UPDATED: The ascending aorta is the first and most proximal portion of the aorta. About 5 cm. in length and 3 cm. in diameter at its origin, its proximal end begins at the superior aspect of the outflow tract of of the left ventricle, at the ventriculoaortic junction. 

The ascending aorta ends superiorly at an imaginary horizontal plane (blue dotted line) that passes through the sternal angle (of Louis), continuing distally with the aortic arch. This is an important anatomical landmark, as many surgeons use as the superior border of the ascending aorta an oblique plane that passes proximal to the brachiocephalic trunk (yellow dotted line). Although this landmark could be useful in surgery, it is not anatomically correct.

Since the sternal angle (of Louis) also indicates the superior border of the pericardial sac, it can be said that the ascending aorta is completely intrapericardial, and in surgery the pericardial sac should be the anatomical landmark used to separate the ascending aorta from the aortic arch.

From its point of origin at the ventriculoaortic junction, the aorta presents with a dilated region where the aortic valve is located. The aortic valve is one of the two  semilunar valves of the heart, and the dilation of this region is caused by the presence of the sinuses of Valsalva. This dilated bulbous segment is known as the aortic root.

The tubular portion of the ascending aorta ascends with an inclination anteriorly and to the right. The ascending aorta presents with a slight anterior bulge causing the transverse section of this aortic segment to be slightly oval.

Only two arteries arise from the ascending aorta, both usually at the aortic root segment, just inferior to the STJ. These are the right coronary artery and the left coronary artery. There are anatomical variations where only one, or up to five different coronary arteries have been described.

Image property of:CAA.Inc.. Artist:Dr. E. Miranda

Kernicterus is a disorder where excess bilirubin accumulates in the deep neural tissues of the brain and can cause brain damage in the newborn.

It is characterized by jaundice and a limpness of the newborn, devoid of energy. Can present with seizures, convulsions, and muscle spasms.

This condition is treatable and requires awareness from the parents if yellowness of the skin (jaundice) is detected along with the above-mentioned signs in the early days post-partum. There are other signs not mentioned in this article

The word [kernicterus] comes from the German word [kern], meaning “nucleus” or “core”. In this particular word the term kern refers to the fact that one of the most importantly affected brain structures in kernicterus are the basal ganglia of the brain (also known as the "central nuclei", found at the "core" of the brain. It also includes the word [icterus] from the Greek word [ικτερός] pronounced (ikterós). The word [icterus] in Greek was originally used to denote a yellow bird, and is now used to denote the yellow color of jaundice.

 
Click on the image for a larger version. 

Sources:
1. Clayman, L. "The AMA Encyclopedia of Medicine" 1989. Random House, NY
2. “The Origin of Medical Terms” Skinner HA 1970 Hafner Publishing Co.

Thanks to Jackie Miranda-Klein for her contribution suggesting this word.

The term [parenchyma] is a Greek term (παράένχέω). Its origin and meaning have little relation to the medical use of the term. The word means "that what is poured" or to "pour in". The actual definition of the term is "the proper mass of a solid organ". If someone refers to the "liver parenchyma", they are referring to the hepatic tissue, so it is with any other solid organ.

The etymology of the word is obscure and reflects ancient physiological theories and history. Vesalius mentions that the word was introduced by Erasistratus circa 300BC. He thought that the blood was "poured" into the organ and then this poured fluid would congeal to form the organ's proper mass. With time this concept was abandoned, but the word persisted to its modern meaning.

Interesting, there are many which accentuate the word wrongly. The accent or stress should be on the letter "e" and not on the letter 'y", so it should be pronounced "parénchyma"

The gastrointestinal (GI) tract is formed, with a few exceptions, by four concentric layers of tissue. These are, from deep to superficial, the mucosa, submucosa, muscular (or muscularis) and the serosa layers. This is the simplified version. The fact is that there are more sublayers.

The mucosa layer is characterized by the presence of intestinal villi, which in the stomach and small intestine contribute to absorption of the digested food. The mucosa has a thin layer of connective called the "lamina propia" and external to it a thin layer of smooth muscle, the muscularis mucosae.

The muscular layer, also known as the "muscularis" is composed of two sublayers of smooth muscle. The deep layer contains circular fibers and is known either as the "circular muscle layer" or the "muscularis interna", the superficial layer contains longitudinal smooth muscle fibers and is known as the "longitudinal muscle layer" or the muscularis externa. Between both muscle layers lies the "myenteric plexus of Auerbach", a layer of sympathetic and parasympathetic nerves and neurons that provides nerve supply to the muscular layer. The combined action of this plexus on the muscular layer is responsible for peristalsis.

The serosa layer is the outer or external layer and is formed by a layer of peritoneum. As such, this layer can also be called "visceral peritoneum".

There are variations from GI organ to GI organ in the arrangement, content, glands, thickness of the layers, etc. The most important differences can be found in the thoracic esophagus and most of the rectum which are devoid of a serosa layer, and in the stomach, where there is a third muscular layer, deep to the circular layer, called the "oblique layer" that contributes fibers to the lower esophageal sphincter found at the esophagogastric junction.

UPDATED: The word [manubrium] is Latin and mean "handle", referring to the area where a person holds an instrument or device. To exemplify this, in Spanish the vernacular use of the word [manubrio] refers to the handles of bicycle or even the steering wheel of a car. 

In anatomy, the term is used with the same meaning. In the malleus, a hammer-like ossicle of the middle ear, the manubrium is the handle-like extension of the bone that attaches to the tympanic membrane.

In the case of the sternum, the [manubrium sterni] is the superior portion bound by the sternal angle (of Louis) inferiorly.  The use of the word manubrium can be explained because in early anatomy, the sternum was known by the Latin term [gladius] referring to the similarity of the sternum to the short sword of the gladiators. The area where you hold the sword is the handle, ergo, manubrium.

The manubrium has a superior and median notch called the "suprasternal notch" or the "jugular notch". It is important because in the case of a mediastinoscopy, the incision is made just superior to this landmark. The manubrium articulates superolaterally with the clavicle and inferolaterally with the superior aspect of the cartilage of the second rib. The rest of the rib cartilage articulates with the body of the sternum.

Image property of:CAA.Inc.. Artist: Mark J. Zuptich

The word [induration] arises from the Latin words induratio, meaning "thick or hard" and indurare, meaning "hardening".

It refers to a pathological hardening of tissues caused by tumoration or edema, increase of fibrous or connective tissue, or other causes. It is a good, descriptive term when stating a patient's symptoms. The term has been in use in English since the 14th century.

Note: The links to Google Translate include an icon that will allow you to hear the pronunciation of the word.