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the uterine tubes are divided into what structural parts:
- 1.infundibulum: surrounds the ovary with fimbriae. Efficient way to receive ova from ovary.
- 2. ampulla: The middle, longest part of the tube. Usual location of fertilization.
- 3. isthmus: Portion of tube that opens into uterus.
Vulva refers to what structures:
- The female external genitalia:
- the mons pubis
- labia majora
- labia minora
- vestibule of the vagina
- vestibular glands
function of mature gonads:
- producing gametes (gametogenesis)
- - spermatozoa (sperm) in male
- -ova (eggs) in female
what are the sex hormones?
- testosterone in males
- estrogen and progesterone in females
- primary female reproductive organs
- produce ova (oogenesis)
- secrete female sex hormones (estrogen & progesterone)
- Essential for ova maturation and release
- Establishment of female secondary sexual characteristics
- Essential for transport of sperm from vagina to fertilization site in oviduct
- Contributes to breast development in anticipation of lactation
- Important in preparing suitable environment for nourishing a developing embryo/fetus
- Contributes to breasts’ ability to produce milk
- Undifferentiated primordial germ cells in fetal ovaries (precursor cells)
- Divide mitotically to give rise to 6 million to 7 million oogonia by fifth-7 month of gestation
- During last part of fetal life begin early steps of first meiotic division but do not complete it until puberty
oogonia remain in meitotic arrest for years until:
they are prepared for ovulation
germ cells undergo:
One chromosome replication followed by two nuclear divisions
the primary oocytes are surrounded by:
a single layer of granulosa cells
oocyte + granulosa =
what are the 2 possible fates for the primary follicle
- reach maturity and ovulate
- degenerate to form scar tissue (atresia)
between puberty and menopause, follicles develop into :
secondary (antral) follicles on cyclic basis
all the eggs present at birth are:
containing ____ chromosomes
- primary oocytes
- 46 chromosomes, each with 2 sister chromatids
what unites with haploid sperm cell during fertilization?
mature haploid ovum
when does the second meitotic division occur?
occurs in a fallopian tube after ovulation, but only after the secondary oocyte is fertilized
after the second meitotic division, what do the daughter cells receive?
- 23 chromosomes, each with a single chromatid
- only ONE daughter cell, the ovum, will receive nearly all the cytoplasm
what is the net result of oogenesis?
each primary oocyte can produce only one ovum
follicles begin as:
Primordial follicles, which consist of one primary oocyte surrounded by a single layer of cells called granulosa cells
Further development from the primordial follicle stage is characterized by:
- an increase in the size of the oocyte
- a proliferation of the granulosa cells into multiple layers
- separation of the oocyte from the inner granulosa cells by a thick layer of material, the zona pellucida
what do the granulosa cells secrete?
estrogen, small amounts of progesterone just before ovulation, and the peptide hormone inhibin.(inhibits FSH)
as the follicle grows by mitosis of granulosa cells, connective tissue cells surrounding the granulosa cells:
- differentiate and form layers, called theca
- the theca plays an imp role in estrogen secretion by the granulosa cells
what begins to form in the midst of the granulosa cells?
the fluid-filled space called the antrum
Granulosa cells differentiate into cells called:
this is imp in:
- during which a single mature follicle and secondary oocyte develop
- Where follicles are growing
beginning after ovulation and lasting until the death of the corpus luteum
The SRY gene "masculinizes" the gonads by coding for production of:
TDF (testes determining factor) aka SRY protein
differences btwn XX and XY exist at 3 levels:
- genetic- depends on combination of sex chromosomes at time of conception
- ----this determines gonadal differentation
- gonadal- whether testes or ovaries develop, presence or absence of Y chromosome determines gonadal differentiation
- ---- gonadal determines phenotype
- phenotypic sex- apparent anatomic sex of individual, determined by gonadal sex
sexes can easily be determined by how many weeks gestation?
differentiation into a male-type reproductive system is induced by:
- -testosterone is the most potent androgen
what are the two primitive duct systems that develop in all embryos?
- Wolffian ducts-XY
- Mullerian ducts-XX
what leads to the dev of Mullerian ducts into female reproductive tract?
and the dev of undifferentiated externl genitalia along female lines?
