Chapter 7 Skeletal System Terminology

Skeletal system

The organ system that includes the bones, and the ligaments and cartilages that hold them together.

Long bone

elongated cylindrical bones that typically have a shaft (diaphysis) and two enlarged ends (epiphysis)

Diaphysis

Shaft of a long bone

Epiphyses

Either end of a long bone.

Periosteum

Dense connective tissue covering the surface of a bone.

Compact bone

Dense bone tissue in which cells are organized in osteons without apparent spaces; cortical bone.

Spongy bone

Bone that consists of bars and plates separated by irregular spaces; also called cancellous bone.

Intramembranous bones

Bone that forms from membrane-like layers of primitive connective tissue.

Endochondral bones

Bone that begins as hyaline cartilage that is subsequently replaced by bone tissue.

Epiphyseal plates

Cartilaginous layer between the epiphysis and diaphysis of a long bone that grows, lengthening the bone

Osteoclasts

Cell that breaks down bone matrix.

Axial skeleton

Pertaining to the head, neck, and trunk.

Appendicular skeleton

Pertaining to the upper or lower limbs.

Pectoral girdle

Part of the skeleton that supports and attaches the upper limbs.

Pelvic girdle

Part of the skeleton to which the lower limbs attach.

Frontal bone

Plane that divides a structure into anterior and posterior portions; pertaining to the forehead.

Parietal bones

Pertaining to the wall of a cavity.

Occipital bone

Pertaining to the lower, back part of the head.

Nasal bones

Pertaining to the nose.

Sphenoid bone

a compound bone that forms the base of the cranium, behind the eye and below the front part of the brain.

Ethmoid bone

a square bone at the root of the nose, forming part of the cranium, and having many perforations through which the olfactory nerves pass to the nose.

Mandible

the lower jaw

Vomer bone

a thin, vertical, and unpaired bone located in the midline of the skull

Lacrimal bones

a small bone forming part of the eye socket

Atlas

the first vertebra that supports and balances the head

Axis

the second vertebra allows the atlas (C1) and the head to pivot on the axis

Thoracic vertebrae

the middle segment of the vertebral column, between the cervical vertebrae and the lumbar vertebrae

Lumbar vertebrae

Pertaining to the region of the lower back.

Sacrum

a triangular bone in the lower back formed from fused vertebrae and situated between the two hip bones of the pelvis

Coccyx

tail bone composed of four fused vertebrae

Clavicles

rodlike bones located between the sternum and the scapulae

Scapulae

shoulder blade

Humerus

long bone in the upper arm that extends from the shoulder to the elbow

Radius

long bone in the forearm that extends from the elbow to the wrist

Ulna

long bone in forearm and associated with the pinky.

Carpal bones

Pertaining to the wrist or any of the individual wrist bones

Metacarpal bones

Any of the five bones of the hand between the wrist bones and finger bones.

Phalanges

Bone of a finger or toe

Ilium

One of the bones making up the hip bone, the largest portion of the hip bone

Ischium

lowest portion of the hip bone

Pubis

the anterior portion of the hip bone

Femur

bone that extends from the hip to the knee

Tibia

bone located on the medial side of the leg

Fibula

bone that is located on the lateral side of the tibia

Tarsal bones

Pertaining to the ankle or any of the individual ankle bones.

Metatarsal bones

Any of the five bones of the foot between the ankle bones and the toe bones.

Joints

Union of two or more bones; also called an articulation.

Fibrous joints

wo or more bones joined by dense connective tissue.

Cartilaginous joints

Two or more bones joined by cartilage.

Synovial joint

Freely movable joint.

Flexion

Movement decreasing the angle between bones at a joint.

Extension

Movement increasing the angle between bones at a joint.

Plantar flexion

a movement of the foot where the toes point downward and the heel rises

Abduction

Movement of a body part away from the midline.

Adduction

Movement of a body part toward the midline. Rotation

Pronation

Downward or backward rotation of the palm.

Supination

Upward or forward rotation of the palm.

Eversion

Turning the plantar surface of the foot outward, away from the midline.

Inversion

Turning the plantar surface of the foot inward, toward the midline.

Retraction

Movement of a part toward the back.

Protraction

Forward movement of a body part.

Elevation

the movement of a body part upward or higher

Depression

a downward movement of a body part