Adrenal Gland

Adrenal Gland one of two small ductless glands located at the top of each kidney. The adrenal gland is functionally and histologically divided into two parts. The outher part, or cortex, produces an endocrine principle that is necessary for life. Cortical disease produces the syndrome of Addison's disease, which is fatal without treatment. The inner part, or the medulla, secretes the hormone epinephrine ( adrenalin ), which raises the blood pressure by stimulating the heart and contracting blood vessels. As part of the endocrine systemi the adrenal glands may exert their influence indirectly upon structures and functions for the most part controlled by other endocrine glands. The secretion of the adrenal medulla seems to have a protective or defensive function.

Abdomen

Abdomen in man and other vertebrates the region of the body that lies between the thorax and the pelvis is called the abdomen. The abdominal cavity is separated from the thoracic cavity by the diaphragm and contains the viscera. It is lined by a serous membrane , the peritoneum. For convenience in locating ortangs and symptoms of disease , the abdomen is divided into mine regions : The upper regions are caşşed şeft hypochondriac , epigastric , and right hypochondriac ; the middle regions , left lumbar , umbilical , and right lumbar , and the lower , left inguinal , hypogastric , and right inguinal.


Abdominal pain is a symptom of many disorders and may originate outside as well as within the abdomen. Extra - abdominal causes of pain include disease of the chest , spine , or genitalia , poisoning , allergy , emotional upset , and disease of nerves. Within the abdomen pain my result from obstruction , inflammation , infection , disturbed function , or rupture. The treatment of abdominal pain varies with the cause.

In insects and other arthropoda , the abdomen is the posterior region of the body and is usually segmented.

Argus

in Greek mythology, a fabulous creature with 100 eyes, of which only two slept at any one time. Hera placed him as guard over Io after she had been turned into a heifer. Hermes slew him after charming him to sleep with his music. Hera then changed him into a peacock with his eyes in the tail. In zoology, a genus of birds of the family Phasianidae and the subfamily Phasianinae. It contains the argus, or argus pheasant, Argusianus giganteus. The male measures between five and six feet from the tip of the bill to the extremity of the tail and is an eminently beautiful bird, the quill feathers of the wings, which often exceed three feet in length, being ornamented all along by a series of ocellated spots. The name Shetland argus is given to a starfish, Astrophylon scutatum. It is called also the basket urchin, or sea basket.

Argos

Argos, a town in southern Argos and Corin-thia prefecture, northeastern Peloponnesus, Greece. Reputed to be the oldest city in Greece, it figured in Greek legends and in the 8th and 7th centuries B.C. dominated much of the Peloponnesus. It contains numerous ancient ruins. It was a center of worship of Hera.

Aneroid Barometer

Aneroid Barometer, a barometer not containing a liquid and constructed on a totally different principle from that of the mercury barometer. Various forms of the instrument exist; one of these consists of a cylindrical metal box exhausted of air and having a lid of thin corrugated metal with a spring on the inside. An increase in atmospheric pressure forces the highly elastic lid inward; a decrease in pressure forces it outward. Delicate multiplying levers transmit these motions to an index, which moves on a scale and is graduated empirically by a mercurial barometer. The aneroid, being extremely delicate, is apt to get out of order, particularly when it has been exposed to great variations of pressure. When it is properly graduated , it is often used for determining the heights of mountains.