Reproductive System Flashcards
The default pathway in fetal development in the absence of the _____ gene is the development of female reproductive organs.
SRY
The presence of the SRY gene on the Y chromosome triggers the production of _________, leading to the development of male reproductive organs.
testis determining factor (TDF)
____________ is produced by the testes and prevents the development of female reproductive structures.
Anti-Müllerian hormone
True or False: Males have a lower hematocrit than females.
False, they have a higher hematocrit than females
From fetal development to the first year of life, GnRH, gonadotropins, and sex hormones are secreted at relatively _____ levels.
high
During infancy to puberty, the secretion rates of reproductive hormones are very _____, and reproductive function is quiescent.
low
At puberty, secretion rates of reproductive hormones ________ markedly, initiating the period of active reproduction.
increase
In females, hormone secretion at puberty occurs in large _______ swings.
cyclical
Later in life, the gonads become less responsive to _____________, and reproductive function diminishes.
gonadotropins
True or False: In females, reproductive function ceases entirely later in life.
True
The hypothalamus secretes gonadotropin-releasing hormone (GnRH), which stimulates the ___________ gland.
anterior pituitary
The anterior pituitary gland secretes ____________ and follicle-stimulating hormone (FSH).
luteinizing hormone (LH)
In males, LH stimulates _______ cells in the testes to produce testosterone.
Leydig
In males, FSH stimulates _________ cells in the testes to support sperm production.
Sertoli
____________ is the primary male sex hormone.
Testosterone
Sertoli cells produce ________________, which binds to testosterone and concentrates it in the seminiferous tubules.
androgen-binding protein (ABP)
Testosterone is responsible for the development of ______________ in males, such as facial hair and a deeper voice.
secondary sexual characteristics
Testosterone also plays a role in muscle growth and ______ density.
bone
True or False: Testosterone levels decline with age.
True
__________ is a precursor to testosterone and other sex hormones.
DHEA (dehydroepiandrosterone)
True or False: There is not enough scientific evidence to support the claim that DHEA supplements can affect aging.
True
_____________ is the process of sperm production, which takes place in the seminiferous tubules within the testes.
Spermatogenesis
___________ are the stem cells that differentiate into sperm cells.
Spermatogonia
Primary spermatocytes undergo __________ to form secondary spermatocytes.
meiosis I
True or False: Prostate removal leads to sterility.
True and False; unable to naturally eject semen, but it can be removed via needle biopsy due to it still being produced
Secondary spermatocytes undergo meiosis II to form _________.
spermatids
Spermatids differentiate into __________, the mature sperm cells.
spermatozoa
True or False: Sperm production requires a temperature several degrees above normal body temperature.
False, needs a lower temp than body temp (which is why testes are held outside the body).
The ________ helps to regulate the temperature of the testes.
scrotum
_______ cells provide support and nourishment to developing sperm cells.
Sertoli
______ is a fluid that contains sperm and other secretions from accessory glands.
Semen
Sertoli cells also form the ________ barrier, which protects developing sperm cells from the immune system.
blood-testis
The seminal vesicles contribute about ____% of the semen volume.
60%
The seminal vesicle fluid contains ________, which provides energy for the sperm.
fructose
The ___________ contributes about 20% of the semen volume.
prostate gland
The prostate fluid is _______, which helps to neutralize the acidic environment of the vagina.
alkaline
The bulbourethral glands (Cowper’s glands) contribute about _____% of the semen volume.
15%
The bulbourethral gland fluid is _______, which lubricates the urethra.
mucus
The average ejaculate volume is about 3 ml and contains about _____ million sperm.
300
True or False: Sperm can live for many weeks in the male genital ducts.
True
True or False: Once in semen, sperm can survive for 24-72 hours at body temperature.
True
Decreased fertility is observed in males when sperm count is below _________.
35 million
________ is the process of the penis becoming engorged with blood, making it rigid.
Erection
Erection is controlled by the _________.
ANS
At rest, sympathetic input causes norepinephrine (NE) release, leading to arterial smooth muscle _________ and preventing erection.
contraction
During stimulation, inhibition of sympathetics and activation of ____________ noncholinergic autonomic neurons occur.
noradrenergic
Release nitric oxide (NO) causes arterial smooth muscle __________ and allows for erection.
relaxation
_______(drug) enhances the effects of NO by inhibiting the enzyme that breaks it down.
Viagra
Combining Viagra with NO-producing drugs like __________ is contraindicated as it can cause a dangerous drop in blood pressure.
nitroglycerin or nitroprusside
____________ is the expulsion of semen from the penis.
Ejaculation
Ejaculation is also controlled by the _____.
ANS
The _________ are located slightly posterior to the left and right of the opening of the vagina.
Bartholin’s glands
The function of Bartholin’s glands is to secrete _______ to lubricate the vagina.
mucus
True or False: Bartholin’s glands are homologous to the bulbourethral glands in males.
True
A female is born with approximately _________ primary oocytes.
2-4 million
During a woman’s reproductive life, only about ______ oocytes are ovulated.
400
The average reproductive life of a female is between ______ years.
13-50
An average menstrual cycle lasts ________ days.
70-85
The __________ supports the developing embryo if fertilization occurs, and has a lifespan of about ____ days if no fertilization occurs.
corpus luteum, 14
The corpus luteum secretes estrogen, progesterone, and _______.
inhibin
At the beginning of each cycle, 10-25 ___________ begin to develop.
antral follicles
True or False: By week one of the cycle, only one follicle typically continues to develop.
