1984 HUMAN ANATOMY. 



THE GLANDS OF COWPER. 



Cowper's glands (glandulae bulbourethrales) are two small ovoid bodies situated 

 along the under surface of the membranous portion of the urethra (Fig. 1632), one 

 on either side of and close to the mid-line. In general form and size (from 5-8 mm. 

 in diameter) they resemble a pea, although their contour is irregular and somewhat 

 knobbed. Their color is reddish yellow and their consistence firm. They lie within 

 the deep perineal interspace between the two layers of the triangular ligament em- 

 bedded within the fibres of the compressor urethrse muscle. 



The ducts of the glands about 1.5 mm. in diameter and from 3-4 cm. in 

 length run forward and medially, at first between the bulbus spongiosum and the 

 membranous urethra, then within the bulb itself, and, finally, for about 2 cm. be- 

 neath the urethral mucous membrane to open by small slit-like orifices on the lower 

 wall of the bulbus urethrae near the mid-line. The position of these inconspicuous 

 openings is sometimes masked by a fold of mucous membrane or a slight de- 

 pression. Quite frequently the two ducts unite and open by a common orifice. 



Structure. These glands are mucous tubo-alveolar in type, their terminal 

 divisions ending, after more or less branching, in irregularly sacculated compart- 

 ments. In places the latter communicate by means of a reticulum of connecting 

 canals (Braus). The alveoli are lined with low columnar or pyriform epithelial 

 cells, among which mucus-secreting cells are plentiful. The cuboidal epithelium 

 that clothes the smaller ducts and the dilatations connected with them gives place to 

 clear columnar cells within the larger excretory canals. The divisions of the gland 

 are united by interlobular connective tissue and invested in a general fibrous en- 

 velope in which a considerable quantity of unstriped muscle occurs. The secretion 

 of Cowper's glands, clear and viscid and of alkaline reaction, is probably of service 

 in maintaining favorable conditions for the spermatozoa by neutralizing acidity of 

 the urethral canal due to passage of urine (Eberth). In addition to their recognized 

 homology with the glands of Bartholin in the female, the observed histological 

 changes incident to sexual excitation warrant the grouping of these glands as acces- 

 sory sexual organs. 



Vessels. The arteries supplying Cowper's glands are twigs given off from 

 the arteries of the bulb as they course between the two layers of the triangular liga- 

 ment. The veins are tributary to those returning the blood from the bulbus spongi- 

 osum which empty into the internal pudic. The lymphatics are afferents to the 

 internal iliac lymph-nodes. 



The nerves are derived from the pudic. 



Development. The bulbo-urethral glands appear about the end of the third 

 month of foetal life as solid outgrowths from the entoblastic lining of the uro- 

 genital sinus. With the elongation of the latter incident to the formation of the 

 male urethra and the penis (page 2044), the glands assume a lower position and 

 their ducts are correspondingly lengthened. During the first ten or twelve years the 

 glands undergo only small increase in volume, but between the sixteenth and 

 eighteenth years they attain their full size. In aged subjects they atrophy and are 

 frequently so. small that their recognition is difficult. 



Variations. In addition to abnormalities in size, the two glands may be fused into a single 

 mass, or one or both may be wanting. Sometimes their absence is only apparent, since the 

 or^m* may be represented by rudimentary glands embedded entirely within the substance of 

 the corpus spongiosum. 



