Responsible for carrying on the human race, appears to “slumber” until puberty.
the primary sex organs, the testes in males and the ovaries in females.
sex cells produced by the gonads
hormones secreted by the gonads
Accessory Reproductive Organs
All reproductive structures other than the gonads—ducts, glands, and external genitalia
sperm producing, male gonads
a sac of skin and superficial fascia that hangs outside the abdominopelvic cavity at the root of the penis. It is covered with sparse hairs, and contains paired oval testes. A midline septum divides the scrotum, providing a compartment for each testis. Contain the entire ability to father offspring. Viable sperm cannot be produced in abundance at core body temperature (37°C), the superficial location of the scrotum, which provides a temperature about 3°C lower, is an essential adaptation.
layer of smooth muscle in the superficial fascia, wrinkles the scrotal skin.
bands of skeletal muscle that arise from the internal oblique muscles of the trunk, elevate the testes
The outer double layer covering of the testis, derived from an outpocketing of the peritoneum
the fibrous capsule of the testis.
tightly coiled sperm-carrying
“sperm factories.” Surrounding each seminiferous tubule are three to five layers of smooth muscle
straight tubule, or tubulus rectus
convergence of the seminiferous tubules of each lobule
a tubular network on the posterior side of the testis.
also called Leydig cells, produce androgens (most importantly testosterone), which they secrete into the surrounding interstitial fluid.
which branch from the abdominal aorta superior to the pelvis, supply the testes.
Pampiniform Venous Plexus
network in which the testicular veins arise
enclosure of nerve fibers, blood vessels and lymphatic system that passes through the inguinal canal
(“tail”) is a copulatory organ, designed to deliver sperm into the female reproductive tract
The penis and scrotum, which hang suspended from the perineum, make up the external reproductive structures
( “around the anus”) is the diamond-shaped region located between the pubic symphysis anteriorly, the coccyx posteriorly, and the ischial tuberosities laterally
consists of an attached root and a free shaft or body that ends in an enlarged tip
foreskin, The skin covering the penis is loose, and it slides distally to form a cuff
The midventral erectile body(“spongy body”) surrounds the urethra. It expands distally to form the glans and proximally to form the part of the root called the bulb of the penis
The paired dorsal erectile bodies(“cavernous bodies”), make up most of the penis and are bound by the fibrous tunica albuginea.
Crura of the Penis
proximal ends of the corpora cavernosa
It is a single, narrow, tightly-coiled tube (in adult humans, six to seven meters in length) connecting the efferent ducts from the rear of each testicle to its vas deferens.
( “carrying away”), or vas deferens, is about 45 cm (18 inches) long. It runs upward as part of the spermatic cord from the epididymis through the inguinal canal into the pelvic cavity
The expanded terminus of the ductus deferens
enters the prostate, and there it empties into the urethra.
(“cutting the vas”). In this relatively minor operation, the physician makes a small incision into the scrotum and then cuts through and ligates (ties off) each ductus deferens. Sperm are still produced, but they can no longer reach the body exterior
the terminal portion of the male duct system. It conveys both urine and semen (at different times), so it serves both the urinary and reproductive systems.
the portion surrounded by the prostate
in the urogenital diaphragm
Spongy (penile) urethra
which runs through the penis and opens to the outside at the external urethral orifice
include the paired seminal vesicles and bulbourethral glands and the single prostate. Together these glands produce the bulk of semen (sperm plus accessory gland secretions).
is a single doughnut-shaped gland about the size of a peach pit. It encircles the urethra just inferior to the bladder. Enclosed by a thick connective tissue capsule, it is made up of 20 to 30 compound tubuloalveolar glands embedded in a mass (stroma) of smooth muscle and dense connective tissue.
are pea-sized glands inferior to the prostate (Figures 27.1 and 27.4). They produce a thick, clear mucus, some of which drains into the spongy urethra and lubricates the glans penis when a man becomes sexually excited.
is a milky white, somewhat sticky mixture of sperm, testicular fluid, and accessory gland secretions. The liquid provides a transport medium and nutrients and contains chemicals that protect and activate the sperm and facilitate their movement.
enlargement and stiffening of the penis, results from engorgement of the erectile bodies with blood
(ejac = to shoot forth) is the propulsion of semen from the male duct system. Although erection is under parasympathetic control, ejaculation is under sympathetic control.
