Reproductive System Flashcards
sperm and egg cell and ensure the union of gametes in fertilization following sexual
intercourse
gametes
provides the site for the developing embryo/fetus until it
is sufficiently developed to survive outside the womb
uterus
produces the gametes—sperm or egg cells
meiosis
one cell with the diploid number of chromosomes (46 for humans) divides twice to
form four cells, each with the haploid number of chromosomes
meiosis
means half the
usual
diploid number, so for humans the haploid number is 23
haploid
the process of meiosis as it takes place in the testes, the site of
sperm production.
spermatogenesis
Within each testis are seminiferous tubules that contain______,
which are stem cells that generate sperm
spermatogonia
divides by mitosis to form two
cells, one of which will remain in place as a stem cell, while the other differentiates
(specializes) to become a primary spermatocyte that will undergo meiosis
spermatogonium
cell that will undergo meiosis
primary spermatocyte
from the anterior pituitary gland initiates sperm production
follicle-stimulating hormone (FSH)
secreted by the testes when stimulated by luteinizing hormone (LH) from the
anterior pituitary, promotes the maturation of sperm
testosterone
also produced by the testes,
decreases the secretion of FSH.
inhibin
For each primary spermatocyte that undergoes meiosis, four
________ are produced.
functional sperm cells
Sperm production begins at puberty (10 to 14 years of age), and millions of sperm
are formed each day in the testes. Although sperm production diminishes with advancing
age, there is usually no complete cessation, as there is of egg production in women at
menopause.
is the process of meiosis for egg cell formation; it begins in the ovaries
and is also regulated by hormones
oogenesis
initiates the growth of ovarian follicles, each of
which contains an oogonium
FSH
a stem cell for egg cell production
oogonium
FSH stimulates the follicle cells to secrete _______
estrogen
promotes the maturation of the
ovum
estrogen
promotes the maturation of the
ovum
estrogen
for each primary oocyte that undergoes meiosis, only one _________is produced
functional egg cell
other three cells of the primary oocyte in meiosis
polar bodies
They have no function, and will simply
deteriorate
polar bodies
contains the secondary oocyte; the second
meiotic division will take place if and when the egg is fertilized.
mature ovarian follicle
The production of ova begins at puberty (10 to 14 years of age) and continues until
menopause (45 to 55 years of age), when the ovaries atrophy and no longer respond to
pituitary hormones.
diploid number
46 chromosomes
When fertilization occurs, the nuclei of the egg and sperm merge, and the
fertilized egg (zygote) has 46 chromosomes, the diploid number. Thus, meiosis maintains
the diploid number of the human species by reducing the number of chromosomes by half
in the formation of gametes.
means the presence of three (rather than the normal two) of a particular chromosome in the cells of individual
trisomy
may occure because of the non-disjunction (nonseparation) of a chromosome during the second mitotic division, usually in an egg cell. It has a total of 47 chromosome
trisomy
Trisomy 21, is the most common trisomy
down syndrome
Chrildren with ______ are mentally retarded, but there is a great range of mental ability in this group
down syndrome
are produced in the testes and are transported through the reproductive ducts
sperm
are located in the scrotum, a sac of skin between the upper thighs.
testes
The
temperature within the scrotum is about _____F, slightly lower than body temperature, which
is necessary for the production of viable sperm.
96
In fetus, it develop near
the kidneys, then descend into the scrotum just before birth.
testes
is the
condition in which the testes fail to descend, and the result is sterility unless the testes are
surgically placed in the scrotum.
cryptorchidism
result of cryptorchidism
sterility
Each lobe of testes contains several _________, in which
spermatogenesis takes place
seminiferous tubules
Among the spermatogonia of the seminiferous tubules are
___________-, which produce the hormone inhibin when stimulated by
testosterone.
sustentacular (Sertoli) cells
Between the loops of the seminiferous tubules are _______, which
produce testosterone when stimulated by luteinizing hormone (LH) from the anterior
pituitary gland.
interstitial cells
Besides its role in the maturation of sperm, _______ is also responsible
for the male secondary sex characteristics, which begin to
develop at puberty
testosterone
part of the sperm containing the 23 chromosomes
head
On the tip of the head of sperm is the _________, which is similar to a lysosome
and contains enzymes to digest the membrane of an egg cell.
acrosome
Within the middle piece are
_______ that produce ATP.
mitochondria
provides motility, the capability of the sperm
cell to move.
