hormones of anterior pituitary gland

how many hormones does the anterior pituitary secrete

• FSH

• LH

• ACTH

• TSH

• PRL

• GH

main role of anterior pituitary hormone

to regulate function of other endocrine glands and tissues

gonadotropins: LH and FSH

next couple of flashcards

what is the main role of LH in females

triggers ovulation at mid-cycle and maintains the corpus luteum, which secretes progesterone

what is the main role of LH in males

stimulates Leydig (interstitial) cells in the testes to produce testosterone

how is LH secretion controlled

by pulsatile GnRH release from the hypothalamus and feedback from gonadal steroids

which hormone has LH-like activity during pregnancy

human chorionic gonadotropin (hCG)

what is the main role of FSH in females

promotes ovarian follicle development and oestrogen production

what is the main role of FSH in males

stimulates spermatogensis via action on Sertoli cells

what hormone inhibits FSH release by negative feedback

inhibin (from Sertoli cells in males and granulosa cells in females)

what results from hyposecretion of LH and FSH

Amenorrhoea, infertility, loss of sexual potency, and delayed puberty

what may result from hypersecretion of LH and FSH in children

premature sexual development

TSH

next few flashcards

what is the main function of TSH

stimulates thyroid gland to secrete T3 and T4

how is TSH secretion regulated

by hypothalamic TRH and negative feedback from circulating thyroid hormones

what is the consequence of excess TSH

thyroid enlargement

what does hyposecretion of TSH cause

similar symptoms to hypothyroid like fatigue, cold intolerance, weight gain etc

corticotropin

next few flashcards

what is ACTH derived from

preproopiomelanocortin (POMC)

what is the main action of ACTH

stimulates adrenal cortex to secrete cortisol and small amounts of sex hormones

how is ACTH secretion controlled

by CRH and negative feedback from cortisol; it also follows a circadian rhythm

what stimulates ACTH release

stress (e.g. trauma, pain, fear, hypoglycaemia)

what condition results from ACTH release

Cushing syndrome

prolactin

next few flashcards

what is the primary role of prolactin

breast development and initiation and maintenance of lactation

what is prolactin regulation controlled by

under tonic inhibitory control by dopamine

which hormone promotes prolactin release

TRH

what drug class is used to treat hyperprolactinaemia

dopamine agonists (e.g. bromocriptine, caberfoline)

what are symptoms of prolactin hypersecretion

Amenorrhoea, infertility, galactorrhoea, reduced libido, impotence, possible visual disturbances

GH

next few flashcards

main functions of GH

promotes growth of bone and soft tissues; antagonises insulin (diabetogenic)

how are GH’s growth effects mediated

via insulin-like growth factors (IGFs), mainly from the liver

how is GH secretion regulated

stimulated by GHRH

inhibited by somatostatin

released in pulses

what stimulates GH release

stress, hypoglycaemia, cold, surgery and exercise

what does GH hyposecretion in children cause

dwarfism

what does GH hypersecretion cause before puberty

gigantism

what does GH hypersecretion cause in adults

acromegaly

what are the key biochemical findings in acromegaly

elevated GH and IGF-1 levels

name some treatments for acromegaly

• octreotide

• bromocriptine

• cabergoline

symptoms of acromegaly

• abnormal growth of soft tissue → enlarged hands and feet

• enlarged facial features + increased spacing between teeth

• voice changes - snoring, thickening of vocal chords

• thick, oily skin, increased sweating and bodily odour

• tingling/numbness of fingers or hands

• hypertension, muscle weakness, fatihye

• increase in blood glucose may lead to diabetes

• severe headaches

• changes in vision

treatment for acromegaly

overall - key message to learn:

true or false: hormones from the hypothalamus influence secretion of hormones from pituitary gland

true