Page 1:

• Gonads are the primary sex organs

  • Testes in males

  • Ovaries in females

• Gonads produce gametes (sex cells) and secrete hormones

• Sperm is the male gamete

• Ova (eggs) are the female gametes

Anatomy of the Male Reproductive System:

• Testes are connected to the trunk via the spermatic cord

  • Spermatic cord houses blood vessels, nerves, and the ductus deferens

• Coverings of the testes:

  • Tunica albuginea: capsule that surrounds each testis

  • Septa: extensions of the capsule that divide the testis into lobules

• Each lobule contains one to four seminiferous tubules

  • Seminiferous tubules are tightly coiled structures that function as sperm-forming factories

  • Sperm is emptied into the rete testes

• Epididymis:

  • Highly convoluted tube found along the posterior lateral side of the testes

  • Temporary storage site for immature sperm

  • Sperm mature as they journey through the epididymis

  • During ejaculation, sperm are propelled to the ductus deferens

• Vas deferens:

  • Runs from the epididymis via the spermatic cord through the inguinal canal and arches over the urinary bladder

  • Moves sperm by peristalsis into the urethra

Page 2:

• Ampulla: end of the ductus deferens, which empties into the ejaculatory duct

• Ejaculatory duct passes through the prostate to merge with the urethra

• Vasectomy: cutting of the ductus deferens at the level of the testes prevents transportation of sperm (form of birth control)

• Ejaculation: smooth muscle in the walls of the ductus deferens create peristaltic waves to squeeze sperm forward

• Urethra:

  • Extends from the base of the urinary bladder to the tip of the penis

  • Carries both urine and sperm

  • Sperm enters from the ejaculatory duct

  • Prostatic urethra is surrounded by the prostate gland

  • Membranous urethra extends from the prostatic urethra to the penis

  • Spongy (penile) urethra runs the length of the penis to the external urethral orifice

Accessory Organs and Semen:

• Seminal glands (vesicles):

  • Located at the base of the bladder

  • Produce a thick, yellowish secretion (60% of semen) that contains fructose, vitamin C, and prostaglandins

  • Duct of each seminal vesicle joins that of the ductus deferens on each side to form the ejaculatory duct

• Prostate:

  • Encircles the upper (prostatic) part of the urethra

  • Secretes a milky fluid that helps activate sperm

  • Fluid enters the urethra through several small ducts

Page 3:

• Bulbourethral gland:

  • Pea-sized glands inferior to the prostate

  • Produce a thick, clear mucus

  • Mucus cleanses the spongy (penile) urethra of acidic urine prior to ejaculation

  • Mucus serves as a lubricant during sexual intercourse

• Semen:

  • Milky white mixture of sperm and accessory gland secretions

  • Liquid portion acts as a transport medium to dilute sperm

  • Sperm are streamlined cellular "tadpoles"

  • Fructose provides energy for sperm cells

  • Alkalinity of semen helps neutralize the acidic environment of the vagina

  • Semen inhibits bacteria

Scrotum:

• Divided sac of skin outside the abdomen that houses the testes

• Maintains testes at 3°C lower than normal body temperature

Penis:

• Male organ of copulation that delivers sperm into the female reproductive tract

• Regions of the penis:

  • Shaft

  • Glans penis (enlarged tip)

  • Prepuce (foreskin)

  • Folded cuff of skin around proximal end (often removed by circumcision)

• Internally, there are three areas of spongy erectile tissue around the urethra

• Erections occur when this erectile tissue fills with blood during sexual excitement

Page 4:

Testosterone Production:

• During puberty:

  • Follicle-stimulating hormone (FSH) begins prodding seminiferous tubules to produce sperm

  • Luteinizing hormone (LH) begins activating the interstitial cells to produce testosterone

• Testosterone:

  • Most important hormonal product of the testes

  • Stimulates reproductive organ development

  • Underlies sex drive

  • Causes secondary sex characteristics (deepening of voice, increased hair growth, enlargement of skeletal muscles, increased bone growth and density)

Female Reproductive System:

• Ovaries:

