Anatomy Tables - Perineum & External Genitalia

Osteology
Bone Structure Description Notes
ischium (N486, TG3-04)   the "V"- shaped bone that forms the posteroinferior part of the pelvis one of the three bones that form the os coxae: ilium, ischium, pubis
  ischial ramus the limb of the ischium that passes anteriorly and superomedially toward the pubis it articulates with the inferior ramus of the pubis to form the ischiopubic ramus (Greek, ischion = hip joint; Latin, ramus = a branch)
ischial tuberosity the roughened projection that protrudes posteroinferiorly from the body of the ischium it is the site of attachment of the sacrotuberous ligament; it is the site of origin of the inferior gemellus m., quadratus femoris m. and the hamstring mm. (semitendinosus, semimembranosus, long head of biceps femoris, ischiocondylar portion of the adductor magnus) (Greek, ischion = hip joint)
lesser sciatic notch the notch located between the ischial tuberosity and the ischial spine the lesser sciatic notch is converted to the lesser sciatic foramen by the sacrospinous ligament and the sacrotuberous ligament
ischial spine the spine that arises just superior to the lesser sciatic notch it is the site of attachment of t he sacrospinous ligament and the site of origin of the superior gemellus m. (Greek, ischion = hip joint)
ilium (N486, TG3-04) fan-shaped bone that forms the lateral prominence of the pelvis one of three bones that form the os coxae: ilium, ischium, pubis
greater sciatic notch the notch on the inferior portion of ilium located posteromedial to the ischial spine the greater sciatic notch is converted to the greater sciatic foramen by the sacrospinous ligament and the sacrotuberous ligament
coccyx (TG6-01, TG6-02)   the most inferior portion of the vertebral column the coccyx results from the fusion of the four coccygeal vertebrae; it may be a single bone or the first coccygeal vertebra may be separated from the other three; it articulates with the fifth sacral segment; coccygeal vertebrae are reduced in complexity, having no pedicles, laminae or spines (Greek, coccyx = a cuckoo's beak)

Viscera/Fascia/Peritoneum
Organ/Part of Organ Location/Description Notes
bulb of the penis (N379, N382, N418 TG6-27B) expanded part of the corpus spongiosum that attaches to the perineal membrane bulb of the penis is covered on its superficial surface by the bulbospongiosus muscle; it contains a portion of the spongy/penile urethra; it is the homologue of the bulb of the vestibule
bulb of the vestibule (TG6-27A) erectile tissue located on either side of the vestibule of the vagina, attached to the perineal membrane bulb of the vestibule is continuous with the glans clitoris; it is covered on its superficial surface by the bulbospongiosus muscle; it is the homologue of the bulb of the penis
bulbourethral gland (TG6-28B) an exocrine gland located posterolateral to the membranous urethra within the sphincter urethrae muscle (in the urogenital diaphragm) male only; its duct passes through the perineal membrane and drains into the spongy/penile urethra in the bulb of penis
corpus cavernosum (N379, N382, N418, TG6-27A, TG6-27B) primary erectile bodies (paired) of the penis and clitoris corpora cavernosa attach via the crura to the ischiopubic rami and the perineal membrane; each crus is covered by an ischiocavernosus muscle; supplied by the deep a. of the penis/clitoris (Latin, corpus = body)
corpus spongiosum(N379, N382, N418, TG6-27A, TG6-27B) midline erectile body, attached to the perineal membrane at its proximal end (bulb of the penis) corpus spongiosum expands distally as the glans penis which caps the distal ends of the corpora cavernosa; it contains the spongy/penile urethra (Latin, corpus = body)
crus clitoris (N379, N382, N418, TG6-27A, TG6-27B) lateral part of the corpus cavernosum which is attached to the ischiopubic ramus and the perineal membrane crus clitoris is covered on its superficial surface by the ischiocavernosus muscle (Latin, crus = resembles a leg, therefore any structure which resembles a leg. The clitoris and diaphragm are two among many anatomical structures which take origin from crura)
crus of penis (N379, N382, N418, TG6-27A, TG6-27B) lateral part of the corpus cavernosum which is attached to the ischiopubic ramus and the perineal membrane crus penis is covered on its superficial surface by the ischiocavernosus muscle (Latin, crus = resembles a leg, therefore any structure which resembles a leg. The clitoris and diaphragm are two among many anatomical structures which take origin from crura)
