Exam 1 Flashcards
the mentrual cycle consists of..:
The Ovarian Cycle 1. follicular phase 2. ovulation 3. luteal phase The Uterine Cycle 1. Menstrual Phase 2. Proliferative Phase 3. Secretory Phase
Follicular Phase
- (after menstruation) development of follicles within the ovary
- secretion of estradiol
ovulation
release of mature oocyte from the ovary
Luteal Phase
- formation of the corpus luteum
- secretion of estradiol & progesterone
Menstrual Phase
1-7 days, shedding of the uterine lining (endometrium)
Proliferative Phase
growth of new endometrium
secretory phase
thickening of endometrium and increased blood flow & uterine secretions
what causes perfectly timed regulation of menstrual cycle
positive feedback: more estrogen–more FSH & LH
negative feedback: more estrogen–less FSH & LH
hormone signaling of mental cycle
pituitary gland<===> ovaries
pituitary gland hormones
gonadotrophins (FSH & LH) steroid hormones (estrogen & progesterone)
hormone signaling during the follicular phase/proliferative phase
rising (low level) estrogen secreted from follicles leads to accumulation of LH & FSH (not released
during follicular phase/ proliferative phase
hormone signaling during ovulation
high estrogen—> GnRH—>FSH/LH Surge
hormone signaling if fertilization occurs
hCG from fetus/placenta prevents shedding of uterine lining/no disintegration of the corpus luteum
NO MORE period
hormone signaling if fertilization does not occur
progesterone inhibits FSH & LH—> corpus luteum disintegrates—> uterine lining is shed
PERIOD
How does birth control work?
most forms contain: estrogen & progesterone)
progesterone negative feedback
- -decreases GnRH
- -inhibits release of FSH & LH
- -(lack of LH) prevents ovulation
- -increased viscosity of cervical mucus–> reduces sperm motility
low estrogen levels
- -stabilizes endometrium
- -inhibits follicular development via decreased FSH release
how many eggs is a human female born with—>puberty?
1 million or so oocytes–>200,000 oocytes
how many oocytes develop during each month?
12 oocytes
Human Chorionic Gonadotrophin (hCG)
hormone made by the fetus and subsequently the placenta throughout the pregnancy
the vagina serves 3 purposes
- to transport sperm to the uterus & fallopian tubes
- to function as a birth canal through which a baby is delivered
- to allow menstrual secretions to be excreted from the body
ovaries
produce, store, and release eggs into the fallopian tubes
fibriae
when egg/ova is released from the ovary, the fibriaie sweep the ovum into the fallopian tube
oogenesis
process by which a primary egg cell becomes a mature ovum occurring in the outermost layers of the ovaries
before birth and at the time of birth, what phase are all eggs in
all future eggs are in t
oogenesis
process by which a primary egg cell becomes a mature ovum occurring in the outermost layers of the ovaries
diploid primary oocyte in primordial follicle–> diploid primary oocyte in secondary follicle–>in early tertiary follicle–> 1st meiotic division–> haploid secondary oocyte in mature tertiary follicle/1st polar body–> ovulation of haploid secondary oocyte–> mature haploid oocyte (ootid)
before birth and at the time of birth, what phase are all eggs in
primary oocyte begins 1st meiotic division but will be arrested/stopped in prophase where they will remain arrested until puberty/sexual adulthood
polar body
provides a means of reducing the genomic content of the oocyte during meiosis to the appropriate chromatid number
does not have the ability to be fertilized and eventually disintegrates and dies
corpus luteum
secretes estrogen and progesterone which thickens the endometrium in preparation for implantation
testes
male gonads
- produce male gametes (sperm)
- release testosterone
composed of numerous seminiferous tubules
duct system of male reproductive organs consists of
- epididymis
2. vas deferens
vas deferens
transports and stores mature sperm
epididymis
a set of coiled tubes (one of each testicle) that connects to the vas deferens
secretes important substances that help the sperm survive and store mature sperm
scrotum
hold the epididymis and the testes hang in pouch-like structure outside the pelvis
