Etymology of Abdominal Visceral Terms
With particular thanks to Jack Lyons, MD
Palpebral – This adjective referring to the eyelids is from the Latin word for eyelid, palpebra. That word, in turn, is derived from the Ltin verb palpitare meaning to quiver or throb. The eyelids are sometimes known for their fluttering.
Palpitation, the awareness of the beating of one’s own heart, comes from the same verb.
Tegmen tympani – This is the bony roof you remove during the dissection of the ear.
Tegmen is from the Latin verb tego, tegere to cover or shelter. Hence tegmen is the word for roof. Tympani is the possessive form of the Latin noun tympanum meaning a drum. So, the whole phrase just means the roof of the (ear) drum.
Petrous – This adjective is derived from the Latin word for rock “petra”. It is applied to a part of the temporal bone that is particularly hard and rock-like. You may not have realized that the word petroleum has the same word as one of its roots. The other –oleum is the Latin for oil oleum. Petroleum, coming as it does from the earth, is appropriately named. Also, when Jesus gave the keys of the kingdom to Peter, he chose that apostle because of his rock solid loyalty.
Clinoid – You may have noticed that the anterior and posterior clinoid processes surround the sella turcica like the four corners of a four poster bed. And that is what the word means. Cline is Greek for bed. –oid, as usual, indicates a similarity to. When you encounter clinical teaching, that implies teaching that is carried out at the bedside.
Hordeolum – This is the medical term for a stye (a small localized swelling on the eyelid resulting from an infected perifollicular sebaceous gland located there). Hordeum is Latin for barley. Miniaturize this with the suffix –olum and you get barleycorn grain which it might be thought to resemble.
Chalazion –This is a small swelling in the eyelid caused by obstruction of a Meibomian gland. Chalaza is the Greek word for hail and chalazion is its diminutive. Hippocrates used the term for these hailstone-like tumors of the eyelid.
Umbo – This is the word used by the Romans to describe the raised ornamental stud projecting from the center of a shield. It may have helped deflect sword thrusts. We use the word to describe the central point on the eardrum where the handle of the malleus attaches. Why this most depressed part of the eardrum is called umbo is not entirely clear. Incidentally, umbilicus is a diminutive of this word for a projecting part.
Chiasm, chiasma – This a word used by the Greeks to mean crossed like the Greek letter chi (X). In addition to its description of the crossing of the optic nerve, it is used literarily to describe acrossing or reversal of words in the fore- and aft- parts of a literary structure: “Patients don’t care how much you know until they know how much you care”.
Fontanelle - Is the diminutive (-elle) of the Latin word fontana signifying a spring or small fountain. Why these soft spots in the skull got this name is not certain – possibly from pulsations felt at these points.
Parotid – Otos is Greek for ear. Para is a prefix indicating along side of (as a paramedian incision is one along side of the mid or median line of the abdomen). The parotid gland is the large salivary gland along side of the ear.
Mental – Be aware that this adjective has two possible Latin roots. When applied to thought processes, etc., the root is mens meaning mind or intellect. When referring to the chin, the root is mentum. One can easily guess to which the brainy society Mensa is related.
Temple – The name for this area on the side of the skull comes from the Latin word for time, tempus. The connection may be that with the passage of time, grey hairs appear here early on. Or it may relate to the pulsations of the underlying superficial temporal artery, marking the time we have left here. There is also a probable connection with the Greek verb temnion, to wound in battle. The skull is thin in this area and presents a vulnerable area for a blow from a battle ax.
Mastoid process of the temporal bone gets its name from the imagined similarity of its shape to that of the breast. Mastos is the Greek word for breast. The root also appears in the word mastectomy. The –ectomy part of that word is composed of –tomy, to cut and ec- a form of the prefix ex- meaning away from or out of. Our subject anatomy also has the –tomy stem meaning to cut.
Occiput - As you know, this is the posterior part of the head. The word is formed from the Latin prefix ob- = against, used here with the sense of opposite + caput = head – the idea that the occiput is in the back, or opposite part. The prefix is also found in the word obstinate: -Stinate is from the verb stare meaning to stand. So to be obstinate is to stand against something. Obstacle has the same roots: ob- = stare.