epididymis (TG6-32B) beginning of the duct system of the testis the head of the epididymis is located on the superior surface of the testis and receives sperm from the efferent ductules; the body of the epididymis lies posterolateral to the testis and is separated from the testis by the sinus of the epididymis; the tail of the epididymis is located inferiorly and is continuous with the ductus deferens; the ductus deferens ascends to pass through the abdominal wall via the inguinal canal (Greek, epididymis = covering the testicle)
erectile tissue (N379, N382, N418, TG6-27A, TG6-27B) tissue within the corpora cavernosa erection occurs as a result of blood filling the spaces of the corpora cavernosa
fascia, deep penile/clitoral an extension of the muscular fascia of the ischiocavernosus m. and bulbospongiosus m. onto the shaft of penis/clitoris deep fascia of the penis/clitoris forms a tubular sheath surrounding the erectile bodies, dorsal n. of the penis/clitoris, dorsal a. of the penis/clitoris, deep dorsal v. of the penis/clitoris; the superficial dorsal v. of penis/clitoris lies superficial to the deep fascia of the penis/clitoris; deep fascia of the penis is also known as: Buck's fascia
fossa navicularis (TG6-09B) dilation of the spongy/penile urethra in the glans penis the largest diameter of the penile urethra occurs here
fundiform ligament specialization of the membranous layer of superficial (Scarpa's) fascia passing from the lower abdominal wall onto the base of the penis/clitoris suspensory ligament of the penis/clitoris is a deep fascia specialization that lies deep to the fundiform ligament
glans penis/clitoridis (N379, N382, N418, TG6-27A, TG6-27B) expanded distal end of the corpus spongiosum which caps the ends of the corpora cavernosa the fossa navicularis is an expanded portion of the penile urethra that occurs in the glans (Latin, glans = acorn)
greater vestibular gland (N379, TG6-27A) an exocrine gland located in the superficial perineal space posterior to the bulb of the vestibule greater vestibular gland is covered by the bulbospongiosus muscle; it produces a mucous secretion that drains into the vestibule of the vagina for lubrication of the vulva
perineal membrane (N379A, N379B, N381, TG6-27A, TG6-27B) membrane stretching across the urogenital triangle attaching to both ischiopubic rami perineal membrane is pierced by the urethra, vagina and branches of the pudendal neurovascular bundle
root of penis (N379, N382, N418, TG6-27A, TG6-27B) the attached part; consists of the crura, bulb, and ischiocavernosus and bulbospongiosus muscles the root is located in the superficial perineal pouch, betweent the perineal membrane superiorly and the deep perineal fascia inferiorly (Latin, a tail or penis; derived from pendere, to hang down)
scrotal ligament band of connective tissue that attaches the inferior end of the testis to the inner aspect of the scrotal sac scrotal ligament is the remnant of the gubernaculum testis
sinus of the epididymis ( TG6-32B) a thin space within the tunica vaginalis testis between the body of the epididymis and the testis sinus of the epididymis is lined by a serous membrane (visceral layer of the tunica vaginalis testis) (Greek, epididymis = covering the testicle)
suspensory ligament of the penis/clitoris (TG6-31BA) a specialization of deep fascia connecting the proximal end of the penis/clitoris to the pubis and pubic symphysis the fundiform ligament is a specialization of superficial fascia that lies superficial to the suspensory ligament
tunica albuginea, corpus cavernosum (N379, N382, N418, TG6-27A, TG6-27B) outer white fibrous covering of the corpus cavernosum of the penis/clitoris tunica albuginea is a dense connective tissue layer that is not distensible, causing erection when the corpus cavernosum becomes engorged with blood (Latin, tunica albuginea = white coat + corpus = body)
tunica dartos scroti a subcutaneous layer of smooth muscle located in the scrotum fatty and membranous layers of the superficial fascia (as seen in the lower abdominal wall) are fused in the scrotum to form the tunica dartos scroti (Latin, dartos = leather)
urethra (N388, TG6-09A, TG6-09B) duct that drains the urinary bladder urethra has three parts in the male: prostatic, membranous & penile/spongy; female urethra is much shorter than the male urethra, consisting of the membranous part only
