exam 2 lecture notes Flashcards
what was william c youngs hypothesis
during development hormones organize/determine the structure of the nervous system in a way that will determine how the nervous system responds to the activational effects of hormones throughout life
what is the difference between the control of GnRH secretion in males and females
males: tonic activity
females: have phasic activity (cyclical)
what are the two basic functions of gonads
- produce gametes
- produce hormones
what is a follicle
a sphere of granulosa cells surrounding the oocyte
as the follicle matures, what does it become surrounded by
outer layer of theca cells
what is a primordial follicle
a single later of granulosa cells surrounding ovum
what kind of follicle is present in ovaries at time of birth
primordial follicle
what is a primary follicle
single later of granulosa cells surrounded by a single layer of theca cells
what is the zona pellucida
an outer layer of glycoproteins surrounding the ovum (outside the theca layer) that will eventually bind sperm
what is a secondary follicle
several layers of granulosa cells surrounded by a single layer of theca cells
what are tertiary follicles
fluid (secreted by granulosa cells) accumulates within follicle
theca differentiates into theca interna and theca externa layers
what is the space between the oocyte and the outer wall of the follicle called
antrum
what is the juice in the atrium called
liquor folliculi
what is the liquor folliculi rich in
estrogens
during each menstural cycle, how many tertiary follicles develop in each ovary
~10
what is a graafian follicle
the mature follicle
during each cycle, how many follicles become mature
usually only 1
when does ovulation occur
when the graafian follicle ruptures, propelling the ovum towards the mouth of the fallopian tubes
what is mittelschmerz
midpain
-when the woman can feel ovulation occur
the typical women secretes how many ova in a lifetime
400
men produce how many sperm per day
200 million
what kind of hormones are estrogen and progesterone
steroids
what is testosterone a prohormone for
DHT
estradiol
what converts testosterone to estradiol
aromatase
what does LH stimulate in the ovary
the theca interna to produce testosterone
what happens to the testosterone produced in the theca interna cells
it diffuses out into the granulosa cells
what does FSH stimulate in granulosa cells
production of aromatase (enzyme)
what does aromatase do in granulosa cells
converts testosterone to estradiol
after ovulation, what does LH stimulate in granulosa cells
production of progesterone (and estrogen)
is LH or FSH necessary for estrogen production
both
what are the three phases of the human menstrual cycle
menses
follicular phase
luteal phase
what happens during the menstrual phase
sloughing off of uterine lining; bleeding due to exposure of corkscrew blood vessel endings
what are the hormones like during days 1-5 of the menstrual cycle
very low progesterone and estrogen
LH and FSH increase some by day 5 which triggers follicular phase
what happens during the follicular phase
development of follicles and mature egg
what are the hormones like during days 6-12 of the follicular phase
steady increase in estrogen
progesterone remains low
what does the graafian follicle look like
a blister on the surface of the ovary
what happens during day 13 of the follicular phase
surge in LH secretion
what happens during day 14 of the follicular phase
ovulation
- graafian follicle ruptures and the egg is released into the fallopian tube
what happens during the luteal phase
preparation of uterus to receive fertilized egg (pseudopregnancy)
what are the hormones like during days 15-21 of the luteal phase
estrogen returns to high levels after temporary dip
progesterone rises to high levels
what is the corpus luteum
when the graafian follicle collapses, the granulosa and thecal cells become the corpus luteum
what hormones does the corpus luteum produce
progesterone and estradiol
what happens in days 22-28 of the luteal phase in the absence of a fertilized egg
estrogen and progesterone levels decline and the withdraw of progesterone from uterus triggers menstruation
what is the corpus albicans
the dying remnant of the corpus luteal tissue
what are the most common type of oral contraceptives
combination pills containing estrogens and progestins
what is contained in days 1-21 of oral contraceptive pills
steroid containing pills
what is contained in days 22-28 of oral contraceptive pills
placebo pills
(absence of progesterone allows for menstruation)
what does the phasic part of birth control pills refer to
the changes in progestin levels which increase in 2 steps (biphasic) or 3 steps (triphasic) over the 21 days
what is the type of estrogen that is usually used in birth control pills
ethinyl estradiol
what is the mechanism of action of birth control pills
lock the cycle into the luteal phase (high progesterone) to prevent follicle maturation, LH surge, and ovulation
