Reproductive Anatomy Flashcards
What type of joint is the sacroiliac joint?
Diarthrodial synovial joint
What type of joint is the pubic symphysis?
Secondary cartilaginous joint
What is the true pelvis?
The space enclosed by the pelvic girdle and below the pelvic brim: between the pelvic inlet and the pelvic floor
What does the sacrotuberous ligament connects?
Connects ischial tuberosity to lateral borders of lower sacrum
What structures are present in the false pelvis?
Iliac fossa, portions of coccygeal bones and upper portions of sacrum
Describe the difference in the pelvic inlet of the android and gynaecoid pelvis.
In the gynaecoid (female pelvis) the pelvic inlet is oval shaped whereas in the android pelvis the pelvic inlet in heart shaped.
What forms the anterior-inferior wall of the pelvic cavity?
Bodies and rami of the pubic bones and the pubic symphysis
Which muscle is present in the posterior wall of the pelvis?
pisiformis
Which nerve network lies on the muscle forming the posterior wall of the pelvis?
Sacral plexus
What is the Levator ani?
A broad, thin muscle group situated on either side of the pelvis. It is formed from three muscle components: the pubococcygeus, the illiococcygeus and the puborectalis.
What is the innervation of the pelvic diaphragm/floor?
S3-S4
What is a cystocele?
Wall between bladder and vagina weakens. This can lead to the bladder dropping into the vagina.
What is a rectocele?
Wall of tissue between the rectum and the vagina wall weakens. The front wall of the rectum sages and bulges into the vagina.
Why is a mediolateral episiotomy preferable to a midline episiotomy?
Mediolateral episiotomy offers the best protection from an extended tear.
What structures can be palpated during a digital rectal examination of a female?
Cervix, uterus, ovaries
What are the contents of the spermatic cord?
Vas deferens Testicular artery Artery of ductus deferens Cremasteric artery Pampiniform venous plexus Genital branch of genitofemoral nerve Parasympathetic and sympathetic nerves Lymphatic vessels
What is the name of the canal that the testis passes through during development?
Inguinal Canal
Where is the spermatic cord formed?
Opening of the inguinal canal: deep inguinal ring.
Where does the spermatic cord end?
The posterior border of the testes
What is the cremaster muscle?
derived from the internal oblique muscle and its fascial coverings
The cremaster muscle forms the middle layer of the spermatic cord fascia. It is a discontinuous layer of striated muscle that is orientated longitudinally.
What is the tunica vaginalis?
The tunica vaginalis is the pouch of serous membrane that covers the testes.
What are the two layers of the tunica vaginalis?
The tunica vaginalis is said to consist of two layers, the parietal and visceral laminae, although in truth, they form one seamless sheet. The visceral layer covers the tunica albuginea of the testis, whilst the parietal level is reflected onto the scrotum, covering its inner surface.
What is a hydrocele?
Swelling in scrotum, fluid collects between layers of tunica vaginalis
What causes a hydrocele?
Inflammation or injury within the scrotal sac
What is a haematocele?
Collection of blood in between layers of tunica vaginalis.
What causes a haematocele?
Trauma or following surgery
What is the tunica albuginea of the testes?
The tunica albuginea is a layer of fibrous tissue capsule covering the testis. It is covered by the tunica vaginalis, except at the points of attachment of the epididymis to the testis, and along its posterior border, where the spermatic vessels enter the gland. It is thicker than the tunica albuginea of the ovary.
At what vertebral level do the testicular arteries arise from?
L2
What vein does the pampiniform plexus drain into?
Testicular vein
What nerve supplies the cremaster muscle?
Genital branch of the genitofemoral nerve
What temperature do testes best function at?
A temperature just below that of the body
What does the pampiniform plexus act as?
As a heat exchanger, cooling the arterial blood before it reaches the testes.
Where does the right testicular vein drain into?
Inferior vena cava
Where does the left testicular vein drain into?
Left renal vein
What is the role of the vas deferens?
conveys sperm from the epididymis to the ampulla and eventually, to the ejaculatory duct
Describe the wall of the vas deferens.
