The carotid and vertebral arteries discovery ­ initial findings / A descoberta das artérias carótidas e vertebrais ­ achados iniciais

The studies on the vascular system, including the cervicocephalic arteries (carotid and vertebral arteries), present a long trajectory, having their deep roots in the far past, considering the Western authors, having as representatives the Greek sages Alcmaeon, Diogenes, Hippocrates, Aristoteles, Rufus, and Galenus. They produced pivotal knowledge dissecting mainly cadavers of animals, and established solid bases for the later generations of scholars. The information assembled from these six authors makes it possible to build a quite clear picture of the vascular system, here specifically focused on the cervicocephalic arteries, and mainly of the extracranial segments. Thus, the carotid system became fairly well identified, origin, course, and name, as well as the origin of the still unnamed arteries running through the orifices of the transversal processes of the cervical vertebrae, and entering into the cranium. Almost all that was then known about human anatomy, since this period, and then throughout the Middle Ages, was extrapolated from animal dissections. This state of affairs was maintained until the 14th century, when human corpses dissections were again allowed.

Os estudos do sistema vascular, incluindo as artérias cervicocefálicas (artérias carótidas e vertebrais), apresentam um longo percurso, tendo suas raízes profundas no passado distante, considerando os autores ocidentais, tendo como representantes os doutos gregos Alcméon, Diógenes, Hipócrates, Aristóteles, Rufus e Galenus. Eles produziram conhecimento pivotal, dissecando principalmente cadáveres de animais e estabelecendo bases sólidas para as gerações futuras de estudiosos. A informação reunida desses seis autores permite construir um quadro bastante claro do sistema vascular, aqui focado especificamente nas artérias cervicocefálicas e principalmente nos seus segmentos extracranianos. Assim, o sistema carotídeo ficou bastante bem identificado, origem, trajeto e nome, assim como a origem das ainda não nomeadas artérias que percorrem os orifícios dos processos transversos das vértebras cervicais e entrando no crânio. Quase tudo que era conhecido sobre anatomia humana, desde esse período, e depois ao longo da Idade Média, foi extrapolado a partir de dissecções de animais. Esse estado de coisas foi mantido até o século 14, quando a dissecção de cadáveres humanos foi novamente permitida.

Physiological and Functional Magnetic Resonance Imaging Using Balanced Steady-state Free Precession

Balanced steady-state free precession (bSSFP) is a highly efficient pulse sequence that is known to provide the highest signal-to-noise ratio per unit time. Recently, bSSFP is getting increasingly popular in both the research and clinical communities. This review will be focusing on the application of the bSSFP technique in the context of probing the physiological and functional information. In the first part of this review, the basic principles of bSSFP are briefly covered. Afterwards, recent developments related to the application of bSSFP, in terms of physiological and functional imaging, are introduced and reviewed. Despite its long development history, bSSFP is still a promising technique that has many potential benefits for obtaining high-resolution physiological and functional images.

Variant inferior root of ansa cervicalis / Variación de la raíz inferior del asa cervical

Ansa cervicalis is a loop of nerves found in the anterior wall of the carotid sheath in the carotid triangle of neck innervating infrahyoid muscles. Its superior root has fibres from the first cervical nerve that leaves the hypoglossal nerve and joins the inferior root formed by the branches from the second and third cervical nerves. The two roots join to form ansa cervicalis. The ansa cervicalis nerve formation is relatively complex, as its course and location along the great vessels of the neck vary. In the present case on the left side of an adult male cadaver the inferior root was absent and the contributions from C2 and C3 were joining independently with the superior root of ansa to form ansa cervicalis. However no such variation was found in the ansa cervicalis formation on the right side.

El asa cervical es un loop de nervios que se encuentra en la pared anterior de la vaina carotídea, en el triángulo carotídeo del cuello, que inerva los músculos infrahioideos. Su raíz superior tiene fibras del primer nervio cervical que sale del nervio hipogloso y se une a la raíz inferior formada por las ramas de los nervios cervicales segundo y tercero. Las dos raíces se unen para formar el asa cervical. La formación del asa cervical del nervio es relativamente compleja, ya que su curso y ubicación varía a lo largo de los grandes vasos del cuello. En el lado izquierdo del cuello de un cadáver adulto de sexo masculino, la raíz inferior del asa cervical estaba ausente y las contribuciones de los ramos de C2 y C3 se unieron, de forma independiente, con la raíz superior del asa y así formar el loop.

Circuito venoso cervical de la llama (Lama glama) / Cervical venous circuit of the llama (Lama glama)

La particular estructura de la región cervical de la llama (Lama glama) se traduce en numerosas diferencias anátomo-funcionales respecto de otros mamíferos domésticos. Entre ellas merece destacarse un distintivo circuito venoso, cuya descripción es el objetivo de este trabajo. Para el presente estudio, se utilizaron diez llamas, machos, adultos y de aptitud lanera. Para resaltar las venas del cuello se procedió a la repleción de las mismas y, posteriormente, se disecaron los vasos utilizando técnicas e instrumental convencional. Se describe la morfología particular de un circuito venoso, en el cual las venas yugular externa, vertebral e intervertebrales son las principales protagonistas. El hecho destacado radica en las anastomosis establecidas entre las citadas venas, uniones dispuestas en forma metamérica, formando un circuito o by pass yugular-vertebral. La existencia de comunicaciones o shunts venosos, permite definir un circuito de circulación colateral derivando la sangre principalmente hacia la vena yugular externa. La longitud del cuello y los hábitos de pastoreo indican que esta disposición vascular es un hecho facilitador del retorno venoso, en cuanto a su dinámica y al control regional del flujo sanguíneo.

The neck region of the Llama (Lama glama) has several structural and functional particularities in comparison to the same region of other domestic mammals. Among them, it is noticeable a distinctive venous circuit whose description is the purpose of this study. In order to perform the study, the veins of the neck of ten adult, male, wool type llamas were dissected with conventional technique. Previously to dissection, the veins were filled with a repletive substance. The authors describe the morphology of a venous circuit in which external jugular vein (v. jugularis externa), vertebral vein (v. vertebralis), and intervertebral veins (vv. Intervertebrales) are the main participating vessels. The distinctive feature is the fact that the metameric anastomoses between the forenamed veins leads to a jugular-vertebral by pass. The existence of venous shunts provides a circuit of collateral circulation, diverting the blood mainly towards the external jugular vein. Grazing habits and the length of the neck suggest that the vascular structure previously described facilitates the venous return, contributing to the regional blood stream control.

The vertebral artery: its relationship with adjoining tissues in its course intra and inter transverse processes in man

The authors study the vertebral artery from its origin to termination, especially in its course inter and intra transverse process and show its relation to venous and nervous structures, as well as its behavior toward adjacent conjunctive tissue. They discuss the relation of the anatomy to the physiopathology of the vertebral artery and come to the conclusion that the vertebral artery is fixed to adjacent structures in the fibrous osteomuscular tunnel by means of a continuous lamina of collagen along its entire course and that there is considerable independence between the artery and the branches of these final nerves