Lab 1 Pelvis.pdf

HUMAN ANATOMY PART I PELVIS BY Jerzy Gielecki M.D, Ph.D Anna Żurada M.D, Ph.D Lab. session 1 Extraperitoneal space and it’s organs 1. POSTERIOR GROUP OF THE ABDOMINAL MUSCLES............................ 2. THE KIDNEYS......................................................................................

HUMAN ANATOMY PART I PELVIS BY Jerzy Gielecki M.D, Ph.D Anna Żurada M.D, Ph.D Lab. session 1 Extraperitoneal space and it’s organs 1. POSTERIOR GROUP OF THE ABDOMINAL MUSCLES............................ 2. THE KIDNEYS.............................................................................................. 2.1. Localisation of the kidneys.................................................................................. 2.2. The renal hilus....................................................................................................... 2.3. Relations of the kidneys....................................................................................... 2.4. Structure of the kidneys....................................................................................... 2.5. Arterial supply of the kidney............................................................................... 2.6. Venous drainage of the kidneys........................................................................... 2.7. Lymphatic drainage of the kidneys.................................................................... 2.8. Innervation of the kidneys................................................................................... 3. THE URETERS............................................................................................. 3.1. Relations of the two parts of the ureter.............................................................. 3.2. Constrictions of the ureters................................................................................. 3.3. Arterial supply of the ureters.............................................................................. 4. SUPRARENAL GLANDS............................................................................. 4.1. Arterial supply of the suprarenal glands........................................................... 4.2. Venous drainge of the suprarenal glands........................................................... J. J. St. Gielecki and A. Żurada -HUMAN ANATOMY 2 Copyright © 2019 MedRadEd Lower part of the urinary system and internal iliac artery 5. THE URINARY BLADDER.................................................................................... 5.1. Structure of the urinary bladder 5.2. Relations of the bladder 5.3. Arterial supply of the urinary bladder 5.4. Venous drainage of the urinary bladder 5.5. Lymphatic drainage of the urinary bladder 6. THE URETHRA........................................................................................................ 6.1. Male urethra 6.2. Bulbourethral glands 6.3. Female urethra 7. INTERNAL ILAC ARTERY................................................................................... 7.1. Parietal braches 7.2. Visceral branches 3 1. Posterior group of the abdominal muscles See abdomen Lab. 2. The Kidneys Paired kidneys are responsible for removal of useless products of protein metabolism and excess of salts and water from the blood. The kidneys in adult measure about 10-12 cm in length, 5-6 cm in width and 2.5 -3.5 cm in thickness. 12 ey Kidn as Majo r L2 M. Pso L1 Fig. 1.1. Situation of the kidney. 2.1. Localisation of the kidneys The organs lay on the posterior abdominal wall (on the level between Th11-L3) and they are situated retroperitoneally (posteriorly to the peritoneum), both of them are in contact with the diaphragm (posterosuperiorly) and are capped by the adrenal gland (anteromedially). Each kidney is obliquely set because its upper pole is nearer the midline (3.5-4cm) than its lower pole (5.5-6 cm). Superior poles of both kidneys are protected by thoracic cage. The right kidney lies on the slightly lower level then the left one, due to the presence of the liver on the right side. The left kidney's upper pole extends above the posterior segment of the eleventh rib. The superior pole of the right kidney extends above