physiology Flashcards
Secreted molecules (hormones) act on target cells distant from their site of synthesis?
Endocrine signaling
Where is the pituitary gland located?
Base of brain within SELLA Turcica
What is located inside stalk connecting hypothalamus to pituitary gland?
Axons
Portal venous plexus
What cells was Anterior pituitary gland derived from?
Endocrine cells of Foregut (ORAL CAVITY
Because of Anatomic location, Expanding Pituitary lesions often compress what?
Optic chiasm
Most common cause of HYPOpituitarism is?
Adenoma in Anterior lobe
Pituitary lesions Composed of a single cell type and produce a single type of hormone?
Pituitary Adenomas:
Nonfunctional–> hormone @tissue level only
Functional–> hormone has systemic clinical manifestation
Symptoms of hyperthyroidism?
increased BMR Wght Loss + increased Appetite Increased Heat (intolerance) + sweating Increased CO (tachycardia) Dyspnea Goiter Exophthalmos Tremors/ weakness
Symptoms of Hypothyroidism?
Decreased BMR Wght gain + loss of appetite Cold intolerance Lethargy/ confused Drooping Eye lids Myxedema Growth retardation Mental Retardation
Hypothyroidism + Increased TSH= ?
Primarily Thyroid Gland defect
Hyperthyroidism + Decreased TSH=?
Feedback inhibition on Pituitary gland (Graves thus not Pituitary gland issue)
Hypothyroidism + Decreased TSH= ?
Hypothalamus or Anterior pituitary gland Defect
Hyperthyroidism + Increased TSH = ?
Defect is in Anterior Pituitary gland
MOA of PTU?
inhibits Peroxidase enzyme in Thyroid hormone synthesis
Tx of Hyperthyroidism?
PTU
Thyroidectomy
I- Destroy gland
Beta blockers
Affects of Thyroid hormone on Growth?
Bone maturation
CNS maturation
Affects of Thyroid hormone on BMR?
Increases NA+-K ATPase
Increased O2 consumption
Increases Heat
increases BMR
Affects of Thyroid hormone on metabolism?
Increased Glucose absorption increased Glycongenolysis Increased Gluconeogenesis increased Lipolysis Increased protein degradation (catabolic)
Factors stimulating Thyroid hormone release?
TSH
Thyroid stimulating Ig (GRAVES)
Increased TBG (pregnancy)
Factors inhibiting Thyroid hormone release?
I deficiency
Deiodinase deficiency
Excessive I intake (Wolff-Chaikoff effect)
Perchlorate; thiocynate (Na+ I- cotransport inhibit)
PTU (peroxidase inhibitor)
Decreased TBG (Liver disease)
Oxytocin stimulating and inhibiting factors?
Stimulating–> Suckling + Sight sound or smell of infant + Dilation of cervix + Orgasm
Inhibitory–> Opioids (endorphins)
ADH stimulatory factors?
Increased serum osmolarity Decreased ECF volume Angio II Pain/ Nausea Hypoglycemia Nicotine Opiates Antineoplastic drugs (cylclophosphamide)
ADH inhibitory factors?
Decreased serum osmolarity
Ethanol
Alpha adrenergic agonists
ANP
Factors stimulating Prolactin secretion?
Pregnancy (estrogen) Breast-feeding Sleep Stress TRH Dopamine antagonists
Prolactin secretion inhibitors?
Dopamine
Bromocriptine (dopa agonist)
Somatostatin
Prolactin (negative feedback)
Growth hormone secretion stimulators?
Hypoglycemia Hypolipidemia Arginine Fasting or starvation Puberty (Testosterone or estrogen) Exercise stress stages III or IV if SLEEP Alpha agonists
Factors inhibiting GH release?
Hyperglycemia Hyperlipidemia Obesity Senescence Somatostatin Somatomedins Growth Hormone Beta agonists Pregnancy