  • Produce eggs (ova) and hormones (estrogen and progesterone)

  • Each ovary houses ovarian follicles consisting of an oocyte (immature egg) and follicle cells

• Ovarian follicles:

  • Primary follicle contains an immature oocyte

  • Vesicular (Graafian) follicle is a growing follicle with a maturing oocyte

  • Ovulation occurs when the follicle ruptures and the egg is ready to be ejected from the ovary

  • The ruptured follicle is transformed into a corpus luteum

• Ovary support:

  • Suspensory ligaments secure the ovaries to the lateral walls of the pelvis

  • Ovarian ligaments anchor ovaries to the uterus medially

  • Broad ligaments, a fold of peritoneum, enclose and hold the ovaries in place

Duct System:

• Uterine (Fallopian) tubes:

  • Form the initial part of the duct system

  • Receive the ovulated oocyte from the ovaries

  • Provide a site for fertilization

  • Empty into the uterus

  • Little or no contact between ovaries and uterine tubes

  • Supported and enclosed by the broad ligament

• Uterine (Fallopian) tube structure:

  • Infundibulum: Distal, funnel-shaped end

  • Fimbriae: Fingerlike projections of the infundibulum

  • Cilia located inside the uterine tube transport the oocyte

• Uterus:

  • Situated between the urinary bladder and rectum

  • Size and shape of a pear in a woman who has never been pregnant

  • Receives, retains, and nourishes a fertilized egg

Page 5:

• Uterine support:

  • Broad ligament suspends the uterus in the pelvis

  • Round ligament anchors the uterus anteriorly

  • Uterosacral ligament anchors the uterus posteriorly

• Regions of the uterus:

  • Body: main portion

  • Fundus: superior rounded region above where uterine tube enters

  • Cervix: narrow outlet that protrudes into the vagina

• Layers of the uterus:

  • Endometrium: inner layer (mucosa), site of implantation of a fertilized egg, sloughs off if no pregnancy occurs

  • Myometrium: middle layer of smooth muscle that contracts during labor

  • Perimetrium (visceral peritoneum): outermost serous layer of the uterus

• Vagina:

  • Passageway that extends from cervix to exterior of body, located between urinary bladder and rectum

  • Serves as the canal that allows a baby or menstrual flow to leave the body

  • Female organ of copulation, receives the penis during sexual intercourse

  • Hymen partially closes the vagina until it is ruptured

Page 6:

• Labia:

  • Labia majora: hair-covered skin folds, enclose the labia minora and vestibule

  • Labia minora: delicate, hair-free folds of skin

• Vestibule:

  • Enclosed by labia majora

  • Contains external openings of the urethra and vagina

• Greater vestibular glands:

  • One is found on each side of the vagina

  • Secretions lubricate vagina during intercourse

• Clitoris:

  • Contains erectile tissue, corresponds to the male penis

  • Hooded by a prepuce, composed of sensitive erectile tissue, swollen with blood during sexual excitement

  • Lacks a reproductive duct

• Perineum:

  • Diamond-shaped region between the anterior ends of the labial folds, anus posteriorly, and ischial tuberosities laterally

Page 7:

• Hormone production by the ovaries:

  • Estrogen:

    • Produced by follicle cells

    • Causes secondary sex characteristics, enlargement of accessory organs, development of breasts, appearance of axillary and pubic hair, increase in fat beneath the skin, widening and lightening of the pelvis, onset of menses

  • Progesterone:

    • Produced by the corpus luteum

    • Helps maintain pregnancy, prepares the breasts for milk production

• Mammary gland:

  • Present in both sexes, but function only in females

  • Modified sweat glands, produce milk to nourish a newborn

  • Stimulated by sex hormones (mostly estrogens) to increase in size

• Mammary glands:

  • Areola: central pigmented area

  • Nipple: protruding central area of areola

  • Lobes: internal structures that radiate around nipple

  • Lobules: located within each lobe and contain clusters of alveolar glands

  • Alveolar glands: produce milk when a woman is lactating

  • Lactiferous ducts: connect alveolar glands to