Skeletal System Overview and Functions

What is one of the primary functions of the skeletal system?

Which type of bone is characterized by its tubular shaft?

What is the main component of the bone matrix that provides flexibility?

Which cell type is responsible for the formation of new bone?

What comprises approximately 65% of the inorganic material in bone?

What is the role of the periosteum in the skeletal system?

Which of the following best describes the medullary cavity?

What is the primary role of osteoclasts in bone physiology?

What type of bone is notably irregular in shape and does not fit into other categories?

Where is the periosteum found, and what does it contain?

Which of the following best describes the spongy bone?

What happens at the epiphyseal plate during bone growth?

What type of growth allows bone to increase in diameter?

How frequently is the skeleton remodeled in healthy adults?

What is a transverse fracture characterized by?

What main role do osteoblasts play in the remodeling of bones?

Skeletal System Overview

Composed of bones, cartilage, tendons, and ligaments.
Provides structure to the body and enables movement.

Functions of the Skeletal System

Supports body structure and shape.
Protects vital internal organs from injury.
Facilitates movement through connection with muscles.
Stores minerals (e.g., calcium) and fats for energy.
Produces red and white blood cells within bone marrow.

Bone Classification

Osseous tissue is hard, dense connective tissue comprised of an extracellular matrix and bone cells.
Types of bones include:
- Long bones
- Short bones
- Flat bones
- Irregular bones
- Sesamoid bones

Gross Anatomy of Bone

Bone matrix consists of 35% organic (collagen for flexibility) and 65% inorganic materials (hydroxyapatite for strength).
Structure of a long bone features:
- Diaphysis: Long shaft filled with yellow marrow in the medullary cavity.
- Epiphysis: Ends of the bone, containing spongy bone and red marrow.

Bone Markings

Articulation: Where two bones meet.
Projections: Areas of bone that extend above the surface.
Holes: Openings for blood vessels and nerves.

Bone Cells

Osteoblasts: Form new bone; active in growing bone areas.
Osteocytes: Maintain mature bone structure; the most abundant bone cells.
Osteogenic Cells: Multiply and can differentiate into bone-forming cells.
Osteoclasts: Break down bone tissue.

Bone Tissues

Compact Bone: Dense and strong, resists compressive forces; found under periosteum and in diaphysis.
Spongy Bone: Lighter, consists of trabeculae providing strength; contains red marrow for blood cell production.

Bone Growth and Remodeling

Lengthwise growth occurs at the epiphyseal plate, with cartilage being ossified from the epiphyseal to diaphyseal side.
Appositional growth: Increases bone diameter; occurs by osteoclast resorption and osteoblast deposition.
Remodeling: Continuous cycle of bone resorption and formation, renewing about 5-10% of the skeleton annually.

Fractures

Fractures are breaks in bones, categorized by type:
- Transverse: Break occurs straight across the long axis of the bone.

This quiz covers the essential aspects of the skeletal system, including its composition, functions, and classification of bones. It explores how the skeletal system supports the body, protects organs, and facilitates movement, along with details on bone anatomy. Test your knowledge on the core principles of osteology.