Sponsor   

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.

Click on the link below to subscribe to the MTD newsletter. If you think an article could be interesting to somebody else, click on the mail link at the top of each article to forward it. 

You are welcome to submit questions and suggestions using our "Contact Us" form. The information on this blog follows the terms on our "Privacy and Security Statement"  and cannot be construed as medical guidance or instructions for treatment. 


Click here to subscribe to the Medical Terminology Daily Newsletter

fbbuttons sm

We have 158 guests and no members online


A Moment in History

Thomas Willis, MD
Thomas Willis
(1621-1675)

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.

Sources:

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


"Clinical Anatomy Associates, Inc., and the contributors of "Medical Terminology Daily" wish to thank all individuals who donate their bodies and tissues for the advancement of education and research”.

Click here for more information


Rare & Collectible Books at AbeBooks.com 

 

Serratus anterior (magnus)

The serratus anterior or serratus magnus is a is a wide, thin muscle sheet situated on the posterolateral aspect of the thorax and extends between the ribs and the scapula. It is formed by well-defined separate muscular digitations that originate in the external surface and superior aspect of the first superior eight (or nine) ribs. These originating fibers also arise from the fasciae covering the intercostal muscles. This is especially true for the first or most superior digitation which arises from the first and second rib and the intervening external intercostal fascia.

These digitations cover the lateral aspect of the thorax, pass deep to the scapula and converge to insert on the deep aspect of the medial border of the scapula. Some of its fibers may even hug the medial border of the scapula and insert on its anterior aspect. The first digitation is inserted into a triangular area on the ventral surface of the medial scapular angle. The next two digitations spread out to form a triangular sheet, the base of which is directed posteriorly and is inserted into nearly the whole length of the ventral surface of the vertebral border. The lower five or six digitations converge to form a fan-shaped mass, the apex of which inserts into a triangular impression on the ventral surface of the inferior scapular angle. The lower four slips of the serratus anterior interdigitate with the superior five muscular slips of the external oblique muscle.

Serratus magnus muscle - Image modified from the original by Henry VanDyke Carter, MD. Public domain
Serratus magnus muscle.
Click on the image for a larger depiction 
This muscle receives its nerve supply from the long thoracic nerve, (ventral rami of C5-C7), arising from the roots of C5, C6, and C7 (sometimes absent) of the brachial plexus

The word “serratus” is derivates from the Latin word [serro] meaning “saw”. Serratus means “serrated” referring to the multiple tooth-like anterior digitations of the muscle. The plural form for "serratus" is " serrati". The Latin term “magnus” means “great”, “large”, or “mighty”. It points to the fact that this is the largest of three muscles that carry the same name “serratus”. The other two are the serratus posterior superior and the serratus posterior inferior.

Note: The image shown in this article is from “Gray’s Anatomy” by Henry Gray (1918) which is in the public domain. It depicts the serratus anterior in situ and shows the scapula retracted posteriorly.  The scapula is covered on its internal aspect by the subscapularis muscle (number 3 in the image). A better image can be found in “An Illustrated Atlas of the Skeletal Muscles” by Bowden (2015) which we cannot publish for copyright reasons.

Sources:
1. “Gray’s Anatomy” Henry Gray, 1918
2. "Tratado de Anatomia Humana" Testut et Latarjet 8th Ed. 1931 Salvat Editores, Spain
3. "Gray's Anatomy" 38th British Ed. Churchill Livingstone 1995
4. “An Illustrated Atlas of the Skeletal Muscles” Bowden, B. 4th Ed. Morton Publishing. 2015

Image modified from the original by Henry VanDyke Carter, MD. Public domain


Deltoid muscle

The deltoid or deltoideus (Latin) is a large, thick, triangular muscle, which covers the glenohumeral joint anteriorly, superiorly, and posteriorly.  It can be described as having three components or segments, anterior, middle, and posterior. The anterior portion originates from the lateral third of the clavicle, on the clavicle’s superior border. The middle portion originates from the lateral border of the scapula’s acromion, and the posterior portion originates from the spine of the scapula. All three portions insert laterally by means of a thick tendon on the deltoid tuberosity of the humerus. At its insertion the muscle gives off an thick connective tissue expansion to the deep fascia of the arm.

