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Physiology > Reproductive > Flashcards

Reproductive Flashcards

1
Q

organs of reproductive system

A

gonads
pathway of gamete transport
accessory reproductive organs/glands

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2
Q

function of gonads

A

gamete production
secrete sex hormones

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3
Q

function of male reproductive system

A

production of gametes
organs for mating
fertilization
propagation of species

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4
Q

anatomy of male r.s.

A

testis (gonads) → epididymis → vas deferens
glands: seminal vesicle, prostate, bulbo-urethral

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5
Q

testes

A

male gonads
housed in scrotum (outside of body)
250-300 compartments; tightly packed seminiferous tubules

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6
Q

spermatic cord

A

collection of tube structures through which vessels, nerves, + vas deferens pass
counter directional blood flow = helps temp regulation

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7
Q

descent of testes

A

3 months in development
7 months → starts to descend
at birth

process regulated by testosterone
spermatogenesis requires temperatures 2 degrees below core body temp

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8
Q

cryptorchidism

A

abnormality - testes remain in abdomen
can be rectified by surgery after birth

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9
Q

seminiferous tubules

A

site of sperm production
packed in testes, converge from compartments into rete testis = network
separate into efferent ductules that join together to become vas deferens

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10
Q

mumps

A

viral infection that causes infertility
attacks germ cells that will develop to produce gametes = larger lumen of seminiferous tubules, smaller cells
preventable by childhood vaccine

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11
Q

leydig cells

A

interstitial cells
secrete testosterone

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12
Q

sertoli cells

A

epithelial cells lining s. tubules
support sperm development
linked by tight junctions

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13
Q

myoid cells

A

smooth muscle lining outside of s. tubule
peristalsis = propel sperm

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14
Q

blood-testis barrier

A

tight junctions between sertoli cells form basal and luminal compartments
keeps sperm safe from blood-carried pathogens

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15
Q

local role of sertoli cells

A
  1. trophic effect to support sperm development
  2. secrete luminal fluid for sperm housing
  3. secrete androgen-binding protein = buffer to maintain steady [androgens] in lumen
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16
Q

endocrine role of sertoli cells

A
  1. act as target cells for testosterone + FSH → secrete paracrine factors that stimulate spermatogenesis
  2. secrete inhibin = negative feedback for FSH
  3. secrete paracrine factors that affect Leydig cell function
  4. phagocytosis of old and damaged sperm
  5. site of immunosuppression (blood-testis barrier)
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17
Q

male gonads

A

production of sperm
production of hormones

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18
Q

scrotum

A

temperature regulation of optimal sperm production

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19
Q

epididymis

A

maturation of sperm following production
temporary storage site for sperm

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20
Q

vas deferens

A

conduit
storage site for sperm

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21
Q

male accessory sex glands

A

production of seminal fluid

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22
Q

corticosteroid synthesis in males

A

cholesterol → progesterone → androgens
conversion to androgens in the gonads (also in adrenal cortex)
lipophilic hormones → cross membrane to intracellular receptors = slow response

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23
Q

production of testosterone in males

A

low levels in childhood to onset of puberty = inability to reproduce
androgens (testosterone) → carried by blood to peripheral tissues:
- direct action
- converted to DHT, estrogen, or inactive molecules

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24
Q

male puberty

A

onset at 10-14
sexual maturation = males can continuously produce sperm
reproductive organs mature = can produce gametes
secondary sexual characteristics develop

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25
Q

plasma testosterone levels in males

A

peaks at:
- mid-fetal development = descent of testes
- neonatal (after birth)
- onset of puberty
levels rise from puberty until adulthood and remain high
small decline at old age
sperm production parallels rise at puberty + adult levels

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26
Q

hypothalamic-pituitary - Leydig cell axis

A

higher centres trigger hypot. to release GnRH → stimulates release of LH from anterior pituitary → stimulates Leydig cells to release testosterone → effects at onset of puberty
testosterone has negative feedback at anterior pituitary + hypot.

