Chapter 6: Skeletal System

Axial Skeleton

Skull, vertebral column, and thoracic cage.

Appendicular Skeleton

Limbs and girdles.

Frontal Bone

Forms the forehead.

Parietal Bones

Form the sides and roof of the skull.

Temporal Bones

Contain structures of the ear.

Occipital Bone

Forms the back and base of the skull.

Sphenoid Bone

"Keystone" bone of the skull.

Ethmoid Bone

Forms part of the nasal cavity and orbits.

Maxilla

Upper jaw.

Mandible

Lower jaw.

Zygomatic Bone

Cheekbone.

Cervical Vertebrae

Seven vertebrae in the neck.

Thoracic Vertebrae

Twelve vertebrae that articulate with ribs.

Lumbar Vertebrae

Five large lower back vertebrae.

Sacrum

Five fused vertebrae.

Coccyx

Tailbone.

True Ribs

Ribs 1–7 attached directly to the sternum.

False Ribs

Ribs 8–12 not directly attached to the sternum.

Floating Ribs

Ribs 11–12 with no anterior attachment.

Clavicle

Collarbone.

Scapula

Shoulder blade.

Acromion

Projection of the scapula that articulates with the clavicle.

Glenoid Fossa

Socket for the humerus.

Humerus

Upper arm bone.

Radius

Lateral forearm bone (thumb side).

Ulna

Medial forearm bone.

Carpals

Wrist bones.

Metacarpals

Palm bones.

Phalanges

Finger and toe bones.

Coxal Bone

Hip bone.

Ilium

Superior portion of the hip bone.

Ischium

Inferior posterior portion of the hip bone.

Pubis

Anterior portion of the hip bone.

Acetabulum

Hip socket.

Femur

Thigh bone.

Patella

Kneecap.

Tibia

Medial lower leg bone.

Fibula

Lateral lower leg bone.

Talus

Ankle bone that articulates with the tibia.

Calcaneus

Heel bone.

Fibrous Joint

Joint connected by dense connective tissue with little or no movement.

Cartilaginous Joint

Joint connected by cartilage with slight movement.

Synovial Joint

Freely movable joint.

Plane Joint

Allows gliding movement.

Hinge Joint

Allows flexion and extension.

Pivot Joint

Allows rotation.

Condylar Joint

Allows movement in two planes.

Saddle Joint

Allows movement in two planes with greater range.

Ball-and-Socket Joint

Allows movement in all directions.

Osteoporosis

Loss of bone density.

Herniated Disc

Rupture of an intervertebral disc.

Kyphosis

Excessive thoracic curvature.

Lordosis

Excessive lumbar curvature.

Scoliosis

Lateral curvature of the spine.