Friday, 12 September Chapter 11 The Endocrine System

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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

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Endocrine Organs (Table 11-1)
Hormone Paracrine agent Autocrine
agent Neurotransmitter Neuromodulator

• Pituitary Gland
• Thyroid Gland
• Pancreas
• Gonads
• Gastrointestinal Tract
• Heart
• Kidney
• Hypothalamus
• Liver
• Etc.

Hormone chemical messengers carried by blood to
target cellsupon which they act.
Only those cells having receptors Can respond to
a given hormone
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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)

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Fig. 11.01
AmineHormones
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Fig. 11.02
ExamplesInsulin, glucagonprolactin,
erythropoietin,parathyroid hormone,gastrin,
leptin, growth hormone,oxytocin,
vasopressin,FSH, LH, GHRH, andmany more!
Peptide Hormones
Soluble in plasma
e.g.Beta cell
Guess peptide!
Cell surface receptors on target cells
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Fig. 11.03
Steroid hormones
not soluble in plasma, not storable in vesicles
Bound Free
Target cells have intracellular
receptors,Commonly changes is gene
expressionTimecourse?
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Questions so far?
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Know Table 11-2 p 323

• Hormone class
• Major form in plasma
• Location of receptors
• Signal transduction mechanisms
• Rate of excretion / metabolism

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Fig. 11.05
Adrenal Gland
Part of Sympathetic Nervous System
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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

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Hormones of the Adrenal Cortex
DHEA
Mineralicorticoid
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Fig. 11.06
Gonadal Steroids(not adrenal cortex)