p<0.029). The average distance between these two cranial nerves on the left was 8.44+/-3.66 mm and on the right was 7.31+/-2.41 mm. In addition, the average clival length was 56.96+/-5.91 mm (range: 42-71 mm). CONCLUSIONS: Most of the surgical procedures performed in this area are to remove tumors which significantly modify the local anatomy. Knowledge of morphometric variations can increase the success of cranial nerve preservation during surgical procedures of the posterior cranial fossa.

The anatomy of the carotico-clinoid foramen and its relation with the internal carotid artery.

The carotico-clinoid foramen is the result of ossification either of the carotico-clinoid ligament or of a dural fold extending between the anterior and middle clinoid processes of the sphenoid bone. It is anatomically important due to its relations with the cavernous sinus and its content, sphenoid sinus and pituitary gland. In this study the ossification state of the carotico-clinoid ligament, the diameter of the internal carotid artery and the carotico-clinoid foramen has been studied on 50 autopsy cases. Of the 100 carotico-clinoid foramina examined, in 27 sides (15 right, 12 left) the carotico-clinoid ligament was completely ossified, in 18 sides (9 right, 9 left) the carotico-clinoid ligament was incompletely ossified and in 55 sides (26 right, 29 left) it was a ligamentous structure. The correlation of the dimensions of the carotico-clinoid foramen and the internal carotid artery showed no statistical significance, except between the carotico-clinoid foramen with a fibrous carotico-clinoid ligament and the internal carotid artery on the right side (p=0.007, r=0.51). The existence of a bony carotico-clinoid foramen may cause compression, tightening or stretching of the internal carotid artery. Further, removing the anterior clinoid process is an important step in regional surgery; the presence of a bony carotico-clinoid foramen may have high risk. Therefore, detailed knowledge of the type of ossification between the anterior and middle clinoid processes can be necessary to increase the success of regional surgery.

The afferent connections of the posterior hypothalamic nucleus in the rat using horseradish peroxidase.

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.

Cerebellar connections to the dorsomedial and posterior nuclei of the hypothalamus in the rat.

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.

Trifurcation of the left common carotid artery: a case report.

During dissection of the carotid triangle, a carotid trifurcation was encountered. The left common carotid artery gave off three terminal branches: external carotid, internal carotid, and occipital arteries. The level of trifurcation was 35 mm above the superior margin of the thyroid cartilage. Further, the superior thyroid artery arose from the common carotid artery instead of the external carotid. Herein, we describe the detailed anatomical features of the variant branching pattern of the left common carotid artery and its clinical implications.

Rare variation of the axillary artery.

The third part of the axillary artery unilaterally divides into two major arterial stems, named according to their localization as deep brachial artery and superficial brachial artery (brachial artery). The deep brachial artery gives off the posterior circumflex humeral artery, anterior circumflex humeral artery, subscapular artery, and profunda brachii artery. It continues its course in the arm lateral to the median nerve and terminates by giving a minute twig to the radial artery. The superficial brachial artery is larger in caliber than the deep brachial artery and gives no branches in the arm region. In the cubital fossa it gives the ulnar and the radial arteries. This case is a variant of the axillary artery that has been rarely (0.12-3.2%) documented in the literature. Accurate knowledge of the normal and variant arterial anatomy of the axillary artery is important for clinical procedures in this region. Clin. Anat. 13: 66-68, 2000.

An unusual flexor hallucis longus muscle.

During the dissection of the posterior compartment of the left leg, an unusual flexor hallucis longus muscle of a fifty two years-old male cadaver was observed. On the medial side of the flexor hallucis longus, on its lower distal half, a prominent aponeurotic structure was observed. A small unusual muscle mass was attached to this aponeurotic structure. The muscular fibres of the unusual mass were arranged in form of bipennate muscle. It originated via a broad tendon from the muscular fibres of the tibialis posterior and the deep transverse fascia covering the same muscle. It inserted on the aponeurosis of the lower medial half of the flexor hallucis longus muscle. Having in mind the very different pathology in the region of the ankle and the foot, the significance of such a muscle mass could be of practical importance.

The effects of cold-restraint stress on urinary bladder wall compared with interstitial cystitis morphology.

