Skeletal System Functions and Anatomy Quiz

Skeletal System Functions

• Supports internal organs
• Enables movement (with muscles)
• Stores minerals (calcium, phosphorus, vitamin D)
• Produces blood cells (hematopoiesis)
• Stores energy (fat in yellow marrow)

Bone Shapes

• Long bones
• Short bones
• Flat bones
• Irregular bones

Microscopic Bone Anatomy

• Osteocytes: Mature bone cells in lacunae, maintain the bone matrix.
• Osteoblasts: Bone-forming cells.
• Osteoclasts: Bone-destroying cells.
• Lacunae: Cavities in bone matrix where osteocytes reside.
• Osteon: Complex consisting of central canal and concentric rings of matrix.
• Haversian canal: Canal carrying blood vessels and nerves in bone.
• Volkmann's canal: Canal perpendicular to Haversian canal.
• Medullary cavity: Cavity in bone shaft filled with yellow bone marrow (fat).
• Periosteum: Fibrous membrane covering bone diaphysis.
• Epiphyseal plate: Cartilage in young bones; causes lengthwise growth.
• Articular cartilage: Hyaline cartilage covering epiphyses.
• Diaphysis: Shaft of a long bone.
• Epiphysis: Ends of a long bone, composed of thin layers of compact bone filled with spongy bone.

Red vs. Yellow Bone Marrow

• Red bone marrow: Produces blood cells, found in certain bones (pelvis, ribs, vertebrae).
• Yellow bone marrow: Stores fat, found in medullary cavity of long bones.

Compact vs. Spongy Bone

• Compact bone: Dense, outer bone layer; provides strength.
• Spongy bone: Lighter, inner bone; contains trabeculae (structures for shock absorption).

Ossification

• Process where bone forms, replacing cartilage.

True/False Bone Growth

• a: False. Bone growth width is controlled by sex hormones and growth.
• b: False. Articular cartilage is found at the ends, not in the middle; it is replaced by new bone during length growth.
• c: False; New bone develops on the inner surface of the epiphyseal plates.
• d: False, Appositional growth is added to the exterior of the bone while the interior is removed.
• e: False, Bone growth width results in widening of the diaphysis and not the medullary cavity.

Intervertebral Discs

• Cushions and supports vertebrae, allows for movement.
• A pinched disc can cause pain, numbness, and weakness, depending on the pinched nerve's location.

Spinal Curvatures

• Spine curves for better support and balance (cervical, thoracic, lumbar, sacral).

Thoracic Cage Function

• Protects the heart and lungs, supports the shoulder girdle and assists in respiration.

Pelvic Differences

• Female pelvis: Wider, larger pelvic inlet for childbirth.
• Male pelvis: Narrower, robust.

Longest, Strongest, Heaviest Bone

• Femur

Joint Classification

• Based on structure (fibrous, cartilaginous, synovial) and function (immovable, slightly movable, freely movable).

Skeletal System Parts

• Axial: Skull, Vertebral Column, Rib Cage
• Appendicular: Limbs, shoulder girdles, pelvic girdles

Other Key Information

• Vertebrae numbers: 5 lumbar, various counts for cervical and thoracic, important for spine structure.
• Bone functions: Protection and support across entire skeleton; movement in conjunction with muscles.
• Bone composition: Concentric circles in lamellae arranged around central canal; bone cells (osteocytes) in lacunae are important for function.
• Bone growth: controlled by hormones and bone replacing cartilage.
• Bone types: Shapes include long, short, flat and irregular, reflecting different functions and locations. Different types of bone marrow exist (red and yellow) performing varying roles.

Test your knowledge on the functions of the skeletal system and its microscopic anatomy. This quiz covers bone shapes, cell types, and the overall structure of bones. Perfect for students studying biology or anatomy!