Transcript CHAPTER 6 *Bones and Skeletal Tissue*

Bones
SKELETAL SYSTEM:
Include all bones (206) in the body associated cartilage and joint.
Functions:
1. Support and movement
2. Protection
3. Mineral storage
4. Electrolyte balance
5. Formation of blood cell
6. Detoxification by absorbing heavy minerals
Composition of Bone
 compact and spongy bones are composed of bone cells and
collagenous organic matrix (calcium and phosphate that deposited
as a complex inorganic hydrated hydroxyapatites) which gives the
strength of the bone.
 Type of bone cells:
1. Osteoclasts: Bone destroying cells “C” means chewing
2. Osteoblasts: Bone generating cells “B” means building
3. Osteocytes: Mature bone cells, spider shaped and maintain bone
tissue
Types of Bones cells
Control of Bone Growth
• Minerals, vitamins, and hormones influence growing of the bone.
• The specific hormones which affect growth are growth hormone (GH),
thyroid hormone (T3 and T4), and the sex steroids (estrogen and
tesstosterone).
• The growing of the bone increasing until adulthood then start
remodeling constantly.
• Each week we turn over about 5% of our bone mass.
Bone profile
Bone Profile test which measures proteins, minerals and enzymes
involved in bone turnover and can indicate problems with bone.
Specimen
Serum in gold-top vacutainer
Serum:
Calcium, Phosphate, ALP, Mg, Vitamin D.
Plasma:
PTH
Parathyroid hormon
Parathyroid gland secrete PTH into the bloodstream in response to low blood
calcium levels.
Function:
 takes calcium from the body's bone
 stimulates the activation of vitamin D in the kidney
 Increase reabsorption of Ca and increase seretion of phosphate
As calcium levels begin to increase in the blood, PTH normally decreases.
 Normal values are 10 - 55 (pg/mL).
Excess PTH secretion may be due to
• kidney failure and rickets
• benign parathyroid tumor
• vitamin D deficiency
Low levels of PTH may be due to conditions causing
• low levels of magnesium
• abnormality in PTG
Vitamin D
 The main role of Vitamin D is to help regulate the absorption of
calcium, phosphorus, and magnesium and helps form and maintain
bones.
 These happen by
active forms of vitamin D 1,25-dihydroxycholecalciferol (calcitriol)
 Hydroxylation of vitamin D by (25- hydroxylase) in the liver and
(1αhydroxylase) in the kidney.
 The normal range is 30.0 to 74.0 (ng/mL).
25-hydroxlase
1α-hydroxlase
7-dehydrocholesterol
calcitriol
Vitamin D deficiency can result from
 inadequate intake
 inadequate sunlight exposure
 limit its absorption
without it, bones will be soft, malformed, and unable to repair
themselves normally, resulting in diseases
called rickets in children and osteomalacia
in adults.
Increase amount of Vitamin D will be
toxic when we take overdosing of supplements.
Calcium
Calcium that is present in the bloodstream circulates in the free
state(ion), bound to organic substances, and bound with albumin.
Most of the physiological functions of calcium depend upon the
ionized fraction, but for routine work only total calcium in serum is
estimated.
total calcium level is affected by the amount of protein present.
Corrected calcium = [Ca]+ 0.02*{40-[alb]} if [alb]<40
= [Ca]+ 0.02*{[alb]- 45} if [alb]>40
Function: (ionized form)
muscular contraction, cardiac functioning, hormone secretion,
cell division, and the transmission of nerve impulses, blood
coagulation .
Normal Results
Total plasma calcium 9.0-10.5 mg/dl
Free calcium 3.9-4.6 mg/dl
Hypercalcemia can be indicative
of:
Hypocalcemia can be indicative of:
•Cancers of the lung, breast, thyroid,
kidney,
•hyperparathyroidism
•Paget's disease of bone,
•prolonged immobilization
•Addison‘s disease.
•hypoparathyroidism
• renal failure
• Vitamin D deficiencies
• malabsorption
Low ionized calcium can subsequently lead to coagulation and hemostasis problems
Principle:
Serum + ammonium oxalate
ppt calciumoxalate
The precipitate is washed with ammonia to remove excess oxalate
calcium oxalate + sulphuric acid
oxalic acid
The latter is titrated with standard potassium permanganate.
Procedure:
1. Measure 2 ml of serum, 2 ml of water and 1 ml of 4%
ammonium oxalate in a centrifuge tube.
2. Mix and allow to stand for at least half an hour thin Mix again
and centrifuge at 1,500 r.p.m. for 15 minutes.
3. Pour off the supernatant fluid and drain the tube by keeping it
inverted on a filter paperfor a few minutes. Wipe the mouth of
the tube dry with a filer paper.
