module 4 study gudie anatomy

What is an Osteoblast?

A bone-forming cell that produces the bone matrix.

What is an Osteocyte?

A mature bone cell completely surrounded by bone matrix.

What is an Osteoclast?

A large, multinucleated cell responsible for breaking down bone tissue.

What is a Hematoma?

A localized mass of blood confined to a specific organ or space (the first stage of bone repair).

What is a Callus?

A mass of tissue that connects the broken ends of a bone during the healing process.

What is the Anatomical Position?

Standing erect, feet facing forward, arms at sides, with palms facing forward.

What are the two principal agents involved in bone composition?

Hydroxyapatite (calcium salts) and Collagen.

What is Hydroxyapatite?

Provides hardness and compression strength (prevents crushing).

What is Collagen?

Provides flexibility and tensile strength (prevents shattering).

What are Canaliculi?

Tiny channels that allow osteocytes to communicate and share nutrients.

What are the six reasons for bone remodeling?

1. Regulating blood calcium; 2. Repairing micro-damage; 3. Adapting to mechanical stress; 4. Reshaping bone during growth; 5. Replacing old/brittle bone; 6. Converting cancellous bone to compact bone.

What is the relationship between Epiphyseal thickness and bone growth?

It stays the same because bone is added to the diaphysis side at the same rate new cartilage is produced on the epiphysis side.

What is Appositional Bone Growth?

The process where osteoblasts lay down new bone matrix on the surface of the bone, increasing its thickness.

What is the sequence of events in the bone healing process?

1. Hematoma forms; 2. Callus forms; 3. Callus is ossified; 4. Bone is remodeled.

What is the function of the External Callus?

Acts as a biological splint to stabilize the outside of the break.

What is the function of the Internal Callus?

Forms between the broken ends to eventually create new bone tissue.

What is the effect of Calcitonin?

Inhibits osteoclasts, which stops bone breakdown and lowers blood calcium levels.

What is the effect of PTH (Parathyroid Hormone)?

Stimulates osteoclasts to break down bone, releasing calcium into the blood.

What does a High Calcitonin level indicate?

It indicates that the calcium level in the blood was too high.

What is the role of Growth Hormone?

Stimulates the overall growth of bone and soft tissue.

What role do Sex Hormones play in bone growth?

Cause a rapid growth spurt during puberty but eventually trigger the ossification of the epiphyseal plates, ending growth.

What are the three types of joints?

Fibrous, Cartilaginous, and Synovial.

What is a Ball-and-Socket joint?

A type of joint that allows for rotational movement in multiple directions.

What is a Plane (Gliding) joint?

A joint that allows for sliding or gliding movements.

What is Articular Cartilage?

Provides a smooth, slippery surface to reduce friction during movement.

What is Synovial Fluid?

Lubricates the joint and provides nutrients to the cartilage.

What is Flexion?

A bending movement that decreases the angle between body parts.

What is Extension?

A straightening movement that increases the angle between body parts.

What is Circumduction?

A circular movement of a limb that describes a cone.

What is Pronation?

A movement that turns the palm down.

What is Dorsiflexion?

An upward movement of the foot.

What is Abduction?

A movement away from the midline of the body.

What is Adduction?

A movement toward the midline of the body.