friday, 12 september chapter 11 the endocrine system classes of hormones the adrenal gland fates of...
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Friday, 12 SeptemberChapter 11 The Endocrine System
• Classes of hormones• The adrenal gland• Fates of hormones• RAA system• -------------------------------• Hypothalamus-Pituitary System• Hormone interactions• Control of hormone secretion• Categories of endocrine disorders
Endocrine Organs (Table 11-1)
• Pituitary Gland• Thyroid Gland• Pancreas• Gonads• Gastrointestinal Tract• Heart• Kidney• Hypothalamus• Liver• Etc.
Hormone: chemical messengerscarried by blood to target cells
upon which they act.
Only those cells having receptorsCan respond to a given hormone
Hormone
Paracrine agent
Autocrine agent
Neurotransmitter
Neuromodulator
3 Chemical Classes of Hormones
• 1: Amine hormones (from amino acid tyrosine)– Thyroid hormones – Adrenal medullary hormones (catecholamines)
• 2: Peptide hormones (peptides & proteins)• 3: Steroid Hormones (derivatives of cholesterol)
Fig. 11.01
Catecholaminessoluble in plasma
ThyroidHormones Not soluble in plasma, bound & free
AmineHormones
Adrenalmedulla
NT
NT
Fig. 11.02Peptide Hormones
Examples:Insulin, glucagonprolactin, erythropoietin,parathyroid hormone,gastrin, leptin, growth hormone,oxytocin, vasopressin,FSH, LH, GHRH, andmany more!
Cell surface receptors on target cells
Guess peptide!
Soluble in plasma
e.g.Beta cell
Fig. 11.03Steroid hormones
not soluble in plasma, not storable in vesicles
Target cells have intracellular receptors,Commonly changes is gene expression
Timecourse?
Bound & Free
Questions so far?
Know Table 11-2 p 323
• Hormone class
• Major form in plasma
• Location of receptors
• Signal transduction mechanisms
• Rate of excretion / metabolism
Fig. 11.05
Adrenal Gland
Part of Sympathetic Nervous System
Adrenal Medullary Hormones• Adrenal medulla is modified sympathetic ganglion• Catecholamines: EPI (80-85%), NE (15-20%)• Short half-life in plasma (soluble)• Receptors on surface of target cells (adrenergic) • Effects response to stress• Effects generally prepare for “Fight or Flight”
Hormones of the Adrenal Cortex
Glucocorticoids
Mineralicorticoid
Androgens
DHEA
Fig. 11.06Gonadal Steroids(not adrenal cortex)
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