6. Bones & Skeletal Tissue

During fetal intramembranous ossification, bone develops from __________.

Intramembranous ossification __________.

Long bone growth at the epiphyseal plate is similar to __________.

In adolescence, the 'growth spurt' that is observed is mainly attributed to an increase in __________.

Most bones below the base of the skull form by endochondral ossification.

Before eight weeks, the skeleton of the human embryo is composed of __________.

Rickets can be caused by __________.

A condition that produces a reduction in bone mass sufficient to compromise normal function is __________.

Mary is 50 years old. During a checkup, a bone scan reveals that portions of her skeleton show signs of osteoporosis. After reviewing the test results, her physician suggests hormone therapy. What hormone is prescribed for Mary?

If a breastfeeding mother becomes vitamin D deficient, what disease is most likely to develop in the nursing infant?

Bone remodeling in adults is regulated and directed mainly by a. growth hormone b. thyroid hormones c. sex hormones d. mechanical stress e. PTH.

The disorder in which bones are porous and thin but bone composition is normal is a. osteomalacia b. osteoporosis c. Paget's disease.

Describe in proper sequence the events of endochondral ossification in a long bone.

As we grow, our long bones increase in diameter, but the thickness of the compact bone of the shaft remains relatively constant. Explain this phenomenon.

Describe the process of new bone formation in an adult bone. Use the terms osteoid seam and calcification front in your discussion.

a. Why are fractures most common in elderly individuals? b. Why are greenstick fractures most common in children?

Why do you think wheelchair-bound people with paralyzed lower limbs have thin, weak bones of the leg and thigh?

Mrs. Abbruzzo brought her 4-year-old daughter to the doctor, complaining that she didn't 'look right.' The child's forehead was enlarged, her rib cage was knobby, and her lower limbs were bent and deformed. X rays revealed very thick epiphyseal plates. Mrs. Abbruzzo was advised to increase dietary amounts of vitamin D and milk and to get the girl outside to play in the sun. Considering the child's signs and symptoms, what disease do you think she has? Explain the doctor's instructions.

What would a long bone look like at the end of adolescence if bone remodeling did not occur?

Noah Beckenstein went to weight-lifting camp in the summer between seventh and eighth grade. He noticed that the camp trainer put tremendous pressure on him and his friends to improve their strength. After an especially vigorous workout, Noah's arm felt extremely sore and weak around the elbow. He went to the camp doctor, who took X rays and then told him that the injury was serious, for the 'end of his upper arm bone was starting to twist off.' What had happened? Could the same thing happen to Noah's 23-year-old sister, Karen, who was also starting a program of weight lifting? Why or why not?