posterior segment of the right twelfth rib. Each kidney (ren) is located: on the ventral surface of the quadratus lumborum muscle laterally to the psoas muscle and the vertebral column. J. J. St. Gielecki and A. Żurada -HUMAN ANATOMY 4 Copyright © 2019 MedRadEd The kidney has: a. upper & lower poles (extremitas seu polus superior et inferior), b. anterior & posterior surface (facies anterior et posterior), c. lateral (convex) & medial (concavity with renal sinus) margin (margo lateralis s. convexus et margo medialis s.concavus) 2.2. The renal hilus The concave medial border of the kidney contains the renal hilus (hilum, hilus renalis), through which the renal pelvis and vein leave the kidney, and also the renal artery enters there to the kidney. The hila are located about the level of the transpyloric plane. At the hilus opens medially the renal sinus, the cavity of the kidney. The renal vessels and the renal pelvis, the distended pre-ureteric portion of the urinary tract, are arranged in the following order: a. superior to inferior, at the renal hilum: renal vein, renal artery, renal pelvis. b. anterior to posterior, at the renal hilum: renal vein, renal artery, renal pelvis. 2.3. Relations of the kidneys Both kidneys have similar posterior relations:  the diaphragm separates the upper pole from the costodiaphragmatic recess of pleura (superior one-third area),  below three muscular areas from the medial to lateral  psoas muscle (musculus psoas major)  quadratum lumborum muscle (musculus quadratus lumborum)  transversus abdominis muscle (musculus transversus abdominis). 5 Right suprarenal vein Suprarenal surface Hepatic surface Duodenal surface Left suprarenal vein Suprarenal surface Gastric surface Splenic surface Pancreatic surface Colic surface (Descending colon) Jejunal surface Colic surface (Right flexure) Jejunal surface Left ovarian/testicular vein Right ovarian/testicular vein Inferior vena cava Abdominal aorta Fig. 1.2. Anterior relations of the kidneys. The left kidney is related anteriorly to :  area of the suprarenal gland (anteromedialy),  area of the stomach,  area of the pancreas (tail),  area of the spleen,  area of the jejunum,  area of the splenic flexure of the colon J. J. St. Gielecki and A. Żurada -HUMAN ANATOMY 6 Copyright © 2019 MedRadEd Diaphragmatic surface Abdominal aorta Inferior vena cava XI XI XII XII Left ureter Right ureter Surface for psoas major Surface for quadratus lumborum Surface for transversus abdominis tendon Fig. 1.3. Posterior relations of the kidneys. The right kidney is related anteriorly to:  area of the suprarenal gland (anteromedialy),  area of the duodenum (2nd part),  area of the liver,  area of the jejunum,  area of the hepatic flexure of the colon. 7 Right triangular ligament Parietal peritoneum Hepatorenal ligament Omental bursa Gastrosplenic ligament Right suprarenal gland Left suprarenal gland Transverse mesocolon Fibrous colic surface Phrenico-colic ligament Fibrous duodenal surface Fibrous colic surface Fig. 1.4. Posterior relations of the kidneys. 2.4. Structure of the kidneys The kidney has two capsules: a. The false capsule (of Gerota) or perirenal fascia. This layer arises from the prevertebral fascia. It divides into two layers:  anterior layer (lamina anterior seu fascia prerenalis),  posterior layer (lamina posterior seu fascia retrorenalis). The fascia splits inferiorly into two leaflets and fuse superiorly and lateraly for enclosing the kidney and suprarenal gland. It sourounds the kidney and suprarenal gland. The renal fat is associated with the kidney and it also sourounds kidney and suprarenal gland and it is called fat capsule (capsula adiposa). The renal fascia fuses around the renal vessels and forms the periuretral sheath. b. The true fibrous renal capsule (capsula fibrosa) separates the kidney from the suprarenal gland. The kidney is divided into two parts: a. The cortex is composed of:  the renal corpuscles (corpuscula renis)  the proximal convoluted tubules (tubuli contorti I oridinis), J. J. St. Gielecki and A. Żurada -HUMAN ANATOMY 8 Copyright © 2019 MedRadEd  the distal convoluted tubules (tubuli contorti II oridinis). b. The medulla is formed by 10 -20 renal pyramids (pyramides renales). Every pyramid contains:  the proximal straight tubules (tubulus rectus proximalis),  the Henle's loops (ansa Henlei).  