Endo Flashcards
Persistence of tyroglossal duct leads to
Pyramidal lobe of thyroid
Adrenal cortex derived from?
Adrenal medulla derived from?
Mesoderm
Neural crest
Most common ectopic thyroid tissue site?
tongue
Medullary chromaffin cells are considered as?
Modified postganglionic sympathetic neurons
Acidophils secrete what and basophils secrete what of anterior pituitary?
Acidophils-Prolactin, GH
Basophils-FSH, LH, ACTH, TSH
What secretes MSH?
Melanotropin (MSH) secreted from intermediate lobe of pituitary
Difference in insulin and C-peptide in insulinoma, sulfonyurea, and exogenous insulin
Insulinoma + sulfonylurea both increase insulin and C-peptide while exogenous insulin lacks C-peptide
does insulin cross placenta?
no
What is the known mechanism under which TNFalpha, glucagon, and glucocorticoids, high FFA cause insulin resistance?
Serine phonsphorylation through activation of serine kineases which result in phosphorylation of serine/threonine residues in Beta subunit of insulin receptors hindering downstream signaling resulting in resistance to normal actions of insulin.
GLUT 1 GLUT 2 GLUT 3 GLUT 4 GLUT 5
RBC, Brain Cornea (Insulin independent)
B-cells pancreas, liver, kidney, small intestine
Brain
Adipose tissue, striated muscle (insulin dependendent)
(fructose): spermatocytes, GI tract
GH and B2 agonists have what effect on insulin?
increase insulin through insulin resistance
Early and Late treatment for severe hypoglycemia
Early (mild/moderate hypoglycemia)-fast acting carbohydrates (glucose tablet, sweetened fruit)
Late (unconscious)-IM glucagon.
*IM Glucose is not an option
Prolactin is under the control of and controls what?
Under control of dopamine where relased is decreased and It is increased by TRH
Somatostatin function
Decrease GH, TSH
TRH function
Increase TSH, prolactin
Analog of GHRH used to treat HIV associated lipodystrophy
Tesamorelin
Excess prolactin is associated with what response
Prolactin inhibits GnRH–>inhibiting LH/FSH–>amenorrhea/hypogonadism and excessive decreases libido
Stimulators of prolactin secretion (2)?
Estrogen (OCPs, pregnancy) +TRH
Another name for IGF-1
Somatomedin C
Direct tissue effects of GH and effects on liver
Tissue effects: Increase insulin resistance (increase glucose), increase lipolysis (increased FFA), increased protein synthesis
Effect on liver: increase IGF-1–>acts on growth and development of bone, cartilage, and soft tissue
Growth hormone secretion increases and decreases with what?
Increases with exercise/sleep, decreases with glucose/somatostatin (via negative feedback by somatomedin)
Leptin
Secreted by?
Function?
Regulation in various conditions?
Adipose tissue
Satiety hormone
Decreased with decreased sleep, starvation, mutation in leptin gene
Ghrelin
Secreted by?
Function?
Regulation in various conditions?
Stomach
Stimulates hunger
Increased with decreased sleep, Prader willi
Cortisol function (BIG FIB)
Increase BP, Insulin resistance (diabetogenic), Increase gluconeogenesis, lipolysis, and proteolysis, decrease fibroblast activity, decrease inflammatory and immune responses, decrease bone formation
What affect does increase in pH have on albumin and calcium?
increase pH–>increased affinity of albumin (increased negative charge ) to bind Ca2+–>hypocalcemia
3 types of CA2+
Ionized, bound to albumin, bound to anions
CAH treatment
Low dose corticosteroids. Decrease ACTH–>decrease adrenal cortex stimulation (Normally increased ACTH because decreased cortisol secretion)
Where oes calcium and phosphate reabsorption occur in kidney?
Calcium-DCT
Phosphate-PCT
Is calcitonin a significant calcium regulator hormone?
No thyroidectomy would not cause significant changes in calcium levels
4 main functions of T3 hormone
1) Bone growth
2) BMR increase
3) Brain maturation
4) B-adrenergic effect
Where does T3 bind?
Nuclear receptors specifcically in hormone binding regions in DNA promoter
How is MIT/DIT recycled after I4/I3 released from thyroglobulin to enter the periphery?
Iodotyrosine deiodinase
Rule of 10s for pheochromocytoma
10%:
Bilateral, malignant, calcify, extra-adrenal, kids
5 episodic hyperadrenergic symptoms of pheochromocytoma
Pressure (increase BP), Pain (headache), Perspiration, Palpitations (tachycardia), Pallor
How to avoid hypertensive crisis in pheochromocytoma tumor resection?
alpha antagonists (phenoxybenzamine) followed by beta bolckers prior to tumor resection. alpha antagonists must be achieved prior to beta blockers
What represents an increase in BMR in hyperthyroidsim?
Increase in Na+/K+ ATPase channels synthesis +activity
Treatment for thyroid storm
3 P’s
Propanalol (b-blockers), Propylthiouracil, Prednisolone (corticosteorids)
Antibodies in hashimoto
Antimicrosomial (anit-thyroid peroxidase), and antithyroglobulin
Tender vs nontender thyroid in causes of hypothyroidism
Tender-Subacute dequarvain
Nontender-Hashimoto thyroiditis
Most common enzyme deficient in dyshormonogenetic goiter in cretinism?
Thyroid peroxidase
Hashimoto, subacute de quervain granulomatous thyroidisits, and riedel thyroiditis type of thyroid
Hashimoto-nontender
Subacute thyroiditis-very tender!!
Riedel-nontender
lymphoid aggregate with germinal center
hashimoto thyroiditis
granulomatous inflammation with very tender thyroid
subacute dequervain thyroiditis
thyroid replaced by fibrous tissue (hypothyroid)
riedel thyroiditis
How is biopsy performed for characterizing thyroid nodules
fine needle aspiration
Medullary carcinoma of thyroid associated with what mutation?
RET
IGF-1 has what functions
secreted by liver and acts on bone, soft tissue, cartilage
Na+ level in Central DI, nephrogenic di, psychogenic polydipsia
Central and nephrogenic >142 while
Treatment of nephrogenic diabetes insipidus
HCTZ, indomethacin, amiloride
Type of hyponatriemia in SIADH
Euvolemic hyponatremia
Why is there elevated risk of lactic acidosis with metformin?
Increase production of lactate by anaerbic glycolysis. Normally, lactate produced in intestine converted to glucose via gluconeogenesis in liver, but metformin inhibits this gluconeogenic process. Results in elevated lactate circulating levels with risk of lactate acidosis.
4 actions of PPAR target genes
1) increase adiponectin (which decreases insulin resistance)
2) increase fatty acid transport protein3) increase insulin receptor substrate
4) increase GLUT-4
This drug decreases gastric emptying and decreases glucagon that can be used in type I dm and type 2 dm
pramlintide
Sensitizes Ca 2+ sensing receptor in parathyroid gland to ciculating Ca2+–>decrease PTH
Cinacalcet
