Question | Answer |
A bone-forming cell | Osteoblast |
A mature bone cell surrounded by bone matrix | Osteocyte |
A large, multinucleated cell that breaks down bone | Osteoclast |
A mass of blood that is confined to a limited space | Hematoma |
A mass of connective tissue that connects the ends of a broken bone | Callus |
The position acquired when one stands erect with the feet facing forward, the upper limbs hanging at the sides, and the palms facing forward with thumbs to the outside | Anatomical position |
What are the 2 principal agents in bone matrix, and how do they each affect the properties of bone tissue? | Collagen, which provides tensile strength; and hydroxyapatite, or calcium salts that provide hardness and compressive strength. |
A bone is completely surrounded by bone matrix. What kind of bone cell is it? | Osteocyte. |
A bone cell has more than one nucleus. What kind of bone cell is it? | Osteoclast. |
Looking at bone tissue under a microscope, you see no osteons. Is this compact or cancellous bone tissue? | Cancellous. |
What kind of tissue contains trabeculae? What do you often find in the space between trabeculae? | Cancellous bone tissue. Bone marrow and blood vessels. |
What is the term for the layers of bone tissue that form an osteon? What is the terms for the layers of bone between osteons? | Concentric lamellae. Interstitial lamellae. |
What are canaliculi? | A channel in the bone that the osteocytes' processes go through. |
There are at least 6 reasons why bone must be continually remodeled. Can you list at least 5 of them? | Bone growth, to bear weight more easily, reshaping, healing breaks, convert cancellous bone to compact bone, increase/decrease mass based on stress, replace worn collagen or hydroxyapatite, regulate calcium levels in blood |
Bone growth occurs when new cartilage is added to the bone’s epiphyseal plate. Why doesn’t the epiphyseal plate get thicker as the bone grows? | New cartilage is being formed at the same rate that the cartilage at the other side is being ossified. |
The epiphyseal plate separates the diaphysis from the epiphysis. On which side of the plate does the tissue ossify? | Diaphysis. |
If a long bone has no epiphyseal plates because they have become epiphyseal lines, is there any way that a bone can grow? | Yes. It can only grow in width. |
What is appositional bone growth? | Bone growth in diameter rather than length. |
The following are processes that occur when bone is repaired. Order then according to the sequence in which they occur. | The external callus is removed by the osteoclasts, and cancellous bone is remodeled as needed. 4.
A hematoma forms. 1.
The callus is ossified. 3.
The callus forms. 2. |
What is the purpose of the external callus? What is the purpose of the internal callus? | To stabilize the bone as it reforms. To eventually become new bone tissue. |
Which gland secretes calcitonin? | Thyroid. |
What is the effect of calcitonin on bone cells? | Decrease the activity of the osteoclasts, less calcium in blood. |
A person’s medical tests show a large increase in the calcitonin levels of the body. What does that tell you about the calcium level in that person’s blood? | It was very high. |
Which gland secretes PTH? | Parathyroid. |
What is the effect of PTH on bone cell? | Increase the activity of the osteoclasts, more calcium in blood. |
Which gland secretes growth hormone, and what affect does this hormone have on bone tissue? | Pituitary gland. |
What effect do the sex hormones have on bone growth? | They stimulate it. They also stimulate ossification of the epiphyseal plates causing long bone growth to stop. |
What are the 3 major types of joints in the body, and which type is associated with most of the movement in the skeleton? | Fibrous, cartilaginous, and synovial. Synovial. |
What is the purpose of articular cartilage in a synovial joint? | To protect the bones. |
What is the purpose of the synovial fluid in a synovial joint? | Lubrication for the joint. |
What produces synovial fluid? | The synovial membrane. |
List the 6 major types of synovial joints in order of decreasing range of motion. Assume the pivot joints offer slightly more motion than hinge joints. | Ball-and-socket, saddle, ellipsoid, pivot, hinge, plane. |
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