The word [parietal] has its origin in the Greek term [paries] meaning "wall". [Parietal] then means "pertaining to a wall", wall-related", or simply stated, "wall". Following are some examples of the use of this term.

The parietal bones of the cranium (os parietale), create the lateral "wall" of the cranium. These quadrangular bones join in the midline forming the sagittal suture. (see image). Click here for a detailed description of the parietal bone.

The term [parietal] is also used to denote membranes that are related to the body wall. The parietal peritoneum is the portion of the peritoneal membrane that is found away from the viscera and in relation to the abdominal wall.  The pleura is a membrane that lines the lungs, and it has a component that is related to the wall of the thorax. This is the [parietal] pleura.

An interesting use of the term is legal, where a [parietal] law, is used to denote a law that establishes boundaries or "walls" between legal parties.

Original image and links courtesy of bartleby.com

These two terms are related by the Greek root term [-gnos-] which means "knowledge".

The first word [diagnosis] has the prefix [dia-] meaning "apart" or "to take apart". [Diagnosis] then means "to discern", or in a more detailed explanation, it is "knowledge by taking apart", identifying a pathology by looking at all its components.

The second word [prognosis] has the prefix [pro-] meaning "forward". Prognosis is then "forward knowledge", an statement of outcome of the course of a pathology.

Words suggested by: Sara Mueller

The term [coronary] comes from the Latin root [corona] meaning "crown", therefore [coronary] is used to denote a structure that surrounds another as a crown or a garland. In the heart, the coronary arteries and their branches form a crown that surrounds the heart at the level of the atrioventricular sulcus. There are two coronary arteries, the right coronary artery (RCA), and the left coronary artery (*). Both these coronary arteries are the only branches that arise from the ascending aorta.

The right coronary artery passes from the anterior to the posterior surface of the heart, ending in a terminal branch, the posterior descending artery, or PDA. The left coronary artery, sometimes called the "left main", gives origin to two branches: the circumflex artery (CFX) and the left anterior descending artery (LAD). Each one of these arteries gives origin to several named branches. 

Image property of: CAA.Inc.. Artist: Victoria G. Ratcliffe

The Latin word [ventriculus] means "little sac" or "little belly" and arises from the Latin term [venter] meaning "belly" or "abdomen". Originally the term [ventricle] was used to denote the stomach. This use of the word has changed and now the term [ventricle] denotes a "sac" or "cavity", as in the "ventricles of the brain". The term [ventricular] means "pertaining or related to a ventricle".

In the case of the heart, the ventricles represent the two inferior chambers of the heart. (see image, items "C=right ventricle" and "D=left ventricle"). The anatomy of the right and left ventricles is quite different. The left ventricle has a thicker lateral muscular wall, almost three times thicker than the lateral wall of the right ventricle.

Image property of: CAA.Inc.. Photographer: D.M. Klein

The term [perineum] has two definitions:

1. It is the area of the trunk inferior to the pelvic diaphragm. As such, the perineum contains the ischioanal fossa, the urogenital diaphragm, and the superficial genitalia.

2. It is the area of the body between the upper thighs containing the external openings of urethra, vagina, and anus. This area is delimited (see image) by the symphysis pubis, ischial tuberosities, and coccyx.

The perineum, as described in the second definition, is formed by two large triangular regions. The anterior region (in purple) is called the urogenital triangle, and the posterior region (in yellow) is called the anal triangle. 

Image property of: CAA.Inc.. Artist: D.M. Klein.
Word suggested and edited by: Dr. Sanford S. Osher , MTD Contributor

The pelvic diaphragm is one of the four diaphragms in the human body (do you know the other three?) and it represents the lower boundary of the abdominopelvic cavity. This thin and  transversely oriented structure is formed from anterior to posterior by the puboccygeus, the iliococcygeus, and the coccygeus muscles.

The first two anterior muscles overlap, the pubococcygeus muscle being superior to the iliococcygeus muscle. Both of them attach laterally to a thickening of the obturator internus fascia that covers the obturator internus muscle. This thickening is known as the arcus tendineus levator ani (ATLA in the image). Because of the relation of the medial fibers of the puboccygeus muscle to the anal canal (puborectalis muscle), and what happens when these muscles contract, these two anterior muscles are known by one common name, the "levator ani" muscle. Click on the picture for a larger image.