the distal straight tubules (tubulus rectus distalis),  the collecting tubules. The collecting system of the kidney is composed of three elements: a. minor calyces (calyces renales minores) which fuse and join to form 2-4 major calyces, b. major calyces (calyces renales maiores) which fuse and join to form renal pelvis, c. the renal pelvis (pelvis renalis) narrows to form the ureter. The urine empties into minor calyces from the collecting tubules. The minor calyces envelop the renal papillae and urine pierces the tip of the renal papillae. 2.5. Arterial supply of the kidney The renal arteries (arteriae renales) arise from the lateral aspect of the abdominal aorta and divide into branches near the hilum. The left and right renal arteries arise usually between L1 and L2, just below origin of the superior mesenteric artery. The right renal artery passes posteriorly to the inferior caval vein. The left and right renal arteries give rise to the inferior suprarenal arteries outside the kidney and the arterial twigs to the ureter. The renal arteries divide into segmental arteries (arterie segmentales) within the renal sinus. This division defines five segments: a. superior segmental artery (arteria segmentalis superior), b. anterior-superior segmental artery (arteria segmentalis anterior superior), c. anterior-inferior segmental artery (arteria segmentalis anterior inferior), d. inferior segmental artery (arteria segmentalis inferior), e. posterior segmental artery (arteria segmentalis posterior).  The interlobar arteries (arteriae interlobares) arise from each segmental artery. Each interlobar artery enters a renal column. Each gives off the arcuate arteries, which run across the bases of the pyramids between the cortex and medulla.  The arcuate arteries (arteriae arcuatae) give of the interlobular arteries, which course between the medullary rays.  The interlobular arteries (arterie interlobulares) supply the afferent glomerular arterioles. 9 2.6. Venous drainage of the kidneys a. The right renal vein (vena renalis dextra) enters the inferior vena cava at the lower point then the left renal vein. It usually has no significant tributaries. b. The left renal vein (vena renalis sinistra) is longer than the right and crosses anteriorly the abdominal aorta. It receives:  the left gonadal vein (vena ovarica {testicularis} sinistra),  the left suprarenal vein (vena suprarenalis sinistra),  the left inferior phrenic vein (vena phrenica inferior sinistra)  communicates with the accesory azygos vein (vena azygos accesoria). 2.7. Lymphatic drainage of the kidneys All lymph drain to the renal lymphatic nodes (nodi lymphatici renales) and next to the lumbar lymphatic nodes (nodi lymphatici lumbales). 2.8. Innervation of the kidneys The kidneys are supplied by the coeliac plexus, which gives fibres (sympathetic fibres from coeliac plexus and parasympathetic fibres from cranial nerve X) to the renal plexus (plexus renalis). 3. The ureters The ureters (ureteres) are the excretory tubes which convey urine from the kidneys to the bladder. The ureters are thick-walled, muscular tubes in which peristaltic waves occur at that time when urine passes along the tube. They are 25-30 cm long. Each ureter descends retroperitoneally from the renal pelvis (L2) to the urinary bladder (S 4). Cours of each ureter has two stages: a. abdominal part (pars abdominalis), b. pelvic part (pars pelvica). In the abdomen, each ureter descends retroperitoneally and in its abdominal course the ureter courses anteriorly to the psoas major muscle, then crosses over the proximal part of the external iliac a. from lateral to medial side, to enter the cavity of the true pelvis. The gonadal vessels cross anteriorly to the middle 1/3 of the ureters. The right ureter descends close to the right margin of the I.V.C. while the left ureter passes inferiorly under the descending colon. After crossing over the pelvic brim, near the sacral promontory (promontorium, level of L5/S1), the ureter enters the cavity of the true (lesser) pelvis. The pelvic portion of the ureter runs along the lateral wall of the true pelvis, then it turns medially to enter the posterior aspect (the fundus) of the urinary bladder. In males, near the bladder, ductus deferens loops over the ureter to reach the seminal vesicles and prostate. In the mnemonic for this crossing over there is a "bridge" J. J. St. Gielecki and A. Żurada -HUMAN ANATOMY Copyright © 2019 MedRadEd 10 (ductus) over "water" (ureter). In females, the ureter passes deeply to the uterine vessels, near the ischial spine, a place of great danger during hysterectomy procedures. 