Calcium and Parathyroids Flashcards by Mark Next

Hyperparathyroidism is a disease of impaired _________

calcium

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Too much PTH will move into the ______ cause destruction and results in _______ and ________

bones / osteoporosis / high serum calcium

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What can high serum calcium levels cause?

increased BP, heart attack, stroke

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Why is caclium important?

nerve conduction, bone formation, muscle formation, blood coagulation, cerebral and cardiac function, capillary permeability, cell growth and division, neurotransmitter action

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The body contains __ to __ of calcium: __% in skeleton, ____% in plasma, ___% in ECF, __% in cells

1-2kg / 98% skeleton / 0.03% plasma / 0.1% ECF / 1% cells

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Plasma calcium is present in the following forms

50% ionized (active form) / 41% protein bound (primarily to albumin) / 9% combined anions (diffusible)

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Plasma calcium equilibrates with ____ calcium, but only 0.5% of _______ calcium is readily exchangeable

bone / bone

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________ results in nervous system excitement. There is an increased neuronal permeability to _____, which results in easy action potentials

hypocalcema / Na

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50% ionized or 35% total decrease leads to _____ _____

spontaneous discharges

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Tetany and seizures from hypocaclemia are most commin in the _____ or ______

HAND or FACE

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Hand and hypocaclemia

carpopedal spasm

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Face and hypocaclemia

positive Chvosteks sign is from tapping on the facial nerve leads to twitching

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In hypocalcemia, the ___ can be prolonged. What can this advance to?

QT / You can develop R on T phenomenon and advance to Torsades

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The chief manifestation of hypercalcemia is ________

skeletal muscle weakness

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Hypercalcemia can manifest as nervous system _______. This results in SHORT QT interval, LONG PR interval, constipation, anorexia

depression

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Treatment for Hypercalcemia

maintain UOP, hydrate, administer MITHRAMYCIN in severe cases

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The body contains ___ of phosphorous. __% skeletal, __% muscle/tissue, ___% ECF

1 kg / 85% skeletal, 15% musle/tissue, 1% ECF

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Phsophorous circulates in plasma and about ___% is protein bound

12%

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Phsophorous levels fluctuate more significantly than ______ because Phos moves between ECF and bone as well as ECF and ICF

calcium

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T/F There are minimal effects with large fluctuations in phosphorus

TRUE

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Phos enters the ECF via ___, ____, _____. It is easily absorbed in _____

GI, ICF, bone / GI

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Phosphorous leaves via ____, ____, ____

urine, ICF, bone

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Major control site for phos is the _______.

kidney

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urinary excretion of Phos balances ____ uptake.

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PTH ______ urinary excretion of phos. So does calcitonin but to a lesser extent

increases

GI absorption of phos is increased by what vitamin?

1,25 D3

The parathyroid consists of 4 glands behind the ___ and ____ poles of the thyroid gland

upper and lower

The parathyroid contain mainly ____ cells and ______ cells

chief / oxyphil

**CHIEF cells secrete ________

PTH

**Synthesis and secretion of the PTH is related to _____ concentrations in the blood

calcium

Parathyroid glands can be enlarged from prolonged stimulation, _________ and _______

pregnancy and lactation

Decreases in calcium concentration in the ECF ______ secretion of PTH

increases

Increases in calcium concentration in the ECF ________ the activity of the parathyroid gland

decreases

Vit D, calcitonin, and PTH all help with reabsorption of calcium from the _____ ________ of the kidney

proximal tubule

PTH increases bone resorption to mobilize ____ and ______

calcium and phosphate

Bone resorption is the process by which _______ break down bone and release _______ from bone fluid to blood

osteoclasts / calcium

PTH increases reabsorption of calcium in the kidneys _______ tubules

distal

PTH decreases reabsorption of _______ in the renal tubule

phosphate

**PTH increases the production of 1,25 dihydroxycholecalciferol. This is a vit D metabolite which ______ intestinal Calcium absorption

enhances

**Major stimulus for PTH is what?

low serum calcium level

Increases in PTH results in what serum changes?

