Abraham Baldwin Agricultural College CH14 Mineral & Bone Metabolism HW Hello I need help to answer these discussion questions about chemistry in 3-4 senten

Abraham Baldwin Agricultural College CH14 Mineral & Bone Metabolism HW Hello I need help to answer these discussion questions about chemistry in 3-4 sentences for each question separately after you view the short video you will be able to answer these questions.Also please answer the 15 other questions all of them multiple choice just mark the correct answer in yellow . please find attached the questions and the chapter.Thank you CH14-Mineral & Bone Metabolism
Name___________________________________
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
C) Calcitonin
D) 1, 25- dihydroxy Vitamin D3
1
D) beriberi.
–
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
C)
Leukocytes
D)
2
Large proteins
3
Clinical Laboratory Chemistry
Second Edition
Chapter 14
Mineral and Bone
Metabolism
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Minerals, Parathyroid Hormone, Vitamin D, and Calcitonin
• Calcium Homeostasis
– 98% in bones as
hydroxyapatite and teeth
– In blood, calcium exists
as:
▪ Free or ionized (50%)
▪ Complexes with anions
(10%)
– Bicarbonate
– Lactate
– Phosphate
– Citrate
▪ Bound to protein (40%)
continued on next slide
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Minerals, Parathyroid Hormone, Vitamin D, and Calcitonin
• Calcium Homeostasis
– Involves participation of:
▪ Small intestine
▪ Kidneys
▪ Skeleton
– Regulatory hormones include:
▪ Parathyroid hormone (PTH)
▪ 1,25-dihydroxycholecalciferol
▪ Calcitonin
– Calcium functions
▪ Nerve impulse transmission
▪ Cofactor in certain enzymes
▪ Coagulation of blood
▪ Skeletal mineralization
▪ Preservation of cell membrane integrity and permeability
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FIGURE 14-1 Calcium homeostasis. Decreased blood levels of calcium stimulate the
release of PTH from the parathyroid glands. PTH enters the circulatory system and is
transported to the kidneys, intestines, and bone. In the kidney, calcium is reabsorbed while
phosphate is excreted. PTH increases intestinal calcium absorption by increasing
1,25(OH)2D3. In bone, PTH stimulates an increase in the release of minerals (e.g., calcium
and phosphate) from bone into the extracellular fluid.
Copyright © 2018, 2011 Pearson Education, Inc. All Rights Reserved
continued on next slide
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Minerals, Parathyroid Hormone, Vitamin D, and
Calcitonin
• Urinary Calcium
– Concentration of
calcium in urine
reflects:
▪ Intestinal absorption
▪ Skeletal resorption
▪ Renal tubular
filtration and
reabsorption
– Increased urinary
calcium concentration
may be associated
with an increase in
osteoclastic bone
resorption.
continued on next slide
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Minerals, Parathyroid Hormone, Vitamin D,
and Calcitonin
• Phosphorus Homeostasis
– Human body contains about
620 g of phosphorus entirely
in the form of phosphate
(PO42-).
– Phosphate ions are
distributed equally.
▪ Intracellular
▪ Extracellular
– Intracellular phosphate occurs
mainly as a component of
macromolecules (e.g.
phospholipids and
phosphoproteins).
continued on next slide
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Minerals, Parathyroid Hormone, Vitamin D, and Calcitonin
• Phosphorus
Homeostasis
– Approximately 85% of
extracellular phosphate
occurs in inorganic
form as hydroxyapatite.
– In plasma, most
phosphate exists in the
inorganic form as
mono- or dihydrogen
phosphate ions.
– Three major organs
involved in phosphorus
homeostasis are the
small intestine,
kidneys, and skeleton.
continued on next slide
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• Phosphorus Levels in Blood
continued on next slide
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• Magnesium Homeostasis
– In a normal adult, the total
body magnesium is ∼ 25g.
– About 55% of the total body
magnesium is in the skeleton
and the rest is intracellular.
– Magnesium serves as a
cofactor for more than 300
enzymes.
▪ Required for enzymesubstrate (ES) formation
▪ Functions as an activator for
many enzyme systems
Magnesium is required for:
-Cellular energy
metabolism and membrane
stabilization
-Nerve conduction
-Ion transport
-Ca2+ channel activity
continued on next slide
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• Magnesium Levels
– Urinary magnesium levels
provide the clinician with
valuable data to evaluate
patients who present with
hypomagnesemia that
develops late in the course
of magnesium deficiency.