3.1. Relations of the two parts of the ureter a. The abdominal part is similar in male and female bat the relations of two sides differ:  the right ureter has the following relations:  it is posterior to the descending portion of the duodenum,  it lies posteriorly to root of mesentery proper,  it is posterior to the right gonadal vessels.  the left ureter has the following relationships:  it is posterior to the left colic vessels,  it is adjacent to the left gonadal vessels.  it lies posteriorly to sigmoid mesocolon. b. The pelvic part:  in the male it crosses:  the common iliac vessels in front of the sacroiliac joint,  the vas deference posteriorly.  in the female is crossed superiorly by:  the uterine artery. The following provides the anterior and posterior relations of the abdominal portion of the ureters: RIGHT anterior Peritoneum Duodenum Ileum Root of mesentery of small intestine Right colic and ileocolic vessels Gonadal vessels (testicular/ovarian) LEFT anterior Peritoneum Sigmoid Sigmoid Sigmoid mesocolon RIGH Posterior relations Psoas major muscle Genitofemoral nerve Bifurcation of external iliac arteria LEFT Posterior relations Psoas major muscle Genitofemoral nerve Bifurcation of common iliac arteria Left colic vessels Gonadal vessels 11 3.2. Constrictions of the ureters The ureters display three constrictions: a. at the constriction of the renal pelvis to become the ureter proper, b. near the sacral promontory (level of S1), where the ureter crosses the pelvic brim to enter the true (lesser) pelvic cavity, c. at the fundus where the ureters perforate the musculature of the urinary bladder. The three ureteric constrictions become problematic when renal calculi are passed to the bladder. 3.3. Arterial supply of the ureters The blood supply of the ureters is very variable. Each ureter is serviced by: a. arterial twigs from the renal arteries, b. abdominal aorta, c. small arteries of the posterior abdominal wall, d. gonadal arteries, e. common and internal iliac arteries, f. inferior vesical arteries. 4. Suprarenal glands Two suprarenal endocrine glands (glandulae suprarenales) are situated on the upper poles of the kidneys. They are asymmetrical. The right gland is pyramidal in shape and lies in the front of the right crus of the diaphragm behind the inferior vena cava and bare area of the liver. The left is crescent and its lower end reaches the hilum of the kidney. It lies in the front of the left crus of the diaphragm, and behind the splenic vessels and the pancreas. 4.1. Arterial supply of the suprarenal glands Suprarenal arteries arise from three sources: a. The superior suprarenal arteries (arteriae suprarenales superiores) arise from the inferior phrenic artery which is paired parietal aortal branch. b. The middle suprarenal arteries (arteriae suprarenales mediales) arise directly from the abdominal aorta. c. The inferior suprarenal arteries (arteriae suprarenales inferiores) arise from each renal artery. J. J. St. Gielecki and A. Żurada -HUMAN ANATOMY 12 Copyright © 2019 MedRadEd 4.2. Venous drainge of the suprarenal glands Suprarenal vein exits at the hilus of each suprarenal gland. a. The right suprarenal vein (vena suprarenalis dextra) drains to the inferior vena cava. b. The left suprarenal vein (vena suprarenalis sinistra) drains usually to the left renal vein. 5. The urinary bladder The main function of the highly muscular urinary bladder (vesica urinaria) is storage of urine to an average capacity of 500 ml. It is located within the true pelvic cavity, rests on the lining of the inner aspect of the pubis and floor of the