The entire ejaculatory event
following orgasm a period of muscular and psychological relaxation
Erectile dysfunction (ED)
the inability to attain an erection
(“sperm formation”) is the sequence of events in the seminiferous tubules of the testes that produces male gametes
Diploid Chromosomal Number
The normal chromosome number in most body cells
Haploid Chromosomal Number
The number of chromosomes in human gametes is 23
(“a lessening”), a unique kind of nuclear division that, for the most part, occurs only in the gonads
sometimes called the reduction division of meiosis because it reduces the chromosome number from 2n to n.
the pairing of two homologous chromosomes that occurs during meiosis
also called chiasmata (singular: chiasma), are formed within each tetrad as the free ends of one maternal and one paternal chromatid wrap around each other at one or more points.
little groups of four chromatids
The second meiotic division, meiosis II, mirrors mitosis in every way, except that the chromosomes are not replicated before it begins. Instead, the sister chromatids in the two daughter cells of meiosis I are simply parceled out among four cells.
(spermatogenic = sperm forming), give rise to sperm in the following series of divisions and cellular transformations
Type A Daughter Cell
remains at the basal lamina to maintain the germ cell line.
Type B cell
gets pushed toward the lumen, where it becomes a primary spermatocyte destined to produce four sperm.
two smaller haploid cells, Each primary spermatocyte generated during the first phase undergoes meiosis I, forming two smaller haploid cells
(“animal seed”), has a head, a midpiece, and a tail, which correspond roughly to genetic, metabolic, and locomotor regions
(“tip piece”) Sperm tip, The lysosome-like acrosome is produced by the Golgi apparatus and contains hydrolytic enzymes that enable the sperm to penetrate and enter an egg.
contains mitochondria spiraled tightly around the microtubules of the tail.
which extend from the basal lamina to the lumen of the tubule.
extends from the basal lamina to their tight junctions and it contains spermatogonia and the earliest primary spermatocytes
lies internal to the tight junctions and includes the meiotically active cells and the tubule lumen
Blood Testis Barrier
This barrier prevents the membrane antigens of differentiating sperm from escaping through the basal lamina into the bloodstream where they would activate the immune system.
(rich in androgens and metabolic acids) that provides the transport medium for sperm in the lumen, and phagocytize faulty germ cells and the excess cytoplasm sloughed off as the spermatids transform into sperm
releasing hormone (GnRH) - which reaches the anterior pituitary cells via the blood of the hypophyseal portal system. GnRH controls the release of the two anterior pituitary gonadotropins: follicle-stimulating hormone (FSH) and luteinizing hormone (LH), both named for their effects on the female gonad.
Binding protein (ABP) - keeps the concentration of testosterone in the vicinity of the spermatogenic cells high, which in turn stimulates spermatogenesis.
a protein hormone produced by the sustentacular cells, serves as a “barometer” of the normalcy of spermatogenesis
Male secondary sex characteristics
features induced in the nonreproductive organs by the male sex hormones (mainly testosterone)—make their appearance at puberty. These include the appearance of pubic, axillary, and facial hair, enhanced hair growth on the chest or other body areas in some men, and a deepening of the voice as the larynx enlarges. The skin thickens and becomes oilier (which predisposes young men to acne), bones grow and increase in density, and skeletal muscles increase in size and mass.
the female gonads, are the primary reproductive organs of a female, and like the male testes, ovaries serve a dual purpose: They produce the female gametes (ova) and sex hormones, estrogen and progesterone
Female Internal Genitalia
the ovaries and duct system (uterine tubes, the uterus, and the vagina)
The paired ovaries flank the uterus on each side. Shaped like an almond and about twice as large, each ovary is held in place by several ligaments in the fork of the iliac blood vessels within the peritoneal cavity
anchors the ovary medially to the uterus
anchors the ovary laterally to the pelvic wall
suspends it in between suspensory ligament and ovarian ligament
serves the arteries
fibrous covering of ovaries
tiny saclike structures embedded in the highly vascular connective tissue of the ovary cortex
immature egg, encased by one or more layers of very different cells.
if a single layer is present
when more than one layer is present.
one layer of squamouslike follicle cells surrounds the oocyte.
has a single layer of cuboidal or columnartype follicle cells enclosing the oocyte.
formed when two or more layers of granulosa cells surround the oocyte.
