mod 3: The Male and Female Reproductive Systems Flashcards
gonads (definition)
sex organs that produce gametes. testes and ovaries are gonads
sperm (definition)
the male gamete, formed in the testes and stored in the epididymis
sex hormone (definition)
a biochemical compound controlling the development, maintenance, and function of the reproductive system and secondary sex characteristics
primary sex characteristics (definition)
structures that are directly essential for reproduction
secondary sex characteristics (definition)
structures that are distinguish male from female but are not essential for reproduction
gamete (definition)
haploid cell made during meiosis that participates in fertilization to make a zygote. sperm and ova are gametes
testes (definition)
paired male gonads that produce sperm and secrete testosterone
scrotum (definition)
pouch of skin located below the penis that holds the testes
seminiferous tubules (definition)
coiled, hollow tubes in the testes within which sperm are produced
Sertoli cells (definition)
nurse cells in the seminiferous tubules that assist in spermatogenesis and produce the hormone inhibin. they also protect sperm from attack by the body’s immune system
epididymis (definition)
a cap on each testis where sperm are matured and stored prior to ejaculation
ductus deferens (definition)
smooth muscle tube that carries the sperm from the epididymis to the penis
ejaculatory duct (definition)
a short tube from the ductus deferens to the penis
seminal vesicles (definition)
glands producing a fluid containing fructose, which supplies energy for use by sperm and is a component of semen
prostate gland (definition)
a muscle-like gland secreting alkaline fluid to neutralize acids the sperm may encounter such as in the vagina or from traces of urine in the urethra. secretes a component of semen
Cowper’s gland (definition)
a gland that secretes alkaline fluid that neutralizes acid in the urethra and lubricates it, supposedly making ejaculation smoother. secretes a component of semen
urethra (definition)
the tube leading from the bladder to the penis. the ejaculatory duct leads to the urethra. urine and semen both use this duct, though a sphincter of the bladder prevents from urine exiting at the same time as semen
ejaculation (definition)
release of semen from the penis. sensory stimulation, arousal, and coordinated muscle contractions combine to trigger the release of semen from the penis
interstitial cells (definition)
cells within the testes outside the seminiferous tubules (between them). produce testosterone
sperm pathway (step by step description)
1) sperm is produced in the testes (gonads that produce gametes and sex hormones), which takes 64-72 days within the seminiferous tubules, and where sertoli cells nourish them.
2) the sperm travels to the epididymus, where the sperm matures for 10-14 days and is stored
3) sperm moves from the epididymus into the ductus deferens
4) the sperm becomes a component of semen: the seminal vesicles secrete a fructose-containing fluid that will nourish the sperm and keep it alive, and the prostate and Cowper’s glands secrete alkaline fluids that protect the sperm from acidic environments and lubricate the urethra
5) the semen moves into the ejaculatory duct from the ductus deferens and into the urethra
6) sensory stimulation, arousal, and coordinated muscle contractions combine o trigger the ejaculation of semen from the penis
sperm (structure)
three parts:
1) the oval head: contains the nucleus and 23 chromosomes, covered in a cap-like structure: the acrosome, which stores enzymes necessary to penetrate the protective layer surrounding the egg cell
2) a cylindrical middle piece: contains mitochondria that provide energy for the end of the sperm
3) an extended tail: the “flagellum” propels the sperm forward with a lashing/whipping motion at a stunning speed of 3 metres per hour
menarche (definition)
a person’s first menstrual cycle
menstruation (simple definition)
the monthly shedding of the endometrial lining
ovaries (definition)
paired female gonads that produce eggs and secrete progesterone and estrogen hormones
egg cell (definition)
“ovum”, “ova”, “oocyte”. female gamete that contributes half of the chromosomes to the zygote in sexual reproduction. produced in the ovaries
follicles (definition)
specialized cells that surround and nurture the developing ova in the ovary and that secrete estrogen and progesterone
fimbriae (definition)
finger-like projections that sweep ovulated ovum into the oviduct
oviduct (definition)
“Fallopian tube”. the cilia-lined tube of smooth muscle that carries the ovulated egg from each ovary to the uterus
uterus (definition)
the reproductive organ in which embryonic and fetal development occurs
zygote (definition)
“fertilized egg”. a single cell produced by the fusion of a sperm and an egg cell
endometrial lining (definition)
the lining of the uterus that is thickened monthly to allow the implantation of an embryo, and is shed in menstruation if fertilization does not occur
cervix (definition)
the tightly constricted opening from the vagina into the uterus
vagina (definition)
the muscular tube that leads from the uterus to the external environment
embryo (definition)
the offspring in the period of development from the cleavage of the zygote to the ninth week, at which point the embryo becomes a fetus
vulva (definition)
external female genital organs. includes the labia major and minor–two skin flaps that protect the opening of the vagina–as well as the glans clitoris, which becomes erect during arousal
dysmenorrhea (definition)
a condition where menstrual cramps are so painful that normal function during the day is affected
ovum pathway (step by step description)
1) ovaries produce one egg cell each month, and tend to alternate so the two ovaries take turns. follicles within the ovaries contain and develop one ovum, which matures and ruptures from the follicle
2) when the ovum is released (process known as ovulation), fimbriae sweep it into the oviduct, where cilia sweep the ovum into the uterus
3) A. if the egg is fertilized (which would have happened in the oviduct) the zygote (fertilized egg) adheres to the endometrium within the uterus, which had already been thickening for some time to prepare for the zygote
B. if the egg is not fertilized, the thickened endometrium and the egg are both expelled from the body during menstruation.