pelvis. The superior surface of the empty bladder reaches the pubic crest, and as the organ fills with urine it distends superiorly into the abdominal cavity to reach, under extreme conditions, the umbilical region. The superior surface of the bladder is covered with a sheet of peritoneum which continues with the peritoneal reflections over the uterus, in the female, and along the upper anterior surface of the rectum in the male. The bladder shape vary with the amount of the urine it contains and also is determined by organs, which are closlely related to it. 13 Median umbilical ligament Ureter Apex Superior surface Inf ero -la ter al su rfa ce Posterior surface (base) Neck of bladder Urethra Fig. 7.1. Schematic drawing of the urinary bladder. 5.1. Structure of the urinary bladder Urinary bladder has: a. the apex (apex vesicae) - anterior end of the urinary bladder. The median umbilical ligament (remanat of the embryonic urachus) arises from the apex and (enclosed in the peritoneum) forms the median umbilical fold (pica umbilicalis mediana), b. the neck - inferolateral part connecting the apex and the body, c. the body, d. the fundus of the urinary bladder (base) - posteroinferior surface. The wall of the bladder consists of the muscular part (smooth muscles) and the mucous membrane. J. J. St. Gielecki and A. Żurada -HUMAN ANATOMY 14 Copyright © 2019 MedRadEd a. Mucous membrane is loosly connected to the muscular layer exept the area located in the fundus, which is triangular in shape and is called trigone of the bladder (trigonum vesicae). The ureteric orifices are located in the two upper angels of the trigone of the bladder. The interureteric fold is sutuated horizontaly between them. In the lower angle of the trigone of the bladder there is the internal urethral orifice (ostium urethrae internum). b. Muscular wall consists of three layers (fibres of each of them penetrate to the others):  external longitudinal layer (stratum longitudinale externum),  circular layer (stratum circulare),  internal longitudinal layer (stratum longitudinale internum). The smooth muscles of all layers form the detrusor muscle (musculus detrusor urinae). Fibres of all layers run toward to the neck of the bladder and form the internal sphincter (musculus sphincter vesicae). 5.2. Relations of the bladder a. The superior surface of the bladder in the male is covered by the peritoneum and comes in contact with coils of the small intestine. In the female, with an empty bladder, the superior surface of the organ is overlapped by the uterus. b. The two inferolateral surfaces of the bladder are positioned against the fat-filled retropubic space which is traversed by a multitude of veins (prostatic or vesical tributaries of the internal iliac vein). The inferolateral surfaces of the bladder meet at the neck of the organ which relates to the prostate, in the male, and the pelvic diaphragms (pubococcygeal part of the levator ani muscles) in the female pelvis. c. The posterior surface or the base of the bladder is related to the seminal vesicles and ampullae of ductus deferens and rectum in the male pelvis. In the female, the base relates to the anterior wall of the vagina and to the supravaginal part of uterine cervix. 5.3. Arterial supply of the urinary bladder The urinary bladder is supplied by branches from internal iliac artery: a. the superior vesical arteries (arteriae vesicales superiores), from the umbilical artery branch from the internal iliac artery b. the inferior vesical arteries (arteriae vesicales inferiores) from the internal iliac atrtery. 15 5.4. Venous drainage of the urinary bladder All veins from bladder drain into the internal iliac vein and correspond to adequate arteries. The vesical venous plexus (plexus venus vesicalis) envelops the base of the bladder and prostate and comunicates freely with the prostatic plexus (plexus venus prostaticus) in male, the veins from the seminal vesicles, and ductus deferentes. 5.5. Lymphatic drainage of the urinary bladder From the superior part of the bladder lymph drains into external iliac lymphatic nodes (nodi lymphatici iliaci externi), and next to the common iliac nodes (nodi lymphatici iliaci communes). From the inferior part of the bladder lymph drains into the internal lymphatic nodes (nodi lymphatici iliaci interni), and next to the common iliac nodes. 