Click for a larger image

The duodenum is a mostly retroperitoneal organ, part of the digestive tract, and the most proximal portion of the small intestine. This organ is approximately 10 inches in length (24.5 cm). It starts at the pylorus of the stomach, has a "C" shape, curving around the head and the neck of the pancreas, to end at the duodenojejunal junction.

The duodenum is described as having four segments of differing length, usually named numerically:

• First segment: about two inches in length, it is dilated and called the "duodenal ampulla", or "superior duodenum"
• Second segment: about three inches in length, it receives bile and pancreatic juice through the hepatopancreatic ducts and ampullae. It is also called the "descending duodenum"
• Third segment: about four inches in length, it crosses the midline, and is also known as the "horizontal" or "transverse duodenum"
• Fourth segment: one inch in length, this is the shortest segment, it ascends towards the duodenojejunal junction, which is tethered to the diaphragm by a fold of peritoneum around a fibromuscular band called the "ligament of Treitz". At this point the retroperitoneal duodenum becomes the intraperitoneal jejunum. This fourth segment is also called the "ascending duodenum"

The name of the organ is interesting. Most textbooks claim that is originates from the Latin [duodeni], meaning "twelve". The fact is that the duodenum was originally named in Greek [δώδεκα δάχτυλαν] meaning "twelve fingers". If you place both your hands together and add 1/4 of an inch to each side (as if you had an extra finger on each hand) that measures approximately 10 inches. The term was shortened by an incorrect translation to "twelve" by Gerard of Cremona (1114 - 1187) who called it "duodenum", a bad translation, as twelve fingers in Latin is [duodecim digitorum].

While most of the duodenum is retroperitoneal, the first inch of the superior duodenum (first segment) is intraperitoneal as it shares a small portion of the lesser omentum with the stomach and liver.

Sources:
1. "Clinically Oriented Anatomy" Moore, KL. 3r Ed. Williams & Wilkins 1992
2. "The origin of Medical Terms" Skinner, AH, 1970 
Image property of: CAA, Inc. Artist: Dr. E. Miranda

This prefix is derived from the Greek and means "slow". Most everybody knows about [bradycardia] meaning "slow heart", but there is a large number of applications of this prefix as follows:

• Bradytrophia: from the Greek [trophe] meaning "to feed" or "nutrition". Braditrophia is a slow nutritional process
• Bradypnea: from the Greek [pnoia], meaning "breath" or "air". Bradypnea is an abnormally slow breathing rhythm
• Bradylalia: from the Greel [lalein] meaning "to talk". Bradylalia is a slow articulation or formation of words, sometimes also known as [bradyarthria] or [bradyphasia]. See the article on aphasia and dysphasia here
  
• Bradykinesia: from the Greek [kinesis], meaning "movement". Bradykinesia means "slow movement", also known as [bradypragia]
• Bradycrotic: from the Greek [krotos], meaning "pulse" "or pulsation" A bradycrotic agent slows down the patient's pulse or heart rate.
• Bradytocia: from the Greek [tokos], meaning "birth". Bradytocia is a slow birthing process

Click for a larger image

The word [bregma] is Greek and means "the front of the head". It is actually the point of intersection of the the coronal and sagittal sutures. The coronal suture is the articulation or joint between the frontal and parietal bones, and the sagittal suture is the median joint between both parietal bones. 

The term was first used in anatomy as a craniometric point by Paul Broca (1824 - 1880). The image shows a superior view of two heads and the location of the coronal and sagittal sutures. The bregma is the point of intersection of these two articulations.

Click on the image for a larger view. 1 = coronal suture 2 = sagittal suture 3 = lambdoid suture. The bregma is the point of intersection of 1 and 2

Original image courtesy of Wikipedia

This article is part of the series "A Moment in History" where we honor those who have contributed to the growth of medical knowledge in the areas of anatomy, medicine, surgery, and medical research.