increased calcium and decreased phosphate

Increases inPTH results in what urine changes

decreased calcium and increased phosphate

Increases in PTH increases the ________ of phosphate, potassium, and sodium by increasing the CALCIUM/MAG/HYDROGEN _______. This happens largely where?

excretion / reabsorption / distal tubules and collecting ducts

**Calcitonin _______ the parathyroid hormone

opposes

**Calcitonin is produced in the ________ of the thyroid

parafollicular (clear or C cells)

In general, Calcitonin has the opposite effect of ____

PTH

Calcitonin inhibits bone _______. It increases ______excretion of calcium

resorption / urinary

Immediate effect of calcitonin is it _________ osteoclastic activity and osteolysis of osteocytes

decreases

Delayed effect of CALCITONIN is it _______ osteoclast formation

decreases

Calcitionin effect on serum

decreased calcium and decreased phosphate

Calcitonin effect on urine

increased calcium excretion and increased phosphate excretion

Secretion of Calcitonin is controlled by serum ______ level

calcium

Increased serum calcium level would lead to ________ calcitonin secretion

increased

T/F Exact role is unclear but excess or deficient calcitionin does not lead to defects in bone or calcium metabolism

TRUE

Vitamin D has a potent effect to increase calcium absorption from the _____ _____

intestinal tract

Vitamin D has important effects both on bone _____ and bone ______

depositation / reabsorption

** Vitamin D is not iteslf an active substance, but must be converted to its active product _________

1,25 dihydroxylcholecalciferol

**Vitamin ___ is formed in the skin by exposure to sunlight

** Vitamin D3 is converted to 1,25 dihydroxylcholecalciferol in by the ______

liver

GI absorption of calcium is increased by _____

Vit D

Urinary excretion of calcium is decreased by ______ and increased by ________

PTH / Calcitonin

Bone resoprtion of calcium is increased by _____ and inhibited by _______

PTH / calcitionin

Hypoparathyroidism is usually a result of surgical damage to the gland during ______ surgery

thyroid

After thyroid surgery, calcium levels could fall below normal in 24-72 hrs which results in what?

Tetany (calcium ion interferes with membrane transport and interferes with the relaxation of the muscle), muscle cramps, Grand Mal seizures, cardiovascular collapse

Treatment for Hypoparathyroidism is what?

PTH (expensive and short half life) OR high calcium and Vit D intake

**Hypomagnesemia can cause hypocalcemia resistant to _______. So must treat with _______ first.

calcium / magensium

Magnesium suppresses the release of ____

PTH

Primary HYPERparahyroidism is from inappropriate hypersecretion of PTH resulting in ________.

hypercalcemia

Net effect of increased PTH secretion

hypercalcemia, hypercalciuria, HYPOphosphatemia, HYPERphosphaturia, bone demineralization

Net cardiac effects of increased PTH secretion

short QT interval, depresses relaxation

Net kidney effects of increased PTH secretion

kidney stone formation as calcium is mobilized from bone that is excreted by kidneys

Most common cause of hyperparathyroidism is _______ hyperplasia or _______ tumor

parathyroid / parathyroid

Pregnancy may ______ the parathyroids

stimulate

Vitamin D deficiency can be from inadequate dietary intake and often due to fat _______ syndrome. Can also be from inadequate sunlight

malabsorption

In Vitamin D deficiency you have decreased absoprtion of ______ and _______, decreased serum calcium and phosphate, and increased ____ and increased _______ resorption

calcium and phosphate / PTH and bone

In adults, Vitamin D deficiency can result in _______ or softening of the bones

osteomalacia

In children, Vitamin D deficiency can result in ______ - bones fail to mineralize, epiphysis fail to fuse, epiphyseal plates widen and bowing and fractures occur

Rickets

One gram of Calcium Chloride contains the equivalent amount of ionized calcium of what?

3 grams of Calcium gluconate

Calcium is indicated fro treatment of ______ induced EKG changes because of its cell membrane stabilizing effecs

HYPERKALEMIA

Calcium is indicated in patients with ________ associated with either CCB or beta-adrenergic blockers

hypotension

Calcium is contraindicated in patients with _______ toxicity as it may cause _______

digoxin / lethal arrhythmias

Calcium and Parathyroids Flashcards

(81 cards)