Uterus
Uterus is hollow pyriform (pear shaped muscular organ).
Location;
Situated in pelvis between bladder infront and rectum behind.
Postion of uterus; normal position of uterus is Anteverted uterus.
Measurement of Uterus
8cm long, 5cm wide at fundus, wall thickness 1.25cm
Weight; 50-80gm
Parts of Uterus
1. Body or Corpus
2. Isthmus
3. Cervix
1. Body or Corpus
Fundus; Uppermost part, widest part of uterus.
Lie above opening of uterine tube.
It connects to fallopian tube.
Body lie between the opening of uterine tube and isthmus
Corpus where fertilized egg implant during pregnancy.
2. Isthmus
Constricted part, between body and cervix (0.5cm).
Below internal OS lie between corpus and cervix (narrow part of uterus).
3. Cervix
Mainly composed of fibrous connective tissue.
Cervix open to vagina.
Extends from isthmus and ends at external OS.
Cervix
Supravaginal; cervix part lying above vagina called supravaginal.
Vagina cervix; cervix part lies within vagina called vaginal cervix.
Body Cavity
Triangular shape, there is no Ccavity in fundus.
Length of uterine cavity; 6.5-7cm
Cervical canal is fusiform (spindle) and measure 2.5cm
Associated Structure of Uterus
Anteriorly; Above internal OS, body form uterovesical pouch, below the internal OS, it separated from base of bladder by loose areolar connective tissue.
Posteriorly; Form pouch of Douglas containng wall of intestine.
Laterally
Broad ligament attached to lateral side of uterus on each side.
Uterovesical Pouch; fold of peritoneum over inferior wall of Uterus and bladder.
Rectouterine pouch (Pouch of Douglas); peritoneal fold between posterior wall of uterus and rectum.
Structure of Uterus
Layers of Uterus
Body consist three layers;
1. Parametrium (perimetrium)
2. Myometrium
3. Endometrium
1. Parametrium
Parametrium is also known as perimetrium
It is outer layer.
It is protective layer.
2. Myometrium;
Myometrium is middle layer. Thick bundle of smooth fibres held by connective tissue.
Arranged in;
Outer longitudinal
Middle interlacing
Inner circular
Myometrium layer expand during pregnancy and contract to push baby out.
3. Endometrium; inner layer, uterine layer
Mucus lining cavity called endometrium, shed during menstrual cycle.
It contains endometrial glands, vessels, nerves.
Layers of Endometrium
Layers of endometrium are;
1. Stratum compactum
2. Stratum spongiosum
3. Stratum basalis
Endometrium layer divided into Two layer;
1. Functional layer
2. Basal layer
1. Functional layer
It is site of proliferation, secretion and degeneration.
2. Basal layer
Regenerative endometrium after menstrual loss of functionalis.
Endometrium – Changes to (Decidua) during pregnancy.
Blood supply of Uterus
1. Uterine artery
2. Internal iliac artery
3. Ovarian artery
4. Vaginal artery
Vein
Drain into internal iliac veins.
Lymphatics
From fundus; lymphatic drain into periaortic lymph node.
Cornu drain; to superficial inguinal lymph node.
Lower part of uterus drain to external iliac lymph node.
Cervix; sensitive to touch, heat and grapsed by instrument.
Drainage from;
External iliac
Obturator lymph node
Paracervical lymph node
Internal iliac lymph node
Sacral lymph node
Nerves
Ovarian plexus nerve
Uterovaginal plexus
Pelvic plexus
