BIOCHEM 3H03 Lecture Notes - Lecture 12: Median Eminence, Hypothyroidism, Homeostasis
Document Summary
Several systems to mediate function: exocrine hormones into duct, endocrine ductless, into bloodstream, paracrine local action, autocrine same cell, neuroendocrine neuronal cells into blood stream. Anterior pituitary, posterior pituitary, hypothalamus and median eminence, thyroid gland, four parathyroid glands, two adrenal glands (cortex and medulla), duodenum, stomach, kidney, pancreas (islets of langerhans), two testes/ovaries. Steroid: cholesterol-derived: synthesized as needed by certain target organs (adrenals, gonads, placenta) Albumin: non-specific, low affinity, high capacity carrier protein. Major protein of oncotic pressure; high concentrations g/mol concentrations while hormones are in pico-mole easily carried in the blood because of such a large amount of carrier protein relative to the hormone. Specific carrier proteins such as cortisol binding globulin (cgb: lipid soluble and generally hydrophobic, the unbound or free hormone is biologically active. Need to figure out ratio of unbound: bound hormone important for treating patients and physiological homeostasis.