BMS175: Topic 5: The Skeletal System

What are the six main functions of bone?

1. Provides framework that supports the body. 2. Protects vital organs. 3. Acts as levers for muscle movement. 4. Reservoir for minerals. 5. Produces blood cells in red bone marrow. 6. Stores fat in yellow bone marrow.

What are the four types of cells found in bone tissue?

1. Osteogenic cells 2. Osteoblasts 3. Osteocytes 4. Osteoclasts

What is the difference between compact bone and spongy bone?

Compact bone is dense and has hollow tubes (osteons), while spongy bone has a trabecular structure that aids in resisting stress.

What structure connects skeletal muscles to bones?

Tendons connect skeletal muscles to bones.

How do bones grow in width?

Through appositional growth, where osteoblasts add bone matrix at the surface while osteoclasts break down bone from within.

What law states that a bone's structure is determined by stress placed upon it?

Wolff's law of bone.

What is the main function of osteoclasts?

To remove old bone tissue.

What is the structure of a long bone?

A long bone, like the femur, consists of a shaft (diaphysis) and two ends (epiphyses), with a central medullary cavity containing bone marrow. The outer layer is primarily compact bone, while the ends contain spongy bone

What protects the brain?

The fused bones of the skull.

What are the components of the bone matrix?

Bone matrix has two parts: soft organic components and hard inorganic components.

What is the function of osteocytes?

To maintain the daily metabolism of bone tissue.

How many bones make up the adult human vertebral column?

26 irregular bones.

What does the pelvic girdle contain?

It contains the sacrum and a pair of hip bones.

What bones comprise the thoracic cage?

Thoracic vertebrae, ribs, sternum, and costal cartilages.

How many separate bones are in each upper limb?

30 separate bones.

What are the two main classifications of joints?

Structure and function.

What is found between the bones in fibrous joints?

No joint cavity but connective tissue full of collagen fibers

What type of movement is permitted at a synovial joint?

Freely movable.

What absorbs compression in synovial joints?

Thin sponge-like cushions called articular cartilage

Define flexion in terms of joint movement.

A bending movement that decreases the angle between two body parts.

What is hyperextension?

Continuing extension past the anatomical position.

What separates the articulating bones in synovial joints?

A fluid-containing joint cavity.

What kind of tissue is cartilage classified as?

Supportive connective tissue.

What structures form the skeleton?

Bones, cartilages, joints, and ligaments.

How many total bones are in a fetal/infant vertebral column?

33 bones, with 9 fusing to form the sacrum and coccyx.

What is the role of cartilage in cartilaginous joints?

It acts as flexible, cushioning material that connects the articulating bones and provides support.

Describe the main feature of flat bones.

They are thin, flattened, and usually slightly curved, consisting of a layer of spongy bone between two layers of compact bone.

What do osteoblasts do?

They are bone-producing cells that synthesize and secrete collagen fibers and other organic components.

How are the joint surfaces of bones protected?

They are covered by cartilage.

What is red bone marrow primarily responsible for?

The production of blood cells.