BCH 4123 Lecture Notes - Lecture 6: Pituitary Adenoma, Optic Chiasm, Posterior Pituitary
2 Feb 2017
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Document Summary
Study if patients have too much or too little hormones. Hormone: produced from a source gland with its action far away, distribution in the blood, must be metabolized to prevent indefinite signalling, need a functioning targeting receptor! Mechanism of action: water soluble hormones bind cell membrane receptors. Generate 2ndary messengers that modulated intracellular kinases. Tend to have immediate affect like opening a channel (transcription rare: lipid soluble. Activated receptors bind to dna to regulate gene expression. Negative feedback: most common pathway, hormone decreases the stimulus for its own production. Oxytocin for milk letdown and estrodiol for ovulation: hormone stimulates signal for its production. Tumor could cause blindness as optic chiasm would be compressed. Small gland located at base of skull. Anterior gland (adenohypophysis: tsh, prl, acth, gh, fsh, lh, largely under hypothalamic control, prolactin and gh have inhibitory signals with da and somatostatin, respectively, releasing hormone in very low concentrations. Different types based on size of hormone.