ovulation (simple definition)
the rupture of the follicle and release of the mature ovum from it into the oviduct
spermatogenesis process (step by step description)
sperm are produced continuously from the walls of the seminiferous tubules, which are lined with stem cells that may undergo meiosis to produce an ultimate product: spermatozoa. as they growth they move close to the centre of the tubule to the youngest are closer to the walls and stem cells. Sertoli cells within the tubule nurse and nourish sperm cells and also protect sperm (which the body identifies as foreign) from attacks by the immune system. the inhibin produced by sertoli cells inhibits production of FSH, the lack of which causes a drop in testosterone and sperm production. this drop is detected and FSH levels rise again, causing the Sertoli cells to be activated and secrete inhibin–this negative feedback loop prevents overproduction and underproduction fo sperm
oligospermia (definition)
a condition where sperm count is less than 20 million per millilitre of semen, a number that would make it very unlikely for the person to be able to have children
oogenesis process (step by step description)
egg cells begin as oogonia and turn unto primary oocytes prenatally before going dormant until puberty. after puberty, one ovum awakes from dormancy every month and completes development. the primary oocyte develops within the the primary follicle, which is made up of many follicle cells. FSH stimulates the continuation of meiosis that begun in prenatally and this causes the primary oocyte to divide into a secondary oocyte and a polar body, which is then reabsorbed by the body. at this point the egg is ovulated
spermatozoa (definition)
mature sperm. stored in epididymis
inhibin (definition, function)
hormone produced by Sertoli cells during spermatogenesis that inhibits the production of FSH, preventing excessive sperm production
oogonia (definition)
diploid cells in the ovary that undergo meiosis prenatally
oocyte (definition)
cell that is undergoing meiosis in the ovary
primary oocyte (definition)
cells in the first meiotic division of oogenesis that have not completed it yet. the egg that the follicle is developing in the follicular stage of the ovarian cycle
corpus luteum (definition)
the structure that develops from a matured follicle that has released its egg. produces mostly progesterone and some estrogen. it eventually degenerates and is reabsorbed by the body. hormones produced during pregnancy prevent the corpus luteum from degenerating as quickly as when there is no pregnancy
fraternal twins (definition)
“dizygotic twins”. twins produced the two different eggs are fertilized by two different sperm. not identical, may be different genders.
Y chromosome (definition)
contains the TDF gene
TDF gene (definition)
“testis determining factor”. triggers the production of male sex hormones (androgens), which initiate the development of male sex characteristics
androgens (definition)
male group of steroid hormones. includes testosterone
testosterone (definition)
an androgen. secreted by the interstitial cells in the testes. result in male primary and secondary characteristics. stimulates development of sperm–higher testosterone = greater sperm production.
gestation (definition)
the period of pregnancy
STI (definition)
“sexually transmitted infection”. includes those caused by bacteria, fungus, virus. often asymptomatic but still contagious
STD (definition)
“sexually transmitted disease”. includes those caused by bacteria, fungus, or virus. causes symptoms
venereal (definition)
referencing the genitals or external sex organs
endometriosis (definition)
excessive buildup of the endometrial lining of the uterus
ovarian cysts (definition)
fluid-filled swellings on the ovary
impotence (definition)
inability to sustain an erection
PID (definition)
“pelvic inflammatory disease”. infection in the uterus and surrounding tissues. may results in scarring and infertility
laparoscopy (definition)
non-invasive surgical technique using cameras, specialized tools, and small incisions
chlamydia (type, transmission, effects)
bacterial STI.
transmitted during vaginal, anal, or oral sex. can be passed onto child during childbirth.
usually asymptomatic. can cause PID
AIDS (type, transmission, effects)
viral STI. (type of HIV)
transmitted by sexual contact or sharing needles. may be passed on to children before or after birth or during breastfeeding.
prevents the immune system from working properly, allowing opportunistic infections to take hold
hepatitis B (type, transmission, effects)
viral STI.
transmitted by sexual contact or sharing needles. may be passed on to children before or after birth or during breastfeeding.
may go away on its own–some people recover but some become asymptomatic carriers.
genital herpes (type, transmission, effects)
viral STI.
transmitted through oral sex or genital contact.
may cause blisters on genitals. never asymptomatic and incurable.
gonorrhoea (type, transmission, effects)
bacterial STI.
transmitted during vaginal, anal, or oral sex. can be passed onto child during childbirth.
usually asymptomatic. can cause PID
HPV (type, transmission, effects)
bacterial STI.
transmitted through skin-to-skin contact.
linked to cervical cancer. flat or raised warts around genital area. sometimes asymptomatic
syphilis (type, transmission, effects)
bacterial STI.
transmitted during vaginal, anal, or oral sex. can be passed onto child during childbirth.
mild symptoms early on but then affects cardiovascular and nervous system. may infect an embryo at any point, causing stillbirth or birth defects.
