GLOSSARY ' 439 



Digestion. (From the Latin word digerere, "to digest.") Those 

 processes whereby the food taken into the alimentary canal is made 

 capable of being absorbed and assimilated by the tissues. 



Dilator Nans Anterior (muscle). Anterior dilator of the nostril. 



Dilator Naris Posterior (muscle). Posterior dilator of the nostril. 



Diploblast. (From the Greek words meaning double sprout.) 

 Formed of two layers. 



Diploe. (From the Greek word meaning a fold.) The cancellous 

 bony tissue between the outer and inner tables of the skull. 



Disintegration. (From the Latin words dis, " apart; "integer, 

 the whole.") The act of breaking up or decomposing. 



Distal. (From the Latin word distare, "to be at a distance.") 

 Extreme; at the greatest distance from a central point. 



Diverging. To proceed from a common point in different directions. 



Dorsal. (From the Latin word dorsum, "back.") Pertaining to 

 the back of the body or organ, etc. 



Dorsalis Pedis. The back of the foot. 



Dorsum. The back or posterior of the body, organ, etc. (See 

 Dorsal.) 



Duct. (From the Latin word ducere, "to lead.") A tube or channel, 

 especially one for conveying the secretions of a gland. 



Ductus Arteriosus. A short vessel in the fetus connecting the 

 pulmonary artery with the aorta. 



Ductus Communicus Choledochus. The common bile duct. 

 (Literally, the duct which receives the bile.) The common excretory 

 duct of the liver and gall-bladder. 



Ductus Venosus. A branch of the umbilical vein in the fetus which 

 empties directly into the ascending vena cava. 



Duodenum. (From the Latin word duodeni, "twelve each." So 

 called because it is about twelve finger-breadths in length.) The 

 first part of the small intestine . 



Dura Mater. (From the Latin words dura, "hard;" mater, 

 "mother.") The fibrous membrane forming the outer covering of the 

 brain and spinal cord. 



Ectoderm. (From the Greek words meaning outside, the skin.) 

 The outer of the two primitive layers of the blastodermic vesicle in 

 the embryo. 



Edema. Is a swelling of the subcutaneous tissues of the body due 

 to an abnormal or excessive transudation of the fluid portion of the 

 blood into or its abnormal retention in the lymph spaces. 



Efferent. (From the Latin word efferens, "carrying from.") Carry- 

 ing away, as the efferent nerves conveying impulses away from the 

 central nerve system; also bloodvessels and lymphatic vessels con- 

 veying blood and lymph respectively from the tissues. 



Embryo. (From the Greek words meaning within, to swell with). 

 The product of conception up to the fourth month. 



Embryonic. Pertaining to the embryo. 



Emissive. Sending out, as nerve impulses. 



Enarthrosis. A ball-and-socket joint. Like the articulation of the 

 hip and femur. 



Encephalon. (From the Greek word meaning brain.) Brain. 



Endo. A prefix meaning within. 