6. The urethra The main function of the urethra is to convey urine from the bladder to the external environment external urethral orifice (ostium urethrae externum), and to allow the passage of sperm between the prostate and the tip of the penis during ejaculation in male. In male it also provides seminal fluid. The male urethra is represented by a 15 - 20 cm long passage lined by a few types of epithelium. The normal transverse width of urethra, 5 to 6 mm, can be stretched up to 26 mm for examination of the urinary tract and bladder. 6.1. Male urethra The male urethra can be subdivided into three functional parts: a. prostatic (pars prostatica) - 2.5 to 4.5 cm long, the prostatic urethra extends between the internal urethral orifice and the superior fascia of the urogenital diaphragm. It passes through the prostata downwards as a anteriorly concave curve. This part is the widest and dilatable part of the male urethra, which is narrowest in the superior and inferior segmnet of the prostatic urethra. b. membranous (pars membranacea) – 1.0 to 1.5 cm long, goes via urogenital diaphragm c. spongy (pars spongiosa) - 14 to 15 cm - the longest part of the urethra passes through the root and body of the penis, within corpus spongiosum of the superficial perineal pouch. J. J. St. Gielecki and A. Żurada -HUMAN ANATOMY 16 Copyright © 2019 MedRadEd Pubic symphysis Urinary bladder Prostate Suspensory ligament of penis Urethra masculina Internal orifice Intramural part Corpus cavernosum penis Prostatic urethra Intermediate part Bulb of penis Spongy part of urethra Scrotum Prepuce Glans penis Corpus spongiosum penis External urethral orifice Fig. 7.2. Course and relations of the male urethra. 17 Proximal part Prostata Ejaculatory duct Urethral crest Seminal colliculus Prostatic utricle Prostatic ducts Distal part Fig. 7.3. The beginning part of the male urethra opened and seen from above. 6.2. Bulbourethral glands The bulbourethral glands (glandule bulbourethrales) of the male are located on either side of the urethra as the latter passes between the muscular fasciculi of the sphincter urethrae muscle of the deep perineal pouch. 6.3. Female urethra The female urethra is a 4 cm long and 5 mm width muscular tube. The superior part of the female urethra is coresponding to the prostatic part of the male urethra and inferior part is adequate to the membranaceus part. The female urethra originates in the apex of the urinary bladder, passes posteriorly, and next inferiorly to the pubic symphysis. The female urethra lies anteriorly to the vagina and ends in the vestibule of the vagina (vestibulum vaginae) as external urethral orifice, which is located between the labia minora, below the clitoris and in front of the vaginal opening. It is surrounded there by the sphincter urethrae muscle (musculus sphincter urethrae). The female urethra with the vagina passes through the uretrogenital diaphragm and the perineal membrane. J. J. St. Gielecki and A. Żurada -HUMAN ANATOMY 18 Copyright © 2019 MedRadEd The female urethra can be divided into four parts: a. intramural (intraparietal) portion - inside the bladder's wall, b. supradiaphragmatic portion - above the uretrogenital diaphragm, runs along the anterior wall of the vagina, c. diaphragmatic portion - surrounded by the sphincter urethrae muscle, d. infradiaphragmatic portion - between the paraurethral glands. There are the paraurethral glands (glandulae paraurethrales) on each side of the female urethra, which are homologous to the prostate in male. The ducts from the paraurethral glands open near the external urethral orifice in the vestibule of the vagina. 