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27
Q

puberty changes in males

A

growth spurt = ↑ muscle mass
↑ body hair
voice changes
pubic hair grows + genitals develop

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28
Q

effect of androgens in males

A

stimulate spermatogenesis
promote development of secondary sex characteristics during puberty + maintenance throughout adulthood
increase sex drive
promote protein synthesis in skeletal muscle
stimulate growth hormone secretion = permits bone growth during adolescence
promote development of male reproductive structures during embryonic life

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29
Q

testosterone anabolic action

A

promote protein synthesis in skeletal muscle

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30
Q

spermatogenesis

A

production of gametes
begins at onset of puberty
occurs in s. tubules → from basement membrane to lumen; in space between adjacent sertoli cells

mitosis of spermatogonia = primary spermatocytes → meiosis I = secondary spermatocytes → meiosis II = spermatids → differentiate into spermatozoa
takes ~64 days after mitosis

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31
Q

mitosis (males)

A

ensures continuous supply of spermatogonia
one daughter cell continues differentiation + other restarts mitosis to maintain germ line

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32
Q

meiosis (males)

A

chromosome number becomes half

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33
Q

spermatogonia

A

2n chromosomes

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34
Q

primary spermatocytes

A

2n x2 chromosomes

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35
Q

secondary spermatocytes

A

n x 2 chromosomes

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36
Q

spermatids

A

n chromosomes

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37
Q

differentiation of spermatozoa

A

specialization for transport + delivery of proper genetic material

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38
Q

spermiogenesis

A

differentiation of spermatid to spermatozoa = ~24 days
acrosomal vesicle migrates to nucleus = enzymes to support sperm head during fertilization
elongation of tail
mitochondria migrate to middle
shed cytoplasm

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39
Q

structure of a sperm

A

head:
- nucleus = chromosomes
- acrosome = enzymes for fertilization
midpiece:
- mitochondria = energy source
tail:
- movement of cell; slow wave becomes whiplike to propel

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40
Q

sperm maturation

A

spermatozoa released into lumen of s. tubules = immotile; ~20 days
fluid secreted by Sertoli cells generates pressure to push sperm into epididymis = reside 6-12 days; aquire motility; fluid is reabsorbed + sperm is concentrated
move to vas deferens by peristalsis → remain until ejaculation

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41
Q

defects in sperm maturation

A

affected sperm structure or count can cause infertility
optimum number = 300 million sperm/ejaculation vol (3 mL)

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42
Q

gonadotropins (males)

A

FSH = stimulates gametogenesis/spermatogenesis in sertoli cells
LH = stimulates androgen secretion from Leydig cells

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43
Q

hypothalamic-pituitary testicular axis

A

hypot. = pulse generator → releases GnRH in pulses
stimulates anterior pituitary to release LH + FSH
testosterone + androgen-binding protein combine to effect local actions in s.tubules

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44
Q

pulse generator

A

active at onset of puberty
pulses of GnRH secretion is sufficient to stimulate pituitary release of hormones (one large secretion is insufficient)
frequency + amplitude of pulses change every 90 min for males

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45
Q

testosterone negative feedback

A

at hypot. = ↓ amplitude of GnRH released
at ant. pit. = ↓ responsiveness of cells to GnRH
works to regulate rate of spermatogenesis

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46
Q

seminal vesicle

A

gland that releases seminal fluid into vas deferens (join before entering urethra
secretes alkaline fluid with fructose, enzymes, and prostaglandins

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47
Q

prostate gland

A

organ that empties secretions through pores into urethra; below entry of vas deferens
secretes citrate + enzymes (prostate specific antigen = PSA)

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48
Q

seminal fluid

A

dilutes sperm
provides energy (fructose)
forms semen clot

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49
Q

PSA levels

A

increased by hypertrophy or cancer in prostate gland
= biomarker for cancer detection

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50
Q

bulbourethral gland

A

secrete viscous fluid with mucus into seminal fluid
below prostate gland

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51
Q

semen

A

sperm + seminal fluid

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52
Q

male sexual response

A

controlled by autonomic nervous system
active = parasympathetic control

external stimulation or various neural inputs → reflexes at T, L, S spinal levels
1. erection = parasymp. → relaxation of vasc smooth muscle = ↑ blood flow to erectile tissue
2. emission = symp. stimulation to smooth muscles of ducts = contraction
3. ejaculation = somatic spinal reflexes → contraction of skeletal muscle for semen expulsion

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53
Q

parasymp. control of erection

A

stimulation → SC → ↑ activity in parasymp. neurons → relaxation of smooth muscle of arteries supplying blood to erectile tissue
= ↑ blood flow = ↑ blood vol and pressure
positive feedback (compression of veins = ↓ outflow of blood = ↑ blood vol + pressure)

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54
Q

vasodilation

A

activation of parasympathetic nerve = ↑ Nitric oxide (NT) = ↑ cGMP (2nd messenger) → vasodilation = ↑ blood flow

