Skeletal+System+NLL

Skeletal System

1. What are the four main functions of the skeleton? (p. 208) The skeleton protects soft body parts. The bones of the skull protect the brain; the rib cage protects the heart and lungs. The vertebrate protects the spinal cord, which makes nervous connections to all the muscles of the limbs. The skeleton produces blood cells. All bones in the fetus have red bone marrow that produces blood cells. The skeleton stores mineral and fat. All bones have a matrix that contains calcium phosphate, a source of calcium ions and phosphate ions in the blood. The skeleton, along with the muscles, permits flexible body movement. While articulations occur between all the bones, we associate body movement in particular with the bone of limbs.

2. What is the difference between cartilage and bone? (P.208) Cartilage is not as strong as bone, but it is more flexible because the matrix is gel-like and contains many collagenous and elastic fibers. The cells called chondrocytes lie within lacunae that are irregularly grouped. Cartilage has no nerves, making it well suited for padding joints where the stresses of movement are intense. Cartilage also has no blood vessels, making it slow to heal.

3. Why is vitamin D important to bone growth? How do we get vitamin D? (p. 212) Vitamin D is formed in the skin when it is exposed to sunlight, but it can also be consumed in the diet. Milk in particular, is often fortified with vitamin D today, In the kidneys Vitamin D is converted to a hormone that acts on the intestinal tract. The chief function of Vitamin D is intestinal absorption of calcium. In the absence of vitamin D, children can develop rickets, a condition marked by bone deformities including bowed long bones. Vitamin D helps the bones grow.

4. Insert an image of a skeleton. You will need to know the location of the following bones. Skull: frontal bone, parietal bone, temporal bone, occipital bone, zygomatic bone, maxilla, mandible Pectoral girdle: clavicle, scapula Upper limb: humerus, ulna, radius, carpals, metacarpals, and phalanges Rib Cage: sternum, ribs, costal cartilages Pelvic girdle: coaxyl bones, sacrum, coccyx Lower limb: femur, patella, tibia, fibula, tarsals, metatarsals, and phalanges