Lecture 10 Flashcards
Professor Roger Short definition to describe interactions between the conceptus and mother to establish and maintain pregnancy
Conceptus must signal its presence to the mother and prevent the withdrawal of progestagenic support that would normally occur with luteolysis
Source of signals from the conceptus
Synthesised and secreted by trophoblast
Timing of signals from the conceptus
Failure to secrete signal at right time or in correct amount is probably the main reason for loss of pregnancy
What are human chorionic gonadotrophin produced by
Syncytiotrophoblasts of implanting blastocyst from 6-8 days after fertilisation
Where does human chorionic gonadotrophin pass through and bind to
Maternal blood to the corpus luteum and binds to LH receptors
What secretes Interferon-tau
Cytrotrophoblast
What does Interferon-tau inhibit
expression of oxytocin receptors
Where does the first secretion of oestrogen’s act
Endometrium to induce secretion of various growth factors
What does the second secretion of oestrogens cause
PGF2a to be secreted into uterine horn
What is a unique feature in horse pregnancy
- Conceptus must migrate throughout the uterus
- Conceptus remains spherical
- Migration inhibits PGF2a secretion
What is relaxin produced by
Corpus luteum in the later part of pregnancy in a number of species
What is prolactin produced by
Placenta and decidua
List the Epitheliochorial placenta
- Diffuse
2. Cotyledonary
List the Endotheliochorial placenta
- Zonary
List the Hemochorial placenta
- Discoid
What do primates secrete to keep the pregnancy
Chorionic gonadotrophin (CG) - luteotrophin
What do ruminants secrete to keep the pregnancy
Interferon-tau - anti-luteolytic protein
What do pigs, horses secrete to keep the pregnancy
Anti-luteolytic agents
What do mice secrete to keep the pregnancy
Prolactin until day 10 then lactogens from the placenta
What is interferon-tau secreted by from day 10-20
Cytotrophoblast
What does interferon tau inhibit
Oxytocin receptors
Which secretion is important to prevent the break down of the corpus luteum in horses
The second secretion of oestrogens
