Question

Look Out Below: A Case Study on Bone Tissue Structure and Repair An elderly patient arrived at the emergency room unconscious after an accident in which a heavy overhead shelf struck her arm. Upon auscultation, a large open wound on her arm was evident with what appears to be bone tissue sticking out of the skin. She also has bruises covering her left shoulder, left wrist, and lower back. To determine the extent of her injuries the patient undergoes several x-rays, which reveal the following:

1) fracture of the left humerus at the proximal diaphysis,

2) depressed fracture of the occipital bone,

3) fracture of the 3rd lumbar vertebral body. Answer the Following (short answer) \

1. Define the following terms, used in the case and also in associated questions: a. Comminuted fracture b. Epiphyseal plate c. Bony callous d. Paget’s Disease

2. What is the difference between the Calcification zone and the Ossification zone found.

3. What type of bone tissue makes up the majority of the vertebral body? Describe the structure and function of this type of bone.

4. Describe the layers of compact bone.

5. Most connective tissue, including bone, is highly vascular. Which anatomical structures in the patient’s compact bone house blood vessels?

6. What term is used to describe the addition of new bone tissue? Identify which bone cell is responsible for this process and explain how it occurs.

7. What makes up the organic and inorganic portions of the bone’s extracellular matrix (ECM)? 8. Describe the structure of an osteon.

Discussion:

Further diagnostic tests on the patient revealed a lack of estrogen and calcium. Elaborate on how these factors may have made the injury worse. In normal conditions, what would be the response to falling calcium levels? Post your response and respond to two of your classmates using at least 3-5 sentences to receive full credit (10 points).

Answer 1

As per the guidelines I answer the first four questions.

1) a. Comminuted fracture is occurred mainly due to high impact traumas such as vehicle accidents and in this fracture the bone breaks into more than two fragments.

b. Epiphyseal plate is mainly indicates the growth of the long bones so it is also called as growth plate, and it is situated in between the epiphyses and metaphyses as a thin layer of cartilage.

c. Bony callous is present during the process of healing of a bone fracture. It is seen in between and around of bone fractures as a bony deposit.

d. Paget's disease is a disease usually caused with increase in age or with a family history. In this condition the replacement of old bone tissue with new bone tissue is disrupted.

2. The difference between the calcification zone and the ossification zone are:-

In the calcification zone, the matrix surrounds the enlarged lacunae is deposited by minerals which leads to cause the cell death.

In the ossification zone, matrix on exposed plates of calcified cartilage is deposited by osteoblasts.

3. Cancellous bone tissue is the type of bone tissue makes up majority of the vertebral body. Structure :- It have a sponge or honey comb resembled structure with the presence of trabeculae. So it is also known as spongy bone. There are three types of bone cells named as osteoblasts, osteocytes and osteoclasts within the trabeculae. Function :- Cancellous bones are filled with red bone marrow. So red blood cells are mainly produced from this cancellous bones.

4. Compact bone have a central canal which contains blood vessels and nerve fibres. Then around the central canal lamellae are present which are the layers of concentric circles. Spaces present between the lamellae are called lacunae, that contains osteocytes. Then osteons which are cylindrical units present in the compact bone formed from the lamellae.