Thyroid Gland

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Thyroid Gland

• located at _________________________________
• two important thyroid hormones (which regulate
  body metabolism, growth, and differentiation of
  tissues)
• __________________________________________
• __________________________________________

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Hormones that affect metabolism

• Three different glands affect metabolism
• ____________________________________________
• helps regulate body metabolism (glucose oxidation
  rate)
• produces three hormones
• triiodothyronine, thyroxine, calcitonin
• ______________________________________________
• produces parathyroid hormone
• helps regulate calcium levels in blood and lower
  phosphate levels
• _______________________________________________
• produces growth hormones and regulatory hormones

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Hormones That Affect Metabolism
Gland Hormone Action
Thyroid

Parathyroid
Anterior Pituitary Gland
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Thyroid Gland

• individuals who secrete higher levels of
  thyroxine oxidize sugars and other nutrients
  _____________
• __________________________________________
• When glycogen stores are filled, excess sugar is
  converted to ___________________________
• control of thyroid hormones is accomplished by
  ____________________

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Feedback loop...

• receptors in hypothalamus are activated if the
  metabolic rate __________________________
• nerve cells secrete ______ (thyroid releasing
  hormone)
• this stimulates pituitary to release
  _________(thyroid stimulating hormone)
• carried by blood to thyroid gland which then
  releases ___________________________which raises
  metabolism by _______________________________
• ____________________________________by cells
• high levels of thyroxine cause pathway to be
  turned ________________, inhibiting release of
  TRH
• Thyroid gland also contains ______________________
  __
• hormone acting on _________________cells to lower
  level of __________________________found in blood

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Oh no!

• when inadequate amounts of iodine are obtained
  from the diet, thyroid enlarges, producing a
  _________.
• If thyroxine levels ?s, TSH ?s, and thyroid is
  stimulated more and more
• Thyroid cells continue to develop and thyroid
  _________________

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Parathyroid Glands

• ____________________parathyroid glands hidden
  within larger thyroid gland
• Usually nerves or other hormones regulate the
  endocrine glands with the parathyroid glands
  being the ________________________________
• These maintain homeostasis by responding
  __________________________________in their
  immediate surroundings (low calcium levels)
• PTH raises _______________levels in the blood
•  PTH (parathyroid hormone) also help activate
  vitamin D. (Low levels of vit D cause rickets!)

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Rickets and Goiters...
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Regulation of Blood Calcium
Endocrine System Control
Feedback
calcitonin
? kidney reabsorption of Ca
Ca depositedin bones
blood calcium level(10 mg/100mL)
? Ca uptakein intestines
activated Vitamin D
? kidney reabsorption of Ca
bones release Ca
parathyroid hormone (PTH)
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Human Growth Hormone (aka Somatotropin)

• Too little __________
• Too much __________
• Released by Ant. Pit.
• GH increases cell __________in muscle cell and
  connective tissue by promoting Protein Synthesis
  (increasing Amino Acid uptake)
• Promotes fat burning
• Dec. Levels of GH with age

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HGH and Controversy...

• Should you take it?

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• GH affects all body cells BUT mainly
  ____________cells
• _____________________________bones of jaw,
  forehead, fingers and toes increase in width,
  once other bones can no longer increase in length
  (growth plates fused)