338 Life and Health 



Al-ve'o-lus, pi. alveoli (Lat. alveolus, a little hollow). A small cavity, or 



socket, as the sockets for the teeth in the jawbone, the air sacs of the 



lungs, and the secreting recesses of certain glands. 

 A-mce'ba (Gr. d/iot/3^, a change). A single-celled, protoplasmic organism, 



which is constantly changing its form by protrusions and withdrawals 



of its substance. 



A-mce'boid. Like an amoeba in form or in movement. 

 Am-puria (Lat. ampulla, a wine flask). The dilated part of the semi- 

 circular canals of the internal ear. 

 Am'y-lop'sin (Gr. &/JLV\OV, starch, and 6\f/is, appearance). A ferment found 



in the pancreatic juice, which changes starch into sugar. 

 A-nab'o-lism (Gr. ava.pd\\eiv, to throw or build up). The process by which 



simpler elements are built up into more complex. 

 An'aes-thet'ic (Gr. &v, without, and alae-rjcria, feeling). A substance which 



produces insensibility to pain or to touch, etc., as chloroform, ether, etc. 

 An'ti-dote (Gr. avri, against, and 8i86vai, to give). A substance given to 



prevent or counteract the action of a poison. 

 An'ti-sep'tic (Gr. avrl, against, and <rri\j/is, poison). A remedy or agent 



which prevents the development of bacteria, or prevents the growth of 



bacteria upon which putrefaction depends. 

 An'ti-tox'in (Gr. avri, against, and ro|t/c6i', poison). A substance which 



neutralizes the action of the toxins of bacteria. Antitoxins are used in 



the treatment of certain infectious diseases, like diphtheria. 

 An'trum (Lat. antrum, a cave). The cavity in the upper jaw. 

 Ap'o-neu-ro'sis (Gr. d?r6, from, and vevpov, a nerve). A fibrous, membranous 



expansion of a tendon. 

 Ap'pa-ra'tus. Used to designate collectively organs which perform a 



certain function. 

 Ap-pen / di-ci / tis (Lat. appendix, and if is). Inflammation of the appendix 



vermiformis of the caecum. 

 A'que-ous hu'mor (Lat. aqua, water). The watery fluid occupying the 



space between the cornea and crystalline lens of the eye. 

 A-racb/noid mem'brane (Gr. dpdxvi], a spider, and eTSos, form). The thin 



covering of the brain and spinal cord, between the dura mater and the 



pia mater. 

 Ar'bor vi'tse. Literally, "the tree of life"; a name given to the tree-like 



appearance of a section of the cerebellum. 

 A-re'o-lar tis'sue (Lat. areola, a small space, dim. of area). Connective 



tissue containing small spaces. 

 Ar-tic'u-la'tion (Lat. articulus, a joint). The more or less movable union 



of bones, etc. ; a joint. 



