Endocrine Patho I Flashcards
3 classifications of hormones
Peptide (pituitary, insulin, glucagon)
Amino acid derivative (catecholamines, thyroid hormone, serotonin/melatonin)
Lipid (cholesterol derived; gondatropin, estrogen, progesterone etc)
4 types of cell surface receptors
Tyrosine Kinase Receptors
G Protein S receptors (increase lvl of cyclic AMP)
G Protein I receptors (decrease lvl of cyclic AMP)
G Protein Q receptors (IP,DAG processes)`
2 types of steroid hormone receptors
- Cytoplasmic (glucocorticoid, mineral corticoid, androgen)
2. Nuclear (Estrogen, thyroid hormone receptors, vit D receptors, retinoid acid receptors)
general s/s of hormone excess/deficiency
excess- endocrine gland hyperplasia caused by increased tropic stimulus to secretion
Def- Endocrine gland atrophy due to loss of tropic stim to secretion
what are the 3 possible scenarios of hormonal cell secretion
Autocrine- cell has hormonal production and releases signal onto itself
Paracrin- Cell releases hormone that travels a short distance to reach target
Endocrine- Cell releases hormone that travels far to reach target
tumors that can affect hypothalamus fundtion
Pituitary (mc)
Craniopharyngioa
midline hamartoma
langerhans histiocytosis
Inflammatory disorders altering hypothalamic functoon
Sacroidosis (produces granulomatous inflammation in the hypothalmus
Mengitis
Clinical findings of hypothalamic dysfunction
Secondary hypopituitarism
Central diabetes insipidus
What is hyperprolactinemia
Loss of dopamine inhibition of prolactin causes an increase in prolactin leading to milk prod in females
What causes precocious puberty
Midline hamartoma
What usually causes a bitemporal hemianopia
due to compression of the optic chasm by a suprasellar mass
what is the site for melatonin prod
Pineal gland
Superior cervical sympathetic ganglia stims receptors on pinealoctes to cause release
What are the majority of pineal gland tumors
Majority are germ cell tuors
2 major clinical findings/disorders of pineal gland disorders
Visual disturbances- Paralysis uff upward gaze (parinaud syndrome)
Obstructive hydrocephalus- due to compression of the aqueduct of Sylvius
What is a crainiopharyngioma, age, and types (2)
rare type of benign tumor that begin just above the pituitary gland
5-15 + 60+
Adamantimatous (can cacify)
Papillary (rarely calcify)
symptoms of a craniopharyngioma
depends on loc
-Growth failure, delayed puberty, loss of mentrual function, loss of sex drive, increased sensitivity to cold, fatigue
mc benign tumor classification of pituitary + clinical manifistation
pituitary adenoma
clinical manifestation
- single hormone overlord
- destruction of surrounding normal pituitary function
5 of the pituitary adenomas (and mc)
Prolactinoma (mc)
GH secreting (acromegaly if adult, giantism if child)
ACTH secreting (bushings)
Plurihormonal
Null cell
What is the stalk effect in a pituitary adenoma
mass pressing on the stalk will prevent dopamine from reaching the pituitary gland, causing increased levels of prolactin without actually producing prolactin
clinical pres and dx of prolactinoma
Prolactinomas are dx earlier in females than males
-pts present w symptoms of galactorrhea, infertility, amenorrhea
Basal prolactin lvl of 200ng/ml
what can primary hypothyroidism(destruction of thyroid gland itself) cause
Both TSH and TRH are elevated
-stims release of TSH, TRH causes release of prolactin
what is the mutation in GH secreting adenomas and clinical presentation in children/adults
40% have mutation in the GNAS1 gene on chromosome 20q13
In children= gigantism
In adults= Acromegaly
classic signs of acromegaly
Growth of skin, soft tissues, organs
- mc finding is sacral enlargement or widening of the hands/feet and coarsening of facial features
- persistent levels of GH
How to diagnos Acromegaly
Failure to suppress GH levels with an oral load of glucose
