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Two main divisions of the human skeleton

The axial skeleton and the appendicular skeleton

Axial skeleton

Division comprising the skull, vertebral column, and rib cage that supports and protects vital organs

Appendicular skeleton

Division consisting of the limbs and girdles that facilitates movement and environmental interaction

Primary functions of the skeletal system

Providing structural support, protecting vital organs, and facilitating movement as levers for muscles

Cervical vertebrae (C1-C7)

Seven neck vertebrae that support the skull and allow for head mobility

Atlas

The cervical vertebra, which directly supports the skull

Axis (C2)

The second cervical vertebra, which allows head rotation

Thoracic vertebrae (T1-T12)

Twelve vertebrae that articulate with the ribs to provide upper-back stability

Lumbar vertebrae (L1-L5) (Lower)

lower-back vertebrae that bear the majority of the body's weight

True ribs (ribs 1-7)

Rib pairs that attach directly to the sternum through their own individual costal cartilage

False ribs (ribs 8-10)

Rib pairs that attach indirectly to the sternum by connecting to cartilage above them

Floating ribs (ribs 11-12)

Rib pairs that lack any attachment to the sternum, permitting greater movement

Clavicle

The clavicle (commonly known as the collarbone) is a long, S-shaped bone located horizontally at the front of the shoulder girdle that connects the arm to the trunk of the body, articulating with the sternum

Scapula

The shoulder blade, providing muscle attachment points and enabling arm mobility

Humerus

Upper arm bone allowing a wide range of motion at the shoulder and elbow

Femur

The longest bone in the body, designed to support weight during standing and walking

Tibia

The larger bone of the lower leg, essential for bearing the body's weight

Fibula

The smaller bone of the lower leg, primarily providing lateral stability

Foramen magnum

Large cranial opening through which the brainstem and spinal cord pass

Acetabulum

The hip bone socket that articulates with the head of the femur

Hyoid bone

A U-shaped neck bone supporting the tongue that does not articulate directly with other bones

Articular cartilage

Smooth connective tissue on bone ends at synovial joints that reduces friction and absorbs shock

Ligaments

Fibrous bands connecting bone to bone that stabilize joints and prevent excessive motion