Question

1. describe the structure of the spinal column and list the sections that make up the spinal column. 4. how is a long bone constructed? 5. how do long bones grow?

Explanation:

1. The spinal column is a flexible column - like structure made up of 33 individual vertebrae. The sections are cervical (7 vertebrae), thoracic (12 vertebrae), lumbar (5 vertebrae), sacral (5 fused vertebrae), and coccygeal (4 fused vertebrae).
2. A long bone has a diaphysis (shaft), epiphyses (ends), metaphyses (regions between diaphysis and epiphyses), and a medullary cavity in the diaphysis. It also has a periosteum covering the outer surface and endosteum lining the medullary cavity.
3. Long bones grow through a process called endochondral ossification. Cartilage at the epiphyseal plates (growth plates) proliferates, is replaced by bone tissue, and this process continues until the growth plates close during late adolescence or early adulthood.

Answer:

1. The spinal column is composed of 33 vertebrae in sections: cervical (7), thoracic (12), lumbar (5), sacral (5 - fused), coccygeal (4 - fused).
2. A long bone has a shaft (diaphysis), ends (epiphyses), regions between them (metaphyses), a medullary cavity, periosteum, and endosteum.
3. Long bones grow via endochondral ossification at epiphyseal plates until they close.