A Comparative Quantitative Analysis of the Postnatal Changes in the Myocardium of the Left and Right Ventricles in Rats.

BACKGROUND: The growth of the heart during the foetal and early postnatal development takes places mainly due to hyperplasia. The late postnatal development is characterised by cardiomyocytic hypertrophy in response to normal physiological mechanisms and increased load. To study the cell size most authors measure the diameter either directly or indirectly. AIM: The aim of the present study was to make a comparative quantitative analysis of the postnatal changes observed in the left and right ventricles in rat by evaluating the changes in three morphometric parameters - thickness of the free wall, transverse section of the cardiomyocytes and cardiomyocytic density in the left ventricle and right ventricle. MATERIALS AND METHODS: In the present study, we used histological material from the hearts of 15 male Wistar rats, distributed in five groups aged 2 weeks, 1 month, 3 months, 6 months and 12 months, respectively. RESULTS: In both ventricles, the wall thickness and the transverse section of the cardiomyocytes increased with age, while the cardiomyocytic density decreased. Changes were identical in both ventricles; however, they were more dynamic and pronounced in the left ventricle. CONCLUSIONS: The studied morphometric parameters reveal that age-related hypertrophy and the gradual loss of cardiac muscle cells take place in both ventricles but have a more dynamic pattern of progression in the left ventricle as compared with the right ventricle.

Superficial occipital artery: report of a rare case and literature review

We report a rare case of an aberrant occipital artery found during routine dissection of the right posterior neck and the occipital region of an embalmed 67-year-old Caucasian male cadaver. The right occipital artery, having considerable size (diameter 4 mm), arose from the postero-lateral side of the external carotid artery just above the posterior belly of the digastric muscle. Consequently, the aberrant occipital artery turned laterally around the posterior belly of the digastric and the stylohyoid muscles, reaching the subcutaneous layer as it passed transversely over the upper attachment of the sternocleidomastoid muscle. Distally, the artery showed typical branching pattern. Detailed knowledge about the basic anatomy of the occipital artery, as well as its variations, are highly important in preventing complications during extra-to-intracranial bypass surgery and therapeutic embolization via this vessel. A careful preoperative examination of the artery is necessary to reveal some of its rarest anatomical variation

No disponible

Some unusual types of formation of the ansa cervicalis in humans and proposal of a new morphological classification.

Ansa cervicalis (ansa hypoglossi) is a peripheral nerve structure-the primary choice for laryngeal reinnervation. Because the ansa formation is quite variable in humans, it is an object of a number of proposed classifications. Two interesting cases of formation of the ansa cervicalis were found during routine anatomical dissections. In the first case the unusual ansa had three basic roots-a superior one from the hypoglossal nerve, an aberrant middle root from the vagus nerve and an inferior root, coming from the cervical ventral branches. In the second case an ansa was described having roots from the vagus nerve and cervical ventral branches. Based on the reported variations and extensive review of the pertinent literature, a new morphological classification of the ansa cervicalis formation in human is proposed here.

An aberrant flexor digiti minimi brevis manus muscle.

During routine anatomical dissection in the right volar wrist region of a 43-year-old female cadaver, we discovered a unique flexor digiti minimi brevis (manus) muscle. The aberrant muscle arose from the medial edge of the flexor carpi radialis tendon and passed obliquely, distally and ulnarward, crossing over the median nerve and then the ulnar artery and nerve at the Guyon canal. The aberrant muscle inserted to the anteromedial surface of the base of the fifth proximal phalanx. The deep branch of the ulnar nerve innervated this muscle. The potential clinical implications of the variant flexor digiti minimi brevis muscle are briefly described.

Variety of transversus thoracis muscle in relation to the internal thoracic artery: an autopsy study of 120 subjects.

BACKGROUND: The transversus thoracis muscle is a thin muscular layer on the inner surface of the anterior thoracic wall that is always in concern during harvesting of the internal thoracic artery. Because the muscle is poorly described in the surgical literature, the aim of the present study is to examine in details its variations. METHODS: The data was obtained at standard autopsies of 120 Caucasian subjects (Bulgarians) of both sexes (97 males and 23 females), ranging in age from 18 to 91 years (mean age 52.8 ± 17.8 years). The transversus thoracis morphology was thoroughly examined on the inner surface of the chest plates collected after routine incisions. RESULTS: An overall examination revealed that in majority of cases the transversus thoracis slips formed a complete muscular layer (left - 75.8%, right - 83.3%) or some of the slips (left - 22.5%, right - 15%) or all of them (left - 1.7%, right - 1.7%) were quite separated. Rarely (left - 3.3%, right - 5.8%), some fibrous slips of the transversus thoracis were noted. In 55.8% of the cases there was left/right muscle symmetry; 44.2% of the muscles were asymmetrical. Most commonly, the highest muscle attachment was to the second (left - 53.3%, right - 37.5%) or third rib (left - 29.2%, right - 46.7%). The sixth rib was the most common lowest attachment (left - 94.2%, right - 89.2%). Most frequently, the muscle was composed of four (left - 31.7%, right - 44.2%) or fifth slips (left - 53.3%, right - 40.8%). CONCLUSIONS: This study provides detailed basic information on the variety of the transversus thoracic muscle. It also defines the range of the clearly visible, uncovered by the muscle part of the internal thoracic artery and the completeness of the muscular layer over it. The knowledge of these peculiar muscle-arterial relations would definitely be beneficial to cardiac surgeon in performing fast and safe arterial harvesting.

On the clinical significance of the sternalis muscle.

During routine anatomical dissection, two cases of sternalis muscle were described. In the first case a unilateral sternalis on the left side was observed. It started from the fibres of the sternal membrane, then passed downwards in a slightly arch-shaped course and ended in the pectoral fascia at the level of 6-7 costal cartilages. In the second case, a bilateral sternalis muscle composed of two bellies (right and left) was detected. It arose from the sternal membrane covering the sternal angle. The right belly was attached to the fourth costal cartilage at the sternal junction; the left one was inserted into the third costal cartilage also at the sternal junction. In these cases sternalis muscles were supplied by perforating branches of the internal thoracic arteries and innervated by anterior branches of the intercostal nerves. We have also reviewed the available literature concerning the clinical importance of the sternalis and summarized it clearly for clinical anatomists, plastic surgeons, breast surgeons and radiologists.