helps to regulate the temperature for hormones, sperm production/maintenance
accessory glands
seminal vesicles
prostate gland
provide fluids that lubricate the duct systems and nourish the sperm
spermatogenesis
process of a diploid spermatogonium transforming into 4 haploid spermatids
development of sperm cells within the testes
starts at puberty and is triggered by LH–>promotes production of testosterone in testes
Peptide/protein hormones
bind to extracellular receptors to regulate intracellular signals
FSH/LH
Steroid hormones
can pass through cell membranes and act on receptors inside cells
estrogen androgen
progesterone
hypothalamus
GnRH
–> Posterior/Anterior Pituitaries
anterior pituitary
LH/FSH
posterior pituitary
vasopressin
oxytocin
theca cells
produce androgens
granulosa cells
converts androgens into estrogen
luteal cells in corpus luteum
produce progesterone & estrogen
graafian follicle (tertiary follicle)
theca cell–androgen–granulosa cell–estrogen
luteal cell
progesterone & estrogen
sertoli cells
act as nurse cells providing the structural support for the sperm development
produces aromatase–>
testosterone can be converted to estradiol
FSH binds to Sertoli cells, functioning together with testosterone to maintain germ cells
also induces Scells to produces inhibin, ABP, aromatase
aromatase
converts adrogen —> estrogen
spermiogenesis
process of spermatids transformed into spermatozoa (sperm cells)
leydig cells
secrete testosterone in response to LH
spermatagonia
stem cells within the seminiferous tubules that are constantly producing immature sperm cells (spermatocytes)
seminiferous tubules
testes composed of seminiferous tubules where sperm cells are produced
one immature germ cell takes
74 days to reach final maturation
spern
usually consists of 2 morphologically and functionally distinct regions: head/tail
head region
comprised of nucleus/acrosome
acrosomal vesicle
anterior end of the nucleus is a specialized cap-like secretory vesicle
contains enzymes that help the sperm to penetrate the egg’s outer coat
neck
located at the junction of the sperm head and midpiece containing centriole housed in centrosome
centriole
provide the power for movement
basal bodies
specialized centrioles which work as tiny motors to create the bending motion of the flagellum
tail (sperm)
long flagellum whihc propels the sperm to the egg and helps it to burrow through the egg coat
mitochondria
placed in midpiece which provides energy reqyired for movement
mitosis
when a somatic (body) cell divides producing
2 identical copies of itself with 46 chromosomes
meiosis
begins in the primordial germ cells
when a sex cell divides producing 4 daugter cells: 4 sperm/1 oocyte (gametes)(diploid)
not identical, 23 chromosomes (haploid)
interphase
most of the life of a cell is spent in this phase–normal state until mitosis
3 stages of interphase
G1: first growth stage; cells grow to nearly its full size and forms many of its biochemical functions to keep the cell alive/active
S: synthesis; DNA in nucleus replicates–> 2 copies of DNA strand
G2: gap 2; more growth occurs
centrosomes
set of protein cylinders next to the nucleus
control the movement of the chromosomes during mitosis
4 distinct phases of Mitosis
- Prophase
- Metaphase
- Anaphase
- Telophase
metaphase
longest phase of mitosis–20 min
chromosomes attach to the microtubules at their centromeres =, line up along center of the cell
anaphase
chromosomes start to separate from their sister chromatids and dragged towards either side of cell
telophase
nuclear membrane forms around chromosomes, relax back into chromatin
crease forms at center
cytokinesis
as 2 nuclei move apart, the result is 2 genetically identical cells each with a full set of 46 chromosomes (daughter cells)
sister chromatid
duplicates of chromosomes attached at the centromere
homologous chromosomes
corresponding chromosomes with sister chromatids from the other parent
one from mom; one from dad
primordial germ cells
diploid stem cell population that specifically make germ cells
placenta
nutrient, respiratory, and excretory organ for the fetus
fetal in origin
what day does implantation occur?
