1. APL2 and 3 Skeletal Anatomy
The evil that men do lives after them, the good is oft interred with their bones. —William Shakespeare ( ) Julius Caesar, Act III, Scene 2

2. 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

3. 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

4. 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

5. 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

6. 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)

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

8. 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 (living=organic)
May “cement” themselves in Lacunae (cavity)
Osteocyte is mature osteoblast

9. Femoral Epiphyseal disk: F=14-16 M=16-18
Sacral / Hip: F= M=23-25

10. 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

11. 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

12. Haversian(osteonic) System=canal, lamellae, osteocytes and canaliculi
Lamella: Concentric ring
Haversion’s (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

16. “Bone destroyers” Osteoclasts (microscopic)
Multi-nucleated cells
Release “digestive” enzymes to reshape or remodel bone

17. 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”

18. Nutrition Corner! www.waltonfeed.com/self/health/vit-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 mg mg mg mg mg
Pregnant mg
Lactating mg
What is the reasoning?

19. Compare the X-rays
Pediatric X-Ray
Adult X-Ray

20. Use vs. Disuse
Increased use (exercise): increases deposition of collagen and calcium(inorganic=non-living) salts
Bones get stronger
Decreased use: compact bone in diaphysis thins out & calcium removed from bone
Bones get weak and fragile

21. 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?

22. 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

23. 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?

24. Osteoporosis cont’ Factors which INCREASE risk
Low intake of dietary calcium
Lack of physical exercise
Menopause:
ovaries produce less estrogens…ceases
decreases bone absorption of Calcium…
Decreasing secondary sex characteristics

26. 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?

27. 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)

28. Homework www.waltonfeed.com/self/health/vit-min/calcium.html
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.