7. Internal ilac artery Internal ilac artery (arteria iliaca interna): Origin of the vessel: It's origin is located in front to the sacroiliac joint on the lewel fifth lumbar vertebra as the terminal branch of the common iliac artery. End of the vessel: It divides into two terminal branches: inferior gluteal and pudendal arteries Course of the vessel: It passes downwords and behind the internal iliac vein /located behind and partly medialy to the artery/ along the pelvic wall and is covered medialy by the parietal peritoneum. It is main artery, which supplies all pelvic viscera, perineum and postero-anterior side of the taight. Branches: It gives of many branches which arise from it, as two main trunks: anterior and posterior. a. Anterior trunk runs posteriorly into the grater sciatic foramen. It gives off only parietal braches. b. Posterior trunk passes anteriorly to the piriform muscle and ends at the inferior part of the greater sciatic foramen. 7.1. Parietal braches a. Iliolumbar artery (arteria iliolumbalis). It passes symilarly to the lumbar arteries and divides into two terminal branches:  lumbar branch,  ilac branch. b. Lateral sacral arteries (arteriae sacrales laterales), which pass on the pelvic side of the sacral bone. 19 c. Superior gluteal artery (arteria glutea superior), which leaves the pelvic cavity through superior part of the greater sciatic foramen. d. Obturator artery (arteria obturatoria). It pasess through the obturator chanel and supplies the adductor muscles. e. Inferior gluteal artery (arteria glutea inferior), which arises from the anterior trunk and leaves the pelvic cavity through inferior part of the grater sciatic foramen. It supplies the gluteal region and posterior side of the tight. Umbilical artery Obturator: Nerve Artery Vein Obturator internus muscle Bladder Levator ani muscle Prostate Urethra Sphincter urethrae muscle Fig. 7.4. Relations of the obturatory nerves and vessel on the coronal section. 7.2. Visceral branches a. Umbilical artery (arteria umbilicalis), which is partly closed after birth, but first part carry blood to it's branches :  superior vesical arteries (arteriae vesicales superiores). b. Inferior vesical artery (arteriae vesicales inferiores), which in female partly supply the vagina. In male it gives off the prostatic branch. Both the superior and inferior vesical arteries supply the urinary bladder. c. In female - uterine artery (arteria uterina) or in male - artery of the ductus deferens (arteria ductus deferentis). Artery of the ductus deferens passes in the spermatic cord. The uterine artery supplies the uterus, vagina, ovary and uterine tube. It pasess into the isthmus of the uterus, where the vaginal branch (ramus vaginalis) arises and crosses anteriorly the ureter. Near the margin of the uterus the uterine artery ascends along the lateral margin of the uterus /there it gives of uteral branches/, and next it divides into terminal branches : J. J. St. Gielecki and A. Żurada -HUMAN ANATOMY 20 Copyright © 2019 MedRadEd ovaric branch (ramus ovaricus),  tubal branch (ramus oviductus). d. Middle rectal artery (arteria rectalis media), which anastomoses with the superior and inferior rectal arteries and all rectal arteries thet supply the rectum. e. Internal pudendal artery (arteria pudenda interna), which is one of two terminal branches of the internal iliac artery and supplies mostly external genital organs and perineum. It divides into:  inferior rectal artery (arteria rectalis inferior),  perineal artery (arteria perinealis),  artery to the bulb of vestibule (arteria bulbi vestibuli vaginae) or artery to the bulb of penis (arteria bulbi penis),  urethral artery ( arteria urethralis),  deep artery of penis (arteria profunda penis) or deep artery of clitoris (arteria profunda clitoridis),  dorsal artery of penis (arteria dorsalis penis) or dorsal artery of clitoris (arteria dorsalis clitoridis). Aortical bifurcation Inferior epigastric artery Common iliac arteries Sacral median artery Umbilical artery Umbilical ligament Iliolumbar artery Lateral sacral arteries Superior gluteal artery (b) Superior vesical arteries (a) Obturatory artery Pubic branch A. of deferent duct/ /Uterine artery Middle rectal artery Inferior vesical artery (c) (e) (d) Inferior gluteal artery Internal pudendal artery Inferior rectal arteries Perineal artery Fig. 7.5 Branches of the internal iliac artery (a) (b) (c) (d) (e) – lacuna vasorum – space for vessels – suprapiriform part of major sciatic foramen – infrapiriform part of major sciatic foramen – minor sciatic foramen – obturator foramen 21