how does the progesterone in oral contraceptives prevent the LH surge
by maintaining high negative feedback on LH secretion
(high progesterone contributes to high negative feedback on the system)
what is the effect of oral contraceptives on endogenous estradiol secretion
decreased endogenous estradiol secretion
how does plan B work
high does of synthetic progesterone intended to suppress ovulation and interfere with the ability of sperm to migrate into the fallopian tubes by thickening cervical mucus
what is RU486
a synthetic progesterone receptor antagonist intended to cause miscarriage by inducing menstruation
what is the feedback loop in response to low levels of estrogens and progesterone
negative feedback
what is the feedback loop in response to high levels of estrogen
positive feedback
what will high levels of estrogen cause
GnRH surge which will trigger an LH surge
why can GnRH secretion not be measured like LH can
GnRH is not systemic
where is the surge center
in rats, believed to be in hypothalamus
in rats, what kind of trait is having/not having a surge center
sexually dimorphic (only females have a functioning surge center)
what does it mean to say that rats are altricial
they are born in a very premature stage of development
what occurs in a male rat pup on the first day after they are born
a large surge in testosterone secretion
what is the ovulation outcome in a male rat that had no neonatal manipulation but was given an ovary as an adult
no ovulation
what is the ovulation outcome in a male rat that had neonatal castration and was given an ovary as an adult
ovulation
(suggests the rat has a functional surge center)
what is the critical period for castration of the male rat
must take place first day after birth
what is the ovulation outcome in a female rat that had neonatal treatment with testosterone and no adult manipulation
no ovulation
what is the critical period of testosterone treatment in the female rat
first 10 days of birth
what is the ovulation outcome in a female rat that had neonatal treatment with estradiol and no adult manipulation
no ovulation
what enzyme converts testosterone to estradiol
aromatase
where is aromatase located
granulosa cells of ovary and neurons in the hypothalamus
what is the ovulation outcome in a male rat that had neonatal day 1 inhibition of aromatase and was given an ovary as an adult
ovulation
(testosterone is not being converted into estradiol)
what is the ovulation outcome in a female rat that had neonatal treatment with DHT but had no adult manipulation
ovulation
(DHT cannot be converted into estradiol)
what conclusion do the rat experiments lead to about the effect of estrogen on the surge center
estradiol is responsible for blocking the surge center from forming
the ability of an adult rat to respond to estrogen positive feedback is an example of
the organizational effect of hormones
(if there is a functional surge center or not)
why is the fetus’ surge center not affected by the estrogen from their mom
estradiol is bound strongly to alpha-fetal carrier protein and is not able to cross the BBB so therefore it cannot have effects in the hypothalamus
does alpha fetal protein bind testosterone
no
what sexual anomaly did Mrs. Brown in the video have
testicular feminization mutation (androgen insensitivity)
(characterized by no pubic hair, no womb, general female appearance)
how did researchers assess whether individuals had a female or male organized brain (ex. functional surge center)
positive feedback response to a high does of estrogen
what are the implications of the Mrs. Brown study video result for organizational effects of hormones on gender identity
maybe male gender identity requires activation of androgen receptors
what response did the homosexual men in the study have on the test
LH levels increased (what happens in a female response pattern)
what organizational effects on the brain during fetal development cause masculinization or defeminization of brain development
androgens acting at androgen receptors
what is the sex difference in brain size
males have about 10% bigger brains
no differences in IQ
what did the study of sexual dimorphism of brains in rats determine about the synapses on dendrites in the difference sexes of rats
females: more synapses on dendritic spines
males: more synapses on dendritic shafts
is the medial preoptic area necessary for normal male rat mating behavior
yes
what does the male pattern of MPOA development require
presence of estrogen during neonatal brain development
what is the sexual dimorphic nucleus that was found near the preoptic area by gorski and colleagues
sexually dimorphic nucleus of the preoptic area of the hypothalamus (SDN-POA)
was the SDN-POA bigger in males or females
males
what does the size of the SDN-POA depend on
local presence of estrogen during neonatal development
what is the human brain analog of the SDN-POA
interstitial nuclei of anterior hypothalamus subregions 1-4 (INAH)
