Test 4: lecture 2 and 3: female Flashcards
where do oocytes develop?
in the cortex of the ovary
ovaries in horse vs human
cortex and medulla switched
in horses cortex on the inside with a ovarian fossa where oocyte is released
what are the major function of the ovaries
endocrine → hormone production
exocrine → gametes
three parts of the uterine tube
Infundibulum and fimbriae - lots of fold to draw in oocyte- beating cilia
Ampulla - fertilization happens here
Isthmus- movement up or down, sperm storage
duplex uterus
uterus bipartius
uterus bicornis
uterus simplex
functions of the uterus
house fetus
makes prostaglandin which signals to the CL
immune defense
maternal recognition of pregnancy
layers of the uterus
Perimetrium
Myometrium
Endometrium
effects of estrogen on the uterus
uterine edema
promotes development of endometrium glands
effects of progesterone on the uterus
(when uterus is quiet)
immune suppression- prevent fetus from being attacked
inhibit myometrium
what hormone during diestrus and pregnancy keeps the cervix closed?
progesterone
during estrus and parturition what hormone keeps the cervix relaxed and open?
estrogen
prostaglandin E2- more for parturition
what passes through the cervix
semen
not urine
babies
semelparous animals?
animal that will die after mating
iteroparous
animals that can reproduce multiple times throughout life
oogenesis
mitosis during fetal development → arrest at prophase 1 until puberty
then continues and goes through meiosis 1 → arrests at (metaphase 2) meiosis II until fertilized then continues to one egg and two polar bodies
ovarian cycle of follicle
primordal follicle
primary
secondary
graafian (tertiary)
ovulation of the oocyte
corpus luteum
corpus albican
primordial follicle
Simple squamous follicle cell layer surrounds a primary oocyte
- Oocytes are arrested in prophase I
- The majority of oocytes are in this stage
primary follicle
Follicle cells become cuboidal and proliferate ( membrana granulosa→ granulosa cells)
- Theca folliculi forms - from stroma cells
- Zona pellucida forms
(oocyte → arrested at prophase 1)
secondary follicle
Follicular growth in response to FSH
- Multiple layers of granulosa cells
- Antrum becomes apparent
- Theca cells further differentiate
- Theca interna : vascular; hormone secretion
• Theca externa:connective tissue
graafian follicle
Dominant follicle is selected/atresia of others → only one egg will survive others will regress
- Increased FSH receptors on granulosa cells
- Meiosis I is completed
cumulus oophorus and corona radiata
how does LH work in female cycle
binds to theca cell → androstenedione (androgens)
androstenedione will move to granulosa cell
FSH binds to granulosa cells and will change androgens into estradiol(estrogen)
later in development what cells develop LH receptors
granulosa cells
after ovulation theca and granulosa cells will leutenize (will start to produce progesterone)
what happens during ovulation
surge in LH → starts ovulation, oocyte enters metaphase II
follicular cells (theca and granulosa cells) → luteal cells
corpus hemorrhagisum (CH) and then corpus luteum(CL)
CL cells produce progesterone
corpus luteum produce
progesterone
CL turns into
corpus albicans (drop in progesterone)
will regress if no fertilization
The presence of a ___prolongs the life of the CL
(maternal recognition of pregnancy)
conceptus → fetus
around day 14, there is no fertilization so the CL → albicans this will decrease amount of progesterone and cause the uterus to increase the amount of PGF2
ruminants have their artery and vein right next to each other, PGF2 will be transferred to artery and back to uterus
oocyte vs follicular development
induced ovulators
cats
won’t have luteal phase unless they have been breed → will stay in follicular phase
during early to mid follicular phase negative feedback by ___
during late follicular phase + feedback by ___
negative feedback during luteal phase
in female reproductive cycle surge in LH causes ___
ovulation
decrease in estrogen
increase in progesterone
what triggers the drop in progesterone?
increase in PGF2 alpha
estrous cycle vs menstrual cycle
Estrous cycle: endometrium is reabsorbed if fertilization does not occur
Menstrual cycle: endometrium is shed if fertilization does not occur (after luteal phase)
bleeding during menstrual vs estrous cycle
menstrual → after luteal phase → not fertile
estrous → in heat → before and during fertile → edema will cause blood leakage
Monoestrous • Polyestrous • Seasonally polyestrous • Induced ovulators
cycle once a year
throughout the year (humans)
depends on the season (horse)
copulation induces cycle (cat)
stages of estrous cycle
Proestrus
Estrus
Metestrus
Diestrus
Anestrus
proestrus
first stage of estrous cycle
Occurs during early follicular phase
Estrogen levels rising; progesterone declines
estrus
Sexually receptive “in heat”
- Occurs during late follicular phase
- Estrogen levels high
- Changes observed in the uterus, cervix, and vulva
Metestrus
- Immediately post ovulation
- Estrogen declining; progesterone rising → will tighten uterus
Diestrus
- Not sexually receptive
- Occurs during the luteal phase
- Changes observed in uterus, cervix, vulva
progesterone rising → will tighten uterus
Anestrus
- Occurs in seasonal breeders
- Can occur during lactation
- Complete shutdown of reproductive system
how does light effect reproduction
Light triggers affects seasonality in some animals
- Darkness stimulates the production of melatonin
- Melatonin alters the rate of GnRH pulses
bruce effect
CL formation can be delayed in the presence of pheromones (males)
how to hasten ovulation
Human chorionic gonadotropin (hCG)
• Mimics LH
• Induces ovulation in mares
GnRH agonists
• Deslorelin acetate IM
how to shorten diestrus
push CL → CA
need CL to produce progesterone to keep pregnancy
prostaglandin (PGF2 alpha) will terminate the pregnancy
superovulation
acts on FSH receptors → leads to more follicles developing
Pregnant mare serum gonadotropin/equine chorionic gonadotropin