urethra, membranous (N388, TG6-09A, TG6-09B) part of the urethra that passes through the urogenital diaphragm (sphincter urethrae muscle and perineal membrane) female: membranous urethra connects the urinary bladder to the external urethral orifice at the vestibule of the vagina; male: membranous urethra connects the prostatic urethra with the spongy/penile urethra
urethra, penile (N388, TG6-09A, TG6-09B) part of the urethra contained within the bulb and the corpus spongiosum of the penis longest part of male urethra; penile urethra has a dilation in the region of the glans called the navicular fossa; also known as: spongy urethra
urethra, prostatic (N388, TG6-09A, TG6-09B) part of the male urethra passing through the prostate gland prostatic urethra begins at the internal urethral orifice at the anteroinferior angle of the vesical trigone; posterior wall of the urethra has an elevated ridge called the urethral crest with a prominence called the seminal colliculus (veru montanum = spitting mountain); seminal colliculus has a blind diverticulum called the prostatic utricle with orifices of ejaculatory ducts located below it
urethra, spongy (N388, TG6-09A, TG6-09B) part of the urethra contained within the bulb and the corpus spongiosum of the penis longest part of male urethra; spongy urethra has a dilation in the region of the glans called the navicular fossa; also known as: penile urethra

Joints
Joint Description Significance
sacrospinous ligament (N353, N503, TG6-06, TG3-28) the ligament that connects the ischial spine to the lateral surface of the sacrum and coccyx together with the sacrotuberous ligament, it converts the greater and lesser sciatic notches into greater and lesser sciatic foramina
sacrotuberous ligament (N353, N503, TG6-06 the ligament that connects the ischial tuberosity to the lateral surface of the sacrum and coccyx together with sacrospinous ligament, it converts the greater and lesser sciatic notches into greater and lesser sciatic foramina

Muscles
Muscle Origin Insertion Action Innervation Artery Notes Image
anal sphincter, external (N390, N392, N393, N394, TG6-15, TG6-27) perineal body or central tendinous point of the perineum encircles the anal canal; superficial fibers attach to the coccyx constricts the anal canal inferior rectal nerves (from the pudendal nerve) inferior rectal a. skeletal (voluntary) muscle, as contrasted with sphincter ani internus, which is smooth (involuntary) muscle; the external anal sphincter is considered part of the pelvic diaphragm (Greek, sphincter = that which binds tight)
anal sphincter, internal (TG6-15) encircles the anal canal encircles the anal canal constricts the anal canal parasympathetic fibers from S4 middle rectal a. smooth muscle (involuntary), as contrasted with sphincter ani externus, which is skeletal muscle (voluntary) (Greek, sphincter = that which binds tight)
bulbospongiosus, in female (N379, N382, TG6-27A, TG6-27B) perineal body and fascia of the bulb of the vestibule perineal membrane and corpus cavernosum of the clitoris compresses the vestibular bulb and constricts the vaginal orifice deep branch of the perineal nerve (from pudendal nerve) perineal a. skeletal muscle
bulbospongiosus, in male (N379, N382, TG6-27A, TG6-27B) central tendinous point and the midline raphe on the bulb of the penis perineal membrane, dorsal surface of the corpus spongiosum, deep penile fascia compresses the bulb of the penis, compresses the spongy urethra deep branch of the perineal nerve (from pudendal nerve) perineal a. expels the last drops of urine from urethra; expels semen during ejaculation
ischiocavernosus (N379, N382, TG6-27A, TG6-27B) medial surface of the ischial tuberosity and the ischiopubic ramus corpus cavernosum and crus of the penis/clitoris compresses the corpus cavernosum deep branch of the perineal nerve (from pudendal nerve) perineal a. ischiocavernosus m. is closely applied to the surface of the crus penis/clitoris
obturator internus (N358, N360, N379, TG6-21, TG6-21, TG3-28) the internal surface of the obturator membrane and margin of the obturator foramen greater trochanter on its medial surface above the trochanteric fossa laterally rotates and abducts the thigh nerve to the obturator internus m. obturator a. the obturator internus m. leaves the pelvis by passing through the lesser sciatic foramen; the superior and inferior gemellus mm. insert on the obturator internus tendon
