Ch 27, L8

The Uterus

• The uterus is a hollow, thick-walled muscular organ.
• It receives, retains, and nourishes fertilized eggs.
• The major portion is known as the body, the rounded superior region is known as the fundus and the narrowed inferior region is known as the isthmus.
• The cervix projects into the vagina.

Wall of Uterus

• The endometrium is the inner mucosa that lines the uterine wall.
• If fertilization occurs, the embryo burrows into the endometrium, implants, and resides there for its development.
• The functional layer of the endometrium is shed during menstruation in response to hormone changes.
• The basal layer of the endometrium contains stem cells that form a new functional layer after each menstrual cycle.

The Vagina

• The vagina functions as a birth canal, a passageway for menstrual flow, and an organ for copulation.
• The urethra runs parallel to the vagina anteriorly.
• The vagina has an outer fibrous layer, a layer of smooth muscle, and an inner mucosa.
• The mucosa has no glands and is lubricated by cervical mucous glands.
• The hymen is an incomplete partition over the vaginal opening.
• The hymen is found in women who have not had sexual intercourse.
• The hymen will sometimes bleed after it has been breached.

External Genitalia

• External genitalia refers to the female reproductive structures external to the vagina, also called the vulva.
• The external genitalia include the mons pubis, labia, clitoris, and structures associated with the vestibule.
• The perineum is the diamond-shaped region between the coccyx and pubic arches

External Genitalia - Vestibule

• The vestibule contains the external openings of the urethra and vagina.
• Greater vestibular glands secrete lubricating juices that help with sexual intercourse.

Mammary Glands

• Mammary glands are present in both male and female but function normally only in females.
• The main function is milk production for newborns.
• They are modified sweat glands consisting of 15–25 lobes.
• The areola is the pigmented skin surrounding the nipple.
• Suspensory ligaments attach the breast to underlying muscle.
• Lobules within lobes contain glandular alveoli that produce milk.
• Breast size is due to the accumulation of fat deposits.
• Each lobe contains lobules with alveoli, which are glandular tissue.
• Milk production occurs in lactating women in the alveoli.
• Milk flows from the alveolar gland through lactiferous ducts to the surface.