The wall of the vas deferens consists largely of smooth muscle, arranged in three muscle layers:
- inner layre: longitudinal smooth muscle
- circular smooth muscle
- longitudinal smooth muscle
What is the anatomical course of the vas deferens?
It is continuous with the tail of the epididymis.
Travels through the inguinal canal, as part of the spermatic cord.
Moves down the lateral pelvic wall close to the ischial spine.
Turns medially to pass between the bladder and the ureter and then travels downward on the posterior surface of the bladder.
The inferior narrow part of the ampulla joins the duct from the seminal vesicle to form the ejaculatory duct.
What is testicular torsion?
Testicular torsion is a surgical emergency, where the spermatic cord twists upon itself. This can lead to strangulation of the testicular artery, resulting in necrosis of the testis.
What is the most common cause of testicular torsion?
A common cause of testicular torsion is spasm of the cremasteric muscle fibres which then force the testicle to spin around its own cord. Certain anatomic conditions (e.g. a loose testicle in a large peritoneal sac – tunica vaginalis) may facilitate this movement.
What is the function of the epididymis?
Stores sperm that is produced by the testis
What secretions are produced by the seminal glands?
Thick alkaline seminal fluid with fructose which mixes with spree from the ductus deferens to form seem which is expelled during ejaculation.
What secretions are produced by the prostate?
Proteolysis enzymes, prostatic acid phosphatase, fibrinolytic, zinc and PSA
What are the bulbourethral glands?
These are small, paired structures located in the urogenital diaphragm which empty into the penile/spongy urethra.
What secretions do the bulbourethral garlands produce?
Alkaline nucus-like fluid
What are the histological features of the seminal vesicle?
No sperms in the lumen
Highly recessed and irregular lumen forming crypts and cavities giving a honey-combed appearance
Well-developed muscular externa
What are the histological features of the ductus deferens?
Lumen Stellate in shape
A thick-walled muscular tube
Epithelial lining and its supporting lamina propria are thrown into longitudinal folds
What are the histological features of the testis?
Convoluted tubules sectioned in various planes
4-8 layers of cells
Spermatozoa in the lumen
Leydig cells in the interstitial spaces between tubules
What are the histological features of the prostate?
Serous alveoli with infolding epithelium
Trabeculae of muscular stroma
Amorphous eosinophilic masses, called corpora amylacea, in the alveoli in older men
What are the 3 layers of the uterus?
Endometrium, myometrium, perimetrium
When a caesarean delivery is done which part of the uterus is opened to deliver the baby?
Lower segment
What are the fornices of the vagina?
Recesses of the vagina formed by the protrusion of the cervix into the vaginal vault
How many fornices of the vagina are there?
One anterior, one posterior, two lateral
Through which vaginal fornix can the rectouterine pouch be accessed?
Posterior
Fertilisation occurs in which part of the uterine tube?
Ampulla
What ligament attaches ovary to lateral pelvic wall?
Suspensory
What ligament attaches uterus to ovary?
Ovarian ligament
Which ligament contains the ovarian artery and vein?
Suspensory ligament
What is the mesosalpinx?
The fold of peritoneum draping over both uterine tubes
What is the mesovarium?
The fold attaching the anterior portion of each ovary to the posterior part of the broad ligament
What are the 4 parts of the uterine tubes?
Infundibulum
Ampulla
Isthmus
Intramural or uterine part
At which vertebral level do the ovarian arteries originate?
L2
Which vessel anastomoses with the uterine artery?
Ovarian artery
What does the uterine artery cross over and where?
The ureter at the level of the ischial spine, junction of the cervix and lateral part of fornix.
Which group of lymph nodes drain the ovary?
Para-aortic nodes
What lymph nodes drain the uterine body?
External illiac lymph nodes
What lymph nodes drain most of the uterine body?
External iliac nodes
What lymph nodes drain the cervix and upper vagina?
Internal iliac and sacral lymph nodes
What lymph nodes drain the lower vagina?
Superficial inguinal and perirectal nodes
Describe the formation of the gonadal ridge.
Mesonephros thickens anteriorly. Medial part of mesonephric ridge becomes thickened to form a genital/gonadal ridge.
Describe the formation of the indifferent gonad.
