Follicular (Chapter 9) Flashcards
(23 cards)
What is the term used to describe CL formation?
Luteinization
What structure is present during metestrus?
Corpus Hemoragicum
What is the term used to describe the destruction of the CL?
Luteolysis
Which cells become the small luteal cells and what do they produce?
Thecal cells
Small amounts of progesterone
The granulosa cells will turn into what type of cells in the Corpus Luteum and what will they produce?
Large luteal cells
Large amounts of progesterone
Why is there a loss of color of the CL during luteolysis?
Because of the lack of blood flow
What are unique about a horses oocytes and what needs to be done to see them?
They are located in the middle of the ovary
Need to use ultrasound to see them, as opposed to palpating like other animals
The corpus luteum secretes what hormone and has a negative feed back on what three function?
Progesterone
Surge center (LH)
Hypothalamus (GnRH)
Myometrium (muscle contraction)
The corpus luteum has a positive feedback on what two functions?
Alveolus (mammary gland growth)
Endometrium (stimulate secretions)
What is the first step in creating progesterone?
Bringing cholesterol into the cell
Where is the LH receptor located, why, and what does it activate?
Plasma membrane
LH is lipophobic
Secondary messenger
What molecule brings cholesterol into the mitochondria and what is the significance of this?
STARP?
It is the rate limiting step
What precursor of progesterone is created in the mitochondria and what happens after it is made?
Pregnenolone
It is kicked out of the mitochondria to become progesterone
Why does the CL stay around for so long when the uterus is removed?
No production of PGF2-Alpha
(T/F) The uterus is not required for cyclicity
False, it is required for the production of prostaglandin
What does the term ipsilateral refer to?
It means the uterine horn that is on the same side as the CL
How does prostaglandin get to the ovary?
It is transported into the veins, then jumps into the artery that goes to the ovary
It takes how many pulses of what hormone in how many hours to achieve luteolysis?
5 pulses of prostaglandin in 25 hours
How does prostaglandin work on the cells?
It binds to its receptor (on luteal cell)
Opens calcium channels to cause apoptosis
Activates protein kinase that shuts down conversion of cholesterol to progesterone via vasoconstriction
What structure produces prostaglandin in humans/primates, what mode of action is this and what hormone regulates this?
Ovaries (paracrine)
Oxytocin (posterior pituitary)
What hormone does CIDR mimic?
Progesterone
Why does shots of prostaglandin have no effect on cows within the first 0-6 days?
The receptors on the CL are not functioning yet
In what species is it impractical to give prostaglandin shots and why?
Pigs because we are only saving 5 or 6 days, which is not worth the price of the shot