Late Secondary Follicle
results when small fluid-filled spaces appear between the granulosa cells.
also called a Graafian or tertiary follicle, forms when the fluid-filled pockets coalesce to form a central fluid-filled cavity called an antrum.
After ovulation, the ruptured follicle is transformed into a very different looking glandular structure called the corpus luteum
form the initial part of the female duct system They receive the ovulated oocyte and are the site where fertilization generally occurs. Each uterine tube is about 10 cm (4 inches) long and extends medially from the region of an ovary to empty into the superolateral region of the uterus via a constricted region called the isthmus
The distal end of each uterine tube expands as it curves around the ovary
an open, funnel-shaped structure bearing ciliated, fingerlike projections called fimbriae (“fringe”) that drape over the ovary.
Pelvic Inflammatory Disease (PID)
extreme severe inflammation of the peritoneal cavity
(Latin for “womb”) is located in the pelvis, anterior to the rectum and posterosuperior to the bladder It is a hollow, thick-walled, muscular organ that functions to receive, retain, and nourish a fertilized ovum
of the uterus is its narrow neck, or outlet, which projects into the vagina inferiorly.
The cavity of the cervix
Papanicolaou (Pap) smear
or cervical smear test, some of these cells are scraped away and then examined for abnormalities.
(“mesentery of the uterus”) portion of the broad ligament
Lateral Cervical (cardinal) Ligaments
extend from the cervix and superior vagina to the lateral walls of the pelvis
secure the uterus to the sacrum posteriorly.
fibrous ligament that binds the uterus to the anterior body wall
Uterus sinks inferiorly, until the tip of the cervix protrudes through the external vaginal opening
the incomplete outermost serous layer of the uterine wall
(“muscle of the uterus”) is the bulky middle layer of the uterine wall, composed of interlacing bundles of smooth muscle
the mucosal lining of the uterine cavity
functional layer layer of the endometrium, undergoes cyclic changes in response to blood levels of ovarian hormones and is shed during menstruation
or basal layer, forms a new functionalis after menstruation ends.
arise from the internal iliacs in the pelvis, ascend along the sides of the uterus, and send branches into the uterine wall
branches of the uterine arteries within the myometrium
shoots of the arcuate arteries into the endometrium
Spiral (coiled) Arteries
to the stratum functionalis. The spiral arteries repeatedly degenerate and regenerate, and it is their spasms that actually cause the functionalis layer to be shed during menstruation.
(“sheath”) is a thin-walled tube, 8–10 cm (3–4 inches) long. It lies between the bladder and the rectum and extends from the cervix to the body exterior
incomplete partition of the mucosa near the distal vaginal orifice
a vaginal recess produced by the upper end of the vaginal canal loosely surrounds the cervix of the uterus
The female reproductive structures that lie external to the vagina are called the external genitalia, these structures include the mons pubis, labia, clitoris, and structures associated with the vestibule.
(“mountain on the pubis”) is a fatty, rounded area overlying the pubic symphysis.
External fatty skin fold, running posteriorly from the mons pubis
(“smaller”) enclosed by the Labia Majora two thin, hair-free skin folds, homologous to the ventral penis.
(“entrance hall”), which contains the external openings of the urethra and the vagina.
Greater Vestibular Glands
homologous to the bulbourethral glands of males. These glands release mucus into the vestibule and help to keep it moist and lubricated, facilitating intercourse.
Ridge where labia minora come together at the extreme posterior end of the vestibule
(“hill”),a small, protruding structure composed largely of erectile tissue, which is homologous to the penis of the male
exposed portion of the clitoris
Prepuce of the Clitoris
skin fold covering of the clitoris
Bulbs of the Vestibule
which lie along each side of the vaginal orifice and deep to the bulbospongiosus muscles, are the homologues of the single penile bulb and corpus spongiosum of the male. During sexual stimulation the bulbs of the vestibule engorge with blood. This may help grip the penis within the vagina and also squeezes the urethral orifice shut
a diamond-shaped region located between the pubic arch anteriorly, the coccyx posteriorly, and the ischial tuberosities laterally
are present in both sexes, but they normally function only in females.The biological role of the mammary glands is to produce milk to nourish a newborn baby, so they are important only when reproduction has already been accomplished
that attach the breast to the underlying muscle fascia and to the overlying dermis
produce milk when a woman is lactating.
open to the outside at the nipple.
milk accumulates during nursing.
