A&P 27: The Reproductive System Flashcards
Reproductive system
system that slumbers until puberty
Primary sex organs
gonads; testes in males; ovaries in females
Gametes
gonads produce these sex cells
Sex Hormones
gonads secreted a variety of steroid hormones, commonly called this
Accessory reproductive organs
remaining reproductive structures - ducts, glands, external genitalia
Testes
sperm-producing male gonads; lie within the scrotum
Scrotum
sac of skin and superficial fascia that hangs outside the abdominopelvic cavity at the root of the penis
Dartos muscle
layer of smooth muscle in the superficial fascia; wrinkles the scrotal skin
Cremaster muscles
bands of skeletal muscle that arise from the internal oblique muscles of the trunk; elevate the testes
Tunica vaginalis
two-layered tunic derived from the outpocketing of the peritoneum
Tunica albuginea (male)
deep to the serous layer (tunica vaginalis), fibrous capsule of the testis; “white coat”
Semineferous tubules
1-4 tightly coiled tubes that make up the actual “sperm factories”, consisting of thick stratified epithelium surrounding a central fluid-containing lumen
Myoid cells
3-5 layers of smooth muscle-like cells surrounding each seminiferous tubules; contract rhythmically to help squeeze sperm and testicular fluids through the tubules and out of the testes
Straight tubule
the seminiferous tubules of each lobule converge to form this tube that conveys sperm into the rete testis
Rete testis
a tubular network on the posterior side of the testis
Interstitial endocrine cells
lying in the soft connective tissue surrounding the seminiferous tubules are these Leydig cells that produce androgen (most importantly testosterone)
Testicular arteries
long arteries that branch from the abdominal aorta superior to the pelvis
Testicular veins
veins that drain the testes
Pampiniform venous plexus
testicular veins arise from this “tendril-shaped” network that surrounds the portion of each testicular artery within the scrotum like a climbing vine
Spermatic cord
connective tissue sheath encloses nerve fibers, blood vessels, and lymphatics; collectively these structures make up the __ ___, which passes through the inguinal canal
Perineum
suspends the scrotum and contains the root of the penis and the anus; diamond-shaped region located between the pubic symphysis anteriorly, the coccyx posteriorly, and the ischial tuberosities laterally
Penis
copulatory organ, designed to deliver sperm into the female reproductive tract
External genitalia (male)
penis and scrotum
Glans penis
enlarged tip of the penis
Prepuce
foreskin; cuff around the glans penis
Corpus spongiosum
midventral erectile body; surrounds the urethra; expands distally to form the glans and proximally to form the part of the root called the bulb of the penis
Bulb of the penis
part of the root of the penis; bulbospongiosus muscle covers it externally and secures it to the urogenital diaphragm
Corpora cavernosa
paired dorsal erectile; make up most of the penis, bound by the fibrous tunica albuginea
Crura of the penis
proximal ends of the corpora cavernosa from these “legs”
Accessory ducts
epididymis, ductus deferens, ejaculatory duct, and urethra
Epididymis
cup-shaped; 3.8cm long; head contains efferent ductules, caps the superior aspect of the testis; its body and tail are on the posterolateral area of the testis
Duct of the epididymis
most of the epididymis consists of this highly coiled portion, which has an uncoiled length of 6m
Ductus deferens
45cm long; runs upward as part of the spermatic cord from the epididymis through the inguinal canal into the pelvic cavity
Ampulla
expanded end of the ductus deferens
Ejaculatory duct
ductus deferens joins with the duct of the seminal gland to form this short duct
Vasectomy
tying off of the ductus deferens so that sperm are still produced, but they can no longer reach the body exterior
Urethra
terminal portion of the male duct system; conveys both urine and semen, so it serves both the urinary and reproductive systems
Accessory glands
include the paired seminal glands and bulbo-urethral glands and the single prostate
Seminal glands
AKA seminal vesicles; lie on the posterior bladder surface; fairly large, hollow glands about the shape and length of a little finger; pouched/coiled/folded back on itself; uncoiled = 15cm; its fibrous capsule encloses a thick layer of smooth muscle that contracts during ejaculation to empty the gland
Prostate
single doughnut-shaped gland about the size of a peach pit; encircles the urethra just inferior to the bladder; enclosed by a thick connective tissue capsule; made up of 20-30 compound tubuloalveolar glands embedded in a mass (stroma) of smooth muscle and dense connective tissue
