Reproduction 4&5 Flashcards
What does MRP stand for?
Maternal recognition of pregnancy
What is the attachment period of dogs
3 weeks
WHen are most embryos lost?
Hatching or attachment
The endoderm becomes which features?
Digestive
Lungs
Endocrine
Mesoderm becomes what tissues?
Muscles
Skeletal tissue
Cardiac
Reproductive
Ectoderm becomes which tissues?
Nervous
skin
Hair
When do extraembryonic membranes begin forming?
Before attachment
What is the allantochorion? What does it do?
Foetal contribution to placenta
Provide attachment for endometrium
What is the difference between primate and non-primate placenta attach/?
Non-primate: longer, more layers between foetal and maternal blood
What does the placenta do? what glands does it contain? What do these do?
Allow metabolic exchange between mother and foetus
Transitional endocrine glands
Stimulate mammary tissue, foetal growth and hormones to maintain pregnancy
What are the 2 types of placenta? Which animals are they found in?
Contyledonary - ruminants
Diffuse - horse/pig
What type of structure if the contyledonary placenta?
Button like
What kind of placenta is the diffuse placenta?
Attachments all over
Microvilli
What blood vessels are found in the umbilicus cord? What else is found here?
Two arteries
One vein
Urachus
What is the urachus?
Part of the allantois
Drains urine from foetus
Early embryos have bipotential for gender. Which protein causes the Y chromosome? Do females have this?
SKY protein
No - males only
In the male embryo, leydig cells produce what? What does this do?
Testosterone
Stimulate development of male duct
At what stage of the pregnancy do female embryos have their complete tract?
1st trimester
What is a freemartin in cattle?
Twins with 1 girl and 1 boy
Sharing placenta/blood supply
Testosterone enters female and causes sterility
What does the hormone prostaglandin do? What affect does it have during early pregnancy? What about late pregnancy?
Inhibits progesterone
Causes luteolysis - termination
End of pregnancy - induces labour
Describe stage 1 of parturition. Who initiates it?
Foetus - overcrowding —> corticoids.
Increases myometrial uterine contractions
Cervix softens and pelvic ligaments become more elastic/
which molecule makes the pelvic ligaments elastic and softens the cervix?
Elastin
What is stage 2 of parturition/
allantois ruptures in vagina Amnion may burst out of vulva or cover head of offspring High oxytocin prostaglandin levels Foetus expelled Ferguson reflex
Describe the Ferguson reflex in the 2nd stage of parturition
oxytocin increases uterine contractions when the foetus stretches the cervix
Causes prostaglandin release
What can be given as a drug to induce labour? Why?
Oxytocin
Causes prostaglandin release
What happens during stage 3 of parturition?
Myometrial contractions continue
High levels of oxytocin and prostaglandins
Oxytocin causes placenta release
what is uterine involution? In which animals is it a problem? How can it be reversed?
Diary cows
Uterus returns to pre pregnant state
Suckling reflex
How long is the bitch oestrus cycle/
150 days
How long is the beef oestrus cycle?
50-60 days
How long is the dairy oestrus cycle?
18-25 days
Describe the stage of egg growth
Germ cell cyst Primordial oocyte Primary oocyte Secondary oocyte Antral Preovulatory Ovulation Corpus luteum
During what stages of egg growth is GnRH required?
Germ cell cyst— secondary oocyte = GnRH independent
Antral - corpus luteum = GnRH dependent
What is the order of female puberty?
First oestrus
First ovulation
Age when can first support a successful pregnancy
