197, 200, 201, 220, 221 embryology and anatomy Flashcards
What are the primordia of the urogenital system?
intermediate column mesoderm, splanchnopleure of the hindgut
The intermediate column develops a urogenital ridge, with a medial _______________ and a lateral ______________.
The intermediate column develops a urogenital ridge, with a medial gonadal ridge and a lateral nephrogenic cord.
Where do primary germ cells migrate from to the gonadal ridge?
migrate from the gut tube to the gonadal ridge
What embryonic structure is the first functioning kidney?
mesonephros
What do the permanent kidneys develop from?
mesodermal ureteric bud off the mesonephric duct
What two structures develop from the division of the cloaca?
rectum and urogenital sinus
What are the major structures of the “indifferent stage” of urogenital development?
metanephros, mesonephros, gonads attached to mesonephros at genital ridge, mesonephric (Wolffian ducts), paramesonephric (Mullerian) ducts, UG sinus, genital tubercle (phallus), labioscrotal folds
What does this structure become in males and females:
indifferent gonad
males: testis
female: ovary
What does this structure become in males and females:
primary sex cords
male: seminiferous tubules (sertoli cells)
female: rete ovarii (medulla)
What does this structure become in males and females:
secondary sex cords
male: n/a
female: ovarian follicles (cortex)
What does this structure become in males and females:
gonad mesenchyme
male: rete testis, leydig cells, stroma
female: ovarian stroma
What does the mesonephric duct become in males?
ductus (vas) deferens and epididymus
What does the paramesonephric duct become in females?
uterine tube, uterus, upper vagina
What does the genital tubercle develop into?
male: penis
female: clitoris
What does the lower UG sinus become in males and females?
male: prostate gland, prostatic urethra, bulbourethral and paraurethral glands, and most of the penile urethra
female: urethra, vestibule, greater vestibular glands, paraurethral glands
How is the penile urethra formed?
part from the UG sinus, part from the navicular fossa (epithelial invagination in the tip of the penis)
failure to fuse = hypospadius
Which of the following could persist as a cystic structure in the middle of the broad ligament of the uterus?
a) urogenital sinus
b) mesonephric duct
c) allantois
d) paramesonephric duct
e) metanephric duct
b) mesonephric duct
A woman is infertile because of an absence of ova. Where might primordial ova have failed to differentiate?
a) genital ridge mesoderm
b) primary sex cords
c) hindgut endoderm
d) secondary sex cords
e) paramesonephric duct
c) hindgut endoderm
primordial germ cells originate in the hindgut and migrate into the genital ridge mesoderm
sex cords give rise to epithelial components of gonads
Where in the adult female is the junction of derivatives of the paramesonephric ducts and urogenital sinus?
a) uterine tubes and uterus
b) uterine fundus and cervix
c) uterus and vagina
d) middle of the vagina
e) vagina and vestibule
d) middle of the vagina
urogenital sinus forms the lower half of the vagina, paramesonephric ducts form the upper vagina
Where in the male is the junction of the urethra derived from the urogenital sinus and surface ectoderm?
a) urinary bladder and prostatic urethra
b) beginning of the penile urethra
c) proximal and distal halves of the penile urethra
d) penile urethra and navicular fossa in the glans
e) penile urethra and distal epidermis of the glans
d) penile urethra and navicular fossa in the glans
Which of the following is the largest structure in the 8-week indifferent stage?
a) mesonephros
b) gonad
c) metanephros
d) urogenital sinus
e) paramesonephric ducts
a) mesonephros
Which of the following muscles can rotate the trunk to the same side as the unilateral contracting muscle?
a) transversus abdominis
b) internal oblique
c) rectus abdominis
d) external oblique
b) internal oblique
Which of the following muscles or structures does NOT contribute to a covering of the spermatic cord?