– Reference range for 24h
urinary magnesium is 6.0–
10.0 mEq/L to 51 – 269
mg/24h.
continued on next slide
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Copyright © 2018, 2011 Pearson Education, Inc. All Rights Reserved
• Parathyroid Hormone (PTH)
– An 84-amino acid peptide
synthesized by the chief
cells of the parathyroid
gland
– Secretion is highly
dependent on the ionized
calcium concentration via a
negative feedback loop.
– Serum PTH concentration
decreases as the serum
calcium concentration
increases.
Biological actions
-Stimulation of osteoclastic bone
reabsorption and release of
calcium and phosphate from
bone.
-Stimulation of calcium
reabsorption and inhibition of
phosphate reabsorption from the
renal tubules.
-Stimulation of renal production of
1,25(OH)2 vitamin D3, which
increase intestinal absorption of
calcium and phosphate.
continued on next slide
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– Role of Vitamin D in
Calcium Metabolism
• Vitamin D and Metabolites
– Vitamin D3, or cholecalciferol, is a
prohormone.
– Almost all of vitamin D3 in plasma is
bound to serum alpha globulin.
– Steroid hormone 1,25(OH)2D3 is the major
biologically active metabolite of the
vitamin D sterol family.
– Previtamin D3 is either ingested or
synthesized in the skin from 7dehydrocholestrol through exposure to
sunlight.
▪ Increases plasma
calcium and phosphate
concentration by
increasing the absorption
of calcium and
phosphate from the
gastrointestinal tract.
▪ Increases bone
resorption and enhances
the effects of PTH in the
nephron to promote renal
tubular calcium
reabsorption.
continued on next slide
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FIGURE 14-2 Metabolism of vitamin D in the liver and kidneys.
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• Calcitonin
– Calcitonin is a 32-amino acid
peptide synthesized and
secreted by the parafollicular
cells of the thyroid gland.
– Ionized calcium levels are
significant regulators of calcitonin
secretion.
– While the precise biological role
of calcitonin is uncertain, it does
directly inhibit osteoclastic bone
resorption.
– Useful in the evaluation of
patients with nodular thyroid
disease
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Mineral Disorders
– Common disorder
▪ Affects about 1% of the
general population
– Two principle causes
▪ Malignancy
▪ Primary
hyperparathyroidism
– Categories
▪ Deficiency in PTH
production and secretion
▪ Resistance to PTH
secretion
▪ Deficiency in vitamin D or
vitamin D metabolites
▪ Deficiencies in bone
mineralization with normal
metabolism of PTH and
vitamin D.
continued on next slide
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Copyright © 2018, 2011 Pearson Education, Inc. All Rights Reserved
TABLE 14-1 Causes of Hypercalcemia and
Hypocalcemia
Hypercalcemia
Hypocalcemia
Primary hyperparathyroidism
Renal failure
Renal transplantation
Malignancy
Immobilization
Thiazide diuretics
Lithium
Vitamin D or A intoxication
Thyrotoxicosis
Hypoparathyroidism
Chronic renal insufficiency
Malignancy
Extreme physical activity (ionized Ca2+
decreases)
Calcimimetic drugs
Vitamin D deficiency
Septic shock
Pancreatitis
Rhabdomyolysis
Post thyroidectomy
Calcium deficiency rickets
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Mineral Disorders
• Primary
Hyperparathyroidism
(PHPT)
– Caused by a disorder of
calcium metabolism in
relationship to excessive
PTH release.
– Characterized by
excessive secretion of
calcium in the absence of
an appropriate
physiological stimulus.
– Common symptoms
involve lethargy, coma,
psychosis, anorexia, and
hypertension.
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TABLE 14-2 Typical Findings for Serum Total
Calcium and PTH Concentrations in Selected
Disorders
Disorders
Total Calcium
PTH
Primary hyperparathyroidism
Increased
Increased
Hypercalcemia of malignancy
Increased
Decreased
Hypoparathyroidism
Decreased
Decreased
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Bone Structure, Physiology, and Metabolism
• Collagens
– Provide the structural
framework of bones and
cartilages
– Approximately 27 genetically
distinct collagen types in
vertebrates
– Structural feature is the triple
helix.
