Pituitary and Hypothalamus Flashcards
Which pituitary tumour has dystrophic calcification forming a pituitary stone?
Prolactinomas
Sheehan’s syndrome
Pituitay infarct and subsequent necrosis due to reduced blood flow during childbirth as there is loss of blood in delivery.
What suprasellar tumoursaffect the functioning of the pituitary?
Craniopharyngiomas arise from remnants of the craniopharyngeal duct and/or Rathke cleft with benign histology and malignant behavior.
Gliomas of chiasm
Kasper Hauser syndome
Psychosocial dwarfism, sometimes called psychogenic or stress dwarfism, or Kaspar Hauser Syndrome, is a growth disorder that is observed between the ages of 2 and 15, caused by extreme emotional deprivation or stress.
What is the effect of rising blood glucose on GH release?
Surpresses GH release
What is the effect of rising blood amino acids on GH release?
Stimulates GH release
What is the effect of rising blood fatty acids on GH release?
Surpresses GH release
Which IGF is more inportant (I or II)?
IGF 1 (aka somatomedin C, aka sulphation factor) -enhances incorporation of sulphate into cartilage
Why does prolonged administration of GH cause diabetes mellitus?
It antagonises the effect of insulin
-increases hepatic gluconeogenesis
decreases tissue glucose uptake and decreases rate of glycolysis
—> increased level of glucose in blood
Does GH promote of inhibit lipolysis?
Promotes lipolysis
-encourages use of fat as fuel, thus conserving glucose
What does GH do with respect ro glycogen?
increases glycogenesis
In presence of GH what substance is preferred as fuel?
Fatty acids
GH spares glucose and amino acids by decreasing its oxidaion
What are pygmies?
GH normal but there post GH receptor defect. IGF II is normal.
What are Laron type dwarfs?
GH is increased. They lack functional hepatic GH receptors. IGF I and II are both decreased.
What are the stimuli for GH release?
Hypoglycemia (so insulin is given to decrease blood glucose level and hence stimulate GH production ) Stress Glucagon Going to sleep GHRH