what categories do the morphological differences in the brains of males and females fall in
brain region volume
brain region connections
(have relevance to lateralization of brain function)
what does lateralization of brain function mean
difference in function between the two hemispheres
what hemisphere of the brain does language processing and production take place
left hemisphere
what area is responsible for language processing
wernickes area
what area is responsible for language production
brocas area
which brain hemisphere is responsible for complex computation
left hemisphere
what is the right hemisphere responsible for
visual-spatial processing
emotional processing
does evidence suggest women have more or less lateralization of function
less lateralization of function than men (more functional communication between the two hemispheres)
are men or women more likely to have aphasia if they have a stroke in the left hemisphere
men because more lateralization of function
what does an fMRI look at
blood oxygenation
in the rhyming study, where was neural activity in men and women
men: primarily in left hemisphere
women: both hemispheres
what is a commissure
bundle of neuronal axons connecting the 2 hemispheres
is the corpus callosum larger in men or women
posterior corpus callosum larger in women
is the anterior commissure larger in men or women
larger cross sectional diameter in women
what is the planum temporale
part of the temporal lobe inside lateral fissure that is the location of wernickes area in the left hemisphere
what are the macroscopic and microscopic sex differences in the planum temporale
macroscopic: larger in women and more symmetrical between the two hemispheres
microscopic: higher density of neurons in women
is there evidence for distinct female vs male organized brains in terms of structure and function
no
although some aspects are sexually dimorphic, every brain has the same combination of features
what do the organizational effects of hormones on human brain development contribute most to
what makes us unique individuals
NOT if we are male or female
do women or men have more sensitive olfaction
women
when does the olfactory sex difference develop for detecting musk-like odors
after puberty
when does the olfactory sex difference develop for detecting volatile amyl acetate
before puberty
(organizational effect)
do women or men have more sensitive taste
women
especially bitter taste
what is the influence of the following on taste:
puberty
menstrual cycle
pregnancy
menopause
puberty: increases after puberty in women
menstrual cycle: increases during follicular phase
pregnancy: increases
menopause: sex differences diminish
does the evidence point to an organizational or activational effect of hormones for taste
activational
what is the sex difference for audition
women have better detection for pure tones (especially high frequencies) and less tolerance for white noise
what is the sex difference for vision
men have better visual acuity
women tolerate higher levels of light intensity and dark adapt more quickly
what is the sex difference for pain
women have more sensitivity to pain
what kind of cognitive tasks do women usually excel at
verbal tasks
perceptual skills
fine motor skills
what kind of cognitive tasks do men usually excel at
quantitative tasks
visuospatial tasks
what is turners syndrome
x chromosome monosomy
(female phenotype but dysfunctional ovary)
do individuals with turners syndrome have good or bad visuospatial ability
poor visuospatial ability
what is congenital adrenal hyperplasia
girls exposed to androgens during fetal development due to fetal adrenal gland over production of androgens
do individuals with congenital adrenal hyperplasia have good or bad visuospatial ability
higher than average visuospatial ability
what is the correlation between the menstural cycle and visuospatial ability
better performance on visuospatial tasks during menstruation compared to the time around ovulation
what is the organizational evidence for the sex differences in verbal ability
girls develop verbal fluency earlier than boys
what is the activational evidence for the sex differences in verbal ability
for simple speech rate and articulation, performance is better around ovulation compared to menstruation
is there evidence for activational differences in hormones determining sexual orientation or gender identity
no
is there evidence for organizational differences in hormones determining sexual orientation or gender identity
maybe
INAH 3 of the anterior hypothalamus varied with sexual orientation
could AIDS be a confound in the INAH study
no because the size of the brain region was consistently bigger between homo and heterosexual men and the size of the other nuclei was consistent
why do the results of the INAH study not prove that the size of INAH3 determines sexual orientation
correlation does not equal causation and it did not determine if INAH caused sexual orientation, sexual orientation caused INAH differences, or if there was a third factor