a) transversalis fascia
b) transversus abdominis muscle
c) internal oblique muscle
d) external oblique muscle
b) transversus abdominis muscle
The aponeurosis of the external oblique muscle forms, contributes to, or is otherwise related to all of the following EXCEPT the:
a) superficial inguinal ring
b) conjoint tendon
c) external spermatic fascia
d) sheath of the rectus abdominis muscle
e) inguinal ligament
b) conjoint tendon
What is the course of a direct inguinal hernia? It passes
a) lateral to the deep inferior epigastric artery
b) through the deep inguinal ring
c) inside a persistent processus vaginalis
d) within the spermatic cord
e) under the conjoint tendon
e) under the conjoint tendon
Describe the descent of the testes.
the gubernaculum guides the descent of the testis (and ovary) into the inguinal canal and scrotum
Match the following abdominal wall layers with their equivalent in the scrotum:
external oblique
internal oblique
transversus abdominus
transversalis fascia
external oblique = external spermatic fascia
internal oblique = cremaster muscle
transversus abdominus = nothing
transversalis fascia = internal spermatic fascia
What is the main difference between direct and indirect inguinal hernias?
indirect = through deep inguinal ring into the inguinal canal
direct = medial to spermatic cord, under the conjoint tendon
What type of joint is the sacroiliac joint?
synovial joint reinforced by ligaments
What are the components of the pelvic diaphragm?
pubococcygeus, iliococcygeus = levator ani
pubovaginalis, levator prostatae, puborectalis
Peritoneal or retroperitoneal:
bladder
rectum
uterus
sigmoid colon
vagina
bladder: retroperitoneal
rectum: retroperitoneal
uterus: peritoneal
sigmoid colon: peritoneal
vagina: retroperitoneal
What structures does the male urethra pass through?
prostate gland, urogenital diaphragm, and penis
What is the pathway of urine transport through the kidney?
pyramids –> minor calyces –> major calyces –> renal pelvis –> ureters –> bladder
Where do kidney stones tend to lodge in the kidney/ureter?
renal pelvis
common iliac vessels
enterance to bladder
What primordia are connected at the pectinate line?
endoderm and ectoderm
What type of muscle is the internal anal sphincter? External anal sphincter?
internal = smooth muscle
external = skeletal muscle
What is the anal innervation above and below the pectinate line?
above = autonomic nerves + visceral sensory neurons
below = somatic innervation via pudenal nerve
What blood source supplies the pelvis except testes, ovaries, and parts of rectum?
internal iliac artery
What are the functions of the parasympathetics of the pelvic plexus?
urination, defecation , erection, and uterine cervical glands
What nerves supply the pelvic and urogenital diaphragms?
somatic innervation (via the pudendal nerve and direct branches) supplies both the pelvic and urogenital diaphragms
What nerves supply the pelvic viscera?
autonomic nerves via the pelvic plexus (which receives nerves from the superior hypogastric plexus and pelvic splanchnic nerves)
What are the insertion sites of the pelvic diaphragm?
perineal body, anococcygeal ligament, and coccyx
What is the innervation of the pelvic diaphragm?
pudenal nerve
Where do lymphatics below the pectinate line drain?
superficial inguinal nodes
Which nerves feed the pelvic plexus?
S2-4
Which one of the following is a landmark for the course of the pudendal nerve?
A. Anterior inferior iliac spine
B. Sacral promontory
C. Ischial spine
D. Pubic tubercle
E. Ischial tuberosity
C) Ischial spine
This is where it goes below the levator ani by looping over the sacrospinous ligament. The anterior superior iliac spine is as far away from the pudendal nerve as any pelvic structure. The sacral promontory is the midline point on the sacrum marking the posterior extent of the pelvic brim. The pubic tubercle is for attachment of the inguinal ligament; it is anterior, while nerves are posterior. The ischial tuberosity is what we sit on; it is inferior to the ischial spine.
Where is the junction of splanchnopleure and somatopleure in the adult?
