endocrine

• Define Ligand

  A chemical messenger that binds to cellular receptors on particular target cells
• Functions of the Endocrine System:

  Regulating development, growth, and metabolism, Maintaining homeostasis of blood composition and volume, Controlling digestive processes and Reproductive activities
• Hormonal Stimulation

  release of another hormone triggers release of the hormone
• Humoral Stimulation

  changes in level of nutrient or ion in the blood triggers release of the hormone
• Steroid Hormones

  lipid soluble molecules formed from cholesterol includes gonadal steroids and steroids synthesized by adrenal cortex examples: estrogen, progesterone, testosterone, cortisol, aldosterone.
• Biogenic Amines (monoamines)

  modified amino acids includes: catecholamines, thyroid hormone, melatonin. Water soluble (except for TH which is nonpolar and only lipid soluble). Examples: norepinephrine, epinephrine, thyroid hormone, melatonin.
• Protein Hormones

  most hormones are in this category and are water soluble chains of amino acids. Examples: antidiuretic hormone, insulin, glucagon, growth hormone, erythropoiten
• Eicosanoids

  a type of local hormone formed from fatty acids within phospholipid bilayer of membrane.
• 3 examples of eicosanoids

  Prostaglandins, Leukotrienes, Thromboxanes
• Eicosanoid formation

  Phospholipase A2 removes arachidonic acid from phospholipid then other enzymes convert arachidonic acid to a subtype of eicosanoid
• Glycogenolysis

  breakdown of glycogen into glucose
• Gluconeogenesis

  conversion of nutrients into glucose
• Glycogenesis

  synthesis of glycogen
• Lipolysis

  breakdown of triglycerides
• Lipogenesis

  formation of triglycerides
• 2 Microscopic Cells of the thyroid- what they secrete/synthesize

  Follicular Cells: cuboidal epithelial cells that surround a central lumen, synthesize thyroglobulin (TGB) produces and releases thyroid hormone (TH). Parafollicular cells: cells between follicles, make calcitonin.
• Mineralocorticoids

  hormones that regulate electrolyte levels, made in the Zona Glomerulosa: thin outer cortical layer. Aldosterone fosters Na+ retention and K+ secretion.
• Synergistic

  one hormone reinforces activity of another hormone
• Permissive

  one hormone requires activity of another hormone
• Antagonistic

  one hormone opposes activity of another hormone
• Glucocorticoids

  hormones that regulate blood sugar, made in the zona fasciculata: larger, middle cortical layer. Cortisol increases blood sugar.
• Gonadocorticoids

  : sex hormones, made in the zona reticularis: thin inner cortical layer, Androgens are male sex hormones made by adrenals. Converted to estrogen in females, amount of produced by adrenals is less than amount from testes.
• Alarm reaction

  initial response Involving sympathetic nervous system activation, epinephrine, norepinephrine.
• Two cell types of the parathyroid

  Between 2 and 6 of them (usually 4) Contains chief cells and oxyphil cells. Chief (principal) cells make parathyroid hormone (PTH) PTH increases blood calcium, liberates it from bone, decreases its loss in urine, activates calcitriol hormone.
• Heart involved in secretion of what hormones

  Endocrine tissue in heart atria secretes atrial natriuretic peptide (ANP) ANP is a hormone that lowers blood pressure (kidneys increase urine output and blood vessels dilate)
• Adipose CT involved in secretion of

  leptin, which controls appetite by binding to neurons in hypothalamus, lower body fat associated with less leptin which stimulates appetite.