AIPMT Biology Aspirants, read out the next AIPMT Biology Study material/ Notes of Female Reproductive System, important for AIPMT Biology.Free online notes for AIPMT. Structure of ovary, fallopian tube, Uterus.
Like the male reproductive system, female reproductive system is also located in pelvic region. It includes the following organs:
- Pair of Ovaries (female gonads)
- Female accessory ducts includes: Fallopian tubes, Uterus, Cervix, Vagina
- External organs or external genitalia called as Vulva, or Pudendum
- Pair of Mammary glands (considered part of both female reproductive system and integumentary system). These glands help structurally and functionally to support the processes of ovulation, fertilisation, pregnancy, birth and child care.
- Ovary is the primary female sex organ that produces female gamete called as Ovum.
- Ovary is homologous organ to testis. (Homologous means that two organs which have the same embryonic origin).
- Ovaries are 2 in no. and are located one on each side of the lower abdomen.
- Ovaries look like unshelled almonds in size and shape.
- Each ovary is about 2 to 4 cm in length and is connected to the pelvic wall and uterus by ligaments
- Ovaries are also called as Egg receptacles. Also produce several steroid hormones called as ovarian hormones.
- Surface of each ovary is covered by a thin simple epithelium called as Germinal epithelium. Inner to germinal epithelium is white layer of connective tissue called as tunica albuginea which encloses the ovarian stroma. Ovarian stroma is divided into two zones – a peripheral cortex and an inner medulla.
- Ovarian cortex consists of ovarian follicles and irregular connective tissue that contains collagen fibers and fibroblast-like cells called stromal cells. Ovarian medulla consists of more loosely arranged connective tissue and blood vessels, lymphatic vessels, and nerves.
- Females have a pair of fallopian tubes (2 in no.). Also called as Uterine tubes, or Oviducts.
- Each fallopian tube is about 10-12 cm long and extends from the periphery of each ovary to the uterus.
- Fallopian tubes provide a route for sperm to reach an ovum and transport secondary oocytes and fertilized ova from the ovaries to the uterus.
- Each fallopian tube can be divided into 3 different parts: (a) Infundibulum, (b) Ampulla, and (c) Isthmus.
- Part of fallopian tube closer to the ovary is the funnel-shaped infundibulum. Finger-like projections at the edges of the infundibulum called as fimbriae, which help in collection of the ovum after ovulation.
- Infundibulum leads to a wider part of the oviduct called ampulla. Ampulla is the longest and widest part of the fallopian tube. The last part of the oviduct is called as isthmus, which has a narrow lumen and it joins the uterus.
- Uterus is single and it is also called womb.
- The shape of the uterus is like an inverted pear.
- It serves two important functions: (1) Provide pathway for sperm deposited in the vagina to reach the fallopian tubes. (2) It is the site of implantation for fertilized ovum, development of the fetus
during pregnancy, and labor.
- Uterus is supported by ligaments attached to the pelvic wall.
- Structure of uterus can be divided into 3 parts: (1) Fundus – domeshaped portion of uterus superior to the uterine tubes, (2) Body – tapering central portion of uterus, and (3) Cervix – inferior narrow portion of uterus. Uterus opens into vagina through cervix.
- Uterine cavity: Cavity in the body of the uterus is called as uterine cavity.
- Cervical canal: Cavity of the cervix is called cervical canal and it opens into uterine cavity at the internal os (os mouthlike opening) and into the vagina at the external os.
- Cervical canal and vagina together forms the birth canal.
- Wall of uterus consists of three layers of tissue: Perimetrium, Myometrium, and Endometrium.
Perimetrium is the external thin membrane. Myometrium is the middle thick layer of smooth muscle. It is thickest in the fundus and thinnest in the cervix region. Endometrium is the inner glandular layer which lines the uterine cavity.
- During menstrual cycle, changes undergo in endometrium while during delivery of the baby, strong contractions required to expel baby occur in myometrium.
NOTE: Hysterectomy is the surgical removal of the uterus.
- Uterine cervix opens into vagina which is a tubular long fibro-muscular canal lined with mucous membrane.
- Opening of the vagina is often covered partially by a membrane called hymen. Hymen is a thin fold of vascularized mucous membrane. It is often torn during the first coitus (intercourse), however it can also be broken by a sudden jerk during lifetime of a female. Presence or absence of hymen is not a reliable indicator of virginity in female.
- Vaginal orifice: Exterior opening of the vagina.
- Vulva refers to the external genitals of the female. It is also called as Pudendum.
- Vulva consists of following components: Mons pubis, Labia majora, Labia minora, Hymen and Clitoris.
- Mons pubis is a cushion of fatty tissue covered by skin and pubic hair. Hymen is a thin membrane covering the opening of vagina.
- Labia majora and labia minora are two sets of skin folds that encloses vagina. Outer, thicker fleshy folds of tissue are the labia majora, which extend down from the mons pubis and surround the vaginal opening. Inner to labia majora, more delicate folds are the labia minora.
- Clitoris is a tiny finger-like structure which lies at the upper junction of the two labia minora above the urethral opening.
- Between the vagina and the clitoris is the opening of the urethra through which urine flows.