PAKIETAL BEANCHES OF THE HYPOGASTEIC AETEEY. 941 



The division sometimes takes place whilst the artery is still between the layers 

 of the urogenital diaphragm. 



Branches. In the pelvis it gives small branches to the neighbouring muscles and to 

 the roots of the sacral plexus. 



In the buttock. (a) Muscular branches are distributed to the adjacent muscles. (6) 

 Anastomotic branches unite with branches of the superior and inferior glutaeal, and 

 . medial circumflex arteries. 



In the ischio-rectal fossa. (c) The inferior hsemorrhoidal artery pierces the wall of 



the fascial canal, and runs obliquely forwards and medially. It soon divides into two or 



three main branches, which may arise separately from the pudendal ; they pass across 



' the space to the anal passage. The artery anastomoses in the walls of the anal passage 



Superficial trans- 

 erse perineal muscle 



/ Crus penis 



Dorsal artery of penis 

 and profunda artery 

 of penis 



Bulb of penis 



Sphincter of 

 membranous urethras 



Artery to bulb 



Perineal artery 



Transverse branch of 

 perineal artery 



Internal pudendal 

 artery 



Inferior hsemor- 

 rhoidal artery 



i. Glutseus maxim us 



.THE PERINEAL DISTRIBUTION OF THE INTERNAL PUDENDAL ARTERY IN THE MALE. 



with its fellow of the opposite side, and with the middle and superior haBmorrhoidal 

 arteries ; it anastomoses with the transverse perineal arteries also ; and it supplies 

 cutaneous twigs to the region of the anus, and others, which turn round the lower 

 border of the glutseus maximus, to supply the lower part of the buttock. 



(d) The perineal artery arises in the anterior part of the ischio-rectal fossa, pierces 

 I the base of the fascia of the urogenital diaphragm, and divides into long slender posterior 



scrotal branches in the male, and posterior labial branches in the female. Those branches are 

 continued forwards, in the urethral triangle, to the scrotum or labium, deep to the super- 

 ficial perineal fascia. They anastomose with their fellows of the opposite side, with the 

 transverse perineal and the external pudendal arteries, and supply the muscles and 

 subcutaneous structures of the urethral triangle. 



(e) The transverse perineal artery is a small branch which arises either directly from the 

 internal pudendal or from its perineal branch. It runs medially along the base of 

 the fascia of the urogenital diaphragm (O.T. triangular lig.) to the central point of 

 the perineum, where it anastomoses with its fellow of the opposite side, with the perineal 

 artery, and with the inferior hsemorrhoidal arteries. It supplies the sphincter ani, 



; the bulbo-cavernosus or sphincter vaginae, and the anterior fibres of the levator ani. 



In the urethral triangle. (/) The artery to the bulb, a branch which is usually of 



tively large size, is given off between the fascial layers of the urogenital diaphragm. 



t runs transversely along the posterior border of the sphincter of the membranous 



