ENDO-hypothalamus and pituitary Flashcards
what is the role of the hypothalamus in the endocrine system?
the master controller
what is the hypothalamus made up of?
groups of nuclei
how is the hypothalamus connected to the pituitary?
infundibulum/pituitary stalk
What does the pituitary gland sit inside?
the pituitary gland sits in a fossa-depression of the sphenoid bone of the skull
what 2 divisions is the pituitary split into?
- anterior
- posterior
what is the role of the anterior pituitary?
makes and secretes hormones
what is the role of the posterior pituitary?
secretes hormones only–secretes the hormones that the hypothalamus makes
how is the anterior pituitary connected to the hypothalamus?
hypothalamus-hypophyseal portal system
how is the posterior pituitary connected to the hypothalamus?
hypothalamo-hypophyseal tract
list the 5 anterior pituitary hormones
- ACTH
- Growth Hormone
- Thyroid stimulating hormone
- Prolactin
- Gonad ones (LH, FSH)
list the posterior pituitary hormones?
- Vasopressin (ADH)
- Oxytocin
what are the stimuli of growth hormone?
- Low glucose
- Low fatty acids
- Low proteins/high amino acids
- Ghrelin (hunger hormone)
which hormone is released by the hypothalamus in response to growth hormone stimuli?
Growth hormone releasing hormone
which cells and hormones are released by anterior pituitary gland in response to Growth hormone releasing hormone?
Somatotrophs =release growth hormone
what are the effects of growth hormone on the body?
- increases protein synthesis
- increases tissue growth
- increases fatty acids
- Increases glucogenesis/glycogenolysis
what substance inhibits growth hormone release?
somatostatin
what are the stimuli causing ACTH release?
Stress, low glucose
which hormone is released by hypothalamus in response to ACTH stimuli?
corticotropin releasing hormone (CRH)
what cell is stimulated in anterior pituitary in response to CRH?
cortiocotrophs
what hormone is stimulated in anterior pituitary in response to CRH?
adrenocortico-tropic hormone
ACTH
what are the effects of ACTH on the body?
- release cortisol (from adrenal gland)
- increase glucogenesis, lipolysis, proteolysis
- maintains BP
which substance inhibits ACTH release?
cortisol
what is the stimulus of TSH release?
low T3/ T4
which hormone is released by the hypothalamus in response to low T3/T4?
TRH
thyroid releasing hormone
which cells and hormone is released from the anterior pituitary in response to TRH?
thyrotropin releases thyroid stimulating hormone (TSH)
what are the effects of TSH on the body?
increase BMR
which 2 substances inhibit TSH release?
T3/T4
what stimulates LH/FSH release?
oestrogens
which is released from the hypothalamus in response to oestrogens?
gonadotropin releasing hormone
GnRH
which cell and hormones are released from the anterior pituitary in response to GnRH release?
gonadotrophs release LH/ FSH
what are the effects of LH/ FSH on the body?
FSH-germ cell development
LH-ovulation/ testosterone production in Leydig cells
which hormones inhibit LH/ FSH production?
Oestrogen & progesterone
what are the 2 stimuli of prolactin release?
- low dopamine
- baby sucking on nipple
what does the hypothalamus do to stimulate prolactin release?
reduces dopamine release
which cell and hormone are released by the anterior pituitary in response to decreased dopamine levels?
-lactotrophs release prolactin
what is the effect of prolactin on the body?
act on mammary gland to release milk after childbirth
which molecule inhibits prolactin release?
dopamine
what is the stimulus of oxytocin release?
uterine stretching during labour
what is the effect on the body of oxytocin release?
- uterine contraction-positive feedback loop
- milk ejection
- bonding after birth
which hormones inhibit oxytocin release?
catecholamines-adrenaline/ noradrenaline
what stimulates vasopressin (ADH) release?
osmoreceptors in hypothalamus detect high blood osmolarity (low water levels)
what is the effect of ADH on the body?
causes aquaporins to bind to CD of nephron inside kidney-increases water retention
what inhibits ADH release?
- alcohol
- low blood osmolarity (high water levels)
what type of receptor are all the receptors for pituitary hormones?
GPCR
what type of hormones are all pituitary hormones?
peptide
Which of the following hormone is NOT secreted by the pituitary gland? A. follicle-stimulating hormone b. glucagon c. oxytocin d, leutinizing hormone e. antidiuretic hormone
b-glucagon
Which of the following statements is false?
a-Aldosterone is created in the adrenal cortex
b-oxytocin is created in the posterior pituitary gland
c-Follicle stimulating hormone is created in the anterior pituitary gland
d-Glucagon is created in the pancreas
b-oxytocin is created in the posterior pituitary gland
Which of the following hormones is controlled by positive feedback mechanism? a-Growth hormone b-Thyroid stimulating hormone c-ACTH d-None of the above
d-none
Where does ADH work for increasing reabsorption? a-DCT b-PCT c-Collecting duct d-Both A & C
d