sphincter urethrae, in female (N379, N382, N385, TG6-28A, TG6-28B) encircles the urethra encircles urethra and vagina; extends superiorly along the urethra as far as the inferior surface of the bladder compresses urethra and vagina deep branch of perineal nerve from pudendal nerve internal pudendal a. skeletal muscle (Greek, sphincter = that which binds tight)
sphincter urethrae, in male (N379, N382, N385, TG6-28A, TG6-28B) encircles the urethra encircles urethra, reaches lateral surface of prostate and inferior bladder compresses urethra deep branch of perineal nerve from pudendal nerve internal pudendal a. skeletal muscle (Greek, sphincter = that which binds tight)

Nerves
Nerve Source Branches Motor Sensory Notes
anterior labial n. (TG6-19A) ilioinguinal n. no named branches none skin of the anterior aspect of the labium majus communicates with the genital br. of the genitofemoral n. (Latin, labial = lips)
anterior scrotal n. (TG6-19B) anterior cutaneous br. of the ilioinguinal n. no named branches none skin of the anterior aspect of the scrotum anterior scrotal n. is the continuation of the ilioinguinal n. at the superficial inguinal ring; it communicates with the genital br. of the genitofemoral n.
dorsal n. of the clitoris (TG6-19A) pudendal n. no named branches sympathetic motor innervation to skin skin of the shaft of the clitoris the terminal branch of the pudendal n.
dorsal n. of the penis (TG6-19B) pudendal n. no named branches sympathetic motor innervation to skin skin of the shaft of the penis the terminal branch of the pudendal n.
inferior rectal n. (TG6-19A) pudendal n. no named branches external anal sphincter skin of the anus inferior rectal nerve is one of the first branches of the pudendal n.
perineal n. (TG6-19B) pudendal posterior scrotal/labial n., deep (muscular) br. muscles of the perineum: bulbospongiosus m., ischiocavernosus m., superficial and deep transverse perineus mm., sphincter urethrae m., sphincter urethrovaginalis, compressor urethrae skin of the posterior surface of the scrotum/labium majus perineal n.branches from the pudendal n. at the posterior margin of the urogenital diaphragm
plexus, prostatic (TG6-19B) inferior hypogastric (pelvic) plexus is continuous with the rectal and vesical plexuses sympathetic: vascular smooth muscle of the pelvic viscera, especially the urethra, prostate gland and ejaculatory ducts; parasympathetic: smooth muscle and glands of the pelvic viscera, especially the urethra, prostate gland, and ejaculatory ducts pain from the pelvic viscera listed at left the autonomic nerve plexuses of the pelvis (prostatic, rectal and vesical in the male; rectal and uterovaginal in the female) are in communication with each other (Latin, plexus = a braid. A network of nerves, blood vessels, or lymphatic vessels)
plexus, rectal (TG6-19B) inferior hypogastric (pelvic) plexus, posterior part no named branches sympathetic: vascular smooth muscle of the pelvic viscera, especially the rectum; parasympathetic: smooth muscle and glands of the pelvic viscera, especially the rectum pain and general sensation from the rectum rectal plexus is continuous with the vesical plexus in the male, uterovaginal plexus in the female (Latin, plexus = a braid. A network of nerves, blood vessels, or lymphatic vessels)
plexus, vesical (TG6-19B) inferior hypogastric plexus continuous with the prostatic plexus sympathetic: vascular smooth muscle of the pelvic viscera, especially the urinary bladder, seminal vesicle, ductus deferens and ejaculatory duct; parasympathetic: smooth muscle and glands of the pelvic viscera, especially the urinary bladder, seminal vesicle, ductus deferens and ejaculatory duct pain and general sensation from the bladder, seminal vesicle and ductus deferens vesical plexus is continuous with the other autonomic nerve plexuses in the pelvis and cannot be distinguished from them (Latin, plexus = a braid. A network of nerves, blood vessels, or lymphatic vessels)
posterior labial n. (TG6-19A) perineal n. (a branch of the pudendal n.) no named branches none skin of the posterior aspect of the labium majus communicates with the perineal br. of the posterior femoral cutaneous n. (Latin, labial = lips)
posterior scrotal n. (TG6-19B) perineal n., from the pudendal n. no named branches none skin of the posterior aspect of the scrotum posterior scrotal n. communicates with the perineal br. of the posterior femoral cutaneous n.