what is the difference between parthenogenesis and sexual reproduction
parthenogenesis: asexual (offspring is a genetic clone of the parent)
sexual: allows mixing of genetic material
what is male mating behavior in rats dependent on
the activating effects of androgens present during adulthood
what happens to mating behavior when an adult male rat is castrated
no mating behavior
what happens to mating behavior when an adult male rat is castrated but then receives a testosterone replacement
yes mating behavior
what happens to mating behavior when an adult male rat is castrated but then receives an estrogen replacement
yes mating behavior
what happens to mating behavior when an adult male rat is castrated but then receives a DHT replacement
no mating behavior
can DHT be converted into estrogen
no
what is the mating behavior in the adult male rat dependent on
estradiol
what happens to mating behavior when a male rat is castrated on the first day of birth and is then given an estrogen replacement as an adult
female mating behavior
(castration causes a female organized brain)
what are the names for phase 1 of sexual behavior
appetitive
drive
courtship
what are the names for phase 2 of sexual behavior
consummatory
performance
copulation
what is a nuclei
cluster of neuron cell bodies, dendrites and axon terminals (gray matter)
what are the four brain components that are best characterized in regards to male mating behavior
medial preoptic area (MPOA)
olfactory system
amygdala
bed nucleus stria terminalis (BNST)
what does the medial preoptic area/anterior hypothalamus do
integrates environmental, physiological and psychological information necessary for successful copulation
what do lesions of the medial preoptic area eliminate
sexual performance
NOT sexual motivation
what do lesions of the olfactory system eliminate
both sexual motivation and sexual performance
what do lesions of the amygdala eliminate
impaired sexual motivation
NOT sexual performance
what happened when rats had lesions in the MPOA and were reared in isolation vs reared with non-lesioned rats
reared in isolation: unable to engage in mating behavior
reared with other rats: able to develop normal mating behavior
what happens when the MPOA is electrically stimulated
increases the amount of mounting and ejaculation
where are the olfactory receptors located
in the nose for detection of odors
what is the vomeronasal organ (VNO)
in the base of the nasal cavity above a small duct in the roof of the mouth
- has receptors for odorless pheromone
what are pheromones
chemical signals emitted by one organism that affects the function of another organism
what is the flehman response
characteristic behavior of many animals that facilitates placement of pheromones from tongue to opening in roof of mouth leading to vomeronasal organ
what was the result of blocking nostrils on mating behavior in rats
blocks mating behavior in male rats
where does the olfactory system send input to
the basolateral and corticomedial nuclei of the amygdala
what are the basolateral nuclei of the amygdala especially important for
sexual motivation
(phase1)
in the study, what was the result of a lesion in the MPOA
impaired sexual performance
in the study, what was the result of a lesion in the basolateral amygdala
impaired drive
in the study, what was the result of a castration
both impaired drive and performance
what restores mating behavior in a castrated male rat
testosterone or estrogen (NOT DHT) microinjected into the MPOA
where is abundant in the amygdala, bed nucleus of the stria terminalis, and the MPOA
androgen and estrogen receptors
what do dopamine agonists do to mating behavior
increase
what do dopamine antagonists do to mating behavior
decrease
where are dopamine neurons located
MPOA
also part of brain’s reward circuit
what are endorphins
endogenous morphine like chemical
what do opiates do to mating
inhibit
is there a relationship between testosterone secretion over the lifespan and sexual behavior
yes, positive correlation
what will daily treatment of men with goserelin (GnRH receptor agonist) do
decrease testosterone production by promoting downregulation of GnRH receptors
what does permissive effects of hormones refer to
their presence is necessary but not sufficient for a particular effect
what is estrus
time of sexual receptivity in females
what is the estrus cycle
a cycle of estrus activity that fluctuates with season and/or ovulation
what is the menstrual cycle
a tonic (continuous) estrus in primates and humans
- ovulatory cycle is marked by menstruation, not behavior
what does the ovulatory cycle in a female rat look like
4-5 days
sexually responsive during only day 1 of their cycle
behavioral estrus occurs on day 4 or 5 right after ovulation
have a short luteal phase and no pseudopregnancy
what is pseudopregnancy
full luteal phase in absence of fertilization