Germ cells migrate from yolk sac via dorsal mesentery into genital ridge to form the indifferent gonad.
Describe the formation of the paramesonephric duct.
Epithelium of the mesonephros invaginate to form a tube. This tube becomes the paramesonephric duct. This duct develops lateral to developing gonads and mesonephirc duct. Funnel shaped cranial end opens into peritoneal cavity. Causally, crosses ventral to mesonephric dusts and projects into dorsal wall of urogenital sinus.
What happens to the mesonephric duct in males?
Develops into epididymis, vas deferens, seminal vesicle.
What happens to the mesonephric duct in females?
Degenerates.
What happens to the paramesonephric duct in males
Degenerates.
What happens to th paramesonephric duct in females?
Forms the Fallopian tube, uterus, cervix part of vagina
What structures arise from the urogenital sinus?
Bladder, urethra. Lower part of vagina in females and prostate in males.
How does the indifferent gonad know whether to develop into a testis or an ovary?
SRY on the Y chromosome encodes for a protein called TDF (testis determining factor).
Primordial supporting cells (within the sex cords of the indifferent gonad) express the SRY. This transforms them into Sertoli cells which secrete Mullerian- INhibiting - Substance (MIS). Paramesonephric duct degenerates. MIS transforms mesenchymal cells between cords to form leydig cells. Leydig cells produce testosterone - male external genitalia.
From which embryological structure do the seminiferous tubules develop?
Primary sex cords
Describe the formation of the rete testes.
Seminiferous cords branch, ends anastomose.
At what point do leydig cells begin to produce testosterone?
Week 8
What stimulates masculine differentiation of mesonephric ducts and external genitalia?
Leydig cells producing testosterone
Describe the formation of the seminal vesicles.
Outgrowth from caudal end of mesonephric duct
Describe the formation of the prostate
Outgrowth(s) from urethra (from urogenital sinus)
What influences the formation of male external genitalia?
Testosterone
In what instance will the indifferent gonad develop into the ovary?
In the absence of TDF. No SRY region on X chromosome
What are primordial germ cells?
Highly specialised cells that are precursors of gametes which following meiosis, develops as haploid sperm and eggs.
Describe the development of the primordial follicle.
Primary sex cords degenerate leaving the primordial germ cells. By 10 weeks, secondary sex cords develop from surface epithelium. Primordial germ cells become incorporated into them. Primordial germ cells then bud off with single surrounding layre of cortical cord cells to form primordial follicles.
What happens to early primordial follicles?
Active mitosis to form additional follicles.
At what point during development have all follicles formed?
7th month
At what stage during meiosis are oocytes arrested until puberty?
Prophase 1st meiosis division
What causes the degeneration of the mesonephros and mesonephric duct in females?
Absense of testosterone.
What happens to the cranial end of the paramesonephric duct in females?
Becomes associated with the ovary
Ron what structure does the superior part of the vagina originate?
Paramesonephric duct
In what region do gonads originally form?
Lumbar region
When does the testes enter the scrotum?
39 weeks
What is the gubernaculum?
A part or structure that serves as a guide, especially a fibrous cord that connects the fetal testis with the bottom of the scrotum and by failing to elongate in proportion to the rest of the fetus, causes the descent of the testis.
Which bony prominences separate the urogenital and anal triangle?
Ischial tuberosity
What is the role of the external anal sphincter ?
Constricts anal canal
What is the function of the superficial transverse perineal muscle?
Stabilises perineal body. Provides structural support to adjacent pelvic and perineal strucutres.
What is the function of the dep transverse perineal muscle?
Stabilises perineal body. Provides structural support to adjacent pelvic and perineal structures.
What is the role of the external urethral sphincter?
Compress urethra to maintain urinalysis continence
What is the role of the bulbospongiosus muscle in the male?
Male: stabilises the perinael body, expels urine and semen from urethra and assists in erection of penis.
What is the role of the bulbospongiosus muscle in the female/
Expresses secretions of greater vestibular glands and assists in erection of the clitoris.
What is the role of the ischialcavernosus muscle?
Assists in erection of clitoris or penis
What is the innervation of the muscles of the perineum?
Perineal nerve S2-4
What is the annococcygeal ligament?