- female repro tract: absence of Mullerian-inhibiting factor
- dev of ext genitalia: absence of testosterone
what leads to the dev of Wolffian ducts into male repro tract?
and dev of undifferentiated ext genitalia along make lines?
- wolffian ducts: Mullerian inhibiting factor
- ext genitalia: testosterone converted to dihdrotestosterone
Granulosa cells secrete a thick, gel-like "rind" that covers the oocyte & separate it from the surrounding granulosa cells. This intervening membrane is called:
function of the corpus luteum:
- to secrete into the blood abundant quantities of progesterone and smaller amounts of estrogen
- also secretes inhibin
what is the corpus albicans?
- "white body"
- if the secondary oocyte is not fertilized, the corpus luteum will degenerate and die. The vascular upply will be withdrawn, and connective tissue rapidly fills in to form a fibrous tissue mass-aka the corpus albicans
purpose of the corpus luteum in pregnancy:
if fertilization does occur, the corpus luteum provides the hormones essential for maintaining pregnancy until the developing placenta can take over the function
what triggers the LH surge?
- triggered by a positive feedback effect
- Rising moderate levels of estrogen early in the follicular phase inhibit LH secretion
- High level of estrogen that occurs during peak estrogen secretion late in follicular phase STIMULATE LH secretion & initiates the LH surge
further development from the primordial follicle stage is characterized by:
- an increase in the size of the oocyte
- a proliferation of the granulosa cells into multiple layers
- separation of the oocyte from the inner granulosa cells by a thick layer of material, the zona pellucida.
Despite the presence of a zona pellucida, the inner layer of granulosa cells remains closely associated with the oocyte by means of
- cytoplasmic processes that traverse the zona pellucida and form gap junctions with the
Asthe follicle grows by mitosis of granulosa cells, connective tissue cells surrounding the granulosa cells differentiate and form layers known as
the theca, which play an important role in estrogen secretion by the granulosa cells.
what happens after the primary oocyte reaches full size?
A fluid-filled space, the antrum, begins to form in the midst of the granulosa cells as a result of fluid they secrete.
- LH--> thecal cells
- FSH --> granulosa cells
the thecal cells convert cholesterol into:
the granulosa cells convert andogen into:
- cholesterol into androgen
- androgen into estrogen
where does the estrogen go?
- secreted into the blood where it exerts effects throughout body
- remains in the follicle and contributes to antral formation
estrogen comes from the thecal cells and the granulosa cells
As the dominant follicle enlarges, mainly as a result of its expanding antrum (increase in fluid), the granulosa cell layers surrounding the egg form:
a mound that projects into the antrum and is termed the cumulus oophorous
Ovulation occurs when the thin walls of the follicle and ovary at the site where they are joined rupture because of
The secondary oocyte, surrounded by its tightly adhering zona pellucida and granulosa cells, as well as the cumulus, is carried out of the ovary and onto the ovarian surface by
the antral fluid
- Operates during first half of cycle
- Granulosa cells of some primary follicles proliferate
- Oocyte inside each follicle enlarges
- Theca cells in follicle secrete increased amounts of estrogen
- Rapid follicular growth continues during follicular phase
- ....One follicle usually grows more rapidly and matures about 14 days after onset of follicular development
- .......Follicle ruptures to release oocyte from ovary
- .......Event is called ovulation
- .......Released oocyte enters oviduct where it may or may not be fertilized
- Last 14 days of ovarian cycle
- Old follicular cells undergo structural transformation to form corpus luteum
- Becomes highly vascularized
- Becomes fully functional within four days after ovulation
- Continues to increase in size for another four or five days
- If released ovum is not fertilized and does not implant, corpus luteum degenerates within about 14 days after its formation
- ....Estrogen and LH decrease
During follicular phase, rise in FSH signals ovarian follicle to
secrete more estrogen
menopause occurs btwn the ages of
period of transition is called:
climacteric or peri-menopause
the menstrual phase is characterized by:
first day of menstruation is considered:
- Characterized by discharge of blood and endometrial debris from vagina
- First day of menstruation is considered start of new cycle
- Coincides with end of ovarian luteal phase and onset of follicular phase