pudendal n. (N404, N405, TG6-28A, TG6-28B, TG6-29A, TG6-29B, TG6-30A, TG6-30B) ventral primary rami of spinal nerves S2-S4 (sacral plexus) inferior rectal n., perineal n., dorsal n. of the clitoris/penis its branches supply: external anal sphincter, bulbospongiosus m., ischiocavernosus m., superficial & deep transverse perineus mm., sphincter urethrae m., sphincter urethrovaginalis, compressor urethrae its branches supply: skin of the anus, posterior scrotum/labium majus, clitoris/penis pudendal n. passes through the pudendal canal formed by fascia on the medial surface of the obturator internus m. (Latin, pudendus = ashamed, the term referred to "the shameful parts", ie the genitals)
uterovaginal plexus (TG6-19A) inferior hypogastric plexus continuous with the rectal plexus sympathetic: vascular smooth muscle of the pelvic viscera, especially the uterus, uterine tubes and vagina; parasympathetic: smooth muscle and glands of pelvic viscera, especially uterus, uterine tubes and vagina pain from the pelvic viscera listed at left the uterovaginal plexus is a subsidiary plexus of the inferior hypogastric plexus (Latin, plexus = a braid. A network of nerves, blood vessels, or lymphatic vessels)

Arteries
Artery Source Branches Supply to Notes
of bulb of penis (TG6-29B) internal pudendal a. no named branches bulb of the penis and associated tissues artery of the bulb of the penis courses within the deep perineal space to enter the deep surface of the bulb (Latin, penis = a tail or penis, derived from pendere, to hang down)
of bulb of vestibule internal pudendal a. no named branches bulb of the vestibule and associated tissues artery of the bulb of the vestibule courses within the deep perineal space to enter the deep surface of the bulb
clitoris, deep a. of (N404, N405, TG6-29A, TG6-29B, TG6-30A, TG6-30B) internal pudendal a. no named branches corpus cavernosum of the clitoris deep a. of the clitoris and dorsal a. of the clitoris are the terminal brs. of the internal pudendal a.
clitoris, dorsal a. of (N404, N405, TG6-29A, TG6-29B, TG6-30A, TG6-30B) internal pudendal a. no named branches superficial structures of the clitoris dorsal a. of the clitoris and deep a. of the clitoris are the terminal brs. of the internal pudendal a.
deep, of penis (N404, N405, TG6-29A, TG6-29B, TG6-30A, TG6-30B) internal pudendal a. no named branches corpus cavernosum of the penis deep a. of the penis and dorsal a. of the penis are the terminal brs. of the internal pudendal a.
dorsal, of penis (N404, N405, TG6-29A, TG6-29B, TG6-30A, TG6-30B) internal pudendal a. no named branches superficial tissues of the penis dorsal a. of the penis and deep a. of the penis are the terminal brs. of the internal pudendal a.
inferior rectal (TG6-28B, TG6-31B) internal pudendal a. no named branches anus, ischioanal fossa inferior rectal a. anastomoses with the middle rectal a. and the superior rectal a.