Thick fibromusclular band that attaches the external anal sphincter to the apex of the coccyx.
What are the potential consequences if the perineal body is damaged/ruptured during childbirth?
May experience incontinence
Which structures pierce through the pelvic diaphragm?
Rectum and urethra
What are the three parts of the male urethra?
Prostatic urethra. Membranous urethra. Spongy/ penile urethra.
What is the widest part of the male urethra?
Prostatic urethra: receives the ejaculatory ducts from the testes and seminal fluid from the seminal vesicles and prostatic ducts.
What is the narrowest part of the male urethra?
Membranous urethra: runs through the pelvic floor and deep perineal pouch. It is surrounded by external urethral sphincter
What comprises the penis?
Left and right cavernosa and single corpus spongiosum
What is the urethra transmitted through?
The corpus spongiosum
What is the sensory innervation of the penis?
Pudendal nerve
What covers the corpus cavernosa?
Tunica albuginea
What is the urethra transmitted through?
The corpus spongiosum
Where is the internal/ vesical urethral sphincter located?
Bladder opening to urethra
Describe the innervation of the internal urethral sphincter.
Involuntary, sympathetic
Where is the external urethral sphincter found in females?
Between vaginal orifice and clitoris
Where is the external urethral sphincter found in males?
Level of membranous urethra
What is the innervation of the external urethral sphincter?
Voluntary: somatic motoneurones
What factors may cause urinary incontinence?
Males: prostatic surgery
Females: childbirth weaken the ligaments supporting the pelvic floor and can increase risk of incontinence.
Both: aging process
What is the perineal nerve a branch of?
Pudendal nerve
What is the vestibule of the vagina?
The area enclosed by the labium minors and contains aspects of the urethra and vagina
What secretions are produced by the bulbourethral glands?
Alkaline mucus like fluid
Describe the course of the pudendal nerve
After its origin from the sacral plexus, the pudendal nerve leaves the pelvic cavity by passing through the greater sciatic foramen. It courses around the sacrospinous ligament and ischial spine to enter the anal triangle of the perineum.
Name structures that pass through the greater sciatic foramen.
Sacral plexus, inferior gluteal artery, pudendal nerve, pudendal artery, pudendal vein, inferior gluteal vein
What structures pass through the lesser sciatic foramen?
Pudendal nerve, internal pudendal artery, internal pudendal vein.
Where do the mammary gland (breasts) lie?
Superficial fascia of the pectoral region
What is an exocrine gland?
Glands which release their secretion through a duct or onto the body surface
What muscles does the breast relate to on its deep surface?
Pectoralis major, pectoralis minor, serrated anterior
What is the tail of the breast?
The extension of the breast tissue into the axilla
What determines breast size and shape?
Genetic, racial and dietary factors
What is the vertical extent of the breast
2nd or 3rd rib- 6th rib
What is the transverse extent of the breast?
Sternal edge to midaxillary line
What does the breast lie on?
Deep pectoral fascia
What attaches the breast to the dermis?
Suspension ligament of cooper
What is the areole?
Pigmented area around the nipple
How many lobules of glandular tissue does the breast contain?
15-20 lobules
What drains each lobule in the breast?
Lactiferous duct
What is the lactiferous sinus?
The dilated portion of the lactiferous duct
What does the areola contain?
Sweat and sebaceous glands
What do the sebaceous glands of the areola produce?
Oily material that provides a protective lubricant for nipple and areola
What is gynaecomastia?
Postnatal development of rudimentary lactiferous ducts in males. 2/3 buys develop varying degrees of hyperplasia of the breasts
What is polymastia?
An extra breast
What is polythelia?
An extra nipple
What is meant by Athelia or amastia?
Absence of nipple or breast
Branches of what three arteries supply the mammary gland?
Lateral thoracic artery, internal thoracic artery, pectoral branch of thoracoacromial artery
What it the nerve innervation to the breast? Describe the fibres these carry.
Anterior and lateral cutaneous branches of 4th-6th intercostal nerves.
They convey sensory fibers to the skin of the breast
They also carry sympathetic fibres to the blood vessels and to the
smooth muscle around the nipple
Where does lymph from the lateral quadrants of the breast drain?
