Female Reproductive System Overview

MPharm Programme: Reproductive System 3 & 4

• Course code: PHA115
• Lecturer: Dr Praveen Bhugra

Learning Objectives

• Students should understand and describe the female reproductive system, including organs, structure, location, and function of ovaries, fallopian tubes, uterus, vagina, and vulva.
• Students should understand and explain the female reproductive physiology, including ovulation, hormones, changes during puberty, and menstruation.
• Students should understand and explain the sex glands, including those in the breasts.

Female Reproductive System

• Essential organs: Ovaries, which produce ova.
• Accessory organs: Oviducts (fallopian tubes or oviducts), uterus, vagina, and vulva, plus sex glands (breasts).

Ovaries

• Structure and location: Paired glands, approximately 3g each, resembling large almonds, attached to ligaments in the pelvic cavity on each side of the uterus.
• Histological structure: Germinal epithelium covers the surface; tunica albuginea is an irregular connective tissue; ovarian cortex contains follicles surrounded by connective tissue; a follicle consists of an oocyte and surrounding cells; mature follicle (Graafian follicle) is ready to release a secondary oocyte; post-ovulation, the follicle becomes the corpus luteum, which produces progesterone, relaxin, and inhibin.

Oogenesis

• The formation of gametes in the ovaries.
• Millions of oogonia are produced in the fetus by mitosis, but most degenerate (atresia).
• Some develop into primary oocytes during fetal development.
• At birth, 200,000 to 2 million primary oocytes are present.
• At puberty, 40,000 remain, and only 400 mature during a woman's reproductive life.
• Monthly, about 20 primary oocytes become secondary oocytes, but only one usually survives ovulation from a Graafian follicle.

Oviducts (Uterine or Fallopian Tubes)

• Narrow tubes (10cm/4 inches) extending from the ovary to the uterus.
• Infundibulum: Funnel-shaped portion near the ovary with fimbriae (finger-like processes) to sweep the secondary oocyte into the tube.
• Ampulla: Central tube region.
• Isthmus: Narrowest portion joining the uterus.
• Oocyte movement is aided by cilia lining the wall.
• Zygote reaches the uterus in about 7 days.

Uterus

• Responsible for maintaining the fetus during development and expelling it at the end of pregnancy.
• The site of menstruation.
• 3 inches long by 2 inches wide and 1 inch thick.
• Subdivided into fundus, body, and cervix.
• Interior contains the uterine cavity accessed by the cervical canal.
• Site of sperm pathway and implantation.
• Fundus is a dome-shaped area above fallopian tubes.
• Body is the tapering central portion.
• Cervix is narrow opening into vagina.

Vagina

• Extends from the exterior to the cervix.
• 10 cm (4 inches) long, fibrous muscular canal lined with mucous membrane.
• Serves as a pathway for sperm and a passageway for delivery of a baby from the uterus.
• Outlet for menstrual flow.
• Fornix: Recess surrounds the cervix.
• Acid environment prevents bacterial growth.
• Smooth muscular layer adjusts for intercourse or birth.
• Hymen: Thin membrane fold that may cover the vaginal orifice.

Vulva (Pudendum)

• Collective term for external female genitalia.
• Mons pubis: Elevation of adipose tissue covered by skin and pubic hair, anterior to vaginal and urethral openings.
• Labia minora and majora: Skin folds surrounding vaginal and urethral openings.
• Clitoris: Small erotic structure at the anterior end of labia minora folds.

Mammary Glands

• Modified sudoriferous glands.
• Nipple: Pigmented projection with openings.
• Areola: Surrounds the nipple.
• Internally: 15-20 lobes; lobules; alveoli (milk-secreting glands).
• Suspensory (Cooper's) ligaments suspend the breast from deep fascia of pectoral muscles.
• Mature at puberty.

Physiology of the Breast

• Synthesis, secretion, and ejection of milk (lactation).
• Oestrogens develop duct systems.
• Progesterone develops milk-secreting alveoli.
• Prolactin stimulates milk synthesis in the alveoli.
• Oxytocin stimulates milk ejection from alveoli.

Female Sex Hormones

• Dominant hormones: Oestrogen and progesterone.
• Produced by ovaries: During fetal development, infancy, and childhood, sex hormone production is low.
• Puberty triggers hormone production surges and secondary sex characteristics.
• Puberty to menopause: Sex hormones control the menstrual cycle and produced cyclically.
• Pregnancy: Hormones are produced at higher levels by the placenta, and inhibit ovulation.
• Androgens are produced in small amounts by ovaries and adrenals, and play important functions in women.

Other Effects of Oestrogen and Progesterone

• Provide details about the effects of oestrogen and progesterone on various parts of the female reproductive system.

Female Reproductive System: Hormones

• Hypothalamus secretes GnRH, stimulating the anterior pituitary to release FSH and LH.
• Ovaries produce oestrogen and progesterone to respond to FSH and LH.

Female Reproductive System: Reproductive Cycle

• Menstrual cycle: Results in monthly uterine bleeding from regular changes in the uterine lining.
• Menarche: First menstrual period.
• Menopause: Cycle termination due to normal ovary aging.

Overview of the Menstrual Cycle

• Detailed description of the menstrual cycle phases like follicular, ovulation, and luteal phases, including the relevant hormones.

Further Reading

• Provides a list of recommended textbooks for further study on the topic.