A + P 2 - Reproductive System : Exam 1

Primary sex organs (gonads)

Testes in males and ovaries in females; produce gametes and secrete sex hormones.

Gametes

Sex cells; sperm in males and ova in females.

Androgens

Male steroid sex hormones, primarily testosterone.

Estrogens

Female steroid sex hormones including estradiol, estrone, and estriol.

Progesterone

Female steroid sex hormone important for maintaining the uterine lining and pregnancy.

Accessory reproductive organs

Reproductive structures other than the gonads; include ducts, glands, and external genitalia.

Scrotum

Sac of skin outside the abdominopelvic cavity that contains the testes.

Raphe

Midline septum that divides the scrotum into two compartments.

Dartos muscle

Smooth muscle that wrinkles scrotal skin and pulls the testes closer to the body.

Cremaster muscles

Skeletal muscles that elevate the testes.

Why are the testes outside the body cavity?

Sperm production requires a temperature about 3°C below core body temperature.

Tunica vaginalis

Outer serous covering surrounding each testis.

Tunica albuginea

Inner fibrous capsule surrounding the testis; sends septa into the testis.

Testicular lobules

Compartments of the testis formed by septa; each contains about 1–4 seminiferous tubules.

Seminiferous tubules

Tubules in the testes where sperm are produced.

Straight tubules

Short tubules that receive sperm from seminiferous tubules and carry them toward the rete testis.

Rete testis

Network of tubules that concentrates sperm and reabsorbs excess fluid.

Pampiniform venous plexus

Network of veins surrounding the testicular arteries that cools arterial blood before it enters the testes.

Spermatic cord

Structure containing the ductus deferens, blood vessels, nerves, and lymphatics supplying the testis.

Epididymis

Coiled duct where sperm mature, gain motility, and are stored.

Head of epididymis

Superior portion of epididymis that receives sperm from efferent ductules.

Tail of epididymis

Lower portion of epididymis where mature sperm are stored before ejaculation.

Ductus deferens (vas deferens)

Muscular duct about 45 cm long that transports sperm from the epididymis toward the ejaculatory duct.

Ampulla (male)

Expanded portion of the ductus deferens where sperm can be stored before ejaculation.

Vasectomy

Procedure in which the ductus deferens is cut and tied off to provide permanent birth control.

Ejaculatory duct

Duct formed by the union of the ductus deferens and seminal gland duct; empties into the prostatic urethra.

Urethra

Terminal duct that carries urine and semen out of the male body at different times.

Prostatic urethra

Part of the urethra surrounded by the prostate.

Intermediate urethra

Short portion of the urethra between the prostatic and spongy urethra.

Spongy urethra

Portion of the urethra that runs through the penis and opens at external urethral orifice.

Penis

Male copulatory organ that delivers sperm into the female reproductive tract.

Glans penis

Enlarged distal end of the penis.

Prepuce (foreskin)

Cuff of loose skin covering the glans penis.

Circumcision

Surgical removal of the foreskin.

Corpus cavernosa

Paired erectile bodies that make up most of the penis.

Corpus spongiosum

Erectile tissue surrounding the urethra that helps keep it open during erection.

Erection

Enlargement and stiffening of the penis caused by blood filling erectile tissue.

Seminal glands (seminal vesicles)

Accessory glands that produce viscous alkaline fluid making up about 70% of semen volume.

Seminal vesicle fluid

Contains fructose, prostaglandins, and coagulating enzymes.

Fructose

Provides energy for ATP production and supports sperm movement.

Prostaglandins

Helps sperm move through female reproductive tract.

Prostate

Doughnut-shaped gland below the bladder that surrounds the urethra.

Prostatic fluid

Milky, slightly acidic fluid containing citrate, enzymes, and PSA; makes up about one-third of semen.

PSA (prostate-specific antigen)

Enzyme in prostatic fluid that helps liquefy semen.

Bulbo-urethral glands

Pea-sized glands inferior to the prostate that secrete clear mucus that lubricates the urethra/glan.

Semen

Milky-white mixture of sperm and secretions from the accessory reproductive glands.

Normal semen volume

Approximately 2–5 mL per ejaculation.

Path of sperm

Seminiferous tubules → straight tubules → rete testis → efferent ductules → epididymis → ductus deferens → ejaculatory duct → urethra → exterior.

