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Question 1

Minerals charcuteries

Answer 1

1-inorganic elements
2-Do not contain carbon.
3-remain intact during digestion.
4- don’t change shape or structure
5- not destroyed by heat, acids, oxygen, or ultraviolet light.
6-Most minerals absorbed from diet are in the form of water-soluble
salts.

Question 2

In general, mineral deficiencies are encountered when foods come from
…….. region,

Answer 2

one

Question 3

Minerals essential for life are divided into:
o major or macro-minerals (or elements) (daily requirement …………..

o trace or micro-elements (daily requirement ………….

Answer 3

> 100 mg).

< 100 mg).

Question 4

Macrominerals (major-elements) are seven:

Answer 4

calcium, phosphorus,
magnesium, sulfur, sodium, potassium and chloride.

Question 5

Microminerals: (trace elements):

Answer 5

iron, cobalt, chromium, copper,
iodine, zinc, manganese, selenium, silicon, fluoride & molybdenum.

Question 6

qFactors that ↑ Bioavailability

Answer 6

§ Deficiency in a mineral increases
its absorption.
§ Cooking increase bioavailability of
mineral legumes.
§ Vita. D→ ↑ absorption of calcium,
phosphorus & magnesium. § Vitamin C→ ↑ absorption of some
minerals as iron.

Question 7

qFactors that ↓ Bioavailability:

Answer 7

§ Oxalates found in some vegetables.
§ Phytates found in grains.
§ Polyphenols found in tea & coffee.
§ Supplementation of a single mineral
affects the absorption of competing
minerals.

Question 8

Sodium is the chief electrolyte which is found in large conc. in ………………..
• The sodium is found in the body mainly associated with …………………..
• Sources: widely distributed in food material; more in ………… sources than …….. • Major source is ………..

Answer 8

extracellular fluid (ECF).

chloride as NaCl & NaHCO 3.

animal sources than plants. • Major source is table-salt.

Question 9

Sodium is absorbed by

Answer 9

actively by sodium pump, (Na +-
K+-ATPase), situated in plasma membrane of intestinal
& renal cells.

It is an enzyme and its activity depends on presence of Na + & K+ and requires ATP & Mg++as cofactors.
The enzyme hydrolyses one ATP molecule to transport
3 Na+ ions outside & simultaneously 2 K+ ions inside
across the cell membrane.

Question 10

Active absorption of Na+ is coupled with

Answer 10

glucose
absorption or amino acid absorption.

Question 11

Functions of Sodium:

Answer 11

• Fluid balance : it maintains osmotic pressure of ECF & helps to maintain
water in ECF.
• Neuromuscular excitability.
• Acid-base balance: Na +-H+ exchange in renal tubule to acidify urine.
• Role in resting membrane potential: Na+ pump keeps Na + conc. outside
higher than inside, creating a membrane potential across the membrane.
• Role in Action Potential: on stimulation, a local depolarization of nerve
or muscle fiber is observed →↑ its permeability to Na+→ trans-
membrane influx of Na+ down its inward conc. gradient.

Question 12

Clincle Aspect; I . Hyper-natremia:

Answer 12

• Simple dehydration: ↑ sweating with inadequate or no water replacement.
• Diabetes insipidus (DI): → water loss caused by ↓ ADH or its failure to act
on its target cells.
• Excess sodium intake: e.g. ↑ use of isotonic saline or administration of
NaHCO 3 in treatment of acidosis.
• Steroid therapy: e.g. mineralocorticoids cause the kidney to absorb Na from glomerular filtrate → ↑ plasma Na concentration.
• Certain tumors of adrenal gland → ↑ aldosterone; the most potent mineralocorticoid (Conn’s syndrome).

Question 13

Clinical Aspect; II. Hypo-natremia

Answer 13

Diuretic medication: (as in CHF, CRF, hypertension).

Excessive sweating: Loss of fluids of high Na + & Cl–

Kidney diseases:

Gastrointestinal loss: Diarrhea

Question 14

K is the major ………….. cation.
• It is widely distributed in vegetables.
• Potassium is easily absorbed & enters the cells. It is excreted is ………
• K is also excreted in GIT; …….,……,…..,….,…

Answer 14

intracellular

urine, saliva, gastric juice, bile,
pancreatic & intestinal juices.

