Hypothalamic-pituitary CIS Flashcards
What parts of the hypothalamus are the axons of the posterior pituitary gland located?
what type of communication occurs between the hypothalamus and the posterior pituitary?
supraoptic nucleus
paraventricular nucleus
communication is neural signaling
what does the posterior pituitary secrete and what are sources within hypothalamus of these hormones?
secretes neuropeptides
ADH from the SON
Oxytocin from the PVN
what are the three degreees of endocrine disorders?
1st degree: low or high levels of hormone due to defect in the peripheral endocrine gland
2nd degree: low or high levels of hormone due to defect in the pituitary gland
3rd degree: low or high levels of hormone due to defect in the hypothalamus
what is released by:
- corticotroph
- Thyrotroph
- gonadotroph
- somatotroph
- lactotroph
Corticotroph: ACTH
Thyrotroph: TSH
Gonadotroph: FSH, LH
Somatotroph: GH
Lactotroph: Prolactin
answer is prolactin because if you resect hypothalamus you wouldnt have dopamine to inhibit.
Hypothalamic- Anterior Pituitary hormone relationships
hormones from hypothalamus target what in anterior pituitary, which secrete what products?
Important implications of the hypothalamic-hypophysial portal vessels
2
what is the pathophysiology of acromegaly?
why prolactin elevated?
why ammenorhea?
high level of growth hormone
IGF-1 is also high
see high fasting glucose in these patients
tumor may compress stalk, disrupt release of dopamine into AP to suppress prolactin
tumor affecting pituitary causing it not to release FSH/LH
what does GH stimulate?
stimulates somatomedin C (IGF-1) gene transcription and secretion by the liver
Draw a diagram of the endocrine axis regulating GH secretion
Pathophysiology of acromegaly
Primary GH excess
Extrapituitary GH excess
GHRH excess
Diagnosis of acromegaly
medications for acromegaly
octreotide/lanreotide: somatostatin analogs
Pegvisomant: GH receptor antagonist
Bromocriptine/carbergoline: dopamine receptor agonists
-may decrease GH secretion, only small portion of patients are responsive to this therapy
what age is GH highest? lowest?
Pathophysiology of GH
-deficiency mechanisms?
excess before puberty leads to?
GH deficiency can come from decrease in GHRH (hypothalamic dysfxn), decrease in GH secretion (primary deficiency), failure to generate somatomedins, GH or somatomedin resistance (deficiency of receptors)
Excess before puberty leads to gigantism
GH acts on which type of cell to cause bone growth?
chondrocytes
what are the metabolic functions of GH?
- Diabetogenic mechanism
- Protein synthesis mechanism
- Linear growth mechanism
Nutritional status and how it relates to GH, IGF-1, and insulin?
lactotrophs
What happens with high prolactin levels?
often amenorrhea, suppresses FSH and LH
what is secreted in cushings disease associated pituitary adenoma?
ACTH
Sheehan syndrome
- what is it?
- Typical pt presentation
45 year old woman has CVA that causes necrosis of the posterior pituitary. which of the following effect is most likely seen?
inability to lactate, hypothyroidism, hypoglycemia, or hypernatremia
hypernatremia, but kinda bullshit
What are the triggers of ADH secretion?
most sensitive to what?
decreased BP, decreased arterial stretch due to low blood volume, increase in osmolarity
most sensitive to osmolarity changes