flagellum
It is the beating of the ______ that requires energy from ATP.
flagellum
Sperm from the seminiferous tubules enter a tubular network called the
rete testis
the first of the reproductive ducts
epididymis
secreted by APG Initiates production of sperm in the testes
FSH
secreted by APG Stimulates secretion of testosterone by the
testes
LH (ICSH)
seceretd by testes (interstitial cells) Promotes maturation of sperm
Initiates development of the secondary sex
characteristics:
—growth of the reproductive organs
—growth of the larynx
—growth of facial and body hair
—increased protein synthesis, especially in
skeletal muscles
testosterone
secretd by testes (sustentacular cells) Decreases secretion of FSH to maintain
constant rate of spermatogenesis
inhibin
In both sexes, _______ (from the adrenal cortex in women) contributes to sex drive
and muscle-protein synthesis.
testosterone
is a tube about 20 feet (6 m) long that is coiled
on the posterior surface of each testis
epididymis
Within the _____________ the sperm
complete their maturation, and their flagella become functional. Smooth muscle in its wall propels the sperm into the ductus deferens.
epididymis
also called vas deferens
ductus deferens
extends from the epididymis in the
scrotum on its own side into the abdominal cavity through the inguinal canal.
ductus deferens
This canal is
an opening in the abdominal wall for the spermatic cord, a connective tissue sheath that
contains the ductus deferens, testicular blood vessels, and nerves.
inguinal canal
an opening in a muscular wall, it is a natural “weak spot,” and it is the most common
site of hernia formation in men.
inguinal canal
Once inside the abdominal cavity, the ductus deferens extends upward over the
urinary bladder, then down the posterior side to join the ejaculatory duct on its own side
The smooth muscle layer of the ductus deferens contracts in waves of peristalsis
as part of ejaculation
receives sperm from the ductus deferens and the
secretion of the seminal vesicle on its own side.
ejaculatory ducts
Both ejaculatory ducts empty into the singe __
urethra
are posterior to the urinary bladder. Their
secretion contains fructose to provide an energy source for sperm and is alkaline to enhance
sperm motility.
seminal vesicles
provide an energy source for sperm
fructose
enhance
sperm motility
alkaline
The duct of each seminal vesicle joins the ductus deferens on that side to
form the ____________.
ejaculatory duct
A muscular gland just below the urinary bladder
prostate gland
It surrounds the first inch of the urethra as it emerges from the bladder
prostate gland
The smooth muscle of the prostate gland contracts during ejaculation to contribute
to the expulsion of semen from the urethra
Cowper’s glands, are about the size of peas and
are located below the prostate gland; they empty into the urethra.
bulbourethral glands
secretions of the male reproductive glands are
alkaline. This is important because the cavity of the female vagina has an acidic pH created
by the ___________, the natural bacterial population of the vagina.
normal flora
last of the ducts through which semen travels, and its longest
portion is enclosed within the penis.
Urethra - penis
an external genital organ
penis
distal end of penis is
called the
glans penis
glans penis is covered with a fold of skin called the ____________.
prepuce or foreskin
the surgical removal of the foreskin
circumcision
Within the penis are three masses of
cavernous (erectile) tissue
consists of a
framework of smooth muscle and connective tissue that contains blood sinuses, which are
large, irregular vascular channels.
cavernous (erectile) tissue
When blood flow through these sinuses is minimal, the penis is _______. During sexual
stimulation, the arteries to the penis _________, the sinuses fill with______, and the penis
becomes ____ and ______. The dilation of _________ and the resulting erection are
brought about by the localized release of _______ and by ________. The erect penis is capable of penetrating the female vagina to deposit_______. The
culmination of sexual stimulation is ________, a sympathetic response that is brought
about by ________ of all of the reproductive ducts and _______of the prostate gland
and the muscles of the pelvic floor.
flaccid
dilate, blood
erect and firm
penile arteries
nitric oxide (NO), parasympathetic impulses
sperm
ejaculation
peristalsis, contraction
consists of sperm and the secretions of the seminal vesicles, prostate gland,
and bulbourethral glands;
semen
During ejaculation, approximately 2 to
4 mL of semen is expelled. Each milliliter of semen contains about 100 million sperm cells.
are
produced in the ovaries and travel through the fallopian tubes to the uterus
egg cells (ova)
is
the site for the growth of the embryo-fetus.
