Calcium, Phosphorus, and Magnesium

Question 1

Increase intracellular calcium results in increased…

Answer 1

Contraction

Question 2

A decrease in serum magnesium, Causes calcium in serum to…

Answer 2

Go down (Into the cell) 

Question 3

An increase in serum magnesium Causes _________ in Serum calcium

Answer 3

Increase (Decrease inside the cells) 

Question 4

Over 300 Enzymatic activity requires magnesium as a…

Answer 4

Cofactor

Question 5

What is the biologically active form of magnesium?

Answer 5

Ionized/free form (about 70%) 

Question 6

Is magnesium extracellular or intracellular cation?

Answer 6

Intracellular, influenced by Hemolysis
*divalent

Question 7

Major source of magnesium?

Answer 7

Diet/reabsorbed in intestine

Question 8

What is the normal value for magnesium in plasma/serum?

Answer 8

1.7-2.2 mEq/L (0. 85-1.10 mmol/L)

• Member first number is twice as much

Question 9

What is the percentages and location of magnesium in the body?***

Answer 9

-bone 50-60%
-muscle 20%, intracellular 20% (Cells equals 40%)
-Serum 1%

Question 10

Magnesium in serum, which accounts for 1% of all body magnesium,  is in what forms? 

Answer 10

-ionized about 70% *
-Protein associated 25%
-Combined ions (Phosphate and citrate) 5%

Question 11

Steroid hormones don’t need plasma ____________

Answer 11

Receptors

Question 12

Three mechanisms of allosteric regulator

Answer 12

-changes structure of proteins so substrate cannot bind
-physically covers the substrate binding site
-Enhances enzymatic activity

Question 13

What are the functions of magnesium?

Answer 13

-enzymatic reactions, energy storage/transfer/production
** Inhibits calcium entry into cells!
* Bone homeostasis (50-60%) 

Question 14

Magnesium in serum is regulated by…

Answer 14

-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)*****

Question 15

What three hormones regulate magnesium?

Answer 15

-thyroxine
-Aldosterone
-Parathyroid hormone PTH

Question 16

Mg inhibits __________ entry into the cell

Answer 16

Calcium**

Question 17

What are symptoms of hyper magnesium?

Answer 17

heart block, vomiting, nausea

Sedation, respiratory depression, paralysis,coma 

Question 18

Causes of elevated magnesium

Answer 18

• adrenal insufficiency: Hypoaldosteronism (aldosterone increases magnesium excretion)
• hypothyroidism
  -Renal Failure
  -Dehydration (Relative amount, not absolute amount) 

Question 19

Symptoms of hypomagnesium

Answer 19

-tetany and seizures, decreasing neural transmission, CV abnormalities, weakness, tremors, paralysis,,, psychiatric disorders

Question 20

Causes of hypomagnesium

Answer 20

• diabetes mellitus (Type two magnesium effects insulin function)
• Diuretic therapy
• alcoholism
  -Drug therapy
• Hyperaldosteronism (Magnesium gets excreted)

Question 21

What is the most abundant mineral in the body, fifth most abundant inorganic element

Answer 21

Calcium

Too much increases apoptosis 

Question 22

 ______% of calcium resides in the bone (reservoir), ___% in plasma 

Answer 22

99
1

Question 23

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?

Answer 23

45-50
40-50

Question 24

________-Calcium specific curator
________-Divalent curator that removes calcium and magnesium

Answer 24

EGTA, EDTA

Question 25

Calcium can be re-distributed Among three plasma pools by…

Answer 25

1. Alteration in the Protane and anion 2. pHchange 3. Changes in free total calcium in serum

Question 26

What are the functions of calcium?

Answer 26

-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

Question 27

Calcium opens up _________ Binding site (Remove troponin) So actin and myosin can bind

Answer 27

Actin 

Question 28

_______________ have higher calcium concentrations than adults

Answer 28

Neonates Calcium levels are dynamic, increase calcium because they are growing and reconstruction of bone

Question 29

Phosphorus in the form of phosphate found ____% In bone

Answer 29

85

Question 30

Phosphorus monovalent or divalent depending on…

Answer 30

pH Decrease pH it will be monovalent

Question 31

What type of ion is phosphorus?

Answer 31

Major intracellular anion

Question 32

Functions of phosphorus

Answer 32

-Energy storage ATP -DNA structure -Buffer in blood -Bone matrix

Question 33

Calcium and phosphorus are ____________ Related (serum concentrations)

Answer 33

Inversely******

Question 34

In bone, phosphate and calcium form_____________ Which is the foundation to the bone

Answer 34

Hydroxyapatite

Question 35

What major organs maintain calcium phosphorus regulation?

Answer 35

-bone -Intestines -Kidney

Question 36

Major hormones for calcium phosphorus regulation

Answer 36

-vitamin D (Calcitrol) -Parathyroid hormones (PTH) -Calcitonin (Thyroid hormone) 

Question 37

Critical bone components: Matrix of primary collagen (Unmineralized)

Answer 37

Osteoid

Question 38

Critical bone components: Calcium, phosphorus, etc.

Answer 38

Minerals

Question 39

What are the three bone cells?

Answer 39

-osteoblasts: Bone formation -Osteocytes: Mature/trapped osteoblasts -Osteoclasts: bone reabsorption (Tear down bone)

Question 40

Osteoblasts are actively regulated by: Osseo class are actively regulated by: 

Answer 40

Calcitrol and PTH Calcitrol PTH and calcitonin * PTH and calcitonin are immediate regulators

Question 41

What are the immediate regulators of calcium? What is the long-term regulator?

Answer 41

* PTH and calcitonin * Vitamin D/Calcitrol

Question 42

What responds when serum calcium decreases?

Answer 42

Parathyroid glands to produce parathyroid hormone to increase calcium

Question 43

Increase parathyroid hormone has what effect?

Answer 43

-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

Question 44

What is the biologically active form of vitamin D/Calcitrol

Answer 44

1, 25 (OH)2D*

Question 45

PTH directly effects…

Answer 45

Calcium and phosphate

Question 46

Major hormone involved with serum calcium and phosphate regulation through intestine, bone and kidney

Answer 46

Vitamin D/Calcitrol

Question 47

Increased PTH _________Phosphorus

Answer 47

Decreases

Question 48

What are the functions of vitamin D

Answer 48

-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

Question 49

What inhibits PTH secretion?

Answer 49

Increased vitamin D

Question 50

increased _____________ Activity and kidney by increase PTH and or decrease phosphate

Answer 50

1-a-Hydroxylase

Question 51

Increased calcium and vitamin D ___________ PTH

Answer 51

Decreases

Question 52

What are the main sources of magnesium, calcium, phosphorus?

Answer 52

Diet

Question 53

When fasting, phosphorus is mainly effected by…

Answer 53

PTH

Question 54

What is decreased and long-term liver disease?

Answer 54

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

Question 55

What is the function of calcitonin?

Answer 55

Decrease serum calcium levels, moves calcium to the bone*

Question 56

What opposes the effect of PTH on calcium and phosphate movement from the bone? 

Answer 56

Calcitonin

Question 57

Calcitonin __________ Calcitrol

Answer 57

Increases “Paradox effect”