Calcium, Phosphorus, and Magnesium Flashcards
Increase intracellular calcium results in increased…
Contraction
A decrease in serum magnesium, Causes calcium in serum to…
Go down (Into the cell) 
An increase in serum magnesium Causes _________ in Serum calcium
Increase (Decrease inside the cells) 
Over 300 Enzymatic activity requires magnesium as a…
Cofactor
What is the biologically active form of magnesium?
Ionized/free form (about 70%) 
Is magnesium extracellular or intracellular cation?
Intracellular, influenced by Hemolysis
*divalent
Major source of magnesium?
Diet/reabsorbed in intestine
What is the normal value for magnesium in plasma/serum?
1.7-2.2 mEq/L (0. 85-1.10 mmol/L)
- Member first number is twice as much
What is the percentages and location of magnesium in the body?***
-bone 50-60%
-muscle 20%, intracellular 20% (Cells equals 40%)
-Serum 1%
Magnesium in serum, which accounts for 1% of all body magnesium,  is in what forms? 
-ionized about 70% *
-Protein associated 25%
-Combined ions (Phosphate and citrate) 5%
Steroid hormones don’t need plasma ____________
Receptors
Three mechanisms of allosteric regulator
-changes structure of proteins so substrate cannot bind
-physically covers the substrate binding site
-Enhances enzymatic activity
What are the functions of magnesium?
-enzymatic reactions, energy storage/transfer/production
** Inhibits calcium entry into cells!
* Bone homeostasis (50-60%) 
Magnesium in serum is regulated by…
-parathyroid hormone PTH (Can stimulate reabsorption in intestine and release from bone) 
-aldosterone (Increases sodium and decreases potassium), And thyroxine.
Aldosterone And thyroxine increase in renal magnesium excretion (Lowers magnesium)*****
What three hormones regulate magnesium?
-thyroxine
-Aldosterone
-Parathyroid hormone PTH
Mg inhibits __________ entry into the cell
Calcium**
What are symptoms of hyper magnesium?
heart block, vomiting, nausea
Sedation, respiratory depression, paralysis,coma 
Causes of elevated magnesium
- adrenal insufficiency: Hypoaldosteronism (aldosterone increases magnesium excretion)
- hypothyroidism
-Renal Failure
-Dehydration (Relative amount, not absolute amount) 
Symptoms of hypomagnesium
-tetany and seizures, decreasing neural transmission, CV abnormalities, weakness, tremors, paralysis,,, psychiatric disorders
Causes of hypomagnesium
- diabetes mellitus (Type two magnesium effects insulin function)
- Diuretic therapy
- alcoholism
-Drug therapy - Hyperaldosteronism (Magnesium gets excreted)
What is the most abundant mineral in the body, fifth most abundant inorganic element
Calcium
Too much increases apoptosis 
 ______% of calcium resides in the bone (reservoir), ___% in plasma 
99
1
Of the 1% of calcium in the plasma what percentage is the free ionized form that is biologically active?
What percentage is bound to proteins?
45-50
40-50
________-Calcium specific curator
________-Divalent curator that removes calcium and magnesium
EGTA, EDTA
Calcium can be re-distributed Among three plasma pools by…
- Alteration in the Protane and anion
- pHchange
- Changes in free total calcium in serum
What are the functions of calcium?
-Key mineral in bone matrix
-Enzymatic activity regulator (Allosteric regulator)
-Component of coagulation and complement system
-Maintenance of skeletal and cardiac muscle tone/contraction, signal transduction, Glycogen metabolism and cell division
Calcium opens up _________ Binding site (Remove troponin) So actin and myosin can bind
Actin 
_______________ have higher calcium concentrations than adults
Neonates
Calcium levels are dynamic, increase calcium because they are growing and reconstruction of bone
Phosphorus in the form of phosphate found ____% In bone
85
Phosphorus monovalent or divalent depending on…
pH
Decrease pH it will be monovalent
What type of ion is phosphorus?
Major intracellular anion
Functions of phosphorus
-Energy storage ATP
-DNA structure
-Buffer in blood
-Bone matrix
Calcium and phosphorus are ____________ Related (serum concentrations)
Inversely****
In bone, phosphate and calcium form_____________ Which is the foundation to the bone
Hydroxyapatite
What major organs maintain calcium phosphorus regulation?
-bone
-Intestines
-Kidney
Major hormones for calcium phosphorus regulation
-vitamin D (Calcitrol)
-Parathyroid hormones (PTH)
-Calcitonin (Thyroid hormone) 
Critical bone components:
Matrix of primary collagen (Unmineralized)
Osteoid
Critical bone components:
Calcium, phosphorus, etc.
Minerals
What are the three bone cells?
-osteoblasts: Bone formation
-Osteocytes: Mature/trapped osteoblasts
-Osteoclasts: bone reabsorption (Tear down bone)
Osteoblasts are actively regulated by:
Osseo class are actively regulated by: 
Calcitrol and PTH
Calcitrol PTH and calcitonin
- PTH and calcitonin are immediate regulators
What are the immediate regulators of calcium? What is the long-term regulator?
- PTH and calcitonin
- Vitamin D/Calcitrol
What responds when serum calcium decreases?
Parathyroid glands to produce parathyroid hormone to increase calcium
Increase parathyroid hormone has what effect?
-Increased Osteoblast and osteoclast *(Tearing down bone) activity in bone
-increase phosphate excretion in kidney
-Results in an increase of calcium and decrease phosphate ion
-Increased Calcitrol
What is the biologically active form of vitamin D/Calcitrol
1, 25 (OH)2D*
PTH directly effects…
Calcium and phosphate
Major hormone involved with serum calcium and phosphate regulation through intestine, bone and kidney
Vitamin D/Calcitrol
Increased PTH _________Phosphorus
Decreases
What are the functions of vitamin D
-increased intestinal calcium absorption
- Increase osteoblast activity in bone cells
-Increase renal calcium and phosphate reabsorption
-Intermediate to longer-term regulator of calcium
-Feedback and Inhibits PTH secretion
What inhibits PTH secretion?
Increased vitamin D
increased _____________ Activity and kidney by increase PTH and or decrease phosphate
1-a-Hydroxylase
Increased calcium and vitamin D ___________ PTH
Decreases
What are the main sources of magnesium, calcium, phosphorus?
Diet
When fasting, phosphorus is mainly effected by…
PTH
What is decreased and long-term liver disease?
Serum levels of calcium, magnesium, and phosphorus
They are normally bound to proteins, in liver disease proteins decrease so these get excreted in urine instead
What is the function of calcitonin?
Decrease serum calcium levels, moves calcium to the bone*
What opposes the effect of PTH on calcium and phosphate movement from the bone? 
Calcitonin
Calcitonin __________ Calcitrol
Increases
“Paradox effect” 