Spermatogenesis

The production of sperm in the seminiferous tubules.

When does spermatogenesis begin?

At approximately puberty, around age 14, and it continues throughout life.

Three steps of spermatogenesis

Mitosis of spermatogonia → meiosis → spermiogenesis.

Spermatids

Immature sperm.

HPG axis (male)

Hypothalamic-pituitary-gonadal axis; hormonal system regulating gamete and sex hormone production.

GnRH

Gonadotropin-releasing hormone released by the hypothalamus that stimulates the anterior pituitary.

FSH (male)

Stimulates sperm production and supports spermatogenesis.

LH (male)

Stimulates testosterone production by the testes.

Testosterone

Main male sex hormone; supports sperm production and male secondary sex characteristics.

Testosterone before birth

Male fetal testosterone levels reach about two-thirds of adult levels.

Testosterone during childhood

Levels decrease after birth and remain relatively low until puberty.

Testosterone secondary sex effects

Promotes facial, chest, and pubic hair; deepens the voice; increases bone density and muscle mass; increases metabolic rate and libido.

Female primary sex organs

Ovaries.

Female gametes

Ova (egg cells).

Female reproductive hormones

Estrogens and progesterone.

Internal female genitalia

Ovaries, uterine tubes, uterus, and vagina.

External female genitalia (vulva)

Labia majora, labia minora, clitoris, mons pubis, vestibule, and greater vestibular glands.

Ovary

Paired female gonad that produces oocytes and secretes estrogen and progesterone.

Ovarian cortex

Outer region of the ovary containing developing ovarian follicles.

Ovarian medulla

Inner region of the ovary containing large blood vessels and nerves.

Ovarian follicle

Saclike structure in the ovarian cortex containing an immature oocyte.

Primordial follicle

Follicle containing a primary oocyte surrounded by a single layer of follicular cells.

Primary follicle

Developing follicle in which follicular cells become cuboidal and proliferate.

Secondary follicle

Follicle with multiple layers of granulosa cells surrounding the oocyte.

Granulosa cells

Follicle cells that support the oocyte and respond to FSH.

Vesicular (antral) follicle

Mature follicle containing a large fluid-filled antrum.

Ovulation

Release of a secondary oocyte from a mature ovarian follicle.

LH surge

Rapid increase in LH that triggers ovulation and formation of the corpus luteum.

Mittelschmerz

Occasional pain or twinge experienced around ovulation.

Corpus luteum

Structure formed from the ruptured follicle after ovulation; secretes progesterone and some estrogen.

Corpus albicans

Scar tissue left behind after the corpus luteum degenerates.

Uterine tubes (fallopian tubes)

Tubes that receive the ovulated oocyte and are the usual site of fertilization.

Infundibulum

Funnel-shaped distal end of the uterine tube that catches the ovulated oocyte.

Fimbriae

Ciliated projections of the infundibulum that sweep the oocyte into the uterine tube.

Ampulla of uterine tube

Widest region of the uterine tube and usual site of fertilization.

Isthmus of uterine tube

Narrow region connecting the uterine tube to the uterus.

Uterus

Hollow, muscular organ that receives, retains, and nourishes a fertilized ovum.

Anteverted uterus

Uterus tilted forward toward the bladder.

Retroverted uterus

Uterus tilted backward toward the spine.

Fundus

Superior rounded portion of the uterus.

Isthmus of uterus

Narrow inferior region between the body and cervix.

Cervix

Narrow inferior neck of the uterus that projects into the vagina.

Internal os

Opening connecting the uterine body to the cervical canal.

External os

Opening connecting the cervical canal to the vagina.

Perimetrium

Outermost serous layer of the uterine wall.

Myometrium

Middle layer of the uterine wall made of smooth muscle; contracts during childbirth.

Endometrium

Inner uterine lining where a fertilized egg implants (2 layers).

Stratum functionalis

Functional layer of the endometrium that responds to hormones and is shed during menstruation.

Stratum basalis

Basal layer of the endometrium that remains after menstruation and regenerates the functional layer.

Vagina

8–10 cm muscular tube serving as the birth canal, passageway for menstrual flow, and organ of copulation.

Vulva

Collective term for the external female genitalia.

Mons pubis

Fatty area over the pubic symphysis that becomes covered with pubic hair.