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.