Bone Tissue and Cartilage Quiz

Bone Tissue and Cartilage

• Bone (osseous tissue) is a hard, dense connective tissue forming most of the adult skeleton.
• Cartilage, a semi-rigid connective tissue, is found where bones move (e.g., ribcage, joints).
• Hyaline, elastic, and fibrocartilage are types of cartilage with varying flexibility.
• The skeletal system (bones and cartilage) supports the body, facilitates movement, protects organs, produces blood cells, and stores minerals and fat.

Bone Classification

• Long bones: Tubular shafts (diaphysis) with wider ends (epiphyses). Examples include the femur and humerus.
• Short bones: Roughly cube-shaped. Examples include carpals and tarsals.
• Flat bones: Thin, flattened, and often curved. Examples include cranial bones and ribs.
• Irregular bones: Complex shapes that don't fit other categories. Examples include vertebrae and facial bones.
• Sesamoid bones: Small, round bones in tendons, reducing pressure. The patella is an example.
• Sutural bones: Small bones found within sutures of the skull.

Long Bone Structure

• Diaphysis: The long, tubular shaft of a long bone.
• Epiphyses: The wider ends of a long bone. Contains spongy bone.
• Epiphyseal plate: Hyaline cartilage in children enabling longitudinal bone growth. Becomes the epiphyseal line after growth ceases.
• Articular cartilage: Covers the ends of bones in joints, providing smooth surfaces.
• Medullary cavity: Hollow space within the diaphysis, containing yellow bone marrow (fat).
• Periosteum: Tough, fibrous membrane covering the bone's outer surface.
• Endosteum: Membrane lining the medullary cavity.
• Compact bone: Dense bone tissue forming the diaphysis's outer layer.
• Spongy bone: Porous bone tissue found in epiphyses and within compact bone. Contains trabeculae (bone struts).
• Red bone marrow (hematopoietic tissue): Produces blood cells, found in spongy bone.

Compact Bone Histology

• Osteon (Haversian system): Basic unit of compact bone.
• Lamellae: Concentric rings of bone matrix in an osteon.
• Central (Haversian) canal: Contains blood vessels and nerves at the center of an osteon.
• Perforating (Volkmann's) canals: Channels connecting central canals.
• Lacunae: Small cavities housing osteocytes (bone cells).
• Canaliculi: Tiny canals connecting lacunae, allowing nutrient and waste exchange.

Axial Skeleton

• Vertebral column: Cervical (neck), thoracic (chest), lumbar (lower back) curvatures. Intervertebral discs cushion vertebrae.
• Scoliosis: Abnormal lateral curvature of the spine.
• Kyphosis: Excessive thoracic curvature (hunchback).
• Lordosis: Excessive lumbar curvature (swayback).
• Fontanelles: Soft spots in infant skulls, allowing for brain growth.
• Skull bones: Frontal, parietal, temporal, occipital, sphenoid, ethmoid, maxilla, palatine, vomer, mandible. Sutures connect skull bones. Important foramina include the foramen magnum, optic canal, and jugular foramen.
• Thoracic cage: Sternum (manubrium, body, xiphoid process) and ribs (true, false, floating). Protects the heart and lungs.
• Ribs: Articulate with thoracic vertebrae posteriorly and sternum (for true ribs) anteriorly.

Number of Vertebrae

• Thoracic vertebrae: 12
• Lumbar vertebrae: 5
• The sacrum and coccyx are also parts of the vertebral column. The sacrum articulates with the iliac bones of the pelvis.

True vs. False Ribs

• True ribs: Directly attach to the sternum via their costal cartilages.
• False ribs: Attach to the sternum indirectly via the costal cartilage of the 7th rib or do not attach to the sternum at all (floating ribs).