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Ch 20 Reproductive
EVMS ch20 reproduction
140
Physiology
Graduate
05/04/2011

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Term
Y chromosome
Definition
induces formation of testes
Term
testerone
Definition
from testes, induces formation of male sex organs, in its absence, female sex organs develop
Term
gametes
Definition
sperm or egg formed in the gonads by meiosis, has a haploid number of chromosomes
Term
Y
Definition
contains 80 genes and is believed to be derived from X, thus males have about 1000 genes represented by a single allele
Term
barr body
Definition
only 1 of the two X chromosomes become active in females, the other one forms a clump of inactive heterochromatin called.., used as test for chromosomal sex
Term
silenced
Definition
in about 80 genes either the maternal or paternal allele is.., accomplished by chemically modifying DNA bases (methylation)
Term
epigenetic changes
Definition
changes that don't change the DNA sequence but they are heritable
Term
genomic imprinting
Definition
is a genetic phenomenon by which certain genes are expressed in a parent-of-origin-specific manner. It is an inheritance process independent of the classical Mendelian inheritance. Imprinted alleles are silenced such that the genes are either expressed only from the non-imprinted allele inherited from the mother
Term
testis-determining factor
Definition
gonads have the potential to become testes or ovaries until this causes conversion to testes
Term
SRY sex-determining region of Y gene
Definition
TDF is produced by this gene
Term
seminiferous tubules
Definition
produce sperm in adults appear 43 to 50 days following conception, contain germinal cells that produce sperm and sertoli cells
Term
Leydig cells
Definition
cells that produce testosterone and appear at day 65 in clusters around STs
Term
testerone
Definition
begin to be secreted at 8 weeks and peak at 12 - 14 weeks to masculinize the embryonic structure, then decline untill puberty
Term
cryptorchidism
Definition
when the testes don't descend into the scrotum, spermatogenesis does not occur becuase requires 3* lower temperature
Term
wolffian ducts
Definition
male accessory sex organs are derived from
Term
male accessory sex organs
Definition
epididymis, vas deferens, seminal vesicles, ejaculatory duct
Term
mullerian ducts
Definition
female accessory sex organs are derived from
Term
female accessory sex organs
Definition
uterus and fallopian tubes
Term
mullerian inhibiting factor
Definition
at day 60 sertoli cells secrete this and causes mullerian ducts to regress
Term
hermaphroditism
Definition
occurs when individuals have both ovary and testis tissue
Term
pseudohermaphrodites
Definition
have either testes or ovaries but have accessory organs and external genitalia that are incompletely developed or inappropriate
Term
congenital adrenal hyperplasia
Definition
most common cause of femal pseudohermaphroditism
Term
testicular feminizing syndrome
Definition
testes are normal but there are no receptors for testosterone, individual develops very femal appearance but is infertile
Term
ovaries
Definition
don't produce much sex steroid until puberty
Term
hypothalamus
Definition
controls release of LH and FSH from anterior pit with GnRH
Term
LH and FSH
Definition
stimulate production of sperm and eggs, and gonadal sex steroids, and maintain size of gonads
Term
sex steroids
Definition
provide negative feedback on hypothalamus and Ant Pit
Term
inhibin
Definition
secreted by gonads which negatively feeds back on FSH secretion
Term
menarche
Definition
1st menstrual cycle
Term
androgen secretion
Definition
growth of pubic and axiliary hair is due to this from the adrenal cortex
Term
puberty
Definition
depends on % body fat and physical activity, girls with low body fat and high activity levels enter at older age
Term
pineal gland
Definition
seems to play a role in seasonal reproduction in animals, secretes melatonin.
