Chapter 22: The Endocrine System -...
Transcript of Chapter 22: The Endocrine System -...
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Chapter 22: The Endocrine System
BIO 218
Fall 2015
Major Regulatory Systems
Endocrine & exocrine glands
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Target Cells for Hormones
• A single target cell may have 2,000 – 10,000
receptors for a particular hormone
• Receptors may undergo down regulation if
hormone levels are in excess
– Decreases target sensitivity to hormone
• Receptors may undergo up regulation if
hormone levels are deficient
– Increases target sensitivity to hormone
Functions of Hormones
1. Regulation of . . .
2. Control growth and development
3. Regulate operation of reproductive systems
4. Help establish circadian rhythms
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Diabetes Insipidus
• Neurogenic – hyposecretion of ADH
• Nephrogenic – kidneys do not respond to ADH
• Excretion of excessive levels of urine
• Excessive thirst
• Dehydration
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Fig. 22.4
Hyperthyroidism
• Increased metabolic rate
• Grave’s Disease
• Exopthalmos
• Goiter formation
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Hypothyroidism
• Decreased metabolic rate
• Tendency to gain weight
• Goiter formation
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Fig. 22.5
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Diabetes Mellitus
Type I – inability to produce insulin
Type II – reduced ability of the body to respond
to insulin
• Excretion of excessive levels of urine
• Excessive thirst
• Dehydration
• Polyphagia