Hypothalamo Pituitary Axis Flashcards
Hypothalamic nuclei
Paraventricular
Anterior
Supraoptic
Dorsomedial
Ventromedial
Arcuate
Posterior
Mamillary body
How many hypothalamic nuclei are there
8
What does the hypothalamus regulate
Pituitary function
Feeding - appetite and satiety
Stress response
Water balance
Sleep wake cycle
Thermoregulation
Emotions
What type of tissue is the adenohypophysis
Glandular
What type of tissue is the neurohypophysis
Neural
What does the pituitary gland sit in
Sella turcica
What structures surround the pituitary gland
Cavernous sinus
ICA
Optic chiasm
What visual defect can a pituitary enlargement cause
Bitemporal hemianopia
What hormones are released by the pituitary
GH
TSH
PRL
ACTH
FSH
LH
What hormone stimulates GH release
GHRH
What does somatostatin do
Inhibits GH and TSH release
Inhibits PRL insulin and glucagon release
How does dopamine effect PRL release
Inhibits
What hormones stimulate ACTH release
CRH and AVP(ADH)
What hormones stimulate FSH and LH release
Kisspeptin
GnRH
Thyroid axis
TRH -> TSH -> t4 -> t3
T4 inhibits TRH and TSH
Where are TRH, TSH, and T4 released
TRH - hypothalamus
TSH - pituitary gland
T4 - thyroid
What is the difference between primary and secondary thyroid underactivity/over activity
Primary caused by decr/incr response in thyroid
Secondary caused by decr/incr response in pituitary
Role of the GH axis
GH regulation
What does GHRH do
Promote GH cell clusters for coordinated responses
Increase GH cell number
Increase GH synthesis
Stimulate GH release
What hormones are in the GH axis
GHRH
SS
Pit-1 + prop1 - trans factors
GH
IGF-I
IGF-II
What causes McCune Albright syndrome
Mosaic mutation in GNAS gene
McCune Albright syndrome classic triad
Fibrous dysplasia of bone
Café au late spots
Endocrine dysfunction + precocious puberty
How many types of somatostatin receptors are there
5 - SSTR1 SSTR2 SSTR3 SSTR4 STR5
What causes pituitary gigantism
Too much GH
Why are males more likely to have pituitary gigantism
Duplication mutation on X chromosome
What hormones are involved in the hypathalamo pituitary adrenal axis
CRH
Arginine-vasopressin
ACTH
cortisol
2 types of Cushing’s syndrome
ACTH dependent
ACTH independent
What causes ACTH independent Cushing’s syndrome
Steroid therapy
Adrenal hyperplasia
Adrenal tumour
What causes ACTH dependent Cushing’s syndrome
Pituitary adenoma
What axis involves kisspeptin, GnRH, LH, FSH, oestrogen, and testosterone
Gonadal axis
What subunit s the same in TSH LH FSH and HCG
Alpha subunit
What happens when there is continuous GnRH drive
Receptor desensitisation
How is the the gonadal axis stimulated medically
Pulsation GnRH
Kallmann syndrome
genetic disorder that prevents a person from starting or fully completing puberty, and no sense of smell
What nuclei are neuronal pathways in the posterior pituitary from
Paraventricular
Supraoptic
Oxytocin functions
Giving birth
Milk ejection
Social recognition
Pro sociality
Perceptual selectivity
What increases vasopressin release
Increased osmolality
What causes cranial diabetes insipidus
Absence of vasopressin
Which part of the brain controls the pituitary
Hypothalamus
How can pituitary tumours cause clinical problems
Local mass effects
Secreting excess hormones
Hypopituitarism