A. Between the sigmoid colon and rectum
B. The top of the anal columns
C. The pectinate line
D. The white line
E. Superficial to the external anal sphincter
C. The pectinate line
Incontinence (loss of bladder control) from a dysfunction internal urethral sphincter would result from damage to which of the following?
A. Pudendal nerve
B. Pelvic splanchnic nerves
C. Sacral sympathetic trunk
D. Lumbar splanchnic nerves
D. Lumbar splanchnic nerves
The sphincter, like most smooth muscle sphincters, is under sympathetic control, and the path is via lumbar splanchnic nerves. The sacral sympathetic trunk (giving rise to sacral splanchnic nerves) does not play a big role in pelvic function. Pelvic splanchnic nerves are parasympathetic to the muscular wall of the bladder causing micturition (urination). The pudendal nerve innervates the striated muscle of the external urethral sphincter.
Which of the following muscles is NOT a part of the pelvic diaphragm?
A. Iliococcygeus
B. Obturator internus
C. Pubococcygeus
D. Puborectalis
E. Coccygeus
B. Obturator internus
The pelvic diaphragm consists of the pubococcygeus, ileococcygeus, and coccygeus (ischiococcygeus). The puborectalis is the most medial portion of the pubococcygeus that sweeps around the rectum.
Which of the following is the largest diameter of the birth canal?
A. Transverse dimension of the pelvic brim
B. From pubic symphysis to sacral promontory
C. Between the ischial spines
D. Between the ischial tuberosities
E. From pubic symphysis to coccyx
A. Transverse dimension of the pelvic brim
A needle through the vagina can most easily sample peritoneal fluid from which of the following locations?
A. Pubovesical pouch
B. Ischioanal fossa
C. Vesicouterine pouch
D. Rectouterine pouch
D. Rectouterine pouch
What are the boundaries of the perineum?
pubic symphysis, ischial tuberosities, coccyx
superior: pelvic diaphragm
lateral: obturator internus, ischiopubic rami
What are the contents of the ischio-anal fossa?
fat, pudendal canal, obturator internus fascia
Where is the deep perineal pouch? What are the contents?
the narrow space between the two layers of UG diaphragm
contains deep transverse perineal muscle, external urethral sphincter, membranous urethra, bulbourethral gland (in males)
What male structures are in the superficial pouch?
penis, bulbospongiosus muscle, ischiocavernosus muscles, superficial transverse perineal muscle
What female structures are in the superficial pouch?
clitoris, bulbospongiosus muscle, ischiocavernosus muscles, superficial transverse perineal muscle, vestibular, greater vestibular gland
What is the function of the bulbospongiosus muscle?
expels semen and empties last drops of urine in the male
What are the three branches of the pudendal nerve?
inferior rectal –> somatomotor to external anal sphincter, sensory to skin of anus
perineal –> skeletal muscles of UG diaphragm, sensory to posterior scrotum/labia
dorsal nerve of penis/clitoris –> general sensory
What is 1-5?
1 and 2: L and R ureter
3 and 4: L and R ductus deferens
5: R. seminal vesical
What is 6-9?
6: membranous urethra
7 and 8: bulb and crura (root of penis)
9: urachus
What is 10-15?
10-11: corpus spongiosum, corpus cavernosa (body of penis)
12: glans penis
13: suspensory ligament attachment
14-15: left and right crus
What is 16-21?