4. Add 3ml of 2% ammonia, shake, centrifuge and drain as before.
5. Add 2 ml of 1 Nsulphuric acid and shake vigorously.
6. Keep the tube in a boiling water-bathshaking intermittently, until
the precipitate completely dissolves.
7. titrate with 0.01 N potassium permanganate until a pinkcolour
develops and persists for at least one minute.
8. Note the volume of 0.01N potassium permanganate used.
Suppose it is x ml.
9. For blank, take 2 ml of1 N sulphuric acid and titrate it with 0.01 N
potassium permanganate exactlyas before, suppose the volume
of potassium permanganate used in y ml.
Calculation:
Phosphate
phosphorus is found in bones and teeth and is combined with calcium.
The rest of phosphorus is in the soft tissues.
Function: Phosphorus in the blood necessary for the metabolism of
glucose, fats, and proteins; and the storage and transfer of energy
Normal Results
• Adults 2.7-4.5 mg/dl
• Children 4.5-5.5 mg/dl
hyperphosphatemia may be due to
or associated with:
Hypophosphatemia may be due to
or associated with:
•Diabetic ketoacidosis (when first
seen)
•Increased dietary intake
•Hypoparathyroidism
•Hypercalcemia,
•Overuse of diuretics
•Rickets and osteomalacia
(due to Vitamin D deficiencies)
•Kidney failure
•Hyperparathyroidism
•Malnutrition
Phosphate levels are normally higher in children than in adults
because their bones are actively growing.
Principle:
Serum is deproteinized with trichloracetic acid.
Protein-free is filtrate.
acid molybdate + phosphate
phosphomolybdic acid.
phosphomolybdic acid
1,2,4-aminonaphtholsulphonic acid
redduced
phosphomolybdous acid
(molybdenum blue)
The intensity of the colour is measured colorimetrically.
Procedure :
UNK
std
blank
Sample (1ml of
serum + 9 ml of
trichloracetic acid )
5 ml of the filtrate
-
-
trichloracetic acid
-
-
5 ml
working standard
phosphorus
-
5 ml
-
water
3.6 ml
3.6 ml
3.6 ml
Mix
Let the tubes stand for 5 minutes
Read at 680 nm
Calculation :Serum inorganic phosphorus
Conc. Of phosphoruse= Abs (unk)/Abs(std)*4
Magnesium
Function:
• muscular contraction
• carbohydrate metabolism
• protein synthesis
It is usually filtered by the kidney through the glomerulus, and
reabsorbed into the bloodstream by the renal tubule.
Normal Results
1.7 to 2.2 mg/dL
High magnesium levels may be due
to :
•
•
•
•
•
Diabetic acidosis
Oliguria
Addison's disease
Chronic renal failure
Dehydration
Low magnesium levels may be due
to :
• Alcoholism
• Chronic diarrhea
• Hemodialysis
• Hepatic (liver) cirrhosis
• Hyperaldosteronism
• Hypoparathyroidism
• Ulcerative colitis
Alkaline phosphatase
ALP : enzyme that found in all body tissues. In the liver, it is found on
the edges of cells that join to form bile ducts, in "osteoblasts“ of
the bone cells.
Normal Results
Adult 17-142 U/L
Children 0-12 yr 145-530 U/L
High level of ALP may be due to:
Low level of ALP may be due to:
•Bone disease (Paget's disease, where •Some drugs (contraceptives )
bones become enlarged and deformed
cancers spread to bone, Rickets,
Osteomalacia)
•Liver disease
•Bile duct damage
•Children & pregnant women
(normal)
*GGT test be done to differentiate between liver and bone disease.
*If calcium and phosphorus measurements are abnormal, usually the ALP is
coming from bone.
Principle :
serum + buffer substrate
phenol + 4-animoantipyrine
phenol
red color
Color is stable for at least an hour so, sodium hydroxide is added
immediately after incubation to raise the pH and stop the reaction.
Procesure:
Calculation:
Referance
 Marie A. Moisio, MA. (1993) Understanding Laboratory and Diagnostic Tests.
 Marshall, W. Bangert, K.(2008) clinical chemistry. 6th ed.
 http://www.westernsussexhospitals.nhs.uk/services-and-treatments/diagnosisand-screening/blood/types/
 http://kidshealth.org/parent/system/index.html#cat174
 http://labtestsonline.org/understanding/analytes/alp/tab/test
 http://www.austincc.edu/search/results.php?cx=003770341465265277363%3Ad
33byhd4au8&cof=FORID%3A11&ie=UTF-8&q=bone
 http://courses.washington.edu/bonephys/opvitD.html
 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1146022/
 http://www.nlm.nih.gov/medlineplus/ency/article/000344.htm