Uterus Flashcards
Short note on uterus
It is a child bearing organ which protects and provides nutrition to a fertilised ovum, enables it to grow into a fully formed foetus.
At the time of child birth the uterus undergoes contraction results in expulsion of foetus from the uterus
It is situated in lesser pelvic between the urinary bladder and rectum
The uterus is 7.5 cm long , 5cm wide and 2.5cm thick and weigh around 30g-40g
Parts of uterus
Uterus is divided into 3 parts
- Fundus:it is a upper portion present above the level of opening of the fallopian tube.
- Body: it is between fundus and cervix.
- Cervix: it is a lower cylindrical part, which enter the vagina, hence divided into supra vaginal part and vaginal parts
Relation of uterus
FUNDUS AND BODY
1. lower surface is flat and faces down ward and forward. It covered by by peritoneum up to the isthmus. It is seperate from urinary bladder by uterovesical peritoneal pouch.
2. Upper surface is convex and directed upwards and back wards. It is seperated from rectum by rectouterine peritoneal pouch (pouch of Douglas)
3. Lateral border provide attachment to the broad ligament of the uterus. The uterine artery ascends between the 2 layer of broad ligament along the lateral border
CERVIX
It has 2 parts the lower part projecting into the vagina is called the vaginal part and the part above the vagina is called supravaginal part.
The cavity of the cervix is called the cervical canal, which opens into vagina at the external osteum
1. Anterior surface of the cervix is seperated from the base of the urinary bladder by loose connective tissue
2. Posterior surface is related to pouch of Douglas
3. On each side the cervix is related to ureter, uterine vessels
The supravaginal part is lined by simple columnar epithelium and the vaginal part by stratified squamous epithelium
Microscopic structure
- Endometrium: it is a mucos membrane consists of surface epithelium and lamina propria. This lamina propria consists of uterine glands and blood vessels, it undergoes changes during menstrual cycle of a female during her life. this cycle occurs every month under the influence of estrogen and progesterone which are secreted by ovary
- Myometrium: it is a muscular layer consisting of smooth muscle fibre. This undergoes strong contraction at a time of childbirth. It has 3 layers outer longitudinal, middle circular and inner reticular
- Perimetrium: the outer most covering of the uterus
Support of uterus
Uterus is a mobile organ, which undergoes extensive changes in size and shape during reproductive period of life
Factors that prevent it from sagging are:-
1. Pelvic diaphragm: it is a muscular structure forming the floor of the pelvis .
2. Perineal body: it is a fibromuscular node which act as an anchor and maintain the integrity of the pelvic floor
3. The external urethral sphincter support the vagina and indirectly support the uterus
4. The axis of uterus is an important mechanical factor stabilizing the uterus
5. The condensation of the pelvic fascia in the form of ligaments support the uterus
a. Pubocervical ligament
b. Transverse cervical ligament
c. uterosacral ligament
Blood supply of uterus
Uterine artery: it is branch of internal iliac artery. It reaches the lateral aspect of the cervix through transverse cervical ligament in the floor of the pelvis. It ascends between the 2 layer of broad ligament.
Ovarian artery: it is a branch from the abdominal aorta. It passes through suspensory ligament of the ovary. It also supplies to uterus.
Uterine, ovarian, vaginal veins which drain into internal iliac vein
Applied Aspects
- The perineal body which supports the uterus, sometimes get torn due to child birth. The unsupported uterus may sink down this condition is called prolapse of the uterus. Usually occurs in old age.
- Hysterectomy: removal of uterus which may take place due to tumor or cancer in uterus
- Cesarean section: abdominal delivery of the baby by laparotomy
- Retroverted uterus - backward tilt from the normal axis causes dysmenorrhea (painful period)
