Repro Week 2 Flashcards
What are the conducing organs?
Uterine tube and uterus
What structures come from the paramesonephric duct?
uterine tube, uterus and vagina
What is different about the equine ovary?
It has an ovarian fossa, the only place for cortex and where the egg will always ovulate from
What is the purpose of the broad ligament?
Supports and suspends ovaries, oviduct, uterus, cervix and anterior vagina
What is the function of the mesosalpinx?
Supports the oviducts and serves as a bursa like pouch surrounding the ovary in some species
What are the 3 regions of the uterine tube?
Infundibulum, ampulla and isthmus
What is the utero-ovarian countercurrent system?
PGF2 alpha is secreted from the endometrium which passes into the ovarian vein
It diffuses back into the artery, maintains high concentrations of PGF2alpha to the ovary
Which species have a bicornuate uterus?
Mare, cow, bitch, queen and sow
What is the oestrogen influence on the caudal vagina?
Squamous epithelium thickens
Which hormone controls early follicular development?
FSH
What hormones to follicles secrete?
Oestrogen and inhibin- negative feedback on pituitary and suppress FSH
What change occurs when a dominant follicle is made?
Transition from FSH to LH dependence
What is the LH surge to ovulation interval of the cow?
24-30 hours
What is different about the bitches luteal development?
It occurs pre ovulatory so there is an earlier progesterone rise. There is hypertrophy and granulosa folds but no follicular collapse. central luteal cavity
What is the luteolytic hormone?
PGF2alpha
What is the structural mechanism for luteolysis?
Reduced blood flow, increase in macrophages and lymphocytes, apoptosis and tissue resorption
What does seasonal polyoestrus mean?
Multiple cycles during 1 season
What does lordosis mean?
Receptive to the male
What is occuring during pro-oestrus and oestrus?
Follicles are developing and the secrete increasing concentrations of oestradiol- leading to oestrus behaviour
What is occuring in metoestrus and dioestrus?
ovarian follicles have ovulated, producing a corpus luteum
CL secretes progesterone into blood, ending with luteolysis by PGF2alpha. During this time follicles develop but fail to ovulate
What is the effect of progesterone on a female?
Increased secretion by glands of uterine epithelium
Gland secretions contain nutrients for fertilised oocytes
Prepares uterus for zygote
Behaviour (rejection)
What is the oestrus length in the mare and when does ovulation occur?
6 days and last day of oestrus
What is the length of oestrus in the cow and when does ovulation occur?
8 hours, 12 hours after end of oestrus
What is the duration of oestrus in the bitch?
7-14 days
Why are mares a problems for getting pregnant?
Return to oestrus is variable and length of oestrus is variable, so hard to predict time of ovulation
What is the best way to detect oestrus in the bitch?
Vaginal cytology or plasma progesterone measurement
How might you detect oestrus in cows clinically?
Low plasma/milk progesterone
Detection of large follicle (absence of CL)- palpation of ultrasound
What are signs of oesrus in the sow?
Swollen vulva, congested prior to oestrus
Seeks boar
Stands to be mounted
Difference between induced and spontaneous ovulators?
Induced need copulation to result in neuro-endocrine response causing an LH surge and then ovulation, whereas spontaneous ovulation occurs at regular intervals and is hormonally induced
What is a silent oestrus?
Ovulation with limited signs of oestrus
What stimulates puberty?
Secretion of GnRH at appropriate frequency and quantity to stimulate gonadotropin release at anterior pituitary
What is the difference between pre puberty and post puberty hormones in the female?
In pre puberty, only tonic LH pulses occur as frequency of GnRH pulses is too low to produce a surge
Oestradiol levels are also low
What factors effect female puberty?
Season
Photoperiod at puberty
Presence or absence of opposite sex at puberty Density of same sex groups
Average age of puberty in the cow?
11 months (male and female)
What is the effect of melatonin in a long day breeder?
Represses reproduction
What is the natural breeding season of sheep?
October to february
What is the time for uterine involution in the bitch?
90 days
What is the hormone profile of an animal in anoestrus?
Low progesterone and low oestradiol
Where are the testis in birds?
Intraabdominal, cranioventral to first kidney lobe
What are the different stages of ovarian follicles?
Numerous small white, large number of small yellow, 10 yolky
What is lacking in avian eggs?
No zona pellucida, membrana granulosa or cumulus oophorus
What do granulosa cells produce in birds?
Progesterone
What is the open period?
Window of time for LH release, lasts 8-10 hours and starts at onset of darkness -> 1 hour after light onset
What leads to ovulation in birds?
High levels of progesterone during open period, LH surge
How long can sperm be stored in female birds?
10-14 days
Where are the gonads located in snakes?
Caudal to gall bladder