uterus
are a pair of oval structures about 1.5 inches (4 cm) long on either side of
the uterus in the pelvic cavity
ovaries
extends from the medial side of
an ovary to the uterine wall,
ovarian ligament
is a fold of the peritoneum that covers
the ovaries. These ligaments help keep the ovaries in place.
broad ligament
are present at
birth which produce mature ova
primary follicles
contains an oocyte,
primary ovarian follicle
a potential ovum or egg cell
oocyte
A mature
follicle may also be called a
graafian follicle
Surrounding the oocyte are the _______, which secrete estrogen
follicle cells
hormone LH from the anterior pituitary
gland causes _____, that is, rupture of the mature follicle with release of the ovum
ovulation
other developing follicles begin to deteriorate; these are called _______ and has no other purpose
atretic follicles
Under the influence of LH, the ruptured follicle becomes the
__________ and begins to secrete progesterone as well as estrogen
corpus luteum
Hormones produced
in smaller amounts by the corpus luteum are______________.
inhibin and relaxin
(also called uterine tubes or oviducts)
fallopian tubes
The lateral end of a fallopian tube encloses an _______ and the medial
end opens into the ______
ovary, uterus
The end of the tube that encloses the ovary has _________,
fringelike projections that create currents in the fluid surrounding the ovary to pull the
ovum into the fallopian tube.
fimbriae
Because the ovum has no means of self-locomotion (as do sperm), the structure of
the _________ ensures that the ovum will be kept moving toward the uterus.
fallopian tube
usually takes place in the fallopian tube.
fertilization
If not fertilized, an ovum dies
within 24 to 48 hours and disintegrates, either in the ______ or ______
tube, uterus
If fertilized, the
ovum becomes a zygote and is swept into the uterus; this takes about 4 to 5 days.
Sometimes the zygote will not reach the uterus but will still continue to develop. This
is called an
ectopic pregnancy
means “in an abnormal site.”
ectopic
is shaped like an upside-down pear, superior to the urinary bladder and between the
two ovaries in the pelvic cavity
uterus
is the upper
portion of uterus above the entry of the fallopian tubes,
fundus
is the large central portion of uterus
body
The
narrow, lower end of the uterus which opens into the vagina
cervix
The outermost layer of the uterus, the ____________, is a fold of the
peritoneum.
serosa or epimetrium
is the smooth muscle layer; during pregnancy these cells
increase in size to accommodate the growing fetus and contract for labor and delivery at the
end of pregnancy.
myometrium
The lining of the uterus is the ________, which itself consists of two layers.
endometrium
layer of endometrium adjacent to the myometrium, is vascular but very thin and is a permanent
layer
basilar layer
layer of endometrium that is regenerated and lost during each menstrual cycle.
functional layer
If fertilization does not
occur, the functional layer sloughs off in menstruation. During pregnancy, the endometrium
forms the maternal portion of the placenta
is a muscular tube that extends from the
cervix to the vaginal orifice in the perineum (pelvic floor). It is posterior to the urethra and
anterior to the rectum
vagina
The vaginal opening is usually partially covered by a thin
membrane called the __________, which is ruptured by the first sexual intercourse or by the use
of tampons during the menstrual period.
hymen
The functions of the _________ are to receive sperm from the penis during sexual
intercourse, to provide the exit for menstrual blood flow, and to become the birth canal at
the end of pregnancy
vagina
_____________(bacteria) of the vagina creates an acidic
pH that helps inhibit the growth
of pathogens.
normal flora
The female external genital structures may also be called the
vulva
is a small mass of erectile tissue anterior to the urethral orifice. The only
function of it is sensory; it responds to sexual stimulation, and its vascular sinuses
become filled with blood.
clitoris
is a pad of fat over the pubic symphysis, covered with skin and pubic
hair.
mons pubis
Extending posteriorly from the mons are the ________- (lateral) and __________
(medial), which are paired folds of skin. These cover these
openings and prevent drying of their mucous membranes.
labia majora, labia minora
The area between the labia minora is called the
_________ and contains the openings of the urethra and vagina.
vestibule
Bartholin’s glands, also called _______________ are within the
floor of the vestibule; their ducts open onto the mucosa at the vaginal orifice. The secretion
of these glands keeps the mucosa moist and lubricates the vagina during sexual intercourse
vestibular glands
are structurally related to the skin but functionally related to
the reproductive system because they produce milk for the nourishment of offspring
mammary glands
is surrounded by adipose tissue
glandular tissue
produce
milk after pregnancy; the milk enters lactiferous ducts that converge at the nipple.