Prostatitis
referes to a number of inflammatory disorders with a variety of causes
Benign prostatic hyperplasia (BPH)
hypertrophy of the prostate; affects nearly every elderly male
Prostate cancer
2nd most common cause of cancer death in men (after lung cancer); 2x as common in blacks as in whites
Bulbourethral glands
pea-sized glands located inferior to the prostate in the urogenital diaphragm; produce a thick, clear mucus, some of which drains into the spongy urethra and lubricates the glans penis when a man becomes sexually excited
Semen
milky white, somewhat sticky mixture of sperm, testicular fluid, and accessory gland secretions
Erection
enlargement and stiffening of the penis; results from engorgement of the erectile bodies with blood
Ejaculation
propulsion of semen from the male duct system; under sympathetic control
Climax (orgasm)
entire ejaculatory event
Resolution
period of muscular and psychological relaxation
Erectile dysfunction (ED)
inability to attain an erection when desired, usually occurs when the parasympathetic nerves serving the penis do not release enough NO
Spermatogenesis
sequence of events in the seminiferous tubules of the testes that produces male gametes
Diploid chromosomal number
normal chromosome number in most body cells
Homologous chromosomes
23 pairs of similar chromosomes
Haploid chromosomal number
number of chromosomes in human gametes (23)
Meiosis
gamete formation in both sexes involves this unique kind of nuclear division, that, for the most part, occurs only in the gonads
Reduction division of meiosis
meiosis I; reduces the chromosome number from 2n to n
Synapsis
process of forming little groups of 4 chromatids
Tetrads
groups of 4 chromatids
Crossovers
AKA chiasmata; form within each tetrad as the free ends of 1 maternal and 1 paternal chromatid wrap around each other at 1 or more points; allows the paired maternal and paternal chromosomes to exchange genetic material
Equational division of meiosis
meiosis II; chromatids are distributed equally to the daughter cells (as in mitosis)
Spermatogenic cells
cells that make up the epithelial walls of the seminiferous tubules; give rise to sperm
Spermatogonia
stem cells; outermost tubule cells, in direct contact with the epithelial basal lamina; divide continuously by mitosis; until puberty, all their daughter cells become spermatogonia
Type A Daughter Cell
during/after puberty, 1 of 2 types of daughter cells; this one remains at the basal lamina to maintain the pool of dividing germ cells
Type B Daughter Cell
during/after puberty, 1 of 2 types of daughter cells; this one gets pushed toward the lumen, where it becomes a primary spermatocyte
Primary Spermatocyte
cell destined to produce 4 sperm
Secondary spermatocytes
2 smaller haploid cells formed from each primary spermatocyte during meiosis I
Spermatids
Daughter cells of secondary spermatocytes
Spermiogenesis
streamlining process, during which each spermatid elongates, sheds its excess cytoplasmic baggage, and forms a tail
Spermatozoon
“animal seed”; has a head, midpiece, and tail, which correspond roughly to genetic, metabolic, and locomotor regions
Head
part of the sperm consisting almost entirely of its flattened nucleus, which contains the compacted DNA
Acrosome
helmetlike tip adhering to the top of the nucleus of a sperm cell
Midpiece
part of the sperm containing mitochondria spiraled tightly around the microtubules of the tail
Tail
part of the sperm; typical flagellum produced by 1 centriole (actually a basal body) near the nucleus
Sustentocytes
Sertoli cells; nonreplicating supporting cells; extend from the basal lamina to the tubule lumen
Basal compartment
1 of 2 compartments of the seminiferous tubule; extends from the basal lamina to their tight junctions and contains spermatogonia and the earliest primary spermatocytes
Adluminal compartment
lies internal to the tight junctions and includes the meiotically active cells and the tubule lumen
Blood testis barrier
tight junctions between the sustentocytes form this barrier, which prevents the membrane antigens of differentiating sperm from escaping the basal lamina into the bloodstream where they would activate the immune system
Testicular fluid
fluid secreted by sustentocytes, rich in androgens and metabolic acids; provides the transport medium for sperm in the lumen
Hypothalamic-pituitary-gonadal (HPG) axis
regulate the production of gamete and sex hormones
Gonadotropin-releasing hormone (GnRH)
