Flashcards in Endocrinology Deck (14):
Give an example of a polypeptide hormone?
What is congenital adrenal hyperplasia?
Women genetically xx
Loss of 21- hydoxylyase
Deficiency leads to adrenal glands producing abnormally high levels of testosterone
Triggers masculinisation of genetically female fetus
In the male LH acts on what? To do what?
In the male FSH acts on what? To do what?
What's the difference between a genotype and phenotype?
Genotype is the genes you have
Phenotype is the characteristics you express
What are the steps of implantation of the blastocyst into the endometrium?
ZP and mucins prevent invasion in wrong location
When in uterus ZP sheds
L-selectin on trophoblast binds to endometrium and rolls
LIF- tells trophoblast to slit into syncytiotrophoblast and to secrete hCG
EGF- correctly aligns blastocyst
Intigrin up regulated on blastocyst so binds to endometrium
Local signalling events break intracellular junctions and syncytiotrophoblasts release lytic enzymes
Give an example of a steroid hormone?
Give an example of an amine hormone
What's the difference between a steroid hormone and a polypeptide hormone?
Polypeptides travel freely in the blood and are stored in secretary vesicles
Steroids are synthesised upon stimulation, diffuse across plasma membrane, they are not very soluble so they travel bound to plasma proteins
Why does receptor desensitisation occur?
Because of prolonged exposure to a signal
What causes the production of male characteristics in a fetus?
SRY gene on the Y chromosome instruct developing gonads to become testes without it ovaries are formed
The drugs danazol and clomiphene cyclofenil do what?
Prevent oestrogens inhibitory effect on anterior pituitary
It prevents normal modulation by negative feedback
Increased secretion of GnRH
What are the stages of follicular development?
Early tertiary follicle (1st meiotic division completed)
Graafian follicle (beginning of 2nd meiotic division)