Part 15: Female Internal Genital Organs and Urethra Flashcards
What is the size and shape of the uterus?
Pear shape
8x5x3cm (3x2x1 inches)
What are the parts to the uterus?
Fundus: Part above entrance of tubes, 5cm side to side, 3cm thick.
Body: Tapers down from fundus and flattened in AP plane
Cervix: Tapers below body and protrudes into vagina
What is the canal of cervix?
Continuous with cavity of body of uterus. Via internal os, passes to vagina then via external os. Circular in nulliparous women, slit like after child birth
What is the structure of uterus?
Parts of uterus covered by peritoneum or perimetrium
Bulk is myometrium which consists of 3 ill defined muscle layers (outer-longitudinal, deep-circular)
Endometrium: the mucous membrane. Lined with columnar epithelium, dips into endometrial stroma to form glands. Thickness changes with cycle.
Where does the epithelium of endometrium change to that of vagina?
Cervix - just inside external os, changes to stratified squamous epithelium. These are mucous secreting with glands.
What is the blood supply of the uterus?
Via uterine artery - branch of IIA via broad ligament, also supplies cervix and vagina and anastomoses with ovarian artery along tubes
What is the venous drainage of the uterus?
Veins form plexus across pelvic floor, communicate with veiscal and rectal plexuses and drains to internal iliacs
What is the lymph drainage of the uterus?
Mainly to external iliac nodes, some also reaches inguinal nodes via round ligament and inguinal canal
What is the nerve supply of the uterus?
Branches of pelvic plexus
Sympathetic provides vasoconstrictor, possible motor effect. Pain runs in sympathetic nerves back to T10-L1 - thus block must be this high during labour.
Mainly hormonal influence.
How does the uterus develop?
Fusion of paramesonephric ducts to form uterus and upper vagina. Incomplete fusion results in a median septum
What position is the uterus normally found?
80% anteverted
20% retroverted
How does uterus maintain its position?
Most fixed part is cervix - via attachments to bladder and vagina - assisted by pelvic diaphragm, pelvic fascia pubvaginalis and perineal body.
The round ligament important as it keeps uterus forward tilting from attachments at cervix.
Describe the broad ligament?
Lax double fold of peritoneum lying laterally between side wall of uterus and pelvis. Posterior layer has ureter adhering to it. Lateral attachment crosses obturator nerve, superior vesical and obturator artery. Upper border has free edge, contains uterine tube (mesosalpinx)
Lateral quarter forms suspensory ligament of ovary
Anterior border is bulged forward by round ligament
Where does the round ligament lie?
From uterus/tube junction to DIR then to labium majus. largely visceral muscle. Lies in anterior part of broad ligament, continuous with ovarian ligament (Remnants of gubernaculum)
What is the lateral ligament?
Also known as cardinal ligament, lateral cervical or Mackenrodt’s ligament.
Thickenings of connective tissue from base of each broad ligament from cervix to vagina, then laterally to side wall of pelvis
Where does the ureter run in relation to uterus?
Pass about 1-2cm lateral then in front of cervix/vagina fornix