Tissues and Organs of the Skeletal System- Learning Outcomes
Name the tissues and organs that compose the skeletal system.
bones, cartilages, ligaments and tendons
State functions of the skeletal system
support, protection, movement, electrolyte balance, acid-base balance and blood formation
Distinguish between bone as a tissue and as an organ.
Osseous tissue is connective tissue with the matrix hardened by mineralization. The skeletal system is an group of bones and other tissues working together to form an organ of the body.
Describe the four types of bones classified by shape
Flat bones- curved by wide and thin, protects soft organs. Long bones- longer than wide, rigid levers acted upon by muscles. Short bones- equal length and width, glide across one another in multiple directions. Irregular bones- shapes that do not fit in any other category.
Describe the general features of a long bone and a flat bone.
Long Bone- outer shell of compact bone, cylinger shaft provides leverage, enlarged ends to attach to joints, spongy bone and marrow inside the shaft and outer fibrous layer of collagen. Flat Bones- sandwich-like construction of two hard bone layers with a layer inside of spongy bone.
List the cells, fibers and ground substance of bone tissue.
Osteogenic cells, osteoblasts, osteocytes, osteoclasts, minerals, collagen and carbohydrate-protein complexes
state the importance of each constituent of bone tissue.
Osteogenic cells- produce osteoblasts, Osteoblasts- form bone tissue, Osteocytes- former osteoblasts that become trapped in the matrix, Osteoclasts- dissolve bone tissue to aid in remodeling and mineral resorption
Compare the histology of the two types of bone tissue.
Spongy bone- connective tissue with a sponge like appearance. Compact bone- connective tissue with a dense appearance due to the cells being very close together.
Distinguish between the two types of bone marrow
Red bone marrow produces blood cells and is found in most bones in children and limited to only a few in adults. Yellow bone marrow consists mostly of fatty tissue and replaces red bone marrow with age.
Describe two mechanisms of bone formation.
Intramembranous ossification- formation of bone tissue when cartilage is not present and Endochondral ossification- the process of cartilage turning into bone tissue.
Explain how mature bone continues to grow and remodel itself.
Ossification happens through appositional growth. This is an increase in bone width by the osteoblasts depositing new osteoid tissue and Bone remodeling happens by a collaborative process between the osteoblasts and osteoclasts.
How are minerals added and removed from bone tissue
osteoclasts and mineralization
Describe the role of the bones in regulating blood calcium and phosphate levels.
osteocytes produce signals that let the body know if the bones need to release minerals or deposit them. Bones store calcium and phosphate for when the blood levels are too high or low. Osteoclasts break down bone tissue and releases the minerals into the blood.
Name several hormones that regulate bone physiology
calcitriol, calcitonin and parathyroid hormone
Name and describe types of fractures
stress fracture- break caused by abnormal trauma to bone. Pathological fracture- break of a weakened bone from disease