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55
Q

viagra

A

“sildenafil”
inhibitor of phosphodiesterase enzyme that breaksdown cGMP = higher concentration
treatment for erectile dysfunction

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56
Q

sperm numbers through female tract

A

200x10^6 deposited
100,000 reach uterus
100 reach ampulla = site of fertilization

many die because of high acidity, or don’t have energy to move forward, cervix leakage

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57
Q

capacitation

A

final maturation of sperm
occurs in female tract (upper body of uterus)
uterine secretions cause changes:
destabilization of sperm surface membrane → multiple fusions, changes in cholesterol = allows for binding with female gamete
activation also changes tail movement from wave-like to whiplash

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58
Q

characteristics of the female reproductive system

A

cyclic changes in activity = menstrual cycle
restricted periods of fertility = ovulation
limited gamete production = pool established at birth

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59
Q

female reproductive activity

A

sexual maturation (early teens+)
phase leading to onset of puberty is not a fixed time period

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60
Q

menarche

A

onset of puberty
first menstrual bleeding
variable age

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61
Q

menstruation

A

female reproductive cycle

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62
Q

menopause

A

after last cycle, females lose ability to reproduce
~ age 45-50

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63
Q

female reproductive organs

A

gonads = ovaries
reproductive tract = uterus, uterine tubes, vagina

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64
Q

ovaries

A

site of ova maturation (produce gametes + reproductive hormones)
consists of connective tissue with follicles
separate from reproductive tract

65
Q

fallopian tubes

A

uterine tubes/oviduct
site of fertilization
transports ova from ovaries to uterus
infundibulum + fimbriae sit on top of ovary and pick up released ovum

66
Q

movement of ovum through uterine tube

A

initially = peristaltic contractions (smooth muscle)
mostly = movement of cilia lining tubules
duration: 4 days to reach uterus

67
Q

ectopic pregnancy

A

implantation of zygote occurs in f. tube instead of uterus = not viable → surgically removed
abnormal + rare (1-2%)
untreated = maternal mortality

can be caused by chlamydia (damages cilia)

68
Q

uterine wall

A

site of fetal development

outer layer = perimetrium
middle layer = myometrium
inner layer = endometrium

69
Q

perimetrium

A

epithelial cells and connective tissue

70
Q

myometrium

A

thickest layer
smooth muscle
= large contractions during parturition

71
Q

endometrium

A

layer of epithelial cells with numerous glands → slough + grow every cycle
glands secrete glycogen to maintain embryo
layer of connective tissue

72
Q

cervix

A

canal leading to vagina
birth canal = cervix + vagina

73
Q

oocyte

A

female gamete (“egg”)
develop within follicles and released from mature follicle

74
Q

ovarian cycle

A

follicular phase + luteal phase

75
Q

follicular phase

A

day 1-14 (variable length)
day 1 = start of menstrual bleeding
follicles grow

76
Q

luteal phase

A

day 14-28 (always 14 days)
begins once follicle releases egg
corpus luteum becomes gland that releases hormones (if fertilization/implantation don’t occur, CL dies + signals to start new cycle)

77
Q

uterine cycle

A

menstrual phase
proliferative phase
secretory phase

78
Q

menstrual phase

A

menstruation
day 1-5 (variable)
layer of endometrium sloughs off
triggered by ↓ estrogen and progesterone (degeneration of corpus luteum)

79
Q

proliferative phase

A

preparation for egg release
day 5-14
estrogen = building of endometrial layer + glands, blood vessels enter tissues to supply O2 and nutrients
smooth muscle layer thickens
cervical glands secrete a thin mucus

80
Q

secretory phase

A

day 14-28
progesterone
glands release secretions: glycogen + fluid
to support zygote development if implantation occurred
↑ blood supply
cervical secretions are more sticky = forms plug
suppresses myometrium contractions

81
Q

hormonal cycle

A

estrogenic stage
progestational stage

82
Q

estrogenic stage

A

day 1-14
estrogen levels build as follicles grow
assists proliferative stage

83
Q

progestational stage

A

day 14-28
corpus luteum releases large amounts of progesterone
= maintain secretory phase
increases body temp following ovulation

84
Q

follicles

A

embedded in connective tissue
each follicle contains 1 oocyte
earliest stage: primordial follicle = single layer of granulosa cells (specialized epithelium)
growth: cells divide to form theca cells

85
Q

stages in folliculogenesis

A

primordial follicle
primary follicle
preantral follicle
early antral follicle
mature (Graffian) follicle