alveolar glands
The skin
around the nipple is a pigmented area called the
areola
The formation of milk is under _______________. During pregnancy, high levels of
_______ and __________ prepare the glands for milk production. ______ from the
anterior pituitary gland causes the actual synthesis of milk after pregnancy. The sucking of
the infant on the nipple stimulates the __________ to send nerve impulses to the
posterior pituitary gland, which secretes ______________ to cause the release of milk.
hormonal control
estrogen, progesterone
prolactin
hypothalamus
oxytocin
secreted by ovary(follicle) and placenta. Promotes growth of duct
system
estrogen
secreted by Ovary (corpus luteum)
Placenta. Promotes growth of
secretory cells
progesterone
secreted by APG. Promotes production of
milk after birth
prolactin
secreted by PPG (hypothalamus). Promotes release of milk
oxytocin
includes the activity of the hormones of the ovaries and anterior
pituitary gland and the resultant changes in the ovaries (ovarian cycle) and uterus (uterine
cycle).
menstrual cycle
four hormones involved in menstrual cycle: _____ and ___ from the anterior pituitary
gland, ________ from the ovarian follicle, and _______ from the corpus luteum. The
fluctuations of these hormones are shown as they would occur in an average 28-day cycle
FSH, LH
estrogen
progesterone
The loss of the functional layer of the endometrium is called
menstruation or the menses. this is actually the end of a menstrual cycle. Menstruation may last 2 to 8 days, with an average of 3 to 6 days. At this time,
secretion of FSH is increasing, and several ovarian follicles begin to develop
menstrual phase
loss of the functional layer of the endometrium is called
menstruation or menses
FSH stimulates growth of ovarian follicles and secretion of estrogen
by the follicle cells. The secretion of LH is also increasing, but more slowly. FSH and
estrogen promote the growth and maturation of the ovum, and estrogen stimulates
the growth of blood vessels in the endometrium to regenerate the functional layer.
This phase ends with ovulation, when a sharp increase in LH causes rupture of a
mature ovarian follicle.
follicular phase
when a sharp increase in LH causes rupture of a
mature ovarian follicle.
ovulation
Under the influence of LH, the ruptured follicle becomes the corpus
luteum and begins to secrete progesterone as well as estrogen. Progesterone stimulates further growth of blood vessels in the functional layer of the endometrium and promotes the storage of nutrients such as glycogen. As progesterone secretion increases, LH secretion decreases, and if the ovum is not fertilized, the secretion of progesterone also begins to decrease. Without progesterone, the endometrium cannot be maintained and begins to slough off in menstruation. FSH secretion begins to increase (as estrogen and progesterone decrease), and the cycle begins again.
luteal phase
inhibits the secretion of FSH, and perhaps LH as well, from the anterior
pituitary gland
inhibin
is believed to inhibit contractions of the myometrium (as does
progesterone), which would help make implantation of the early embryo successful.
relaxin
Women who engage in strenuous exercise over
prolonged periods of time may experience __________, that is, cessation of menses.
amenorrhea
Initiates development of
ovarian follicles
* Stimulates secretion of
estrogen by follicle cells
FSH
Causes ovulation
* Converts the ruptured
ovarian follicle into the
corpus luteum
* Stimulates secretion of
progesterone by the corpus
luteum
LH
Promotes maturation of ovarian follicles
* Promotes growth of blood vessels in the endometrium
* Initiates development of the secondary sex characteristics:
—growth of the uterus and other reproductive organs
—growth of the mammary ducts and fat deposition in the breasts
—broadening of the pelvic bone
—subcutaneous fat deposition in hips and thighs
estrogen
Promotes further growth of blood vessels in the endometrium and storage of nutrients
* Inhibits contractions of the myometrium
progesterone
secreted by ovary (corpus luteum) Inhibits secretion of FSH
inhibin
secreted by Ovary (corpus luteum)
Placenta during pregnancy. Inhibits contractions of the myometrium to facilitate implantation
* Promotes stretching of ligaments of the pubic symphysis
relaxin
has effects on organs such as bones and blood vessels in both men and women.
It is produced in fat tissue in the breasts and hips.
estrogen
In men, ________is converted
to estrogen in the brain.
testosterone