internal pudendal (N404, N405, TG6-28A, TG6-28B, TG6-29A, TG6-29B, TG6-30A, TG6-30B) internal iliac a., anterior division inferior rectal a., perineal a., artery of the bulb of the clitoris/penis, urethral a., deep clitoral/penile a., dorsal clitoral/penile a. anus, muscles of the superficial and deep perineal spaces, clitoris/penis, posterior aspect of the scrotum/labium majus internal pudendal a. is the primary blood supply to the perineum
perineal (TG6-29A, TG6-29B) internal pudendal a. posterior labial/scrotal; deep br. posterior aspect of the scrotum/labium majus; muscles of the superficial perineal space perineal a. courses superficial to the superficial transverse perineus m.; it courses with the perineal n.
posterior labial (TG6-29A) perineal a. no named branches posterior aspect of the labium majus posterior labial a. courses through the superficial perineal space
posterior scrotal (TG6-29B) perineal a. no named branches posterior aspect of the scrotum posterior scrotal a. passes superficial to the superficial transverse perineus m.

Veins
Vein Tributaries Drains Into Regions Drained Notes
internal pudendal v. (TG6-31B) v. of the bulb, posterior labial/scrotal v., inferior rectal v. internal iliac bulb of the clitoris/penis; urogenital region, anal region NOTE: deep dorsal vein, which drains the erectile bodies, does NOT pass to internal pudendal vein (Latin, pudendus = ashamed, the term referred to "the shameful parts", ie. the genitals)
of clitoris, deep dorsal (N N265, N359, N381, N405, TG6-31B, TG6-32B) many unnamed tributaries vesical venous plexus erectile tissue of the clitoris deep dorsal v. of the clitoris passes anterosuperior to the urogenital diaphragm (between the arcuate pubic ligament and the transverse ligament of the perineum) to enter the pelvic cavity; an unpaired vein
of clitoris, superficial dorsal no named tributaries superficial external pudendal v. skin and superficial fascia of the clitoris superficial dorsal v. of the clitoris is located superficial to the deep fascia of the clitoris
of penis, deep dorsal (TG6-31A) many unnamed tributaries prostatic venous plexus erectile tissue of the penis deep dorsal v. of the penis passes anterosuperior to the urogenital diaphragm (between the arcuate pubic ligament and the transverse ligament of the perineum) to enter the pelvic cavity; an unpaired vein
of penis, superficial dorsal (TG6-31A) no named tributaries superficial external pudendal v. skin and superficial fascia of the penis superficial dorsal v. of the penis is located superficial to the deep fascia of the penis
plexus, rectal venous no named tributaries superior, middle & inferior rectal vv. rectum and anal canal; anus rectal venous plexus is a site of portal-caval anastomosis (Latin, plexus = a braid, a network of nerves, blood vessels, or lymphatic vessels)
prostatic venous plexus deep dorsal v. of the penis internal iliac v. penis and the prostate gland prostatic venous plexus is connected with the vesical venous plexus (Latin, plexus = a braid, a network of nerves, blood vessels, or lymphatic vessels)

Topographic Anatomy
Structure/Space Description/Boundaries Significance
anal triangle (TG6-24A, TG6-24B) posterior subdivision of the diamond-shaped perineum; its boundaries are: anteriorly - posterior margin of the perineal membrane (corresponds to an imaginary line connecting the ischial tuberosities); posterolaterally - sacrotuberous ligament anal triangle is the location of the terminal end of the gastrointestinal tract (anus)
ischioanal fossa (TG6-16, TG6-26B, TG6-35, TG6-36) a fat-filled space located lateral to the anal canal and inferior to the pelvic diaphragm; its boundaries are: superomedially - pelvic diaphragm (anterior recess extends superior to the urogenital diaphragm); medially - external anal sphincter muscle and anal canal; laterally - obturator internus fascia and ischial tuberosity; posterolaterally - sacrotuberous ligament and gluteus maximus m.; (posterior recess extends superior to the gluteus maximus m.) the fat and loose connective tissue in the ischioanal fossa compresses to allow passage of feces; also known as: ischiorectal fossa (Greek, ischion = hip joint)
natal cleft (TG6-27A) midline cleft between the buttocks natal cleft lies between the gluteus maximus muscles