Axillary lymph nodes
Where does lymph from the medial quadrants of the breast drain?
Parasternal nodes or to opposite breasts
What does the placenta develop from?
The trophoblast following implantation of the blastocyst into the uterine endometrium.
Describe the maternal surface of the placenta
Disc shaped and the structure is rough and spongy
Describe the foetal side of the placenta
Smooth and bears the attachment of the umbilical cord.
What structure does the umbilical vein persist as?
The round ligament of the liver
What are the attachments of the suspension ligament?
Lateral part of overt, lateral pelvic wall
What can happen when damage occurs to the uterosacral ligament?
Pelvic organ prolapse
What does the round ligament of the uterus connect?
Uterine horn to the labia majora
What are the three sections of the broad ligament?
Mesosalpinx: Fallopian tube. Mesovarium: ovary. Mesometrium: uterus
What does the transverse cervical ligament attach?
Attaches cervix to lateral pelvic wall
What does the transverse cervical ligament contain?
Uterine artery, vein and ureter
Which muscle of the pelvic floor is most likely to be damaged during childbirth?
Pubococcygeus
What is the content of the medial umbilical ligament?
Remnant of embryonic umbilical artery
What is the procedure called that involves taking fluid from the rectouterine pouch?
Culdocentesis
Describe the gynaecoid pelvis?
Obtuse suprapubic angle. Lighter in weight. Pelvic outlet an oval shape. Sacrum is shorter, more curved and with a less pronounced promontory. Illiac crest is lower. Pelvic outlet wider
Describe the android pelvis
Acute suprapubic angle. Heavier in weight. Pelvic inlet heart shaped. Sacrum is longer, more pronounced sacral promontory. Illiac crest higher. Pelvic outlet narrower.
What do the external illiac lymph nodes drain?
Deep layers of the abdominal wall, viscera of pelvis, perineum and lower limb via the inguinal lymph nodes
What do the internal illiac nodes drain?
Gluteal region, deep perineum and inferior pelvic viscera
What do the sacral lymph nodes drain?
Rectum and coccygeal region
What do the para aortic nodes drain?
Three main groups: external, internal, sacral lymph nodes
What does the genital branch of the genitofemoral nerve supply?
Motor innervation to the cremaster muscle. Sensory innervation from the skin in the upper anterior part of the scrotum, spermatic fascia, and tunica vaginalis of testis, or the skin of the mons pubis and labium magus in females.
What is the root of the genitofemoral nerve?
L1-L2
What does the genital branch of the genitofemoral nerve pass through to enter the inguinal canal?
Deep inguinal ring
What does the ilioinguinal nerve supply?
Motor innervation to internal abdominal oblique muscle. Sensory innervation from the scrotum and root of penis, or mons pubis and labium majora in females.
What is the root of the ilioinguinal nerve?
L1
At what point does the ilioinguinal nerve enter the inguinal canal?
Superficial inguinal ring
From which segmental levels does the pudendal nerve arise?
S2-4
What are the branches of the pudendal nerve?
The inferior anal (rectal) nerve, the perineal nerve and the dorsal nerve of the clitoris or penis.
What is the nerve innervation of the Levator ani muscle?
Perineal nerve and anterior ramus of the S4 nerve root.
Describe the sensory function of the pudendal nerve.
Inferior rectal nerve – innervates the perianal skin and lower third of the anal canal.
Perineal nerve – innervates the skin of the perineum, labia minora and majora or posterior scrotum.
Dorsal nerve of the penis or clitoris – innervates the skin of the penis or clitoris. Thus, responsible for the afferent component of penile and clitoral erection.
Describe the motor function of the pudendal nerve.
Bulbospongiosus
Ischiocavernosus
Levator ani muscles (including the iliococcygeus, pubococcygeus and puborectalis).
The nerve also innervates the external urethral sphincter. A branch of the pudendal nerve, the inferior rectal nerve, provides motor supply to the external anal sphincter. Therefore, the pudendal nerve provides the voluntary/somatic control of faecal and urinary continence.
What muscles covers the bulbs of the vestibule?
Bulbospongiosus muscle
What is the function of the bulbs of the vestibule in females?
