Female Reproductive System: Anatomy and Physiology Study Notes 33

Female Reproductive System

Overview

The female reproductive system is responsible for producing ova, supporting fertilization, nurturing the developing embryo, and nourishing the infant after birth. It consists of both internal and external genitalia, each with specialized structures and functions.

Anatomy of the Female Reproductive System

Main Organs

• Ovaries

• Uterine tubes (Fallopian tubes)

• Uterus

• Vagina

Most organs are located within the pelvic cavity and are supported by various ligaments, including the broad, suspensory, and ovarian ligaments.

Ovaries

Structure and Functions

The ovaries are paired female reproductive organs located on either side of the uterus. They have two main functions:

1. Produce ova (oogenesis):

   • Oogenesis is the process of producing female gametes (ova).

   • Ova are produced in follicles located in the ovarian cortex.

   • The ovarian medulla contains blood vessels, lymphatic vessels, and nerves.

2. Secrete hormones:

   • Estrogens (estradiol, estrone, estriol): Regulate development of female secondary sex characteristics and reproductive cycle.

   • Progesterone: Prepares uterus for implantation and maintains pregnancy.

   • Inhibin: Inhibits FSH secretion to regulate ovarian cycle.

   • Relaxin: Relaxes uterine muscles and pelvic ligaments during pregnancy.

Uterine Tubes (Fallopian Tubes)

Structure and Function

The uterine tubes transport ova from the ovaries to the uterus and are the usual site of fertilization.

• Isthmus: Connects uterine tube to uterus.

• Ampulla: Expanded distal end, typical site of fertilization.

• Infundibulum: Funnel-shaped end near ovary, with ciliated fimbriae that sweep the oocyte into the tube.

• Peristalsis and cilia move the oocyte toward the uterus.

Example: Fertilization of the oocyte by sperm usually occurs in the ampulla region of the uterine tube.

Uterus

Structure and Location

The uterus, also called the womb, is a muscular organ located in the pelvis, anterior to the rectum and posterior to the urinary bladder. It is similar in size and shape to an inverted pear.

Functions

• Pathway for sperm to reach the oocyte for fertilization.

• Site of implantation for the fertilized ovum.

• Provides nutritional support for the developing fetus.

• Contracts during birth to expel the fetus.

Regions of the Uterus

Region	Description
Body	Main portion
Fundus	Rounded region superior to entrance of uterine tubes
Cervix	Narrow neck opening to vagina inferiorly

Layers of the Uterus

Layer	Description
Perimetrium	Outermost serous layer
Myometrium	Thick middle smooth muscle layer
Endometrium	Innermost mucous membrane composed of simple columnar epithelium

Vagina

Structure and Function

The vagina is the female copulatory organ and birth canal. It extends from the cervix to the exterior of the body, paralleling the urethra and lying between the urinary bladder and rectum.

• Lined with stratified squamous epithelium for protection.

• Lubricated by cervical mucus from epithelial cells; it contains no glands.

Hymen

• Incomplete partition formed from mucosa near vaginal orifice.

• Vascularized and may bleed when ruptured during first sexual intercourse.

Female External Genitalia (Vulva)

Structure and Function

• Labia majora: Protective skin folds.

• Labia minora: Thinner skin folds within labia majora.

• Vestibule: Enclosed by labia minora; contains urethral and vaginal orifices.

Vestibule

• Contains urethral and vaginal orifices.

• Paraurethral glands secrete mucus into urethra.

• Greater vestibular glands secrete mucus as vaginal lubricant during intercourse.

Clitoris

• Small structure corresponding to corpora cavernosa of penis.

• Engorges with blood and is innervated by sensory, motor, and autonomic fibers.

Female Perineum

• Diamond-shaped region between pubic arch, coccyx, and ischial tuberosities.

• Clinical perineum is the area between vagina and anus.

• Site of incision called episiotomy during childbirth.

Mammary Glands

Structure and Function

Mammary glands are modified sweat glands specialized for milk production to nourish the infant after birth.

Functions of Female Reproductive Structures

Structure	Function
Ovary	Produces oocytes and estrogen, progesterone, and inhibin
Uterine tube	Moves oocytes or fertilized ovum toward uterus; site of fertilization and early development
Uterus	Protects and sustains embryo/fetus during pregnancy; sheds lining in menstrual flow
Vagina	Receives penis during sexual intercourse; provides passageway for menstrual flow, for sperm, and for infant during birth
Labia majora	Enclose and protect other external reproductive structures
Labia minora	Enclose vestibule and protect openings of vagina and urethra
Clitoris	Erectile tissue innervated with sensory nerve endings
Vestibule	Recess that contains external openings of vagina and urethra
Greater vestibular glands	Secrete mucus, which helps lubricate the opening of the vagina

Additional info: The physiological effects of estrogen and progesterone include regulation of the menstrual cycle, development of secondary sexual characteristics, and maintenance of pregnancy. The structure and development of mammary glands are influenced by hormonal changes, especially during pregnancy and lactation.