86
Q

primordial follicle

A

contains primary oocyte + single layer of epithelial cells

87
Q

primary follicle

A

oocyte grows
zona pellucida (glycoproteins) develop as cell layer differentiates into granulosa cells

88
Q

secondary follicle

A

cell layer differentiates
- theca cells (internal + externa)
fluid secreted by granulosa cells forms antrum
only 10-25 each month (preantral → early antral follicles)

89
Q

Graffian follicle

A

large follicle (only 1 will mature)
oocyte is pushed into antrum by granulosa cells - cumulus oophorous

90
Q

FSH → granulosa cells

A

FSH exerts mitotic effect
extend cytoplasmic processes through zona pellucida + form gap junctions with oocyte
delivers nutrients + paracrine factors to help growth

91
Q

corpus luteum

A

follicle after oocyte is released by ovulation
secretory gland → release of estrogen + progesterone
degenerates if no fertilization occurs → corpus albicans

92
Q

FSH effects: mid follicular phase

A

stimulates granulosa cell proliferation
produce estrogen
further growth of antrum
increases aromatase synthesis + granulosa cell activity

93
Q

LH effects: mid follicular phase

A

stimulates theca cells to secrete androgens (coversion of cholesterol → progesterone → androgens)
androgens permeate to granulosa cells

94
Q

aromatase

A

converts androgens to estrogen in granulosa cells

95
Q

estrogen effects: mid follicular phase

A

further granulosa cell growth
up regulation of LH receptors on granulosa cells + progesterone receptors on uterine endometrial cells

96
Q

late follicular phase

A

LH can bind to granulosa cells
chloesterol → progesterone = ↑ levels in blood

97
Q

granulosa cells

A

similar to sertoli cells
provide nutrients for developing oocyte
secretes:
- antral fluid
- paracrines that support follicle development
- inhibin
- estrogens
- substance that forms zona pellucida

98
Q

pulse generator in females

A

frequency + amplitude of pulses change every 24 h over course of menstrual cycle

99
Q

estrogen

A

regulates gonadotropin levels through (-) and (+) feedback depending on phase of menstrual cycle

low levels = (-) feedback on hypothalamus + pituitary
high levels = (+) feedback → initiation of LH surge

100
Q

oogenesis

A

oogonia →mitosis = primary oocyte → meiosis I = secondary oocyte → meiosis II = ovum

101
Q

ovarian hormones

A

not required for female sexual differentiation before birth
required for sexual maturation at puberty and secondary sexual characteristics
maintaining sexual capacity in adult life
regulation of hypothalamic pituitary gonadal axis

estrogen, progesterone, inhibin

102
Q

menstrual cycle

A

follicular phase = follicle development from day 1-14 = ovulation
luteal phase = corpus luteum functions and degeneration after ovulation

103
Q

atresia

A

apoptosis of follicles other than dominant
occurs during follicular phase
estrogen + inhibin → negative feedback = ↓ FSH = follicle death

104
Q

Ovarian hormone actions - ovary

A

estrogen:
- ↑ growth of follicles
- upregulation of E, P, FSH, LH receptors

progesterone:
- ↓ FSH-induced estrogen production
↓ estrogen receptors

105
Q

OHAs - fallopian tube

A

estrogen:
↑ cell growth
↑ contractility
↑ cilia activity = mvt of oocyte
↑ secretions

progesterone:
↓ contractility
↓ cilia number
↓ sercretions

106
Q

OHAs - uterus

A

estrogen:
↑ growth of endometrium + myometrium
↑ contractility
↑ blood flow
↑ sensitivity to oxytocin

progesterone:
↑ endometrial secretions
↓ contractility
↓ sensitivity to oxytocin

107
Q

OHAs - cervix

A

estrogen:
↑ watery + alkaline mucus = sperm-friendly

progesterone:
small amount of viscous, cellular (WBCs) mucus = sperm-unfriendly

108
Q

OHAs - vagina

A

estrogen:
proliferation + cornification of epithelium

progesterone:
WBC infiltration
↓ cornification

109
Q

OHAs - breasts

A

estrogen:
↑ duct growth
↑ fat deposition
↑ size + pigmentation of areola

progesterone:
↑ alveolar growth

110
Q

cornification

A

↑ keratin deposition = hardening of epithelium

111
Q

fertilization

A

fusion of male + female gametes to form zygote
site = female oviduct
sperm viable = 5 days
oocyte viable = 12-24 hours

