Module 04 Case Study: Bone Tissue
Part I— “Marissa” Questions
1. Describe bone tissue and the role each component plays in bone physiology and remodeling. What is the difference between compact and spongy bone? (2 points)
Bone tissue is composed of bone cells and extracellular matrix. It is continuously remodeling its extracellular matrix according to the stresses placed upon it. It has a lot of blood flow and it is supplied by the nervous system. The bone cells includes; Osteocytes, osteoblasts and osteoclasts. The osteoblasts build and repair the bone matrix; the osteocytes are the mature cells that have become surrounded by the matrix while the osteoclasts chew up or break down the bone matrix. The difference between the spongy and compact bone is that the extracellular matrix is arranged differently.
2. Explain the relationship between calcium and bones. (1 point)
Calcium is essential for the maintenance of the necessary level of bone mass in other to support the structures of the body. It aids the development of bones and bone mass.
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. (2 points)
The body controls calcium levels in the bones and blood by virtue of hormonal influences. The parathyroid hormone and calcitonin. The parathyroid hormone (PTH), which is secreted by the parathyroid glands, is responsible for regulating blood calcium levels; it is released whenever blood calcium levels are low. It increases blood calcium levels by stimulating osteoclasts, which break down bone to release calcium into the blood stream. Parathyroid Hormone increases blood calcium levels by increasing the amount of calcium reabsorbed by the kidneys before it can be excreted in the urine. Parathyroid hormone increases blood calcium levels by triggering the formation of calcitriol, which increases absorption of dietary calcium through the intestines. Calcitonin, a hormone produced by the thyroid, acts in opposition to parathyroid hormone by inhibiting osteoclasts, stimulating osteoblasts, and increasing excretion of calcium into the urine by the kidneys.
4 Explain specifically how osteoporosis affects the bone matrix and the normal bone remodeling cycle. (1 point)
In osteoporosis, the osteoclasts are breaking down bone faster than the osteoblasts are building it up - which results in bone porosity (they begin to look like sponge on a microscopic level) which results in increased risk of fractures from stress and trauma.
5. Discuss what scientists know about the genetics behind osteoporosis. (1 point)
Scientists believe that women who have a large number of genetic variants associated with low bone density have up to a 56 percent higher risk of osteoporosis as compared with women who have a normal set-ups of the same genetic variants.
6. List at least 5 controllable and 3 uncontrollable risk factors for this disease.
Uncontrollable risk factors are; Age, Family history, and Body type. The Controllable risk factors are; Eating disorders, Inactive lifestyle, alcohol intake, Smoking and Low calcium intake.
7. What are the symptoms or telltale signs of osteoporosis? (1 point)
The signs and symptoms of osteoporosis include; Back pain, loss of height, a stooped posture and a bone fracture that...
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