in rats, how can a luteal phase be induced
physical stimulation or prolactin secretion
(prolactin secretion triggered by physical stimulation)
what are the kinds of type 1 ovulatory cycles found in mammals
ovulation and pseudopregnancy are spontaneous
- phasic estrus: ex. dogs estrus twice a year
- tonic estrus: ex. primates, humans continuous estrus
what are the kinds of type 2 ovulatory cycles found in mammals
ovulation is induced by copulation (follicle wont rupture until physical act of copulation) and pseudopregnancy is spontaneous
ex. cats
what are the kinds of type 3 cycles found in mammals
ovulation is spontaneous but pseudopregnancy is induced by copulation (luteal phase is skipped if no copulation)
ex. rat, mouse
how can gonadal steroid secretion in women be described in reference to the different hormone profiles that are present during different stages
cyclical
what are the hormones during the follicular phase in humans
steadily increasing estrogen
low progesterone
what are the hormones during the luteal phase
high estrogen
high progesterone
what are the hormones during the perimenstruation phase
low estrogen
low progesterone
what kind of effect do the different periods of hormone profiles have on behavior/mood
activational effects
what are the three stages/phases of mating behavior in females
attractivity
proceptivity (drive, courtship)
receptivity (performance, copulation)
what is the attractivity phase in females
male rate and male primates prefer being with females around her time of ovulation
what is the proceptivity phase in females
drive; flirting and courtship
-females of many species more involved in mate selection than males
what are two things that may contribute to mate preference in humans
symmetry (may suggest immunocompetence)
degree of masculinization
what are two studies that provide evidence for hormonal influence on mate preference in humans
study found women preferred scent of symmetrical men more during ovulation time than at other points in their cycle
study found women preferred more masculine faces during ovulation and more feminine faces at other points
what is the receptivity phase in females
performance (in rats - lordosis)
what kind of effect of hormones are the three stages of female mating behavior dependent on
activational effects of hormones
what hormone is sufficient to activate mating behavior in the female rat
estrogen
in the rat, what hormone is required for mating behavior in both male and female
estrogen
(in males testosterone is converted into estrogen)
what determines whether the pattern of mating behavior will be male or female
organizational events at birth
in females, what brain region is important for sexual behavior
ventral medial hypothalamus
what do lesions in the VMH cause
inhibit proceptive and receptive behaviors
what do lesions in the midbrain central gray cause
inhibit receptive behaviors
what do lesions in the VNAB cause
inhibit receptive and increase proceptive behaviors
what do lesions in the forebrain cause
facilitate receptive
what kind of neuronal cell bodies are in the locus ceruleus
noradrenergic
what do the VMH and midbrain central gray need for optimal mating behavior
direct activating effects of estrogen and progesterone
what does NE do to female sexual behavior
facilitate lordosis
what does dopamine do to female sexual behavior
facilitate proceptive behaviors
what does serotonin do to female sexual behavior
inhibit sexual behavior
what do endorphins do to female sexual behavior
inhibit sexual behavior
what do SSRIs do to female sexual behavior
directly: reduce libido
indirectly: increase libido by reducing depression
what is the lee boot effect
female mice housed 4/cage had lengthened diestrus (inactive) periods
- removal of olfactory bulbs prevented this effect suggesting it might be pheromone related
what is the whitten effect
large number of female mice housed together without males show an extreme interruption in estrous cycle
- male odors induce estrus 48h later
what is the bruce effect
pregnant females with strange males resulted in termination of pregnancy and subsequent mating with new male 3-6 days after termination
what is the vandenbergh effect
females housed with males attain puberty sooner than females housed without males
females housed with other females attain puberty later than females housed by themselves
in general, male rats provide stimulus that
interrupts pregnancy
induces ovulation
accelerates puberty
in general, female rats provide stimulus that
suppresses ovulation
delays puberty
in the study with axillary secretions, what happened to the recipient’s menstrual cycle if the donor secretions were in the follicular phase
decreased recipient’s menstrual cycle
in the study with axillary secretions, what happened to the recipient’s menstrual cycle when exposed to ovulatory phase secretions
increased length of recipient’s menstrual cycle
how do humans detect pheromones without a vomeronasal organ
olfactory receptors