Term
melatonin
Definition
inhibits gonadotopin secretion
Term
excitation phase
Definition
characterized by increased muscle tone and engorgement of sexual organs with blood, vagina lubricates
Term
plateau phase
Definition
clitoris is partiall hidden by swelling labia, areolae continue swelling, outer third of vagina engorges
Term
orgasm
Definition
men ejaculate and women have analogous contractions of uterus and vagina
Term
resolution phase
Definition
body returns to preexcitation conditions, men enter refractory period
Term
seroli cells
Definition
contain receptors for FSH, which stimulates spermatogenesis
Term
Leydig cells
Definition
contain LH receptors which stimulates secretion of testerone
Term
negative feedback and inhibin
Definition
control of LH and FSH secretion
Term
aromatase
Definition
converts testerone to estradiol
Term
estradiol
Definition
mediates negative feedback effects of Testerone
Term
testerone
Definition
secretion declines gradually in aging even though levels of GnRH, LH, FSH are elevated
Term
leydig cells
Definition
testerone secreted by these cells stimulate spermatogenesis, may also secrete ACTH, MSH, and B-endorphin
Term
inhibin
Definition
secretion from tubules may affect sensitivity of leydig cells to LH stimulation
Term
spermatogonia (stem cells)
Definition
germ cells that migrate from yolk sac during development become, replicate selves throughout life by mitosis
Term
meiosis
Definition
spermatogonia give rise to haploid sperm by
Term
spermatogenesis
Definition
occurs in the wall of seminiferous tubules
Term
spermatogonia and primary spermatocytes
Definition
are located in outer part of ST
Term
Sprmatids and mature spermatozoa
Definition
located toward lumen, tails in lumen
Term
spermiogenesis
Definition
maturation of spermatids into spermatozoa, requires participitation of sertoli cells, moset of their cytoplasm is pinched off and ingested by surrounding cytoplasm of sertoli cells
Term
protamines
Definition
during spermiogenesis, these replace the DNA associated histones, cause extreme compaction
Term
acrosome
Definition
cap of digestive enzymes
Term
blood-testes barrier
Definition
created by sertoli cells, prevent autoimmune destruction of developing sperm
Term
FAS ligand
Definition
sertoli secreted, triggers apoptosis of T lymphocytes
Term
androgen binding protein ABP
Definition
secreted by sertoli cells into lumen of seminiferous tubules, binds testerone and concentrateds it in tubules
Term
FSH
Definition
stimulates spermiogenesis through its receptors on sertolis
Term
Sertolis
Definition
provide negative feedback on FSH via production of inhibin
Term
early prophase 1
Definition
formation of primary spermatocytes and entry into this begin during embryonic development and is then arrested until puberty
Term
FSH
Definition
is not essential for spermatogenesis, enhances testosterone stimulated spermatogenesis and at puberty acts with testerone to stimulate proliferation of sertolis
Term
rete testis
Definition
spermatozoa and fluids exit seminiferous Tubules via
Term
vas deferens
Definition
sperm and fluids pass through efferent ductules to epididymus, and leave thru
Term
epididymis
Definition
spermatozoa mature and become motile in
Term
prostatic fluid
Definition
neutralizes pH during ejaculation
Term
Vas deferens
Definition
carries sperm into pelvic cavity
Term
seminal vesicles
Definition
add fluid constituting 60% of ejaculate to that coming from epididymis, contains fructose
Term
vas deferens
Definition
becomes ejaculatory duct which merges with urethra in prostate
Term
semen
Definition
fluid becomes this when prostate secretions containing citric acid and coagulation proteins and Ca, coagulate seamen during ejaculation
Term
erection
Definition
controlled by hypothalamus and sacral cord, occurs as result of parasymp-induced blood flow into erectile tissues of penis
Term
NO
Definition
neurotransmitter for erection
Term
corpus cavernosum and spongiosum
Definition
erectile tissues include
Term
occluded
Definition
venous outflow is partially, aiding erection
Term
emission
Definition
movement of semen into urethra
Term
ejalation
Definition
is forcible expulsion of semen from urethra out of penis
Term
sympathetic activity
Definition
stimulates emission and ejaculation, also causes peristalsis of tubular system, contractions of seminal vesicles, prostate and muscles at base of penis
Term
oligospermia
Definition
sperm count of less than 20 million/ml, associated with decreased fertility, caused by heat, lead, or arsenic poisoning and drugs
Term
gossypol
Definition
interferes with sperm development but also has side effects
Term
gonadotropin secretion
Definition
male contraception efforts have targeted, but limited usefulness due to side effects
Term
vasectomy
Definition
one of the most widely used methods, each vas deferens is cut and tied, 70% develop antisperm antibodies
Term
fimbriae
Definition
extensions of fallopian tubes that partially cover each ovary
Term
perimetrium
Definition
outer layer of connective tissue in uterus
Term
myometrium
Definition
middle layer of smooth muscle in the uterus
Term
endometrium
Definition
hormonally-responsive inner epithelial layer that is shed during menstruation in uterus
Term
1* oogonia
Definition
toward the end of gestation, oogonia begin meiosis but arrest in prophase 1
Term
primary follicles
Definition
primary oocytes are contained in
Term
granulosa cells
Definition
in response to FSH some follicles enter ovarian cycle and grow, producing layers of
Term
secondary follicles
Definition
some primary follicles continue, developing vesicles and becoming
Term
graafian follicle
Definition
