Pregnancy Control and Maintenance Flashcards
Loss of sperm is due to…
Retrogade transport - cervix is a physical barrier, removes abnormal sperm
Mucus Types - sialomucin (low viscocity, helps) - sulfomucin (high viscocity washes out)
Phagocytosis - oestradiol gathers neutrophils in tract - engulf spermatozoa
How is diploidy achieved?
Single sperm needs to fuse with oocyte
Fusion releases phospholipase
Phospholipase releases inositol triphosphate and diacylglycerol
Inositol triphosphate - causes Ca Release
Diacylglycerol - protein kinase C stimulates phosphorylation of proteins
What is the role of calcium?
Release of cortical granules digest stuff in ZP site, prevents sperm fusion
Reactivates meiosis 2
Disorders of ploidy?
Anueploidy - many haploid chromosomes fused - form tumours, embryo loss
What is cleavage?
Rapid mitotic cell division no cell growth
What are the stages of cleavage?
A Zygote with 2 blastomeres
Morula - around 16-32 cells of blastomeres
Blastocyst - group which form an embryoblast at one pole and a blastocyst cavity with a trophoblast
What is gastrulation?
Formation of germ cell layers from cavity ectoderm, mesoderm, endoderm
What is a spontaneous ovulator?
regular frequency no copulation
What is an induced ovulator?
require stimulation of vagina to cause ovulation
What is the process of induced ovulation?
AP are passed through the CNS, innervate the hypothalumus, causes a surge of GnRh
What forms after the germ layers?
Three extra membranes - Amnion, chorion, allantois allowing for placentation to occur
What does antiluteotrophic mean?
prevents the effects of prostaglandin
What does luteotrophic mean?
enhances the survival of corpus luteum
Why are cats and dogs awkward?
As in dogs the CL is long lived and in cats its the same duration as pregnancy
Delayed implantation is caused by two things?
Faculative diapause - metabolic stress
Obligate diapause - environmental conditions
What is the placenta?
An organ from the conceptus to the dam
What does the placenta do?
Endocrine functions - takes over pregnacny maintenance and stimulates mammary glands
What is histiotrophic support?
Nutrition for the conceptus from secretions & breakdown of tissues,
What is haemotrophic support?
Prevents potential damage, highly vascularized, removes metabolic waste
How is a placenta classified?
By the arrangement of villi and the contact between the mother and the foetus
Diffuse placenta?
Is full and is in a horse and pig
Cotyledonary placenta?
Is in circular dots and is in a cow and sheep
Zonary placenta?
Fixed in one zone and is in a cat and dog
Discoidal placenta?
Placenta in a disc at the top in a human and mouse
