A & P Exam 2

Diaphysis

Shaft of a long bone

Episphysis

Ends of a long bone

Metaphysis

Growth plate area between the shaft and end of a long bone

Medullary cavity

Marrow cavity found only in long bones

Articular cartilage

Cartilage covering bone ends at joints

Periosteum

Membrane covering the outside of a bone

Endosteum

Membrane covering the inside surfaces of a bone

Compact bone

Dense outer layer of bone organized into osteons

Spongy bone

Porous interior of bone organized into trabeculae

Red marrow

Bone marrow that makes blood cells

Yellow marrow

Bone marrow that stores fat

Collagen

Component of bone matrix providing flexibility and tensile strength

Minerals

Components of bone matrix (mainly calcium and phosphate) providing hardness

Osteoprogenitor

Stem or precursor bone cell

Osteoblast

Bone cell that builds bone and secretes osteoid

Osteocyte

Mature bone cell that maintains and monitors bone

Osteoclast

Bone cell that breaks down and resorbs bone using acid and enzymes

Intramembranous ossification

Ossification starting with mesenchyme, forming mainly flat skull bones, mandible, and central clavicle

Endochondral ossification

Ossification starting with a hyaline cartilage model to form most bones

Primary ossification center

Center of endochondral ossification located in the diaphysis

Secondary ossification center

Centers of endochondral ossification located in the epiphyses

Appositional growth

Bone growth in width where osteoblasts add bone outside and osteoclasts remove bone inside

Hematoma

First step of fracture repair involving a blood clot

Soft callus

Second step of fracture repair that stabilizes a break

Hard callus

Third step of fracture repair where bone replaces the soft callus

Remodeling

Final step of fracture repair resulting in stronger, organized bone

Parathyroid hormone (PTH)

Hormone released when blood calcium is low, increasing osteoclast activity and kidney calcium retention

Calcitriol

Active vitamin D which increases calcium absorption from food in the intestine

Calcitonin

Hormone released by the thyroid when blood calcium is high, inhibiting osteoclasts and increasing urinary calcium loss

Osteopenia

Below-normal bone mass

Osteoporosis

Severe bone loss resulting in fragile bones and fractures

Axial skeleton

Skeleton consisting of the skull, vertebral column, and thoracic cage for support and protection

Appendicular skeleton

Skeleton consisting of upper limbs, lower limbs, pectoral girdle, and pelvic girdle for movement

Condyle

Large, rounded joint surface

Facet

Small, flat joint surface

Trochanter

Massive rough projection found only on the femur

Crest

Bone ridge

Fossa

Bone depression

Foramen

Bone hole or opening

Fontanelles

Soft connective tissue areas in infant skulls allowing growth

Atlas (C1)

Cervical vertebra responsible for nodding YES

Axis (C2)

Cervical vertebra responsible for rotation NO

Synarthrosis

Immobile functional joint classification

Amphiarthrosis

Slightly movable functional joint classification

Diarthrosis

Freely movable functional joint classification

Gomphosis

Fibrous joint fixing a tooth in its socket

Suture

Fibrous joint connecting skull bones

Syndesmosis

Slightly movable fibrous joint such as radius/ulna or tibia/fibula

Synchondrosis

Cartilaginous joint made of hyaline cartilage

Symphysis

Cartilaginous joint made of fibrocartilage that resists compression

Bursa

Fluid-filled cushion that reduces friction in joints

Tendon sheath

Fluid-filled sleeve around a tendon that reduces friction

Flexion

Movement decreasing the joint angle or bending

Extension

Movement increasing the joint angle or straightening

Abduction

Movement away from the midline

Adduction

Movement toward the midline

Pronation

Movement turning palm down or posterior

Supination

Movement turning palm up or anterior

Osteoarthritis

Arthritis caused by wear and degeneration of cartilage

Rheumatoid arthritis

Autoimmune arthritis

Gout

Arthritis caused by crystal buildup and inflammation