Stress is associated with many diseases of unknown aetiology. This study demonstrates the effects of cold-restraint stress on the morphology of the urinary bladder. Additionally, it compares the results obtained with the morphology of the interstitial cystitis. The animals were subjected to three hours of cold-restraint stress and then starved for 48 h. The morphology and histochemistry of the urinary bladder was investigated with light and electron microscopy. The proliferative activity was analysed via flow cytometry. Increased and degranulated mast cells in the mucosa, leucocyte infiltration in the lamina propria, vacuole formation in the urothelial cells, loose tight junction, dilated intercellular spaces and altered proliferative activity were observed in the stress group when compared with the control. The increase in the number of mast cells and especially degranulated mast cells and vacuole formation and the loose tight junction of the urothelium correlated with the histopathological findings of interstitial cystitis.

A variation of coeliac trunk.

The anatomical variations of the coeliac trunk are due to developmental changes in the ventral splanchnic arteries. This report describes a case in which the left inferior phrenic artery and left gastric artery arose from the long coeliac trunk (4.3 cm.) via a common trunk. The arterial variations, like other anatomical variations, cannot be ignored during the operative procedures in abdomen. Therefore the different forms of variations concerning the coeliac trunk should be kept in mind during both surgical and non-surgical evaluations.

An unusual variation of extensor digitorum brevis manus: a case report and literature review.

An unusual variation of the extensor digitorum brevis manus in a male cadaver is presented. The band-shaped muscle was located at the ulnar side of the hand between the fourth and fifth extensors. It originated from the deep carpal fascia and inserted to the extensor tendons of the fourth and fifth fingers with a tendon and a slip, respectively. The origin, insertion, and location of the muscle differ from those previously reported; with these anatomic features, the muscle variation cannot be placed into the current classifications. The phylogenetic and ontogenetic implications of the muscle are reviewed.

Celiacomesenteric trunk.

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 anatomy of lamina pretrachealis fasciae cervicalis.

The definitions concerning the fascia pretrachealis is either contradictory or insufficient in anatomy textbooks. The fascia pretracheatis is clinically important in the procedure of tracheostomy, mediastinascopy and also in tracheal and bronchial trauma. The anatomy of the fascia pretrachealis (extension, relation and the attachments) was reexamined using cadaveric preparations and the clinical value of the fascia is reinforced. The fascia pretrachealis is attached to the upper brim and to the oblique line of the thyroid cartilage and continued its course on the anterior surface of the trachea and fused with the advantitia of arch of the aorta, posterior aspect of pulmonary artery and the pericardium. Laterally it is attached to the cartilagenous part of the trachea. Also contraversial literature concerning description of the fascia pretrachealis has been evaluated.

A morphological study on the V2 segment of the vertebral artery.

Morphometric investigations on the V2 segment of the vertebral artery, showed that, it did not have a constant calibre during its course within the foramina transversaria. The vertebral artery, entering the foramina transversaria reduced its calibre and further continued to reduce until C3 level, above C3 it began to reincrease its calibre and at C1 level reached its largest calibre. Measurements on the muscular thickness, showed an increase as ascending through the foramina transversaria. The widening and narrowing of the vertebral artery within the foramina transversaria was attributed as tortious artery or congenital anomaly. This study showed that it was the normal anatomy of the artery within the foramina transversaria.

The accessory tendon of the extensor indicis muscle.

The extensor indicis and the extensor pollicis longus muscles differentiates from the extensor digitorum profundus muscle. The extensor indicis muscle is an unstable muscle concerning its variations. Kosugi (1989) found the frequency of variations of this muscle to be 20% and described 18 different types of variations of this muscle. This study describes a rare case of the extensor indicis muscle. The extensor indicis muscle develops an accessory tendon in between the extensor indicis and extensor pollicis longus muscle. It passes under the extensor retinaculum. At the level of 2nd metacarpal bone, the accessory extensor indicis tendon is connected to the tendon of the extensor pollicis longus muscle by a intertendinous connection.

An accessory mylohyoid muscle.

During dissection of the submandibular region of a forty year old male a unilateral left accessory mylohyoid muscle was revealed. This muscle was located between the left anterior belly of the digastric and left mylohyoid muscles. It arose from the left mylohyoid line of the mandible and was inserted into the lower portion of the mylohyoid raphe and hyoid bone. This unilateral accessory mylohyoid muscle is a rare anomaly, which is thought to contribute to the functional support of the floor of the mouth.

A rare case of the posterior inferior cerebellar artery.

The posterior inferior cerebellar artery (PICA) is normally a branch of the vertebral artery. In this rare case, the unilateral left vertebral artery continued its course as the left PICA, and an extremely small caliber left vertebral artery joined the righ vertebral artery to form the basilar artery. This rare feature of the PICA is demonstrated and its relation to neighboring structures is discussed. Also, the literature concerning the PICA is reviewed.