– Bone consists of a large
amount of densely packed
cross-linked heterofibrils of
types I and V collagen.
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Bone Structure, Physiology, and Metabolism
• The Physiology of Bone
– Bones are organized optimally to resist loads imposed by func- tional
activities.
▪ Composition of bone is described as a composite tissue consisting of the
following material in decreasing order of amount:
– Minerals
– Collagen
– Relative percentages of the major
components are:
– Water
▪ ∼ 60% minerals
– Noncollagenous protein
▪ ∼ 35% organic matrix
– Lipids
▪ ∼ 5% cells, and water
– Vascular elements
– Cells
continued on next slide
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Bone Structure, Physiology, and Metabolism
• Cells of Bone
– Osteoclasts
– Osteoblasts
– Osteocytes
– Bone-lining cells
– Precursor of
specialized cells
– Cells of the
marrow
continued on next slide
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Bone Structure, Physiology, and Metabolism
– Bone-resorption
cells
– Multinuclear giant
cells
– Have ruffled
borders that
secrete products
leading to bone
destruction
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Examples of Substances That Promote and Inhibit Osteoclast
Formation
• The following are known to promote
osteoclast formation:
– PTH
– 1,25-dihydroxy vitamin D3
– Osteoprotegerin ligand (OPG-L)
– Receptor activator of nuclear factor
kappa B [nFkB) ligand (RANK-L]
– Interleukin-1,3,6,11
– Transforming growth factor-β
(TGF-β)
• The following agents are known
to inhibit osteoclast formation:
– Calcitonin
– Bisphosphonate
– Osteoprotegerin (OPG)
– 17 β-estradiol
continued on next slide
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Osteoblasts
– Bone-forming cells that:
1. Synthesize and secrete
unmineralized bone matrix (the
osteoid).
2. Participate in the calcification
and resorption of bone.
3. Regulate the flux of calcium ions
and phosphate ions in and out of
bone.
– Occur as a layer of contiguous
cells that in their active state are
cuboidal.
continued on next slide
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• Osteocytes
– Found within the
bony matrix
– Derived from
osteoblasts that
have encased
themselves within
bone
– Represent the
most abundant cell
in the skeleton
continued on next slide
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Biomarkers of Bone Formation and
Resorption
• Assays for Bone Markers
– Numerous assays are available to measure biochemical markers of bone
formation and resorption.
– Specimens for analysis include urine, serum, and plasma.
– Variety of measurement techniques used to measure bone biomarkers:
▪ Spectrophotometry
▪ Immunoradiometric assay (IRMA)
▪ Enzyme immunoassay (EIA)
▪ Enzyme-linked immunosorbent assay (ELISA)
▪ Chemiluminescent immunoassay (CLIA)
▪ High-performance liquid chromatography (HPLC)
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Metabolic Bone Disorders
• Osteoporosis
– A progressive systemic
skeletal disease
characterized by low bone
mass and microarchitectural
deterioration of bone tissue
with a consequent increase
in bone fragility and
susceptibility to fractures.
– Disease associated with
aging
– Represents a significant
expense in health care
– Patients experience fractures
throughout the skeletal
system.
continued on next slide
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Metabolic Bone Disorders
• Osteoporosis
– Primary
▪ Exact etiology of
bone loss is not
known
▪ Most common type is
menopausal
osteoporosis
▪ Manifests itself
primarily as a loss of
trabecular
(cancellous) bone
Copyright © 2018, 2011 Pearson Education, Inc. All Rights Reserved
Metabolic Bone Disorders
• Rickets and Osteomalacia
– Diseases associated with
defective bone and cartilage
mineralization in children and
bone mineralization in adults
– Calcification of cartilage does
not manifest itself properly
▪ Especially at epiphyseal growth
plates
▪ Leads to widening of the
epiphyseal plate, skeletal
abnormalities, and possible
growth retardation
continued on next slide
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Copyright © 2018, 2011 Pearson Education, Inc. All Rights Reserved

In your opinion how much of a medical crisis is the return of Rickets?
What are the three forms of Vitamin D and which is the best form for increasing the bodies
daily level?
List three general symptoms of Vitamin D deficiency?
Do you know your Vitamin D level?

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