Original image courtesy of
Images from the History of Medicine

Marie-Francois Xavier Bichat (1771 - 1802). French physician, surgeon, anatomist and physiologist, Marie-Francois Xavier Bichat was born in the village of Thoirette. His father was a physician, influencing his early instruction and vocation. In Lyon he studied anatomy and surgery. At 28 years of age Bichat was appointed physician to the Hôtel (Hospital) Dieu. His life was influenced by his mentor, Pierre-Joseph Dassault (1738 - 1795). Upon his mentor's death Bichat took upon him to continue and finish his work, while supporting his mentor's family.

Bichat is know for the concept of the body composed of distinct tissues, which he originally called "membranes". Without the aid of the microscope Bichat described 21 different tissues and is considered the founder of the science of histology. His name is preserved in many eponymic structures such as Bichat’s fossa (pterygopalatine fossa), Bichat’s buccal fat pad, Bichat’s foramen (cistern of the vena magna of Galen), Bichat’s ligament (lower fasciculus of the posterior sacroiliac ligament), and Bichat’s tunica intima (tunica intima vasorum). 

Xavier Bichat also contributed to a newer description of the humoral physiological theory, later becoming the basis of hematology. He was also interested in the description of life and death, proposing the existence of an "organic life" and an "animal life". An interesting note is that Bichat died because of an infection he acquired while dissecting a cadaver. Remember that at the time, no embalming was used!

Today Bichat's name is almost forgotten, although in some countries the buccal fat pad is still called "Bichat's fat pad" In many Spanish-speaking countries this structure is referred to as "la bola grasa de Bichat", and many still refer to the removal of this fat pad as "Bichectomy". For an image of the before and after of the procedure, click here.

Sources:
1. "Marie-Fran?ois Xavier Bichat (1771-1802) and his contributions to the foundations of pathological anatomy and modern medicine" Shoja M.M., Tubbs R.S., Loukas M., Shokouhi G., Ardalan M.R.(2008) Annals of Anatomy, 190(5),413-420
2. "Physiological Researches on Life and Death" Bichat, Marie-Francois Xavier, 1827. Translated from French by F. Gold. Richardson and Lord, Boston.
3. "A Historical Perspective: Infection from Cadaveric Dissection from the 18th to the 20th Centuries" Shoja, MM et al. Clin Anat (2013) 26:154-160

This complex medical word is formed by the combination of two root terms: [dacry-] meaning "tear" and [-cyst-], meaning "sac". The combined root [dacryocyst-] means "tear sac" or better, "lacrimal sac" (the Latin word [lacrima] means "tear"). This medical word also has a combined suffix: [-(o)lith], meaning "stone", and [-iasis], meaning "disease or condition".

The word [dacryocystolithiasis] means then, "a condition or pathology of stones (calculi) in the lacrimal sac". The procedure to remove the stones would then be called a [dacryocystolithectomy].

Click for a larger image

The Hamate bone is one of the four bones that comprise the distal row of the carpus or carpal bones that form the wrist. The name arises from the Latin [hamatus], meaning "hooked". The hamate bone has a distinct hook-like bony process in its volar (anterior) surface, known as the hamulus. This bone is also known as the "unciform bone" (from the Latin [uncus], also meaning "hook") or the os hamatum.

The lunate bone has a wedge-like shape and six surfaces (as a die). It articulates with five bones, including the lunate bone, capitate, triquetrum, and the fourth and fifth metacarpal bones.

The hook of the hamate bone is one of the distal boundaries of the carpal tunnel and serves as a pulley for the tendons of the fourth and fifth flexor tendons. It also serves as one of the points of muscular attachment for the following muscles: flexor carpi ulnaris, flexor digit minimi, and opponens digiti minimi. Because of its projection into the palm of the hand, the hamulus is involved in injuries in sports that require the athlete to use an accessory, as in racquetball, tennis, baseball, golf, etc.

The accompanying image shows the anterior (volar) surface of the wrist. 

Image modified from the original: 3D Human Anatomy: Regional Edition DVD-ROM Courtesy of Primal Pictures