Skeletal System: Bones and Joints

Vocabulary flashcards covering the key components, matrix elements, cell types, growth processes, anatomical terms, and divisions of the skeletal system from Chapter 6.

Collagen

A tough, ropelike protein found in connective tissue matrix that lends flexible strength to bone.

Proteoglycans

Large molecules consisting of many polysaccharides attaching to and encircling core proteins, forming aggregates that attract water.

Hydroxyapatite

Calcium phosphate crystals that form most of the mineral component in bone, providing weight-bearing or compression strength.

Long bones

Bones that are longer than they are wide, such as upper and lower limb bones.

Short bones

Bones that are approximately as wide as they are long, such as bones of the wrist and ankle.

Flat bones

Bones with a relatively thin, flattened shape, such as bones of the skull and sternum.

Irregular bones

Bones with shapes that do not fit into long, short, or flat categories, such as the vertebrae and facial bones.

Red marrow

Soft tissue inside bone cavities that serves as the location of blood-forming cells.

Yellow marrow

Soft tissue inside bone cavities consisting mostly of fat.

Osteon

The structural unit of compact bone, including lamella, lacunae, canaliculus, central canal, and osteocytes.

Lamella

Rings of bone matrix located within an osteon.

Lacunae

Spaces located between lamellae in compact bone tissue.

Canaliculus

Tiny canals in compact bone that transport nutrients and remove waste.

Central canal

The center of an osteon that contains blood vessels.

Trabeculae

Interconnecting rods of bone in spongy (cancellous) bone tissue with spaces that contain marrow.

Osteoblasts

Bone cells responsible for the formation, repair, and remodeling of bone.

Osteocytes

Cells that maintain bone matrix, formed from osteoblasts after bone matrix surrounds them.

Osteoclasts

Bone cells that contribute to bone repair and remodeling by removing existing bone in a process called bone reabsorption.

Ossification

The formation of bone by osteoblasts.

Intramembranous ossification

Bone formation occurring within connective tissue membranes, occurring primarily in flat skull bones.

Endochondral ossification

Bone formation that occurs inside hyaline cartilage, where a cartilage model is replaced by bone.

Primary ossification center

The initial area of bone formation in the diaphysis of a long bone during endochondral ossification.

Secondary ossification center

The area of bone formation in the epiphysis during endochondral ossification.

Appositional growth

The increase in bone width or diameter caused by osteoblasts depositing new bone lamellae onto existing bone between the periosteum and existing matrix.

Epiphyseal plate

The site where bone growth in length occurs through endochondral ossification.

Bone remodeling

The process involving the removal of existing bone by osteoclasts and the deposition of new bone by osteoblasts.

Callus

A fibrous network that forms between two bone fragments during bone repair.

Foramen

An anatomical term for a hole in a bone, such as the foramen magnum.

Fossa

An anatomical term for a depression in a bone, such as the glenoid fossa.

Process

An anatomical term for a projection on a bone, such as the mastoid process.

Condyle

An anatomical term for a smooth, rounded end of a bone, such as the occipital condyle.

Meatus

An anatomical term for a canal-like passageway, such as the external auditory meatus.

Tubercle

An anatomical term for a lump of bone, such as the greater tubercle.

Axial skeleton

The central part of the skeletal system composed of the skull, the vertebral column, and the thoracic cage.

Braincase

The portion of the skull enclosing the cranial cavity, consisting of 8 bones that surround and protect the brain.

Hyoid bone

An unpaired, U-shaped bone that does not articulate with any other bone, providing attachments for tongue and neck muscles.

Vertebral column

The central axis of the skeleton extending from the base of the skull to slightly past the pelvis, consisting of 26 individual bones in adults.