Explain external and internal structure of uterus.

$\Rightarrow$ The uterus is a single and it is also called womb.

$\Rightarrow$ The shape of the uterus is like an inverted pear.

- It is supported by ligaments attached to the pelvic wall.

- The uterus opens into vagina through a narrow cervix. The cavity of the cervix is called cervical canal which along with vagina forms the birth canal.

Wall of uterus : The wall of the uterus has three layers of tissue. The external thin membranous perimetrium, middle thick layer of smooth muscle, myometrium and inner glandular layer called endometrium that lines the uterine cavity.

- The endometrium undergoes cyclical changes during menstrual cycle while the myometrium exhibits strong contraction during delivery of the baby.