Hypothalamus releases this hormone, which reaches the anterior pituitary cells via the blood of the hypophyseal portal system; controls the release of FSH and LH
Follicle-stimulating hormone (FSH) & Luteinizing hormone (LH)
anterior pituitary gonadotropins, named for their effects on the female gonad
Androgen-binding protein (ABP)
released by sustentocytes; keeps the concentration of testosterone in the vicinity of the spermatogenic cells high, which stimulates spermatogenesis
Testosterone
male sex hormone
Inhibin
protein hormone produced by sustentocytes; serves as a barometer of the normalcy of spermatogenesis
Male secondary sex characteristics
features induced in nonreproductive organs by the male sex hormones; develop at puberty
Ovaries
female gonads; primary reproductive organs of a female
Estrogen and progesterone
female sex hormones; estradiol is the most abundant form of 1 and is responsible for estrogenic effects in humans
Internal genitalia
ovaries and duct system; mostly located in the pelvic cavity
External genitalia
external sex organs of female
Ovarian ligament
ligament that anchors the ovary medially to the uterus
Suspensory ligament
anchors the ovary laterally to the pelvic wall
Mesovarium
suspends the ovary in between the uterus and the pelvic wall
Broad ligament
the suspensory ligament and mesovarium are part of this peritoneal fold that “tents” over the uterus and supports the uterine tubes, uterus, and vagina; encloses the ovarian ligaments
Ovarian arteries
arteries that serve the ovaries; branches of the abdominal aorta
Tunica albuginea (female)
each ovary is surrounded externally by this fibrous covering, which is in turn covered externally by a layer of cuboidal epithelial cells (germinal epithelium = continuation of the peritoneum)
Ovarian follicles
these tiny saclike structures are embedded in the highly vascular connective tissue of the ovary cortex; each consists of an immature egg
Oocyte
immature egg
Follicle cells
cells surrounding the ovarian follicles if a single layer is present
Granulosa cells
cell surrounding the ovarian follicles when more than 1 layer is present
Vesicular follicle
fully mature follicle; AKA antral or tertiary follicle
Antrum
central, fluid-filled cavity of a vesicular follicle
Corpus luteum
glandular structure; “yellow body”; eventually degenerates
Uterine tubes
AKA fallopian tubes or oviducts; form the initial part of the female duct system
Isthmus
constricted part of the uterine tube
Ampulla
distal end of the uterine tube expands as it curves around the ovary, forming this structure
Infundibulum
the ampulla ends in this open, funnel-shaped structure bearing ciliated, fingerlike projections (fimbriae) that drape over the ovary
Mesosalpinx
short mesentery that supports the uterine tubes; “mesentery of the trumpet”
Pelvic inflammatory disease (PID)
severe inflammation caused by sexually transmitted microorganisms, including gonorrhea bacteria; can cause scarring of the narrow uterine tubes and of the ovaries, resulting in sterility
Uterus
“womb”; located in the pelvis, anterior to the rectum and posterosuperior to the bladder; hollow, thick-walled muscular organ that receives, retains, and nourishes a fertilized ovum
Body
major portion of the uterus
Fundus
rounded region superior to the entrance of the uterine tubes
Cervix
narrow neck/outlet of the uterus; projects into the vagina inferiorly
Cervical canal
cavity of the cervix; communicates with the vagina via the external os and with the cavity of the uterine body via the internal os
Mesometrium
the uterus is supported laterally by this “mesentery of the uterus” portion of the broad ligament
Cardinal (lateral cervical) ligaments
inferior ligaments extending from the cervix and superior vagina to the lateral walls of the pelvis
Uterosacral ligaments
paired ligaments that secure the uterus to the sacrum posteriorly
Round ligaments
fibrous ligaments that bind the uterus to the anterior body wall
Prolapse of the uterus
condition in which the tip of the cervix protrudes through the external vaginal opening
Perimetrium
incomplete outermost serous layer of the uterine wall
Myometrium
bulky middle layer of the uterine wall; composed of interlacing bundles of smooth muscle
Endometrium
mucosal lining of the uterine cavity; simple columnar epithelium underlain by a thick lamina propia
Stratum functionalis
functional layer of the endometrium; undergoes cyclic changes in response to blood levels of ovarian hormones and is shed during menstruation (~ every 28 days)
Stratum basalis