one follicle continues growth, vesicles fuse forming fluid -filled cavity called an antrum and is now called
Term
meiosis 1
Definition
as graafian follicle develops, primary oocyte completes
Term
polar body
Definition
other daughter becomes a small, which will degenerate
Term
secondary oocyte
Definition
arrests at metaphase II
Term
granulosa cells
Definition
form layer around outside of follicle
Term
cumulus oophorus
Definition
oocyte sits on mound in this layer called
Term
corona radiata
Definition
secondary oocyte is enclosed by ring of granulosa cells called
Term
zona pelucida
Definition
between oocyte and radiata is gelatinous layer called, forms barrier to sperm penetration
Term
atretic follicles
Definition
the follicles that that do not suvive and degenerate are known as
Term
corpus luteum
Definition
LH causes empty follicle to become, secretes progesterone and estrogen
Term
corpus albicans
Definition
if there is no fertilization, corpus luteum becomes
Term
estrous cycles
Definition
no shedding of endometium and receptivity is limited
Term
folicular phase
Definition
Day 1 thu ovulation
Term
luteal phase
Definition
time from ovulation to menstruation
Term
FSH
Definition
follicular growth and estogen secretion are dependet on from Ant Pit
Term
granulosa cells
Definition
FSH and Estrogen induce formation of FSH receptors on, causing follicles to become increasingly sensitive to same level of FSH
Term
graafian follicle
Definition
FSH and Estrogen recruit LH receptors in
Term
GnRH
Definition
rapidly rising estroge causes hypothalamus to increase pulses of
Term
LH secreation
Definition
rapidly rising estrogen causes ANT PIT sensitivity to GnRH to increa resulting in greater
Term
LH surge
Definition
cause by a positive feedback between Estrogen and Ant Pit, peaks 16 hours before ovulation
Term
high progesterone and estrogen
Definition
exert strong negative feedback on LH and FSH
Term
inhibin
Definition
from corpus luteum further suppresses FSH
Term
estrogen and progesterone levels decline
Definition
causes menstruation and allowing new cycle of follicle development
Term
proliferative phase
Definition
occurs during follicular phase, estrogen levels increase and stimulates growth of endometrial lining, spiral arteries develop, eestrogen causes cervical mucus to become thin and water to allow sperm penetration
Term
secretory phase
Definition
occurs during luteal phase, endometrium becomes ready for implantation
Term
progesterone
Definition
stimulates development of uterine glands
Term
progesterone and estrogen
Definition
cause endometrium to become thick, vascular, and spongy
Term
progesterone
Definition
causes cervical mucus to thicken and become sticky
Term
menstrual phase
Definition
results from drop in progesterone and estrogen, following corpus luteum degeneration
Term
low progesterone
Definition
causes constriction of spiral arteries, blood flow stops causing necrosis and sloughing of endometrium
Term
dormitory effect
Definition
release of GNRH is regulated by hormonal feedback and higher brain centers, the mechanism by which the olfactory senses pheromones and causes cycles of roomates to synchronize
Term
functional amenorrhea
Definition
cessation of menstruaton when limbic system signals stress to hypothalamus, or thin, atheletic females, may be related to reduced leptin
Term
oral contraceptive
Definition
usually contain estrogen and progesterone and mimic the corpus luteum
Term
rhythm method
Definition
involves daily measurement of oral basal body temperature upon awakening because declining estrogen in day of LH surge drops BT and rising progesterone on the day after the LH surge causes an elevated BT
Term
menopause
Definition
no estrogen from follicles, LH and FSH are high because of no negative feedback, lack of estrogen causes heat flashes, osteoporosis, and increased risk of atherosclerosis
Term
blastocyst
Definition
once fertilization occurs, secondary oocyte completes meiosis and then undergos mitosis resulting in a structure called
Term
HCG
Definition
secreted by cells of blastocyst to maintain corpus luteum of mother and prevents menstruation
Term
oxytocin
Definition
birth is dependent upon strong contractions of the uterus stimulated by
Term
capacitation
Definition
sperm passage thru the female reproductive tract only 10% gain ability to fertilize an oocyte, this ability is called, must be in female tract for 7 hours
Term
chemotaxis and thermotaxis
Definition
sperm is guided to the fallopian tube by
Term
fallopian tubes
Definition
fertilization occurs in the
Term
acrosome
Definition
enzyme filled vesicle above the sperms nucleus, meets the zona pellucida and causes a reaction
Term
zygote
Definition
the fertilized single cell with 23 pairs of chromosomes is called a
Term
cleavage
Definition
the diploid zygote undergos several mitotic divisions called
Term
morula
Definition
ball of cells
Term
blastocyst
Definition
hollow ball of cells
Term
trophoblast cells
Definition
cells of the blastocyst that secreats HCG which functiona like LH and maintins the corpus leutium
Term
placenta
Definition
formed from the trophoblast cells of the fetus and the adjacent maternal tissue in the endometrium
Term
umbilical cord
Definition
contains the fetus's blood and carries it to and from the fetus and the placenta
Term
hCS (chorionic somatomammotropin)
Definition
secreted by placenta, similar to prolactin and GH in its actions
Term
estriol
Definition
the major steroid secreted from the placenta
Term
prostaglandins
Definition
secreted by uterus and stimulates labor
Term
androgens
Definition
primarily DHEAS secreted by fetal adrenal cortex are converted into estrogen by the placenta
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