T1 L1 pt 2 : Introduction to the Endocrine System Flashcards
what nuclei are oxytocin and ADH synthesised in the hypothalamus (1m)
they are synthesised in the Supraoptic and paraventricular nuclei
where are oxytocin and ADH stored (1m)
the posterior pituitary gland
what is the function of ADH ( 2 marks)
Stimulation of v2 receptors causes translocation of aquaporins to the membrane of the kidney tubule, thus allowing water reabsorption.
what is the function of ADH on V1 receptors
and at what concentrations (2m)
it causes vasoconstriction- at abnormal concs
what occurs if there is low blood volume
1m) -(what receptors are stimulated
stim of V1 receptors
what system is stimulated if there is a decrease in blood pressure and what is effect
(2m)
stim of the angiotensin synthesis and increased thirst - increased fluid intake
what is the function of oxytocin (3m)
Incl- how it acts, what secretion is stim by, and what processes its important for
Oxytocin acts via IP3 to cause contraction of the smooth muscle of the genital tract (uterus) and breast.
Secretion of oxytocin is stimulated by stimulation of the genitals and nipples.
Oxytocin is most important at parturition and during lactation
what hormone causes milk let down (1m)
Oxytocin
describe the mechanisms of action for oxytocin in the (2m)
G-protein linked receptor, calcium infux, -1 -contraction of myometrium, increased stim of strtch receptors on uterine wall, expulsion of the foetus.
2- contraction of smooth muscle of the myoepithelium and milk let down
name some hormones secreted by the anterior pituitary gland
5m
Growth Hormone
Prolactin
Thyroid Stimulating Hormone
Adrenocorticotrophic Hormone
Follicle stimulating Hormone
Luteinising Hormone
what cells synthesize the TSH
Thyrotrophe cells
what cells synthesize ACTH
corticotrophe cells
what cells synthesize FSH
gonadotrophe cells
what does GHRH stimulate the secretion of
Growth hormone
where do the releasing hormones travel through
The hypothalamico-hypophyseal portal vessel
what hormones are tested for
TSH & FT4 Cortisol LH & FSH Prl Testosterone / “Periods”
what is done after biochemical tests
Imaging
what tests can be done for the eyes
the visual field tests
what can cause compression of the optic chiasm
enlargement of the pituitary gland
what can enlargement of the pituitary gland cause
Bilateral hemianopsia
what stimulates prolactin synthesis
TRH
give an example of a prolactin release inhibiting factor
Dopamine
what is prolactin secretion stimulated by
Mild stress
Nipple stimulation
Coitus
what is the function of prolactin
promote lactation, and development of breast tissue.
It is most important in females after puberty and during and after pregnancy
what cells is the growth hormone secreted in
the somatotrophe cells
what inhibits GH
(GHRIH)
somatostatin
what is the secretion of the growth hormone stimulated by
decreased carbohydrates and fatty acids and increased amino acids.
what does the GH stimulate in the liver
the release of secondary messengers such as Insulin-like growth factor 1 & 2
what is the growth hormones 3 main functions
protein synthesis and collagen deposition
&
tissue turnover and repair.