112
Q

gestation

A

pregnancy
lasts 40 weeks
first two months = embryo
after 8 weeks = fetus
parturition = birth

113
Q

sperm acrosome reaction

A

happens in fallopian tube prior to fertilization
triggered by zona pellucida → paracrine factors cause release of acrosomal enzymes

114
Q

polyspermy

A

multiple sperm fusing with oocyte → prevented to maintain correct chromosome number

one sperm enters zona pellucida → fuses to egg plasma membrane = change in membrane potential (Ca2+) = release of enzymes from cortical (secretory) granules → enter + harden zona pellucida + inactivate sperm binding receptor
= prevent any other sperm from entering

115
Q

fusion of sperm + oocyte

A

stimulates meiosis II of oocyte → ovum
sperm plasma membrane disintegrates
chromosomes from sperm and ovum migrate to center
DNA is replicated = zygote

116
Q

zygote

A

fertilized ovum
surrounded by zona pellucida
early mitotic divisions = cell cleavage (net cytoplasmic content is constant - no increase in size but increase cell number)
totipotent cells

117
Q

totipotent

A

stem cells
have capacity to develop into any structure
up to 16-32 cell stage

118
Q

morula

A

3-4 days post fertilization
cell cleavage of zygote
totipotent cells
can move from fallopian tube to uterus

119
Q

identical twins

A

division of totipotent morula cells
1 ovum fertilized by 1 sperm later divides

120
Q

fraternal twins

A

non-identical
fertilization of two oocytes released during the same cycle

121
Q

blastocyst

A

4-5 days post fertilization
lost zona pellucida
outer cell layer = trophoblast → will become fetal placenta
inner cell mass → embryo
fluid-filled cavity = blastocoele

totipotency is lost

122
Q

implantation

A

6-7 days after fertilization
trophoblast cells on side near uterus epithelium become sticky
→ differentiate:
- cytotrophoblast = cell layer invades endometrium
- syncytiotrophoblast = fused trophoblast layer → anchors

123
Q

decidual response

A

maternal endometrium response to implantation
↑ blood vessels + glands → glycogen
↑ cytokines + paracrine factors released

124
Q

late embryonic development

A

embryo starts to develop at 3 weeks
placenta becomes to form
at 5 weeks: placenta is functioning + heart beats
at 8 weeks: embryo becomes fetus

125
Q

amniotic cavity

A

supportive environment where fetus grows
surrounded by amnion → chorion

126
Q

placental development

A

chorion extends projections into maternal endometrium = chorionic villus → contain fetal blood vessels
space around villi = sinus → contains maternal blood

no direct contact between maternal and fetal blood → close proximity in placenta = exchange of gases + nutrients

127
Q

functions of placenta

A

endocrine organ = temporary gland
exchange tissue for resp gases, nutrients, and waste products
filter/immunological protection

128
Q

human chorionic gonadotropin

A

hormone used to detect pregnancy
released from chorionic layer
spikes 1-3 months since start of last period; stays above 0 until birth
maintains corpus luteum for 2-3 months
similar action to LH = estrogen + progesterone rise until birth

129
Q

human placental lactogen

A

hCS
see similar curve to E + P through gestation but higher level
GH-like and anti-insulin like actions in mother
keeps ↑ glucose levels in maternal blood = available to fetus

130
Q

hormone exchange between mother - placenta - fetus

A

cholesterol in mother → placenta = converted to P → released to mother + fetus
P in fetus = converted to androgen → sent to placenta = converted to estrogen → sent to mother

131
Q

control of parturition

A

weak uterine contractions → pressure of fetus against cervix = (+) feedback ↑ oxytocin secretion from pit. → strengthens uterine contractions
continuous (+) feedback until parturition

132
Q

myometrial contractions

A

↑ by: E, prostaglandins, oxytocin, stretch
↓ by: P, relaxin

133
Q

cervical ripening

A

dilation
↑ by: prostaglandins, relaxin
↓ by : P

134
Q

relaxin

A

hormone secreted by corpus luteum + placenta
regulation of ↑ in body fluid vol in mother during pregnancy
(present throughout pregnancy)

135
Q

parturition

A

end of pregnancy = cervix ripens
cervix dilates → labour
baby’s head wedges cervix open
expulsion of placenta = after birth