The three portions of the deltoid muscle are usually well defined. As an anatomical variation, the clavicular or the acromial portion of the muscle may be absent.

This muscle is innervated by the axillary nerve (C5, C6), a branch of the brachial plexus, and supplied by the posterior circumflex humeral artery and the deltoid branch of the thoracoacromial artery.

The word deltoid is derivates from the Greek word [δελτοειδής] which is itself formed by the terms [δέλτα] (délta), referring to the triangular shape of the letter delta (uppercase Δ, lowercase δ or 𝛿) and [-οειδής] (-oeidís), a the Greek suffix meaning “similar to”. Delt-oid then would mean “similar to a Δ (delta)".

Deltoid muscle - Image modified from the original by Henry VanDyke Carter, MD. Public domain
Deltoid muscle.
Click on the image for a larger depiction 
Sources:
1. “Gray’s Anatomy” Henry Gray, 1918
2. "Tratado de Anatomia Humana" Testut et Latarjet 8th Ed. 1931 Salvat Editores, Spain
3. "Gray's Anatomy" 38th British Ed. Churchill Livingstone 1995
4. “An Illustrated Atlas of the Skeletal Muscles” Bowden, B. 4th Ed. Morton Publishing. 2015

Image modified from the original by Henry VanDyke Carter, MD. Public domain


Pectoralis major

The pectoralis major muscle is the largest muscle in the anterior aspect of the thorax. It is thick and fan-shaped.  It attaches superiorly to the medial half of the clavicle, and medially to the anterior aspect of the sternum and cartilage of the first to sixth or seventh rib, extending inferiorly to attach to the aponeurosis of the external oblique muscle. Laterally, this muscle attaches to the lateral lip of the intertubercular groove (bicipital groove) of the humerus by a two-layered tendon which inserts each of the two heads of the muscle.

The superficial tendon attaches the clavicular head (red in the accompanying image), which extends between the intertubercular groove of the humerus and the clavicle. The deep tendon attaches the sternocostal head (purple in the accompanying image), which extends between the humeral intertubercular groove and the attachments in the sternum, costal cartilages, and the aponeurosis of the external oblique muscle. There is usually a well-defined interval between the two heads of the pectoralis major.

The pectoralis major is innervated by the medial (C8-T1) and lateral pectoral nerves (C5-C7).

This muscle is covered by the pectoral fascia which extends in different directions. An extension of this fascia is the clavipectoral fascia. In both male and female, the mammary gland is situated anterior to and anchors in the pectoral fascia.

Pectoralis major muscle - Red: clavicular head. Purple: Sternocostal head - Image modified from the original by Henry VanDyke Carter, MD. Public domain
Pectoralis major muscle - Red: clavicular head. Purple: Sternocostal head
Click on the image for a larger depiction 
The word pectoral arises from the Latin term "pectum" meaning "chest, breast". In its true meaning, pectoral or pectoralis refers to a "chest plate" or an "adornment of the chest".

Sources:
1. “Gray’s Anatomy” Henry Gray, 1918
2. "Tratado de Anatomia Humana" Testut et Latarjet 8th Ed. 1931 Salvat Editores, Spain
3. "Gray's Anatomy" 38th British Ed. Churchill Livingstone 1995
4. “An Illustrated Atlas of the Skeletal Muscles” Bowden, B. 4th Ed. Morton Publishing. 2015

Image modified from the original by Henry VanDyke Carter, MD. Public domain


Dr. Elizabeth Murray Honored with American Academy of Forensic Sciences Award

We are proud to announce that our own contributor and associate Dr. Elizabeth Murray, Ph.D., has been awarded the Anthropology Section's 2018 "T. Dale Stewart Award" at the American Academy of Forensic Sciences (AAFS) 71st Annual Scientific Meeting in late February.

Dr. Murray's involvement with AAFS has included chairing the Academy-wide annual meeting as well as committee-level service in long-term planning, Board of Trustees, and the Student Academy.

Well-known and respected as a forensic anthropologist, Dr. Murray teaches at the University of Mount St. Joseph courses in anatomy and physiology, gross anatomy, and forensic science for the Department of Biology. Her most recent book, published in 2019, is "The Dozier School for Boys: Forensics, Survivors, and a Painful Past."

