Lecture 6 – Anatomic Derivatives

Lecture 6

Prefix/Suffix                                 Derivation/Meaning      Example

Extra-                                                   L, outward                             extracellular – in molecular biology (also called cell biology), any bodily fluid that is not contained in cells.  Extracellular fluid is found in lymph, body cavities lined with serous (moisture-exuding) membranes, in the cavities and channels of the brain and spinal cord, in muscular and other body tissues.  It differs from intracellular fluid or fluid within the cells.  Extracellular fluid has a high concentration of sodium and a low concentration of potassium.  Intracellular fluid is the opposite and is high in potassium and low in sodium.  (Just memorize these concepts.  There are no catchy phrases on this one.)

Fossa                                                   L, ditch                                    infraspinous fossa – Just like in math, break it down to the lowest terms if you are puzzled on an exam.  Could this be a depression or low point within the spine?  That is the crude definition using your mastery of Latin and Greek.  The infraspinous fossa is the large, slightly concave area below the spinous process on the dorsal surface of the scapula.

Gastr- (gastro-)                                     G, belly                                    gastric juice- (gastric – having to do with the belly.)  This juice is a thin, strongly acidic acid, meaning it has a pH of 1 to 3.  This liquid is almost colorless and is secreted by the glands of the lining of the stomach.  Gastric juice is composed of digestive enzymes pepsin and rennin, hydrochloric acid and mucus.  Pepsin converts proteins into simpler more easily absorbed substances.  Pepsin is aided by hydrochloric acid, because it provides the acidic environment in which pepsin works best.  Rennin aids the digestion of milk proteins.  Mucus secreted by the gastric glands help protect the lining of the stomach from the action of the gastric juice.  Gastric secretion is stimulated by many hormones and chemical substances, by the presence of food in the stomach, and by psychological factors, such as the smell of a favorite food.  We are referring to a healthy gastric system.  Later we will discuss digestive disorders.

Glenoid                                                            G, socket                     glenoid fossa of scapula- or glenoid cavity, is a shallow pyriform, articular surface, which is located on the lateral angle of the scapula.  It is directed laterally and forward, and articulates with the head of the humerus.  This type of joint is classified as a synovial, ball and socket joint.  It is a shallow fossa which makes it susceptible to luxation, or dislocation.  Strong ligaments and muscles usually prevent dislocation.  Domestic violence is responsible for numerous shoulder dislocations from the victim being pulled by the arms repeatedly, and having arms twisted behind the back.  Flee all violent relationships permanently.  Prayer is great; pray from a distance.

Glosso – (gloss)                                               G, tongue                     styloglossus – a muscle.  In speaking of muscles we speak of an origin or starting place on the body, an insertion or ending place, and an action.   A muscle can originate or insert in more than one place.

Origin: anterior surface and apex of styloid process; upper quarter of stylohyoid ligament

Insertion:  superolateral sides of the tongue – (Hint – superior – upper sides, as opposed to inferior sides, which would be further down on the tongue, or away from the base of the tongue).  Keep thinking!

Action:  Retracts (pulls back) or elevates tongue;  Aids initiation of swallowing.  Swallow and take notice of its action.  It makes sense that we start swallowing at the base of the tongue and not the distal end.  The hypoglossal nerve is XII.  Lingua also means tongue in Latin.  Linguists study language.  Foreign languages are sometimes called tongues, especially in the religious setting.

We will only cover five new terms today, since we are getting very technical and covering a substantial amount of background information for each term.  Read previous notes every day before moving on to new material.  You should be comfortable with the oldest material since it is being reviewed on a regular basis.  We have 24 additional terms to cover before continuing with our discovery on bones.  Have a great day.


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