perineum (TG6-27A, TG6-27B) a diamond-shaped space forming the outlet of the pelvis; its boundaries are: anterolaterally - inferior pubic ramus, ischial ramus and ischial tuberosity; posterolaterally - sacrotuberous ligament perineum is subdivided into the anal triangle and urogenital triangle by an imaginary line connecting the ischial tuberosities
urogenital triangle (TG6-24A, TG6-24B) anterior subdivision of the diamond-shaped perineum; its boundaries are: anterolaterally - inferior pubic ramus, ischial ramus; posteriorly - posterior margin of perineal membrane (corresponds to an imaginary line connecting the ischial tuberosities) urogenital triangle is the location of the terminal portion of the urinary tract and genital tract

Lymphatics
Structure Location Afferents from Efferents to Regions drained Notes
iliac nodes, internal (N257, N387, TG6-33, TG6-34) along the internal iliac vessels lymphatic vessels from the pelvic viscera common iliac nodes, external iliac nodes pelvis, perineum and gluteal region internal iliac nodes are 4 to 8 in number
inguinal nodes, superficial (N257, N387, TG6-33, TG6-34) in the superficial fascia parallel to the inguinal ligament and along the terminal part of the greater saphenous v. lymphatic vessels from the superficial lower limb, superficial abdominal wall, perineum external iliac nodes; deep inguinal nodes lower abdominal wall; external genitalia; superficial parts of the lower limb superficial inguinal nodes are 12-20 in number; they become inflamed during infections of the lower limb; they may become inflamed during infections of the external genitalia

Clinical Terms
Term Definition
circumcision surgical removal of end of the prepuce of the penis
pudendal nerve block the area anesthetized is the skin of the perineum; this nerve block does not, however, abolish sensation from the anterior part of the perineum, which is innervated by the ilioinguinal nerve and the genitofemoral nerve. It will also not anesthetize the perineal branch of the posterior femoral cutaneous nerve. Also, it does not abolish pain from uterine contractions that ascend to the spinal cord via the sympathetic afferent nerves. In the transvaginal procedure the ischial spine is the landmark used for the insertion of the needle
vasectomy surgical sterilization procedure performed in males where a segment of the ductus deferens is removed
orchiectomy surgical removal of the testes
cystoscopy direct visual examination of the urinary tract with a cystoscope
urethral catheterization the penis is held erect at right angles to the anterior abdominal wall; the lubricated catheter is passed through the narrow external urethral meatus. The penis is then lowered toward the thighs, and the catheter is gently pushed through the sphincter. Passage of the catheter through the prostatic urethra and bladder neck usually does not present any difficulty.
episiotomy surgical incision into the perineum and vagina to prevent traumatic tearing during delivery. A mediolateral incision (at 5 or 7 o'clock) is the preferred incision since it is associated with less chance of entrance into the rectum than a median incision.
ischioanal abscess frequent in older people, and are often a result of infections in the anal canal; usually starts as an inflammation of the crypts, which leads to the invasion of normal rectal flora into the ischioanal fossa, and thereby causes an infection
spinal anesthesia an anesthetic agent is injected directly into the subarachnoid space at the L3/L4 vertebral level-anesthetizes essentially everything inferior to the waist; the anesthesia takes effect in about a minute; can result in the patient experiencing a headache due to fluid leaking from the puncture site
epidural anesthesia injection of anesthetic agents into the epidural space as opposed to injection into the subarachnoid space; usually takes 10 to 20 minutes to take effect and has a direct effect on the spinal nerves; often used for operations below the diaphragm and consequently is used in childbirth and cesarean sections

The material presented in these tables is contained in the book:
MedCharts Anatomy by Thomas R. Gest & Jaye Schlesinger
Published by ILOC, Inc., New York
Copyright © 1995, unauthorized use prohibited.
 The excellent editorial assistance of
Dr. Pat Tank, UAMS
is gratefully acknowledged.