| A | B |
|---|
| Skeletal System | Framework of bones and connective tissues that supports the body, protects vital organs, stores minerals, and enables movement |
| Bone | Rigid connective tissue composed of cells and mineralized matrix |
| Ossification | Process of forming new bone |
| Compact Bone | Dense tissue that forms the outer layer of bones and provides strength |
| Cancellous Bone | Spongy, porous inner bone that contains marrow and reduces weight; found in epiphyses of long bones and core of all other bones |
| Bone Marrow | Soft tissue inside bones that produces blood cells |
| Red Marrow | Site of hematopoiesis where blood cells are produced, found in cancellous bone |
| Yellow Marrow | Stores fat and can convert to red marrow if needed; found in medullary cavity (diaphysis) of mature long bones |
| Periosteum | Fibrous membrane covering the outer surface of bone |
| Cartilage | Smooth, flexible tissue that reduces friction in joints |
| Osteocyte | Mature bone cell that maintains bone tissue |
| Osteoblast | Cell responsible for bone formation |
| Osteoclast | Cell responsible for bone resorption and breakdown |
| Long Bone | Bone longer than it is wide such as femur |
| Short Bone | Cube-shaped bone such as the bones of the wrist |
| Flat Bone | Thin bone that protects organs such as skull |
| Irregular Bone | Bone without an easily characterized shape such as vertebrae |
| Sesamoid bone | Bone that resembles a sesame seed; patella |
| Diaphysis | Shaft of a long bone |
| Epiphysis | End of a long bone |
| Metaphysis | Region between the diaphysis and epiphysis of a long bone |
| Epiphyseal plate | Region of a long bone between the epiphysis and the metaphysis; allows longitudinal bone growth |
| Medullary Cavity | Central cavity of long bone (diaphysis) containing yellow bone marrow |
| Axial Skeleton | Bones of the head and torso (80) |
| Appendicular Skeleton | Bones of limbs and girdles (126) |
| Cranium; Skull | Bone that contains the brain; 8 cranial bones, 14 facial bones, 6 auditory ossicles |
| Hyoid | U-shaped bone in the neck that supports the tongue; floating bone |
| Vertebral column | Set of bones that support the head and protect the spinal cord |
| Cervical spine | Neck region of the spine; contains 7 vertebrae |
| Thoracic spine | Chest region of the spine; contains 12 vertebrae |
| Lumbar spine | Lower back region of the spine; contains 5 vertebrae |
| Sacrum | Bone that forms the back of the pelvic girdle |
| Coccyx | Tailbone; bone at the base of the spine |
| Intervertebral discs | Cartilage pads found between vertebrae; allow for spinal flexibility and absorb shock |
| Sternum | Bone of the anterior chest; breastbone |
| Xiphoid process | Pointed lower tip of the sternum |
| Manubrium | top of the sternum |
| Ribs | Bones that form the chest and protect the lungs, heart, liver and spleen; 12 pairs |
| Pectoral Girdle | Bones that attach and support the upper extremity |
| Clavicle | Collarbone; slender bone that connects sternum to scapula |
| Scapula | Shoulderblade; triangular bone that provides attachment for shoulder muscles and articulates with the humerus |
| Acromion | Bony projection of the scapula; forms the point of the shoulder |
| Humerus | Long bone of the upper arm |
| Ulna | Medial bone of the forearm; forms the elbow joint |
| Olecranon | upper end of the ulna that forms the point of the elbow |
| Radius | Lateral bone of the forearm |
| Carpals | eight short bones that form the wrist |
| Metacarpals | Bones that form the palm of the hand |
| Phalanges | Bones that form the fingers and toes |
| Pelvic girdle | Bones that attach and support the lower extremity |
| Ilium | Broad, flaring portion of the hip bone |
| Ischium | Lower portion of the hip bone |
| Pubis | Anterior portion of the hip bone |
| Acetabulum | Cup-shaped socket of the pelvic bone that articulates with the femur to form the hip joint |
| Femur | Bone of the thigh (upper leg), longest and strongest bone of the body |
| Patella | Kneecap; sesamoid bone that protects the knee joint |
| Fibula | slender, non-weight-bearing bone of the lateral lower leg |
| Tibia | Larger, weight-bearing bone of the lower leg |
| Tarsals | Short bones that form the ankle |
| Metatarsals | Bones that form the arch and ball of the foot |
| Suture | Fibrous joint found between skull bones |
| Cartilaginous Joint | Joint connected by cartilage allowing limited movement |
| Synovial Joint | Freely movable joint containing synovial fluid |
| Synovial Cavity | Space within a synovial joint filled with fluid |
| Synovial Fluid | Lubricating fluid that reduces friction between bones |
| Articular Cartilage | Smooth cartilage covering ends of bones |
| Joint Capsule | Fibrous structure enclosing a synovial joint |
| Ligament | Connective tissue that connects bone to bone to provide support for joints |
| Meniscus | Protective cushion inside some synovial joints |
| Bursa | Small, closed sac of fluid located between bones and soft tissues near joints; reduces friction between tissues and cushions joints |
| Hinge Joint | Joint that allows movement in one direction (flexion and extension) |
| Ball-and-Socket Joint | Joint allowing movement in multiple directions |
| Pivot Joint | Joint that allows rotational movement |
| Gliding Joint | Joint where bones slide past each other |
| Condyloid Joint | Joint allowing movement without rotation |
| Saddle Joint | Joint allowing movement in two planes |
| Range of Motion | Extent of movement possible at a joint |