True
____ receptors on granulosa cells mediate follicle development.
FSH
A mature follicle grows to approximately _____ cm in diameter.
1.5 cm
_____ stimulates the anterior pituitary to release follicle-stimulating hormone (FSH) and luteinizing hormone (LH).
GnRH
_____ initiates ovulation.
LH
Theca cells produce androgens, which are then converted to ________ by granulosa cells.
estrogen
__________ is a condition where menstruation is absent due to low leptin levels, leading to decreased GnRH secretion.
Hypothalamic amenorrhea
The mechanism by which leptin influences ______ is complex and involves multiple neuronal pathways, including a1-adrenergic, b-endorphin, + NPY neurons, - NPY neurons, and dopamine systems.
GnRH
________ is the most active form of estrogen.
Estradiol (E2)
True or False: Estradiol acts on both alpha and beta estrogen receptors.
True
True or False: Estrone (E1) is more active than estradiol.
False, it is less active than E2
Estrone primarily acts on ______ estrogen receptors.
alpha
Estriol (E3) has weak activity and acts primarily on _____ estrogen receptors.
beta
The storage form of estrogen is _______.
estrone
Granulosa cells of developing follicles express _________ Hormone.
Anti-Müllerian
Anti-Müllerian Hormone, in a non-developmental role, reduces ______.
menses
The menstrual cycle is a complex interplay of hormonal changes that lead to ______.
menses
High levels of estrogen exert ________ feedback on GnRH.
positive
The LH surge is triggered by high levels of ________.
estrogen
The _______ leads to the completion of the first meiotic division of the primary oocyte, and increases antrum size + blood flow to the follicle.
LH surge
Granulosa cells secrete ___________ and decrease estrogen production in response to the LH surge.
progesterone
The _______ breaks down the follicular-ovarian membrane, allowing the oocyte and granulosa cells to be carried to the surface of the ovary.
LH surge
The __________, formed from transformed granulosa and theca cells, secretes progesterone and estrogen.
corpus luteum
Hormonal contraceptives, such as birth control pills, work by providing negative feedback, preventing the increase of _____ and _____.
FSH, LH
Hormonal contraceptives prevent follicle development, thus preventing the rise in _________.
plasma estrogen
With the use of hormonal contraceptives, there is no LH surge and consequently no __________.
ovulation
Exogenous hormones in _______________ prevent the decrease of plasma estrogen and progesterone.
birth control pills
_______ can dramatically reduce ovulation with consistent use.
NSAIDs
NSAIDs have been shown to inhibit __________ and reduce ___________ levels in young women, potentially undermining fertility.
ovulation, progesterone
A rise in progesterone leads to a/an ________ in basal body temperature.
increase
________ levels can modulate the effect of progesterone on basal body temperature.
Estradiol
__________ is a progesterone receptor antagonist; it also acts as a glucocorticoid receptor antagonist.
Mifepristone (RU486)
__________, the active ingredient in Plan B One-Step, is a synthetic version of the hormone progestin.
Levonorgestrel
Levonorgestrel has been used in birth control pills for over ____ years.
35
True or False: Plan B One-Step contains a higher dose of levonorgestrel than regular birth control pills.
True
The primary mechanism of action of levonorgestrel as a progestogen-only emergency contraceptive pill is to prevent fertilization by inhibiting ________ and thickening cervical mucus.
ovulation
________, in the US, is a prescription drug for medical abortion.
Mifepristone
_________, a prostaglandin E1 analogue, is used in conjunction with Mifepristone to cause uterine contractions.
Misoprostol
The secondary oocyte is surrounded by a cloud of cumulus cells known as the ___________.
corona radiata
Ovulation occurs approximately 35 hours after the ____ peak.
LH
The fallopian tube is approximately ____ cm long.
10 cm
Progesterone modulates the activity of ________, a sperm-specific, pH-sensitive Ca2+ channel.
CatSper
___________ are cells that secrete human chorionic gonadotropin (hCG).
Syncytiotrophoblasts
____________ acts as an LH-like hormone, preventing corpus luteum degradation.
Human chorionic gonadotropin (hCG)
A quantitative _________ test can be used to confirm pregnancy.
hCG blood
In the past, the _________________ was used as a pregnancy test.
South African clawed toed frog (Xenopus laevis)
__________ suppresses estrogen activity.
Estriol (E3)
The __________ is responsible for providing estradiol in early pregnancy.
placenta
The placenta also provides ____________ in early pregnancy.
progesterone
_________ stimulates uterine growth during pregnancy, and also promotes prostaglandin synthesis.
Estrogen
Estrogen thickens the vaginal _________.
epithelium
Estrogen sensitizes the uterus to __________’s effects.
oxytocin
_________ inhibits milk production during pregnancy.
Progesterone
The ____________, also known as the umbilical vesicle, is involved in the formation of the placenta.
chorionic villus
True or False: Polar bodies are critical in humans for fertilization.
False, though they are in other animals
True or False: It is legal to own a Xenopus laevis in Ohio.
True! It is illegal in Kentucky though
The _________ acts as a selective barrier between the mother and the fetus.
placenta
The placenta serves as an __________ organ, producing hormones.
endocrine
__________ is the process of childbirth.
Parturition
__________ is a hormone that stimulates milk production.
Prolactin
___________ is a hormone that stimulates milk ejection.
Oxytocin
Suckling by the infant stimulates _________ and _________ release.
prolactin, oxytocin
Prolactin _________ dopamine release, stimulates __________ release, and __________ GnRH production.
inhibits, oxytocin, decreases
