APL2 and 3 Skeletal Anatomy

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APL2 and 3 Skeletal Anatomy

• The evil that men do lives after them, the good
  is oft interred with their bones. William
  Shakespeare (1564-1616) Julius Caesar, Act III,
  Scene 2

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Functions of Skeleton

• Supporting framework
• Attachment of muscles
• Protects vital organs
• Cranium Brain
• Thoracic Heart lungs
• Reservoir of minerals
• Calcium Phosphorus
• Red bone marrow
• Formation of RBC

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Functions of the skeleton

• 4. cont. Storage Site of Inorganic Salts, such as
  CALCIUM.
• Calcium may be removed from bone to maintain a
  normal blood calcium level, which is essentially
  for BLOOD CLOTTING
• 5. cont. Contains and Protects the Red Bone
  Marrow, Some White Blood Cells (Leukocytes) are
  also produced

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Macroscopic structure of Long Bone

• Epiphysis ends of a long bone.
• Contains mainly spongy bone
• Red Marrow fills it. Its fxn is to produce RBC
• Articular Cartilage covers ends of long bone
• Hyaline cartilage
• Creates smooth surface

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Macroscopic Structure of Long bone

• Endosteum inner membrane lining MC
• MC contains yellow marrow (fat)
• Continuous with spongy bone
• Periosteum tough outer jacket
• Composed of fibrous tissue
• Contains BV, Nerves, and Osteoblasts
• Initiates growth in DIAMETER

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Macroscopic structure cont

• Epiphyseal Disk area of bone where active growth
  occurs.
• AKA growth plates
• Initiates growth in LENGTH
• When growing stops, disk is replaced by
  Epiphyseal line.

• Diaphysis shaft of bone
• Outer wall contains mainly compact bone.
• Strong resistant to bending
• Compact bone encloses Medullary canal.
• MC contains yellow marrow (Fat)

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Formation of Bone

• Using your book as a reference, How does the
  skeleton seem to develop? Ossification starts at
  12 wks.

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Epiphyseal disk (line adult)

• Area of actively reproducing cartilage cells
• Contain osteblasts
• Will close approx 18yr. old

• Osteoblasts bone builders
• Capable of producing collagen fibers
  (livingorganic)
• May cement themselves in Lacunae (cavity)
• Osteocyte is mature osteoblast

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• Femoral Epiphyseal disk F14-16 M16-18
• Sacral / Hip F21-23 M23-25

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Bone Remodeling

• Osseous tissue constantly being formed and
  resorbed (destroyed)
• 3 stages
• Infancy to Adolescent Osteoblastic activity
  dominant
• Adolescent to Mid adult (40-50) Balance
• Post middle age Osteoclastic activity dominant
  leading to certain diseases

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Microscopic Bone structure

• 1. Haversian (osteonic) canal contain blood
  vessels nerves
• 2. Canaliculi interconnecting channels. Allow
  osteocytes to communicate
• 3. Lamellae thin sheets of bone matrix layered
  in circles around the canals
• 4. Lacunae spaces that contain osteocytes

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Haversian(osteonic) Systemcanal, lamellae,
osteocytes and canaliculi

• Lamella Concentric ring
• Haversions (osteonic) canal runs through core
• Perforating canals connect the Haversion canals
• Lacuna contain osteocytes (mature bone cells)
• Types of osteocytes
• osteoblasts build bone
• osteoclasts remove bone

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Bone destroyers Osteoclasts (microscopic)

• Multi-nucleated cells
• Release digestive enzymes to reshape or remodel
  bone

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Homeostasis Alert!!

• 0-18yrs OB forming bone, little OC activity
• 18yrs.-40yrs. Remodeling phase Equal OB
  deposition of bone OC resorption of bone.
• 40yrs (approx) more OC activity to release the
  calcium phosphate from storage

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Nutrition Corner! www.waltonfeed.com/self/health/v
it-min/calcium.html

• Calcium mineral needed as primary make-up of
  inorganic salts of bones
• 99 in bone, 1 in blood
• Vitamin D needed for Ca
• If a 20 year old woman consumes 400 mg of calcium
  a day (half of what is recommended), at age 55,
  she will have lost 1/3 of her calcium.

• RDA Requirements for Calcium
• 0.0-0.5 400 mg
• 0.5-1.0 600 mg
• 1-10 800 mg
• 11-24 1200 mg
• 25 800 mg
• Pregnant 1200mg
• Lactating 1200 mg
• What is the reasoning?

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Compare the X-rays

• Pediatric X-Ray

• Adult X-Ray

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Use vs. Disuse

• Increased use (exercise) increases deposition
  of collagen and calcium(inorganicnon-living)
  salts
• Bones get stronger
• Decreased use compact bone in diaphysis thins
  out calcium removed from bone
• Bones get weak and fragile

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You create the Treatment protocol

• Treatment concerns of 82 y.o. elderly woman (95
  lbs.)
• Concerns for a 47 y.o average sized woman
• Pregnant 31 y.o woman
• 313 lbs. 38 y.o. obese man.
• 200lbs. 22 y.o man
• How should they differ? Be similar?

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Osteoporosis

• Excessive loss of bone volume mineral content.
  Trabeculae of spongy bone is lost/spaces develop
• Spontaneous fracture as result of weakened bone
• Aging reason for large of fractures over age of
  45

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Common Sites of Osteoporotic fractures

• Spinal column (vertebrae)
• Distal Radius / Ulna
• Hip fractures (actually is neck of femur NOT
  actual hip)
• WHY DO YOU THINK?

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Osteoporosis cont

• Factors which INCREASE risk
• Low intake of dietary calcium
• Lack of physical exercise
• Menopause
• ovaries produce less estrogensceases
• decreases bone absorption of Calcium
• Decreasing secondary sex characteristics

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Prevention methods

• How can someone, especially woman, prevent this?
• Calcium supplements 1000mg 1500mg per day.
  Ex 8oz glass milk 275 mg
• Regular physical exercise program. WHY?
• What about Estrogen replacement therapy?

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Homework

• There are many different factors that can affect
  bone growth Your homework is to research how
  one of these affects bone growth.
• 1. Vitamin A,
• 2. Vitamin C,
• 3. Vitamin D
• 4. Pituitary growth hormone (too much, too
  little)
• 5. Female sex hormone (estrogen)
• 6. Male sex hormones (testosterone)

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Homework

• www.waltonfeed.com/self/health/vit-min/calcium.htm
  l
• Please read the following link to the article
  regarding nutritional health of the skeletal
  system.
• What nutrients are important to good bone health?
• Please create a chart including nutrient, why,
  and example in the diet.