16: membranous urethra
17: bulb
18-19: corpus cavernosum
20: glans
21: corpus spongiosum, penile urethra
Where are benign tumors of the prostate usually located?
median lobe
What is the route of sperm during ejaculation?
testes –> epididymus –> vas deferens –> ejaculatory duct –> prostatic urethra –> membranous urethra –> penile urethra –> navicular fossa in glans penis
What are the major ligaments of the female reproductive tract?
ovarian ligament - fibrous cord (continuous with round ligament)
round ligament of the uterus - remnant of the embryonic gubernaculum (continuous with ovarian ligament)
cardinal ligament - lateral thickenings of perivascular pelvic fascia running from the ischium to the cervix, vagina, bladder, and rectum
pubovesicular ligament - dense cord anchoring the bladder to the pubic bone
What major artery is the ovarian artery a branch of? Uterine artery?
ovarian: aorta
uterine: internal iliac
What sensory nerves supply the fundus and body of uterus?
thoracic and lumbar splanchnic nerves
What nerve provides visceral sensation to the cervix and upper vagina?
sacral spinal segments S2-4
The superior rectal artery is a continuation of what artery?
inferior mesenteric artery
Which of the following is in the deep perineal pouch?
a) greater vestibular gland
b) internal anal sphincter
c) prostate gland
d) external urethral sphincter
e) bulbospongiosus muscle
d) external urethral sphincter
All of the following attach to the central tendon of the perineum (perineal body) EXCEPT?
a) external anal sphincter
b) inferior fascia of the urogenital diaphragm
c) obturator internus muscle
d) deep transverse perineal muscle
e) levator ani
c) obturator internus muscle
the obturator internus muscle is the lateral boundary of the ischioanal fossa
Which of the following is NOT a branch of the internal iliac artery?
a) ovarian artery
b) inferior rectal artery
c) oburator artery
d) inferior gluteal artery
e) uterine artery
a) ovarian artery
A woman with chronic, severe cramping of the uterus can get relief from severing or anesthetizing which of the following?
a) pudendal nerve
b) nerve roots in the sacral canal
c) superior hypogastric plexus
d) pelvic splanchnic nerves
c) superior hypogastric plexus
- most of the uterine body and fundus gets sensory innervation via lumbar splanchnic nerves*
- the sensory neurons get to the pelvic plexus and uterine body by passing from the lumbar splanchnics to the aorta plexus, superior hypogastric plexus, then to the left and right hypogastric nerves of the pelvic plexus*
What is the primary structure cut in a midline episiotomy to enlarge the birth canal?
a) anococcygeal ligament
b) perineal body
c) urogenital diaphragm
d) cardinal ligaments
e) pelvic diaphragm
b) perineal body
the perineal body (central tendon of the perineum) is immediately posterior to the vagina and anterior to the rectum
The bulbospongiosus muscle surrounds what in the female?
a) membranous urethra
b) body of the clitoris
c) labia minora
d) cervix
e) vestibule
e) vestibule
Infection in which of the following locations might impair function of the external anal sphincter by interrupting its nerve supply?
a) superficial perineal pouch
b) ischioanal fossa
c) deep perineal pouch
d) rectouterine pouch
e) pelvic peritoneal cavity
b) ischioanal fossa
inferior rectal branches of pudendal nerve cross the ischioanal fossa to reach the external anal sphincter
What structures develop from intermediate column mesoderm?
urogenital ridge
epithelial sex cords
develops into kidneys, gonads
What is the cause of an imperforate anus?
a fistula formation between the rectum and perineum
What is the mechanism of exstrophy of cloaca? Exstrophy of bladder?
cloaca = failure of mesoderm migration into cloacal membrane/ventral abdominal wall
bladder = breakdown of ectoderm/anterior bladder wall
What conditions can be caused by failed obliteration of the tunica vaginalis?
hydrocele or indirect hernia through the processus vaginalis/tunica vaginalis
Where is the point of entry of a direct inguinal hernia?
through the Hesselbech triangle (made by rectus abdominus, inferior epigastric, and inguinal ligament)
medial to the inferior epigastric blood vessels
What are the general functions of the pudendal nerve?
visceral sensory to the perineum, penis/clitoris, posterior scrotum/labia, and anal canal
also responsible for reflex erection; motor innervation to external urethral sphincter, external anal sphinctor, levator ani, bulbospongiosus, and ischiocavernosus
