Bones Quiz/Test

Axial and Appendicular Skeletons

Axial = skull, vertebrae, rib cage; Appendicular = limbs and girdles

Cartilage

Flexible connective tissue, reduces friction in joints, found in ears and joints

Ligaments

Connect bone to bone, stabilize joints, ex. ACL

Tendons

Connect muscle to bone, transmit force, ex. Achilles tendon

Joints

Junctions between bones, allow movement and flexibility

Upper Limb Bones

Arm = humerus; Forearm = radius + ulna; Hand = carpals, metacarpals, phalanges

Radius vs Ulna

Radius = wide distal end; Ulna = wide proximal end

Pectoral Girdle

Clavicle + scapula, connects upper limbs to axial skeleton, increases mobility

Lower Limb Bones

Thigh = femur + patella; Leg = tibia + fibula; Foot = tarsals, metatarsals, phalanges

Pelvic Girdle

Hip bones + sacrum, attaches lower limbs, supports weight, protects organs

Rib Cage

12 pairs ribs, sternum, thoracic vertebrae; protects heart and lungs

Vertebral Column

26 vertebrae, 5 regions (cervical, thoracic, lumbar, sacral, coccyx), flexible, protects spinal cord

Skull

Cranial bones = 8; Facial bones = 14; Mandible = only movable skull bone

Bone Overview

Living organ, all 4 tissue types, constantly remodels, 206 bones

Functions of Skeleton

Support, protection, movement, mineral storage, fat storage, blood cell production, hormone production

Bone Classification

Long, short, flat, irregular; shape dictates function

Long Bones

Longer than wide, act as levers, limbs

Short Bones

Cube-shaped, support/stability, carpals/tarsals, sesamoid (patella)

Flat Bones

Thin, flat, curved, muscle attachment, sternum, scapula, ribs, cranial bones

Irregular Bones

Specialized shape, hip bones, vertebrae

Compact Bone

Dense outer layer, made of osteons, Haversian canal contains vessels and nerves

Spongy Bone

Porous, trabeculae resist stress, contains marrow

Bone Markings

Projections = muscle attachment; Surfaces = joints; Depressions/openings = vessels/nerves

Osteocytes

Maintain bone, monitor structure, in lacunae

Osteoblasts

Build and calcify bone

Osteoclasts

Absorb bone, remodeling

Bone Formation

Ossification = intramembranous (skull/clavicle), endochondral (other bones), cartilage remains in growth plates and articular surfaces

Bone Remodeling

Osteocytes signal, osteoclasts digest, osteoblasts rebuild, macrophages assist

Bone Fracture Repair

Hematoma → fibrocartilaginous callus → spongy bone → remodeling

Articular Cartilage

Smooth tissue at joint ends, reduces friction and absorbs shock

Spongy Bone

Porous bone inside, contains trabeculae and marrow

Compact Bone

Dense outer layer, provides strength and support

Medullary Cavity

Central hollow in long bones, contains yellow marrow

Epiphyses

End portions of long bones, mostly spongy bone

Diaphysis

Shaft of long bone, mainly compact bone

Periosteum

Outer membrane, nerves, vessels, growth/repair cells

Endosteum

Inner lining of medullary cavity, osteoblasts/osteoclasts

Yellow Bone Marrow

Stores fat for energy, in medullary cavity

Red Bone Marrow

Produces blood cells, in spongy bone

Nutrient Artery

Supplies blood to bone interior

Nerves in Bone

Detect pain, regulate blood flow, control growth/remodeling