1. Bone Growth and Fractures

2. hGH- (from Pituitary Gland)
BONE GROWTH - hGH
hGH- (from Pituitary Gland)
Increases size of all organs (including brain)
Increases Protein Synthesis: Builds up Body
Affected by exercise, nutrition, sleep
Increases osteoblast activity
Stimulates growth of cartilage in the epiphyseal plate

3. BONE GROWTH
Disorder: Gigantism- excess growth from too much hGH during childhood, before epiphyseal plates have closed

4. BONE GROWTH

5. Bone Growth
Acromegaly- adult condition, ↑ hGH after Epiphyseal plate closure, disfigured face, pronounced jaw and brow, swelling of internal organs
most common cause: benign tumor of pituitary gland
treatment: surgery

7. BONE GROWTH - 2. Thyroid Hormone (from Thyroid Gland)
Causes elongation of bones through chondrocytes cell division at the epiphyseal plate and stimulates osteoblast activity

8. BONE GROWTH
Estrogen and Testosterone (Male and Female Sex hormones – from ovaries /testes + adrenal glands )
-at puberty released in larger quantities
-increasing osteoblast activity and synthesis matrix
-responsible for “growth spurts” teen yrs.
- Levels of Estrogens (♀)/Androgens(♂) at the end of puberty cause epiphyseal plate to close (epiphyseal line)

9. FACTORS AFFECTING NORMAL BONE GROWTH
A. DIET
1. Minerals
CALCIUM & PHOSPHORUS (& traces of fluoride, magnesium, iron, manganese) for deposition into matrix
Broccoli, Nuts, Seeds, Legumes, Grains, Dairy, Garlic, Chicken and Turkey

10. FACTORS AFFECTING NORMAL BONE GROWTH
A. DIET
2. vitamins
VITAMIN D  stimulates absorption & transport of Ca2+ into blood - can be synthesized by skin in presence of UV light or taken in through diet
(4 glasses milk/day or 1 serving fatty fish)
(10-15 mins 2X/week on face, arms + hands)

11. FACTORS AFFECTING NORMAL BONE GROWTH
A. DIET
VITAMIN D: Deficiency  Rickets in Children/ Osteomalacia in Adults
-Affects long bones: Bowed Legs, Fragile bones, Impaired growth,
Dental problems, Bone pain, Muscle weakness

12. Rickets

13. Rickets Caused by Vitamin D deficiency in childhood
Vit D crucial for calcium and phosphorus absorption in digestive tract
Not enough minerals so bones are too flexible
During Industrial Revolution, a lot of children who worked in factories (little exposure to sunlight and malnourished)
Starting to increase again in urban US because spending so much time in doors and drinking soda instead of milk

14. FACTORS AFFECTING NORMAL BONE GROWTH
DIET
VITAMIN A  balance between deposition and resorption, stimulates osteoblast activity
liver
sweet potatos
carrots
mangoes
spinach
cantaloupe
dried apricots
milk
egg yolks
mozzarella cheese

15. FACTORS AFFECTING NORMAL BONE GROWTH
A. DIET
VITAMIN C  necessary for collagen synthesis, normal bone growth, maintenance, & healing
SCURVY
Symptoms –
spots on skin
spongy gums
bleeding from
mucous membranes

16. BONE REMODELING
- continual trading of Ca2+ between blood & bones; bones are continually remodeled with spongy bone being replaced every 3-4 years and compact bone every 10 years

17. BONE REMODELING
A. BONE DEPOSITION: osteoblasts build bone & deposit Ca2+ and collagen

18. BONE REMODELING
B. BONE RESORPTION: osteoclasts break down bone (acids and enzymes) & release Ca2+ into blood

19. BONE REMODELING
*TOO MUCH Dietary Ca2+  can lead to “bone spurs” (Ca2+ deposits) and muscle weakness, heart failure
*TOO LITTLE Dietary Ca2+ can lead to brittle, weakened bones, muscle spasms

20. BONE REMODELING - *Major Factors Influencing Remodeling:
A. STRESS RESPONSE
osteoblast formation stimulated by physical stress (exercise) from gravitational and mechanical forces

21. BONE REMODELING - *Major Factors Influencing Remodeling:
A. STRESS RESPONSE
CALCITONIN (thyroid gland) is released and inhibits osteoclast activity and encourages osteoblast’s activity and calcium deposition from blood into bone

22. BONE REMODELING
- *Major Factors Influencing Remodeling:
A. STRESS RESPONSE
B. BLOOD CALCIUM & PHOSPHORUS CONCENTRATION HOMEOSTASIS
P5+ needed for phosphates (PO43-) which contribute to ATP, DNA, & RNA

23. BONE REMODELING
- *Major Factors Influencing Remodeling:
B. BLOOD CALCIUM & PHOSPHORUS CONCENTRATION HOMEOSTASIS
Ca2+ needed for normal functioning in: MUSCLES & NERVES BLOOD CLOT RESPONSE
GLANDULAR SECRETIONS CELL DIVISION

24. Ca2+ Regulation Flow Chart:
(bones = storage tank for Calcium (Ca2+))
CALCITONIN (THYROID GLAND) secreted when blood calcium
inhibits osteoclasts
Stimulates osteoblasts
PARATHYROID HORMONE (PARATHYROID GLANDS) secreted when blood calcium
stimulates osteoclasts
Inhibits osteoblasts

25. Thyroid and Parathyroid Glands

26. Calcitonin
High
Osteoclasts inhibited
Ca2+ remains in bones
Blood Calcium Level
Low
Osteoclasts stimulated
Ca2+ added to blood
Parathyroid hormone

27. AGING loss of Ca2+ over time (mostly due to hormonal changes)
-in females  age ~ 30 (accelerates 40-45)
-in males  age ~ 60
loss of protein (organics) from bone matrix = overall weakening of bone tissue

28. Bone Density -soccer + basketball better than running
Some studies show peak bone density may be reached by age 15
After age 15 bone density only slightly increases
Mid 30’s bone density begins to decline 1% /year
menopause ↓ (decreases osteoblast activity)
impact activities stimulate osteoblasts ↑
-soccer + basketball better than running
-strength training – great
-swim/cycle need to do other activities if possible
-walking pretty good
*don’t specialize in one sport
Need sex hormones for osteoblast activity

29. -Bones need sex hormones (stimulate osteoblasts) to maintain density
OSTEOPOROSIS
RISK FACTORS
AGE (Dec. Hormones)
-Bones need sex hormones (stimulate osteoblasts) to maintain density
-estrogen drops dramatically ♀,
in ♂ testosterone declines gradually  male menopause
EATING DISORDERS
LACK OF EXERCISE
Ca2+ Deficiency
VITAMIN D Deficiency
DRUGS (Alcohol, Smoking, some Diuretics, etc.)

30. Bone Fractures and Healing

33. Answer these questions for each patient Can work in groups of 1-3
If it is a fracture, what type is it? If it’s not a fracture, what’s the injury?
List ALL of the bones present in the x-ray and underline which, if any, are the fractured bone

34. Bone Healing Stages