Anterior Pituitary Flashcards
Secretes hormones in response to signals from the h____________
hypothalamus
The anterior pituitary
has no arterial blood
supply but receives
blood through a
p_____ v_____
circulation from the
hypothalamus
portal venous
ACTH only regulates c_______
cortisol
What factors influence whether the hypothalamus releases CRH?
Stress, cytokines and diurnal rhythm
What does CRH stimulate the pituitary to release?
ACTH
What does ACTH stimulate the adrenal gland to release?
Cortisol
What does production of cortisol cause in hypothalamus and pituitary?
Inhibits them from secreting CRH and ACTH (respectively) - negative feedback
What inhibits pituitary releasing GH?
Somatostatin
What does TRH released by the hypothalamus cause the pituitary to release?
TSH
What does TSH stimulate the thyroid to produce?
Thyroxine
What does thyroxine do to hypothalamus and pituitary?
Inhibit them from making TRH and TSH (respectively) - negative feedback
LH stimulates
sex hormone secretion
FSH stimulates
development of follicles
Absense of LH and/or FSH leads to
infertility and hypogonadism
In males, LH stimulates…
Leydig cells to make testosterone
Testosterone inhibits the secretion of
LH and FSH
In males, FSH stimulates _______ cells to release inhibin
Sertoli
Inhibin inhibits the secretion of…
FSH
Prolactin is essential for
lactation
Prolactin inhibits gonadal activity through suppression of ____ so decreased LH/FSH
GnRH
PRL has circadian rhythm with peak during
sleep
Symptoms of acromegaly
Sweating, headaches, aching (osteoarthritis), snoring / sleep apnoea
Clinical features of acromegaly
Leonine facies, broad nose, thick lips
Spade like hands
Increase in ring, hat and shoe size
Skin thickening
Hypertension
Diabetes
Cushing disease features
Central obesity, moon face, “buffalo hump”
Collagen/protein: Thin skin, striae,
easy bruising, myopathy, osteoporosis
Androgen excess: Acne, hirsutism,
amenorrhoea
Other: Hypertension, depression,
diabetes, immunosuppression
