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17 Cards in this Set
- Front
- Back
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where are the parathyroid glands
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they are 4 pea sized glands on the thyroid gland
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what do principal (chief) cells do?
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they produce parathyroid hormone
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what are the 2 types of cells in the parathyroid gland
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principal and oxyphil cells
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what does the oxyphil cells do?
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the function is unknown
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what are the major functions of the parathyroid gland?
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it is the major regulator of Ca2+, Mg2+, and HPO4
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what does PTH do to calcium?
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it raises blood Ca2+ levels
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what does the PTH do to osteoclasts?
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it increases their activity
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how does PTH affect the kidneys?
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it increases reabsorption of Ca2+, promotes formation of calcitrol (vitamin D3)
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how does PTH affect HPO4
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it inhibits the reabsorption of it
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what does calcitrol do?
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it causes absorption of Ca2+ and Mg2+ by the intestinal tract
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what does negative feedback influence?
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it is directly on the secretion of hormones, does not involve the pituitary
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what is the overall effect of PTH on bones
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it stimulates osteoclast to degrade bone, which results in bone resortpion, increase in Ca2+ and HPO4-in the blood
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what is the effect of PTH on the GI?
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it is an indirect effect, calcitrol increases interstitial absorption of Ca2+, Mg 2+, and HPO4-
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cause of hypothyroidism
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accidental removal during thyroidectomy
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what are the symptoms hypothryoidsim
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hypocalcemia, normal bone structure, increased neuromuscular excitability (tetany, larygnospasm, & death from asphyxiation can result), flaccid heart muscle (cardiac arrythmia may develop) and diarrhea
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what are the causes of hyperparathyroidism?
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adenomas of the parathyroid gland, hyperplasia of the parathyroid and carcinomas
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what are the symptoms of hyperparathyroidism?
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hypercalcemia or normal blood Ca2+ levels, CaCO3- deposited throughout the body (renal tubules, lungs, blood vessels, gastric mucosa especially), Bones weaken, neuromuscular system less excitable, weak muscles, increased force of cardiac contraction @ higb blood Ca2+ levels----can lead to cardiac arrest, constipation
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