GnRH (function)
“gonadotropin releasing hormone”. produced by the hypothalamus, stimulates the anterior pituitary to produce FSH and LH
FSH in males (function)
causes spermatogenesis
ICSH (function)
“interstitial cell stimulating hormone”. another name for LH but exclusive for males. causes release of testosterone
anabolic steroids (definition)
androgens that enhance muscle development
steroids (definition)
group of lipids derived from cholesterol. all sex hormones are steroids.
puberty hormone levels (male) (description, effects)
begins around 10–13 years old, when the hypothalamus increases production of GnRH, which causes the anterior pituitary to release ICSH/LH and FSH. FSH stimulates sperm and inhibin production, where the inhibin inhibits release of FSH. when inhibin levels fall again due to the Sertoli cells not being stimulated because of lack of FSH, FSH starts being secreted again, and the cycle restarts, thereby keeping sperm production relatively stable. LH stimulates testosterone production, which acts on various tissues to complete development of primary and secondary sex characteristics. testosterone also inhibits the production of LH and production of it starts again when testosterone levels fall. testosterone increases sperm production but is necessary for other functions, so cannot all be used up in sperm production. inhibin slows sperm production so testosterone can be used elsewhere
menstrual cycle (simple definition)
reproductive cycle of producing an egg and developing then shedding the endometrium every ~28 days. consists of the ovarian cycle and the uterine cycle
genitalia (definition)
internal and external sex organs
menopause (explanation, definition)
as the number of functioning follicles declines, so does sex hormone level, eventually causing period irregularity and the halt of periods altogether at roughly 50 years of age. brings with it infertility, hot flashes, mood changes, rising cholesterol, bone weakness, and increased risk of cancers and bone disease
estrogen (definition)
female sex hormone secreted by the developing follicle prior to ovulation and the corpus luteum (in smaller proportions) after ovulation. develops the endometrium and female secondary sex characteristics. plays a role in maintaining bone density
progesterone (definition)
female sex hormone secreted by the corpus luteum after ovulation. helps estrogen maintain the developed endometrium until menstruation
amenorrhea (definition)
lack of menstruation due to low body fat, stress, or medical problems
osteoporosis (definition)
loss of bone density that increases risk of fracture. usually caused by lack of estrogen after menopause
ovarian cycle process (stages, step by step description)
divided into two stages:
FOLLICULAR STAGE: begins due to raised FSH levels
1) raised FSH levels cause one follicle to mature, which releases estrogen and some progesterone
2) high levels of estrogen inhibit FSH secretion and trigger sudden release of GnHR, causing sharp increase in LH production
3) this triggers ovulation (roughly day 14 of the cycle)
LUTEAL STAGE: begins after ovulation
4) LH causes the ruptured follicle to develop into a corpus luteum, which secretes progesterone and some estrogen
5) rising levels of estrogen and progesterone inhibit FSH and LH production.
6) the corpus luteum degenerates, causing decrease in hormone levels and stimulating FSH production the cycle goes back to step 1)
uterine cycle process (step by step description)
starts at the same time as the ovarian cycle, with raised FSH levels. as estrogen levels are raised by the ovarian cycle and become sufficiently high, the endometrium begins thickening (around day 6). it continues thickening and thickening is accelerated when ovulation occurs due to the corpus luteum producing progesterone. between days 15 and 23, the endometrium may double or triple in thickness. drop of sex hormones as the corpus luteum degenerates causes the endometrium to degenerate and be expelled, beginning menstruation
follicular stage (definition)
the first ~14 days of the menstrual cycle in which the follicle is developing a mature ovum for ovulation and the endometrium is building in preparation for implantation of a possible embryo
luteal stage (definition)
the days of the menstrual cycle following ovulation (~15–28), when the old follicle forms a corpus luteum that secretes progesterone and estrogen to maintain the endometrium
endometrium (definition)
the lining of the uterus that is developed under the influence of estrogen from days 1–14, becoming thick and engorged with blood to accept an implanting embryo in case fertilization takes place
hot flashes (definition)
periods of intense heat and sweating that occur as estrogen and progesterone levels fluctuate during the years of menopause
hormone replacement therapy (definition)
combinations of estrogen and progesterone prescribed to decrease hot flashes and other discomforts that may come with menopause
endocrine disruptor (definition)
substance the interferes with normal function of hormones. may mimic natural hormones or block their effects. attaching of disruptors to hormone receptor sites on cells cause the hormone that was supposed to attach there to attach somewhere else, resulting in the body counting more hormones than there actually are
