Question

Marissa Marisa, a petite, Caucasian, 15-year-old, just learned this morning that her 55- year-old grandmother, with whom she has lived since the death of her parents, was diagnosed with osteoporosis after visiting her doctor because of chronic hip and wrist pain. For the past year, Marisa's life has been one tragedy after another. Her happily married parents were killed in a car crash nine months earlier on the way home from their 16th anniversary surprise party. Her boyfriend of two years moved to a different state a few months back and ended their relationship shortly after. To make things worse, her first year in high school was disastrous. Not only did she fail algebra, she didn't make the soccer team, as she had hoped. Marisa's grandmother lives far from where Marisa used to, and because she is an only child, Marisa often finds herself feeling lonely and on the brink of depression. The only person she feels she can count on besides her grandmother is her best friend, Tara. She told Tara about her grandmother's disease as soon as she found out. Marisa has no idea what osteoporosis is or what it does to the body. All she knows is that her grandmother is the only close living relative she has and she can't fathom losing another loved one 1. Describe bone physiology and the bone remodeling cycle. Be sure to emphasize the two types of bone tissue and the roles of osteoblasts and osteoclasts 2. Explain the relationship between calcium and bones 3. Explain how the body controls calcium levels in the bones and blood. Be sure to describe the roles of parathyroid hormone (PTH) and calcitonin in detail. 4. Explain specifically how osteoporosis affects the bone matrix and the normal bone remodeling cycle 5. List as many risk factors for this disease as you can, both controllable and uncontrollable 6. What are the symptoms or telltale signs of osteoporosis?

Answer 1

1) Bone is a continuously growing tissue and is composed of both organic and inorganic matrix. Organic matrix is composed of collagen fibres and protiens and inorganic matric comprises calcium salta and phosphates.

Calcium the major ion involved in maintaining bone strength and provides mechanical support.

Bone remodelling occurs throughout the life, bone sheds off in the form of calcium that is resorption by action of certain enzymes example- parathyroid hormone and calcitonin and new bone is formed by osteoblast cells.

Bone remodelling occurs through osteoblasts and osteoclasts.osteoclasts romoves old bone which is known as bone resorption,osteoblasts are cells which forms new bone by filling the bone cavities,mineralization and calcification.

2) calcium plays a very important role in the maintenance and remodelling of bone. Body 98% calcium is stored in the bone, it provides strength to the bones.

Calcium is important for bone mineralisation and calcification.

Deficieny of calcium in the bones causes loss of bone mass and affect the bone strength.

3) body control calcium levels under the regulation of three hormones mainly- parathyroid hormone, calcitonin and calcitriol.

Parathyroid hormone acts osteoclasts,activated them and resorption of the bone take place which results into release of calcium in the blood.Stimulus comes from low blood calcium levels.

Calcitonin is responsible for deposition of calcium on the bones. Stimulis comes from high calcium levels.

4) Osteoporosis is a disorder of bone ,more prevalent in women.It occurs due to decreased bone mass and loss of matrix.

Here,bone resorption is faster then bone formation.

Bone become brittle and looks spongy. Bones becous porous.less elastic and less stable. This increases risk of fractures.

5) controllable risk factors

a) low calcium and vitamin D

b) sedentary life style

c) smoking and alcohol consumption

d) Imbalaced diet

e)weight loss

f) intake of caffeine, sodium and protien in excess.

Uncontrollable risk factors

a) age mainly above 50 years that is ij menopausal women due to estrogen imbalances.

b) history of osteoporosis in family

c) low body weight

d) height factor that is height loss.

6) people usually have no symptoms, but these signs can tell about osteoporosis - pain in the lower back and neck and fractures in the bones mainly hip bone, and vetrebrae, stooped posture.