Our congratulations to her for yet another incredible achievement in her illustrious career. We are glad to count her as a friend and as a contributor to "Medical Terminology Daily" and Clinical Anatomy Associates, Inc.

Click here for Dr. Murray's Facebook page.


Holly leaf sign

The Holly is a tree/shrub of the genus Ilex , with perhaps the most well know being Ilex aquifolium. The plant has shiny prickly evergreen leaves and bright red berries. Cut branches of Holly are widely used as a traditionally Christmas decoration especially in wreaths and Christmas cards as illustrations. “The Holly and the Ivy” is a popular traditional English Christmas carol.

The [Holly leaf sign] refers to the appearance of calcified pleural plaques seen on chest radiographs. Pleural plaques are common in patients who have been exposed to asbestos, are asymptomatic and are most useful as a marker of asbestos exposure or asbestosis. They can be identified in 3-14% of dockyard workers and in 58% in insulation workers.

They are themselves not malignant, but patients with this plaques have a greater risk of mesothelioma and bronchogenic cancer than the general population and patients with exposed to asbestos but not pleural plaques.

Holly leaf sign - Case radiograph courtesy of Dr Çağlayan Çakır, Radiopaedia.org. From the case rID: 22986Holly leaf sign.
Click on the image for a larger depiction

The plaques arise in the parietal pleura and have predilection for the diaphragmatic dome and the undersurface of the lower posterolateral ribs. Rarely involve the visceral pleura but occasionally they are found in the fissures of the lungs.

On plain radiographic plaques appear as a geographic, usually calcified, opacities with irregular but well-defined edges. The irregular thickened nodular edges of the pleural plaques are likened to appearance of a Holly leaf, which has sharp spines along its margin.

Sources:
1. Jane R, Gulati A., Dwivedi R., Avula S., Curtis J., Abernethy L. (2013) We wish you a Merry X-Ray-mas: Christmas signs in radiology. BMJ 347:f7020 doi: 10.1136/bmj.f7020
2. Walker C., Takasugi J., Chung J., Reddy, G., Done S., Pipavath S., Schmidt R., Godwin J. (2012). Tumor-like Conditions of the Pleura. Radiographics 32:971–985.
3. Case radiograph courtesy of Dr Çağlayan Çakır, Radiopaedia.org. From the case rID: 22986

Figure below. Ilex aquifolium. Courtesy of A.Prof Frank Gaillard, Radiopaedia.org. From the case rID: 12398

Holly leaf sign - Ilex aquifolium. Courtesy of A.Prof Frank Gaillard, Radiopaedia.org. From the case rID: 12398
Holly leaf sign.
Click on the image for a larger depiction

Article submitted by: Prof. Claudio R. Molina, MsC..


Prostatic utricle

[UPDATED] The [prostatic utricle], also known as "utriculus prostaticus" or "utriculus" is a small 6 mm small dead-end channel found in the male prostatic urethra.

The word [utriculus] is Latin and means "little sac"..

What is interesting about this structure is that it is the embryological remnant in the male of the Müllerian ducts that form the vagina and the uterus in the female. In fact, in some texts the prostatic utricle is referred to as "uterus masculinus". Some researchers differ and point to the fact that this structure may not be a Müllerian duct derivate.

The prostatic utricle is found inside the prostate, forming part of the posterior wall of the prostatic urethra. It is in the upper part of a small mound which is part of the prostatic crest. This mound is called the [colliculus seminalis] or  [verumontanum], which is Latin and translates as the "mountain or mound of truth". On the verumontanum are the two slit-like openings of the ejaculatory ducts. Lateral to the verumontanum are the prostatic sinuses, depressions where the prostatic ducts are found.

Sources:
1. "The prostatic utricle is not a M?llerian duct remnant: immunohistochemical evidence for a distinct urogenital sinus origin" Shapiro E, Huang H, McFadden DE, et al. (2004) J Urol 172; 1753–1756
2. "Gray's Anatomy"38th British Ed. Churchill Livingstone 1995
3. "Tratado de Anatomia Humana" Testut et Latarjet 8 Ed. 1931 Salvat Editores, Spain

Anterior view of section of the prostate. The blue dotted line shows the edges of the prostatic urethra
    Anterior view of a section of the prostate gland. The blue dotted line shows the edges of the prostatic urethra.