Medical Terminology Daily (MTD) is a blog sponsored by Clinical Anatomy Associates, Inc. as a service to the medical community, medical students, and the medical industry. We will post a workweek daily medical or surgical term, its meaning and usage, as well as biographical notes on anatomists, surgeons, and researchers through the ages. Be warned that some of the images used depict human anatomical specimens.

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A Moment in History

Thomas Willis, MD
Thomas Willis

An English physician and anatomist, Willis was born on his parents' farm in Great Bedwyn, Wiltshire, where his father held the stewardship of the Manor. He was a kinsman of the Willys baronets of Fen Ditton, Cambridgeshire. He graduated M.A. from Christ Church, Oxford in 1642. In the Civil War years he was a royalist, and was dispossessed of the family farm at North Hinksey by Parliamentary forces. In the 1640's Willis was one of the royal physicians to Charles I of England. He obtained his medical degree in 1646.

Thomas Willis might well be one of the greatest physicians of the 17th century.He is one of the founders of the Royal Society of London. He is remembered by his many publications, especially "Cerebri Anatome: Cui accessit Nervorum Descriptio et Usu", where he describes the arterial anastomoses at the base of the brain. This work is also the first detailed description of the vasculature of the brain. Willis described nine cranial nerves.

He is considered as the father of Neurology as a discipline. He used the term "neurology" for the first time in 1664. He described several neurological conditions

The Arterial Circle of Willis is a famous eponymous structure found at the base of the brain. It represents an anastomotic roundabout that connects the right and left sides as well as the carotid and vertebral arterial territories that supply the brain. Named after Thomas Willis, this structure was known well before him, but it was Willis who described its function.  If you click on the image or here, you will be redirected to a detailed description of this structure.


1. "The legendary contributions of Thomas Willis (1621-1675): the arterial circle and beyond" Rengachary SS et al J Neurosurg. 2008 Oct;109(4):765-75
2. "Thomas Willis, a pioneer in translational research in anatomy (on the 350th anniversary of Cerebri anatome)" Arraez-AybarJournal of Anatomy, 03/2015, Volume 226, Issue 3
3. " The naming of the cranial nerves: A historical review" Davis, M Clinical Anatomy, 01/2014, Volume 27, Issue 1
4. "Observations on the history of the circle of Willis". Meyer A, Hieros, R.Med Hist 6:119–130, 1962

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The [trapezius] is a bilateral muscle belonging to the superficial muscles of the back. On each side it is a flat, thin triangular muscle that spans the neck, shoulders and the superior and middle aspect of the back. When seen together these two triangular muscles form a diamond-shaped quadrangle from which its name derives. The word originates in the Greek [τραπεζι] meaning "a four-legged table" (four sides). This word later evolved into the New Latin [trapezium].

In the midline the trapezius muscle attaches to the inion (external occipital protuberance), the ligamentum nuch?, the spinous processes of the seventh cervical vertebra (vertebra prominens), and the spinous processes of all the thoracic vertebr?.

The trapezius’ muscle fibers have three orientations. From the midline the superior fibers course inferolaterally to attach to the posterior border of the lateral third of the clavicle. The middle fibers course laterally to attach to the medial margin of the acromion, and posterior border of the spine of the scapula. The inferior fibers course superolaterally to attach to the spine of the scapula by way of an aponeurosis.

Because of their attachments, the superior and inferior fibers of the trapezius act coordinatedly to rotate the scapula, while the middle fibers act to retract the scapula. The superior fibers also act to slightly elevate the scapula. The trapezius muscle is sometimes described as an accessory respiratory muscle.

The trapezius muscle receives muscular innervation by way of the spinal accessory nerve (11th Cranial Nerve) which courses on the deep aspect of the muscle along with the  superficial branch of the transverse cervical artery and vein. The muscle also receives sensory innervation by way of nerves arising from the ventral rami of the 3rd and 4th spinal nerves.

Image courtesy of Bartleby.com 

Posterior view of the superficial and intermediate muscle layers of the back (bartleby.com)
Posterior view of the superficial and intermediate muscle layers of the back (bartleby.com)