Question 15

Functions of Potassium:

Answer 15

• It influences the muscular activity.
• Involved in acid-base balance.
• It has an important role in cardiac function.
• Certain enzymes, as pyruvate kinase, require K+ as a cofactor.
• Involved in neuromuscular irritability and nerve conduction process.

Question 16

potassium value changes in

Answer 16

standing, RBCs hemolyzed

so the plasma potassium must
be measured as soon as possible on fresh sample.

Question 17

Hyperkalemia

Answer 17

-rapid IV infusion of potassium salts.
-Kidney failure with ↓ K+ excretion.
-oAnuria
oSudden release of K+ from the intracellular compartment due to a
varieties of diseases.
oTissue damage
o Addison’s disease: ↓ aldosterone

oDiabetes mellitus In ketoacidosis → loss of intracellular K+ to the ECF
due to ↑ activity of Na -K ATPase

Question 18

Hypokalemia

Answer 18

oLoss of K+ in GI secretions:
- Both prolonged vomiting & severe diarrhea, - Habitual users of laxative → chronic mild diarrhea →↓ K + levels.
- A mucous secreting tumor → secretes ↑ amounts of K+ into the colon.

oLoss of K+ in urine:
- Some diuretics - Conn’s tumor, called primary hyperaldosteronism

oCushing syndrome,

during treatment of diabetic ketoacidosis

• Familial periodic paralysis → sudden shift of K+ into ICF → paralysis.
• In thyrotoxic periodic paralysis (TPP) similar thing happens. Excess thyroid
  hormone level is observed in these patients.
• Renal tubular acidosis:

Question 19

CALSIUM Dietary sources

Answer 19

milk, cheese, egg-yolk,
small fish (with bones as sardines), beans, lentils, nuts, figs, cabbage,
broccoli.

Question 20

Body distribution: The total Ca of the body is 1,000 -1,400 g. About

Answer 20

99%
is found in bones & teeth as Ca carbonate or phosphate.
• Calcium in the body fluids:
• Only 1 % of the body’s Ca circulates in ECF & ICF.

Question 21

Calcium in ICF binds to proteins. These proteins participate in:

Answer 21

• Regulation of muscle contractions,
• Transmission of nerve impulses,
• Secretion of hormones,
• Activation of some enzyme reactions.

Question 22

Calcium in plasma or serum exists in three forms or fractions:

Answer 22

1. Protein-bound calcium: Bouded mainly to albumin.
2. Ionized or free calcium: About 50 % of total calcium & the physiologically
   active form
3. Complexed calcium: Probably complexed with organic acids.

Question 23

Too low or too high blood Ca levels → 3 organ systems respond:

Answer 23

intestines, bones & kidneys.

Question 24

Ca in ………. provides a bank of calcium for the blood.

Blood Ca changes only in response to ……..

Answer 24

bones

abnormal regulatory control, not
to diet.
- A lack of vitamin D or - Abnormal secretion of regulatory hormones.

Question 25

Blood Ca above normal → Ca ………..,
§ Blood Ca below normal → Ca …………..

Answer 25

Blood Ca above normal → Ca rigors, (episode of shaking or exaggerated
shivering).
§ Blood Ca below normal → Ca tetany, (spasm, cramps or twitching of
skeletal muscles).

Question 26

Calcitriol & PTH → ?………. Ca level in blood.
Calcitonin (PTH antagonist) counteracts these processes →………blood Ca.

Answer 26

raise

→↓

Question 27

Calcitriol →↑ Ca absorption in the

PTH supports these processes by

Answer 27

Calcitriol →↑ Ca absorption in the intestines & kidneys by inducing
transporters.
§ PTH supports these processes by stimulating calcitriol biosynthesis in
the kidneys.
§ In addition, PTH directly promotes reabsorption of Ca in the kidneys and
calcium release from bones.