Fills with blood during arousal to cause erection
What do the greater vestibular glands open into?
The vestibule of the vagina
What is the function of the greater vestibular glands?
Produce mucous secretions that function as a lubricant during sexual arousal.
What bony land marks are used when performing a pudendal nerve block during labour?
Ischial Spine
What is the innervation of the uterus?
Sympathetic: sacral splanchnic nerves. Parasympathetic: pelvic splanchnic nerves (S2-S4)
What does the corpus cavernous contain?
Spongy, erectile tissue. Cavernosa arteries run along the middle of each corpus cavernosa.
Hat is the normal position of the uterus?
Anteflexed and anteverted
What could happen if the position of the uterus is very retroverted and retroflexed in early pregnancy?
More pressure on the bladder during the first trimester so increased incontinence or difficulty urinating. Back pain.
What is endometriosis?
Endometrial tissue outside the lining of the uterus. This ectopic tissue behaves the same as endometrium and bleeds.
What are the possible sites of endometriosis?
Outer surface of the uterus. Fallopian tube. Ligaments of the uterus. Anterior fornix. Bladder. Posterior fornix. Ovary.
What is a salpingectomy?
Removal of Fallopian tube
Where do parasympathetic fibres in the pelvis originate from?
Pelvic splanchnic nerves (S2-S4)
Where do the sympathetic fibres in the pelvis originate?
L1-L2 via the hypogastric nerve and terminal aspect of the sympathetic trunk
What forms the lumbar splanchnic nerves?
Sympathetic preganglionic nerve cells are located in first and second lumbar (L1 and L2) spinal cord segments and form the lumbar splanchnic nerves
What is a splanchnic nerve?
A paired, autonomic nerve that carries both visceral sympathetic and sensory fibres except for the pelvic splanchnic nerves which carry parasympathetic fibres.
After rectal surgery, why are some men unable to ejaculate?
Pudendal nerve damage, erectile muscles of perineum no longer Innervated
What causes the maintenance of an erection?
Contraction of perineal muscles: ischiocavernosus, bulbospongiosus
What part of the autonomic nervous system causes an erection?
Parasympathetic: S2-S4
Describe the sensory innervation of the ilioinguinal nerve.
Scrotum and root of penis. Mons pubis and labia majora
Describe the motor innervation of the ilioinguinal nerve.
Internal abdominal oblique muscle
What is the nerve root of the ilioinguinal nerve?
L1
What is the root value of the nerve to the Levator ani?
S3-S4
What is the sensory innervation of the genital branch of the genitofemoral?
Anterior part of scrotum, spermatic fascia, tunica vaginalis, skin of mons pubis and labium majora
Describe the motor innervation of the genital branch of the genitofemoral nerve
Cremaster muscle
Describe the sensory innervation of the perineal nerve.
Posterior scrotal skin. Labium majors. Skin of urogenital triangle.
What is the sensory innervation of the skin of the urogenital triangle?
Perineal nerve
Describe the motor innervation of the perineal nerve.
Somatic innervation to the muscles of the superficial and deep perineal pouches
Describe the sensory innervation of the dorsal nerve of the clitoris/ penis.
Skin of penile shaft, glans penis. Glans of clitoris.
What is the sensory innervation to the skin of the anal triangle?
Inferior anal nerve
What is the motor innervation to the external anal sphincter?
Inferior anal nerve
What is the innervation of the coccygeus muscle?
Anterior rami of fourth and fifth sacral nerves (S4-S5)
What is the somatic innervation of the vulva?
Pudendal nerve, posterior cutaneous nerve of the thigh, genitofemoral nerve, ilioinguinal nerve
What are the contents of the pudendal canal?
Nerve to obturator internus
Internal pudendal artery
Internal pudendal vein
Pudendal nerve
What type of nerve innervation is ejaculation a result of?
Sympathetic, parasympathetic and somatic.
During ejaculation 3 things happen. Closure of internal urethral sphincter - Sympathetic . Contraction of urethral muscle - Parasympathetic. Contraction of bulbospongiosus muscles from pudendal nerve(somatic)
What is the main function of the ovary?
Oogenesis and endocrine secretion
