Anatomy of Bones Quiz

Study Notes

Overview of the Skeletal System

Composed of bones, cartilage, tendons, and ligaments.
Total bones in a baby: 276; adult: 206.

Functions of the Skeletal System (S2PMB)

Shapes and forms the body.
Provides structural support.
Protects vital organs.
Facilitates movement.
Stores essential minerals and fat.
Aids in blood cell production.

Bone Characteristics

Weakest bone: clavicle (collarbone); softest bone in the human body.
Bone weight consists of 31% water.
Longest and strongest bone: femur (thighbone).

Extracellular Matrix Components

Collagen: robust, ropelike protein providing structure.
Proteoglycans: large molecules of polysaccharides attached to core proteins.
Cartilage: contains both collagen and proteoglycans.
Bone: incorporates collagen and minerals, mainly calcium and phosphate.
Hydroxyapatite: crystalline structure of calcium phosphate.

Types of Bones

Long Bones:
- Longer than wide; predominantly made of compact bone; found in limbs.
Short Bones:
- Cube-shaped; mostly spongy bone; examples include wrist and ankle bones.
Flat Bones:
- Thin and flattened; examples include skull, ribs, and scapulae.
Irregular Bones:
- Unique shapes; primarily spongy bone; includes vertebrae and facial bones.

Bone Structure

Diaphysis: Central shaft of a long bone.
Epiphysis: Ends of the long bone.
Epiphyseal Plates: Growth plates indicating bone length increase.
Articular Cartilage: Covers epiphyses ends to reduce friction.
Medullary Cavity: Contains bone marrow; features yellow (fat storage) and red (blood cell formation) marrow.

Bone Histology

Osteoblasts: Cells responsible for bone formation and repair.
Osteocytes: Mature bone cells found in lamellae.
Lacunae: Spaces housing osteocytes within lamellae.
Canaliculi: Tiny channels connecting lacunae.

Classification of Osseous Tissue

Compact Bone: Dense, smooth texture.
Spongy Bone: Composed of needle-like pieces with numerous open spaces.

Bone Development

Embryonic skeleton: primarily hyaline cartilage.
Ossification Processes:
- Hyaline cartilage model is fully encased in bone matrix by osteoblasts.
- Hyaline cartilage model is digested, creating a medullary cavity.

Bone Growth Mechanisms

Balanced activity of osteoclasts (bone removal) and osteoblasts (bone deposition).
Growth Hormone regulates long bone lengthening during puberty.
Appositional growth results in bone widening and diameter increase.

Bone Remodeling and Repair

Occurs to maintain structure in response to growth and stress.
Bone becomes denser and projects form in areas of muscle attachment.
Repair involves clot formation, callus formation, and remodeling to compact bone.

Calcium Homeostasis in Bone

Osteoclasts increase blood calcium levels through bone resorption.
Osteoblasts decrease blood calcium levels by depositing calcium into bone.

Bone Markings

Projections (Processes): Extensions from bone surfaces for muscle and ligament attachment.
Depressions: Indentations or cavities within bones for joint formation.
Examples of projections include tuberosity, crest, and trochanter, while joint-forming features are heads and condyles.

Description

Test your knowledge on the structure and functions of different bone types, including the diaphysis, epiphysis, and marrow. This quiz covers essential concepts of bone anatomy and growth, focusing on irregular bones and their unique characteristics.