basal layer of the endometrium; forms a new functionalis after menstration ends; thinner, deeper than other endometrial layer
Uterine arteries
arteries arising from the internal iliacs in the pelvis, ascending alongside the uterus, and sending branches into the uterine wall
Arcuate arteries
uterine arteries break into these branches within the myometrium
Radial arteries
the arcuate arteries send these branches into the endometrium
Straight arteries
radial arteries gives off these branches to the stratum basalis
Spiral (coiled) arteries
radial arteries give off these branches to the stratum functionalis
Vagina
thin-walled tube, 8-10 cm long; lies beween the bladder and the rectum and extends from the cervix to the body exterior; often called the birth canal; female organ of copulation
Vaginal orifice
vaginal opening
Hymen
incomplete partition formed by mucosa near the distal vaginal orifice; very vascular; may bleed when it stretches or ruptures during the 1st coitus
Vaginal fornix
vaginal recess formed by the upper end of the vaginal canal loosely surrounding the cervix of the uterus
Vulva
external genitalia of the female; AKA pudendum; includes the mons pubis, labia, clitoris, and structures associated with the vestibule
Mons pubis
fatty, rounded area overlying the pubic symphysis; covered with hair after puberty
Labia majora
posterior to the mons pubis; 2 elongated, hair-covered fatty skin folds; homologue of the male scrotum (derived from the same embryonic tissue)
Labia minora
enclosed; 2 thin, hair-free skin fold; homologous to the ventral penis
Greater vestibular glands
glands that flank the vaginal opening; pea-sized; homologous to the bulbourethral glands of males
Fourchette
at the extreme posterior end of the vestibule, the labia minora come together to form this ridge
Clitoris
just anterior to the vestibule; small, protruding structure composed largely of erectile tissue, which is homologous to the penis of the male
Glans of the clitoris
exposed portion of the clitoris
Prepuce of the clitoris
skin fold that hoods the clitoris
Body of the clitoris
part of the clitoris with dorsal erectile columns (corpus cavernosa) attached proximally by crura; lacks a corpus spongiosum that conveys a urethra
Bulbs of the vestibule
bulbs lying along each side of the vaginal orifice and deep to the bulbospongiosus muscles; homologues of the single penile bulb and corpus spongiosum of the male; during sexual stimulation, these engorge with blood; may help the vagina grip the penis and squeezes the urethral orifice shut, which prevents semen and bacteria from traveling superiorly into the bladder during intercourse
Perineum
diamond-shaped region located between the pubic arch anteriorly, the coccyx posteriorly, and the ischial tuberosities laterally
Mammary glands
present in both sexes, but normally function only in females; produce milk to nourish a newborn baby
Areola
ring of pigmented skin below the center of each breast
Nipple
central protruding portion of the breast, ringed by the areola
Lobes
each mammary gland consists of 15-25 of these that radiate around and open at the nipple; padded, separated from each other by fibrous connective tissue and fat
Suspensory ligaments
the interlobar connective tissue forms these ligaments that attach the breast to the underlying muscle fascia and the overlying dermis
Lobules
smaller units within lobes; contain alveoli
Alveoli
glandular tissue within lobules that produce milk when a woman is lactating
Lactiferous ducts
compound alveolar glands pass the milk into these ducts, which open to the outside at the nipple
Lactiferous sinus
each lactiferous duct has this dilated region where milk accumulates during nursing
Mammography
X-ray exam that detects breast cancers too small to feel (less than 1cm)
Radical mastectomy
removal of the entire affected breast, plus all underlying muscles, fascia, and associated lymph nodes
Lumpectomy
excision of a cancerous lump from breast tissue
Simple mastectomy
removes only the breast tissue and perhaps some of the axillary lymph nodes
Oogenesis
production of female sex cells
Oogonia
diploid stem cells of the ovaries
Primordial follicles
follicles that appear as the oogonia transform
Primary oocytes
Oogonia transform into these cells and become surrounded by a single layer of flattened cells (follicle cells)
1st Polar Body
smaller of the 2 haploid cells formed in meiosis I in females
Secondary Ooctye
larger of the 2 haploid cells formed in meiosis I in females; contains nearly all the cytoplasm of the primary ooctye
Ovum
if sperm penetration does not occur, the oocyte completes meiosis II, yielding this large egg & the 2nd polar body