136
Q

mammary gland

A

before puberty: rudimentary ducts, few alveoli
puberty: E = ducts grow + branch; P = alveolar growth
deposition of fat + alveolar tissue
pregnancy + lactation = full development
- prolactin = lactogenesis
- hPL + growth factors
- oxytocin = milk ejection

137
Q

lactogenesis

A

initiation of milk synthesis
prolactin + low levels of E + P

138
Q

galactopoiesis

A

process of maintenance of lactation
requires prolactin

139
Q

alveolar structure

A

alveolar cells = synthesize milk protein
myoepithelial cells have oxytocin receptors → suckling reflex = cells contract and eject milk from alv cells into lumen
also contains blood vessels, connective tissue, and adipose tissue

140
Q

suckling reflex

A

suckling → hypothalamus → ↑ PRH + ↓ PIH secretion → anterior pituitary = ↑ prolactin secretion
↑ oxytocin secretion from posterior pituitary = contraction of myoepithelial cells

141
Q

Jost paradigm

A

determination of sex:
genetic sex (sex chromosomes)→
gonadal sex (gonads)→
genital or phenotypic sex (internal + external genitalia)

142
Q

genetic sex

A

determined at moment of fertilization
XX = female
XY = male

143
Q

gonadal sex

A

determined by chromosomal sex
if Y chromosome is present, SRY gene dictates differentiation of bipotential gonads → become testes
no SRY gene (XX) = default to ovaries

144
Q

bipotential gonads

A

cells are no longer totipotent
gonads are near mesonephros → will become kidneys
Mullerian duct = will become female internal structures
Wolffian duct = will become male internal structures
cloaca = will become internal genitalia

145
Q

Klinfelter’s syndrome

A

XXY (male)
presence of more than one X chromosome impairs spermatogenesis = infertility
taller, ↓ facial + body hair, gynaecomastia, osteoporosis, small testes

146
Q

Turner Syndrome

A

XO (female)
lack of X chromosome (or non-functional) causes streak ovaries = many layers of connective tissue, no follicles
shorter, CV effects

147
Q

genital sex

A

dictated by factors produced in the gonads
if testes develop = cells release hormones that push development towards male
without = develop as female

148
Q

Mullerian Inhibiting Hormone

A

secreted from Sertoli cells in testes
stops development of Mullerian duct = regression of female development

149
Q

testosterone - sexual differentiation

A

secreted from leydig cells in testes
causes development of male internal genitalia from Wolffian duct
T is converted to DHT = masculinization of male external genitalia

150
Q

female sexual differentiation (genital sex)

A

absence of MIH = Mullerian duct grows into female internal genitalia
absence of T prevents development of Wolffian duct = no male internal genitalia
absence of DHT = no masculization of external
female = default

151
Q

pseudohermaphroditism

A

genital sex is not always representative of genetic/gonadal sex
females: congenital adrenal hyperplasia
males: androgen insensitivity syndrome

152
Q

congenital adrenal hyperplasia

A

female - XX; has ovaries but has male external genitalia
enzyme mutation prevents conversion of cholesterol into cortisol in adrenal cortex
= no negative feedback = ↑ ACTH = ↑ cortisol
converted to androgens instead → target cells = virilization
infertility

153
Q

CAIS

A

complete androgen insensitivity syndrome
male - XY; has testes but has female external genitalia
MIH has inhibiting effect on female internal development
mutation of androgen receptor on Wolffian ducts + body tissues = no response to testosterone/DHT
= no male internal + no male external → female external
androgens are converted to estrogen in target tissues
infertile

154
Q

endocrine trigger of onset of puberty

A

↑ secretion of GnRH from pulse generator in hypothalamus
= ↑ LH + FSH = ↑ sex steroids from gonads → pubertal changes

before puberty = low levels → suppression of axis
at puberty: kisspeptin stimulates hypothalamus pulse generator

155
Q

kisspeptin

A

neuropeptide that stimulates neurosecretory cells in hypot.
triggered by leptin from adipose tissue

156
Q

climacteric

A

declining endocrinal, somatic, reproductive, and psychological functions
females = starts with perimenopause
males = andropause

157
Q

perimenopause

A

number of follicles falls to ~1000
↓ follicles + ↓ responsiveness to LH + FSH = ↓ estrogen + inhibin
irregularity + cessation of ovulation + menstrual cycles

158
Q

menopause

A

no ovulation = no corpus luteum → ↓ progesterone
↓ estrogen, inhibin, progesterone = no negative feedback inhibition = ↑ FSH + LH levels

Physiology (12 decks)

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