day 7 after fertilization
hemochorial
maternal blood circulation is next to the fetal portion of the placenta but the blood circulations do not mix
trophoblasts
cells that form the
trophoblasts
cells that form the placenta
they invade the uterine
endometrium to form the nutrients/oxygen during implantation
differentiate and keep the fetal/maternal blood circulations separate in the placenta
also make hormones (hcg, progesterone, estrogen)
Shallow invasion
when trophoblasts cells do not penetrate deep into the mother’s uterus can lead to severe pregnancy complications
tissue layers/sections of placenta:
fetal: chorionic plate
- -fetus is connected via the umbilical cord to the chorionic plate
maternal: decidua basalis
- -anchored in the uterus and blood is supplied by the endometrial arteries/veins
spiral arteriole
primary blood vessel carrying maternal blood supply from the uterus into placenta and to fetal villous projections
maternal blood enters placenta through spiral arterioles which flows through the villous projections where oxygen/nutrients from mother are exchanged (via diffusion) for fetal waste
oxygen rich blood is
carried to the fetus through the umbilical cord vein
deoxygenated blood is
carried to the placenta and out through the uterus
Fetal Alcohol Syndrome
spectrum disorder: depends on the dose of alcohol the mother ingests during pregnancy
alcohol passes the placenta, which the fetus cannot metabolize
affects the baby’s spinal cord and brain
symptoms: abnormal facial features, lower behavioral/cognitive difficulties, stunted growth
CRS
- rubella virus crosses the placenta from infected mother to fetus
- virus crosses placenta and fetus lack immunity to fight it
- causes severe birth defects that cannot be cured
- symptoms: eye anomolies, microcephaly, heart disease, mental retardation, deafness, delayed development
what are the 4 regulatory hormones?
- Estrogen
- Follicle-Stimulating Hormone - (FSH)
- Luteinizing hormone (LH)
- Progesterone
oocyte
specialized haploid sex cell(gamete) which contains abundant nutrients, proteins, and will house half of the
Which chromosome is the SRY gene on?
Y
A tertiary/Graffian follicle has…?
theca cells, granulosa cells, sertoli cells
If the SRY gene is present, the _____ ducts will prevail and form the _____ gonads
wolffian; male (testis)
Sertoli cells convert ______ hormone to make _____ hormone?
Testosterone –>Estrogen
T/F? : Leydig cells located inside the seminiferous tubule?
False
The male reproductive system and sperm production are governed by ______ feedback?
negative feedback
Which of the following hormones are released from the brain and govern reproductive systems in males and females:
FSH
LH
GnRH
Protein hormones require a ______ to bind at the cell membrane in order to have an effect in the cell:
extracellular receptor
All sex steroid hormones can be made via degradative metabolism of which precursor:
cholesterol
In the female menstrual cycle, rising levels of estrogen induce an LH surge, causing ovulation. This is an example of ______ feedback
positive
Which part of the female reproductive system is responsible for “catching” the egg after it is ovulated from the ovary?
fimbriae
The secretory phase of the uterine cycle is predominantly governed by _____ hormone released by _____ structure?
progesterone; corpus luteum
Estrogen levels rise steadily prior to ovulation, they mature the oocyte and prepare the uterine endometrium. This estrogen is primarily secreted by the ______ cells of the ovarian follicle?
granulosa cells
The ovulated egg is a _______ oocyte that is arrested in meiosis II:
secondary oocyte
endometrium
mucosal lining; where implantation occurs
myometrium
muscle layer; accommodates the fetus during the pregnancy, then contacts to expel the fetus
what starts the growth of areolae and ducts outside of the gonads
estrogen
during embryo development the default reproductive system
female
testis makes which hormone
anti-mullerian hormone, testosteron adn dihydro-tesosterone
protein/peptide hormones
generally bind to extracellular portions of cell membrane receptor molecules and perturb the configuration of the molecule–> intracellular changes in the intracellular signaling
steroid hormones
generally pass thru the cell membrane and bind to receptors then move into the nucleus and regulate DNA transcription
central axis
hypothalamus and anterior pituitary gland is the sensor of gonadal activity and sends signals to regulate the level of gonadal function
GnRH
a peptide that triggers receptors on pituitary gonadotrophs to release the gonadotrophins
originate in the nasal epithelium
estradiol
from the gonads inhibits GnRH secretion by the adnohypophysis while inducing the expression of GnRh receptors by LH/FSH-secreting cells of the adenohypophysis
Negative Feedback and Positive Feedback ovarian/endometrial cycles
Some estrogen blocks the LH surge
More estrogen blocks the LH surge
More and more estrogen causes the LH surge
what hormones affect the breast during sexual response?
oxytocin/vasopressin