Question 28

Ca is absorbed by two mechanisms:

Answer 28

1. Simple diffusion. 2. Active transport process involving energy and Ca pump.
   § Both processes require 1,25-dihydroxy-D3 (calcitriol)

Question 29

Factors that ↓ Ca absorption:

Answer 29

§ Lack of stomach acid: alkaline pH
↓ absorption.
§ Vitamin D deficiency.
§ High phosphorus intake.
§ Phytates (seeds, nuts, grains), forms
insoluble Ca phytates.
§ Oxalates: spinach, cabbage, sweet
potatoes → insoluble Ca oxalates.
§ Excess fibers in diet ↓ Ca absorp.
§ Fe in diet:

Question 30

Factors that ↑ Ca absorption:

Answer 30

o Stomach acid: acidic pH ↑absorp.
o Vitamin D.
o Lactose (in infants only).
o High protein diet: a.as

Question 31

Functions of Calcium:

Answer 31

• Calcification of bones & teeth
. • Blood coagulation.
• Neuromuscular transmission.
• Calcium ions are needed for excitability of nerves.
• Normal excitability of heart is Ca ion dependent.
• Calcium plays a role in muscle contraction.
• It acts as a secondary or tertiary messenger in hormone action.

Question 32

Causes of hypocalcemia -Ca level < 8.5 mg/dl,

Answer 32

1. Hypoalbuminemia
2. Hypoparathyroidism 4. Osteomalacia and rickets
3. Renal diseases & failure 5. Magnesium deficiency
4. Neonatal hypocalcemia:
   - Prematurity

Question 33

Causes of hypercalcemia Ca level > 11.0 mg/dL,

Answer 33

1. Primary hyperparathyroidism.
2. Malignancy:
3. Granulomatous Diseases 4. Overdosage of Vitamins: as vitamin D & vitamin A.
4. Drug-induced Hypercalcemia (Iatrogenic):

Question 34

Toxicity Symptoms:Of ca

Answer 34

§ Constipation.
§ Increased risk of kidney stone formation.
§ Interferes with absorption of other minerals as iron, zinc and magnesium.

Question 35

PHOSPHORUS:
Body Distribution

Answer 35

> 85 % is found
in bones combined with calcium,
14% in soft tissues and 1 % in ECF.

Question 36

P Its absorption is stimulated by

Answer 36

both PTH and Vit. D3. § The Ca:P ratio

Question 37

Functions of Phosphorus:

Answer 37

• A constituent of bone & teeth.
• Energy transfer: ATP, creatin-P.
• Phosphorylation/dephosphorylation reactions involve phosphate.
• Acid-base balance
• Enzyme action:
• Constituent of phospholipids, nucleotides/nucleic acids, lipoproteins,
phosphoproteins is phosphate.

Question 38

important dietary deficiency disorders
of Ca, P or vit-D.

Answer 38

• Rickets and osteomalacia

Question 39

Causes of Hypophosphatemia

Answer 39

• Decreased intake or absorption: Starvation, malabsorption, vomiting,
vitamin D deficiency.
• Increased Excretion: diuretics, renal tubular diseases, ↑PTH also →↑
renal excretion of phosphates leading to ↓ its serum level.
• Increased cell uptake: Alkalosis especially respiratory → movement of
phosphates into cells.

Question 40

Causes of Hyperphosphatemia:

Answer 40

Increased intake: Diet, Vit. D.
• Decreased renal excretion: Renal failure, hypoparathyroidism → ↑P
serum level.
• Increased release from cells: DM, starvation, metabolic acidosis which
is associated with ↑ blood K & P concentrations.
• Increased release from bone: Malignancy.
• Cell damage (lysis)

Question 41

Functions of Magnesium:

Answer 41

• Activation of about 300 enzyme systems are Mg dependant.
• A constituent of Bones and Teeth: About 70 % of body Mg is present
in bones & teeth.
• Many biochemical proceses are Mg dependant as:

• Glycolysis. - Oxidative metabolism. - Transmembrane transport of K & Ca.

Question 42

Causes of Hypermagnesemia

Answer 42

Causes of Hypermagnesemia:
• Uncontrolled DM,
• Adrenocortical insufficiency.
• Hypothyroidism.
• Acute or advanced renal failure.

Question 43

qCauses of Hypomagnesemia:

Answer 43

• Malabsorption syndrome and
Kwashiorkor.
• Prolonged gastric suction.
• Hyperthyroidism.
• Liver cirrhosis.
• Prolonged use of diuretics.
• Renal diseases