release of uterine prostaglandin causes:
- Causes vasoconstriction of endometrial vessels
- ---Disrupts blood supply
- ---Causes death of endometrium
- Stimulates mild rhythmic contractions of uterine myometrium
- ---Help expel blood and endometrial debris from uterine cavity out through vagina (menstrual flow)
Proliferative phase begins concurrently with the last portion of:
- the ovarian follicular phase
- ---Endometrium starts to repair itself and proliferate under influence of estrogen from newly growing follicles
- Estrogen-dominant proliferative phase lasts from end of menstruation to ovulation
- Peak estrogen levels trigger LH surge responsible for ovulation
the secretory of progestational phase:
- Uterus enters this phase after ovulation when new corpus luteum is formed
- Corpus luteum secretes large amounts of progesterone and estrogen
- -----Converts endometrium to highly vascularized, glycogen-filled tissue
- Endometrial glands actively secrete glycogen
- If fertilization and implantation do not occur
- ---Corpus luteum degenerates
- ---New follicular phase and menstrual phase begin once again
site of fertilization:
must occur within:
sperm can survive for:
sperm deposited in vagina travel thru:
- normally occurs in upper third of oviduct (ampulla)
- 24 hrs
- 48 hrs, up to 5 days in female reproductive tract
- cervical canal, uterus, and to upper third of oviduct
how does the Female reproductive tract aids in sperm migration?
- Contractions of myometrium
- Upward contractions of oviduct smooth muscle
- Allurin released by mature eggs attracts the sperm
Within hour, sperm and egg nuclei fuse
Fertilized ovum now called a:
Fertilized ovum divides mitotically
Within week grows and differentiates into:
blastocyst capable of implantation
Blastocyst(ball of cells) implants in endometrial lining by means of:
- enzymes released by trophoblasts (outer membrane of blastocyst)
- enzymes digest the endometrial tissue; carving hole for implantation of blastocyst
First few days of fert, zygotes divived to form the morula. After 3-4 days, morula is propelled to the uterus, where it cont to divide.
Two main phases:
cellular multiplication and implantation
placenta develops after implantation.
what is the placenta and what does it do?
whe can HCG be detected?
- Organ of exchange between maternal and fetal blood
- Acts as transient, complex endocrine organ that secretes essential pregnancy hormones
- –Human chorionic gonadotropin (placental hormone) (detects 9 days after implantation)
- »Maintains corpus luteum until placenta takes over function in last two trimesters
- –Estrogen & Progesterone
- »Essential for maintaining normal pregnancy
what develops into the fetal portion of the placenta?
physical changes c/in mother to meet demands of pregnancy:
- Uterine enlargement
- Breasts enlarge and develop ability to produce milk
- Volume of blood increases 30%
- Weight gain
- Respiratory activity increases by about 20%
- Urinary output increases
- Kidneys excrete additional wastes from fetus
- Nutritional requirements increase
- Labor, delivery, birth
- Dilation of cervical canal to accommodate passage of fetus from uterus through vagina and to the outside
- Contraction of uterine myometrium that are sufficiently strong to expel fetus
once contractions begin at labor onset, what progressively increases force?
Pressure of fetus against cervix reflexly increases:
role of oxytocin:
- Causes stronger contractions
- Positive-feedback cycle progressively increases until cervical dilation and delivery are complete
what are the stages of labor?
- 1. Cervical dilation
- --Longest stage
- --Lasts from several hours to as long as 24 hours in a first pregnancy
- 2. Delivery of baby
- --Begins when cervical dilation is complete
- --Usually lasts 30 to 90 minutes
- 3. Delivery of placenta
- --Second series of uterine contractions separates placenta
- --Shortest stage – usually completed within 15 to 30 minutes after baby is born
hw long does it take for uterus to shrink to pregestational size? (involution)
what promotes development of ducts and alveoli in mammary glands?
Elevated placental estrogen and progesterone
prolactin stimulates synthesis of:
what initiates lactation?
- Stimulates synthesis of enzymes essential for milk production by alveolar epithelial cells
- Withdrawal of placental steroids at parturition initiates lactation
lactation is sustained by:
which triggers release of:
- oxytocin and prolactin
Causes milk ejection by stimulating cells surrounding alveoli to squeeze secreted milk out through ducts
Stimulates secretion of more milk to replace milk ejected as baby nurses