Chapter 5: Bones & Axial Skeleton

What are the two main divisions of the skeletal system?

Axial skeleton and appendicular skeleton.

What bones are included in the axial skeleton?

Skull, vertebral column, sternum, and ribs.

What are the primary functions of the skeleton?

Protection, support & leverage, mineral storage, blood cell formation, fat storage, and movement.

What types of tissues are found in bone?

Osseous tissue, marrow (red and yellow), nervous tissue, and vascular tissue.

What are the five types of bone classifications?

Long bones, short bones, flat bones, sesamoid bones, and irregular bones.

Give an example of a long bone.

Humerus, femur, or phalanges.

What is the periosteum?

A dense irregular connective tissue that covers the outer surface of bones.

What is the function of osteoblasts?

To build bone by secreting the organic and inorganic matrix.

What is the role of osteoclasts?

To break down bone through resorption.

What is the composition of the inorganic matrix of bone?

Hydroxyapatite, which provides hardness and compression resistance.

What is the difference between compact bone and spongy bone?

Compact bone is dense and provides strength, while spongy bone has a trabecular structure and contains marrow.

What occurs during the hematoma formation stage of bone repair?

A blood clot forms at the fracture site.

What is endochondral ossification?

The process by which bone develops from hyaline cartilage.

What is osteoporosis?

A condition characterized by porous, weak bones due to an imbalance between osteoblast and osteoclast activity.

What are some causes of osteoporosis?

Aging, estrogen loss after menopause, and lifestyle factors such as smoking and inactivity.

What is Paget's disease?

A condition involving excessive bone resorption followed by excessive bone formation, leading to enlarged and deformed bones.

What is the significance of the epiphyseal plate?

It is the growth region in long bones where new bone is formed during childhood.

What are the zones of the epiphyseal plate?

Proliferation zone, hypertrophic zone, calcification zone, and ossification zone.

What is the stress-strain curve in bone mechanics?

It illustrates the relationship between stress applied to a bone and the resulting strain, showing elastic, plastic, and failure points.

What is the role of red marrow?

To produce blood cells through hematopoiesis.

What is the function of yellow marrow?

To store fat.

What is the nutrient foramen?

An opening in bone that allows entry for nutrient arteries and veins.

What is the role of osteocytes?

To maintain the bone matrix and sense mechanical stress.

What are some clinical cases related to bone health?

Fat embolism syndrome and osteogenesis imperfecta.