2nd Polar Body
if sperm penetration does not occur, the oocyte completes meiosis II, yielding the ovum and this smaller structure
Ovarian cycle
monthly series of events associated with the maturation of an egg
Follicular phase
period when the dominant follicle is selected and begins to secrete large amounts of estrogen; days 1-14; day 14 = beginning of ovulation
Luteal phase
period of corpus luteum activity, typically days 14-28
Secondary follicle
primary follicle becomes this as soon as one more cell layer is present
Theca folliculi
layer of connective tissue and epithelial cells condenses around the follicle, forming this “box around the follicle”
Zona pellucida
thick, transparent extracellular layer/membrane; encapsulates the oocyte
Late secondary follicle
secondary follicle becomes this at the end of stage 3 of the ovarian cycle; clear liquid begins to accumulate between the granulosa cells
Antrum
large, fluid-filled cavity
Vesicular follicle
follicle with an antrum
Corona radiata
surrounding capsule of granulosa cells around the oocyte
Ovulation
stage 5 of the ovarian cycle; occurs when the ballooning ovary wall ruptures and expels the secondary oocyte, still surrounded by its corona radiata, into the peritoneal cavity; some women experience a twinge of pain (mittelschmerz) when this occurs
Menarche
1st menstrual period
Uterine (menstrual) cycle
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
Menstruation (menses)
days 1-5 of the uterine cycle, in which the uterus sheds all but the deepest part of the endometrium; ovarian hormones are at their lowest normal levels and gonadotropins are beginning to rise
Female sexual response
similar to that of males; clitoris, vaginal mucosa, bulbs of the vestibule, and breasts engorge with blood and the nipples become erect
Sexually transmitted infections (STIs)
infectious diseases spread through sexual contact
Gonorrhea
caused by Neisseria gonnorrhoeae, which invades the mucosa of the reproductive and urinary tracts; the “clap”
Syphilis
caused by the corkscrew-shaped bacterium Treponema pallidum; usually transmitted sexually, but can be contracted congenitally from an infected mother
Chlamydia
largely undiagnosed, silent epidemic currently on the rise in college-age students; infects 4-5 million/year; most common bacterial STI in the US; responsible for 25-50% of all diagnosed cases of PID
Trichomoniasis
most common curable STI in sexually active young women in the US; accounts for 7.4 million new cases of STI per year; parasitic infection
Genital warts
due to HPV (group of 60 viruses); 2nd most common STI in the US; 6.2 million new cases/year; HPV increases the risk of cancers in infected body regions & is linked to 80% of all cases of invasive cervical cancer
Genital herpes
caused by herpes simplex virus 2; among the most difficult human pathogens to control; acyclovir = antiviral drug of choice
Sex chromosomes
1 pair of chromosomes of 46 in the fertilized egg
Autosomes
44 of 46 chromosomes in the fertilized egg
X chromosome
large chromosome
Y chromosome
small chromosome
SRY gene
sex-determining region of the Y chromosome; master switch that initiates testes development/maleness
Nondisjunction
abnormal combinations of sex chromosomes that occur in the zygote
Gonadal ridges
gonads of males and females begin their development during week 5 of gestation; these masses of mesoderm bulge from the dorsal abdominal wall just medial to the mesonephros
Paramesonephric (Mullerian) ducts
future female ducts
Mesonephric (Wolffian) ducts
future male ducts
Sexually indifferent stage
stage of development in which the embryo’s gonadal ridge tissue could develop into either male or female gonads and both duct systems are present
Primordial germ cells
shortly after gonadal ridges appear, these cells migrate to them from the hindgut
Genital tubercle
during the sexually indifferent stage, all embryos exhibit this small external projection
Urethral groove
external opening of the urogenital sinus; on the genital tubercle’s inferior surface
Urethral folds
flanks the urethral groove laterally
Labioscrotal swellings
flanks the urethral groove laterally after the urethral folds
Gubernaculum
strong fibrous cord which extends from the testis to the floor of the scrotal sac; guides migration of the testes; there is also one in females which guides ovaries’ descent
Puberty
period of life when the reproductive organs grow to adult size and become functional
Menopause
considered to have occurred when a whole year has passed without menstruation