X-ray examination that detects breast cancers too small to feel
(“breast cutting”), removal of the entire affected breast, plus all underlying muscles, fascia, and associated lymph nodes.
less extensive surgery in which only the cancerous part (lump) is excised
removal of the breast tissue only (and perhaps some of the axillary lymph nodes).
the diploid stem cells of the ovaries
First Polar body
the period of follicle growth, typically indicated as lasting from the first to the fourteenth day of the cycle.
the period of corpus luteum activity, days 14–28
a layer of connective tissue condenses around the follicle
the oocyte secretes a glycoprotein-rich substance that forms a thick transparent extracellular layer or membrane
the fluid between the granulosa cells coalesces to form a large fluid-filled cavity
surrounding capsule of granulosa cells
occurs when the ballooning ovary wall ruptures and expels the secondary oocyte, still surrounded by its corona radiata, into the peritoneal cavity
first menstral cycle
a series of cyclic changes that the uterine endometrium goes through each month as it responds to the waxing and waning of ovarian hormones in the blood.
or menses, the uterus sheds all but the deepest part of its endometrium
Female Sexual Response
similar to that of males in most respects. During sexual excitement, the clitoris, vaginal mucosa, bulbs of the vestibule, and breasts engorge with blood; the nipples erect; and increased activity of the vestibular glands and “sweating” of the vaginal walls lubricates the vestibule and facilitates entry of the penis.
Sexually transmitted infections (STIs)
also called sexually transmitted diseases (STDs) or venereal diseases (VDs), are infectious diseases spread through sexual contact.
is Neisseria gonorrhoeae, which invades the mucosae of the reproductive and urinary tracts. These bacteria are spread by contact with genital, anal, and pharyngeal mucosal surfaces. Commonly called “the clap,” gonorrhea occurs most frequently in adolescents and young adults.
caused by Treponema pallidum, a corkscrewshaped bacterium, is usually transmitted sexually, but it can be contracted congenitally from an infected mother. Fetuses infected with syphilis are usually stillborn or die shortly after birth. The bacterium easily penetrates intact mucosae and abraded skin.Within a few hours of exposure, an asymptomatic bodywide infection is in progress. After an incubation period of two to three weeks, a red, painless primary lesion called a chancre appears at the site of bacterial invasion.
a bacterium with a viruslike dependence on host cells. Its incubation period within the body cells is about one week. Symptoms include urethritis (involving painful, frequent urination and a thick penile discharge); vaginal discharge; abdominal, rectal, or testicular pain; painful intercourse; and irregular menses.
the most common curable STI in sexually active young women in the United States. Accounting for about 7.4 million new cases of STI per year, this parasitic infection is easily and inexpensively treated once diagnosed. Trichomoniasis is indicated by a yellow-green vaginal discharge with a strong odor. However, many of its victims exhibit no symptoms.
due to the human papillomavirus (HPV)—actually a group of about 60 viruses—is the second most common STI in the United States. About 6.2 million new cases of genital warts develop in Americans each year, and it appears that HPV infection increases the risk for cancers in infected body regions. Indeed, the virus is linked to 80% of all cases of invasive cervical cancer. Importantly, most of the strains that cause genital warts do not cause cervical cancer.
the human herpes virus type 2, and these viruses are among the most difficult human pathogens to control. They remain silent for weeks or years and then suddenly flare up, causing a burst of blisterlike lesions.
abnormal combinations of sex chromosomes occur in the zygote and cause striking abnormalities in sexual and reproductive system development.
The gonads of both males and females begin their development during week 5 of gestation as masses of mesoderm
(future female ducts) develop lateral to the mesonephric (Wolffian) ducts (future male ducts), and both sets of ducts empty into a common chamber called the cloaca.
sexually indifferent stage
gonadal ridge tissue can develop into either male or female gonads and both duct systems are present.
all embryos exhibit a small projection
the external opening of the urogenital sinus, is on the tubercle’s inferior surface.
strong fibrous cord that guides the testies
the period of life when the reproductive organs grow to adult size and become functional.
considered to have occurred when a whole year has passed without menstruation.