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