Chapter 2 – Key Terms

amphiarthrosis slightly mobile joint

articular capsule connective tissue structure that encloses the joint cavity of a synovial joint

articular cartilage thin layer of hyaline cartilage that covers the articulating surfaces of bones at a synovial joint

articular disc meniscus; a fibrocartilage structure found between the bones of some synovial joints; provides padding or smooths movements between the bones; strongly unites the bones together

articulation joint of the body

ball-and-socket joint synovial joint formed between the spherical end of one bone (the ball) that fits into the depression of a second bone (the socket); found at the hip and shoulder joints; functionally classified as a multiaxial joint

biaxial joint type of diarthrosis; a joint that allows for movements within two planes (two axes)

bone hard, dense connective tissue that forms the structural elements of the skeleton

bursa connective tissue sac containing lubricating fluid that prevents friction between adjacent structures, such as skin and bone, tendons and bone, or between muscles

cartilaginous joint joint at which the bones are united by hyaline cartilage (synchondrosis) or fibrocartilage (symphysis)

central canal longitudinal channel in the center of each osteon; contains blood vessels, nerves, and lymphatic vessels; also known as the Haversian canal

compact bone dense osseous tissue that can withstand compressive forces

condyloid joint synovial joint in which the shallow depression at the end of one bone receives a rounded end from a second bone or a rounded structure formed by two bones; found at the metacarpophalangeal joints of the fingers or the radiocarpal joint of the wrist; functionally classified as a biaxial joint

diaphysis tubular shaft that runs between the proximal and distal ends of a long bone

diarthrosis freely mobile joint

endochondral ossification process in which bone forms by replacing hyaline cartilage

endosteum delicate membranous lining of a bone’s medullary cavity

epiphyseal line completely ossified remnant of the epiphyseal plate

epiphyseal plate (also, growth plate) sheet of hyaline cartilage in the metaphysis of an immature bone; replaced by bone tissue as the organ grows in length

epiphysis wide section at each end of a long bone; filled with spongy bone and red marrow

extrinsic ligament ligament located outside of the articular capsule of a synovial joint

fibrous joint joint where the articulating areas of the adjacent bones are connected by fibrous connective tissue

flat bone thin and curved bone; serves as a point of attachment for muscles and protects internal organs

gomphosis type of fibrous joint in which the root of a tooth is anchored into its bony jaw socket by strong periodontal ligaments

hematopoiesis production of blood cells, which occurs in the red marrow of the bones

hinge joint synovial joint at which the convex surface of one bone articulates with the concave surface of a second bone; includes the elbow, knee, ankle, and interphalangeal joints; functionally classified as a uniaxial joint

interosseous membrane wide sheet of fibrous connective tissue that fills the gap between two parallel bones, forming a syndesmosis; found between the radius and ulna of the forearm and between the tibia and fibula of the leg

intramembranous ossification process by which bone forms directly from mesenchymal tissue

intrinsic ligament ligament that is fused to or incorporated into the wall of the articular capsule of a synovial joint

irregular bone bone of complex shape; protects internal organs from compressive forces

joint site at which two or more bones or bone and cartilage come together (articulate)

joint cavity space enclosed by the articular capsule of a synovial joint that is filled with synovial fluid and contains the articulating surfaces of the adjacent bones

ligament strong band of dense connective tissue spanning between bones

long bone cylinder-shaped bone that is longer than it is wide; functions as a lever

medullary cavity hollow region of the diaphysis; filled with yellow marrow

meniscus articular disc

modeling process, during bone growth, by which bone is resorbed on one surface of a bone and deposited on another

multiaxial joint type of diarthrosis; a joint that allows for movements within three planes (three axes)

osseous tissue bone tissue; a hard, dense connective tissue that forms the structural elements of the skeleton

ossification center cluster of osteoblasts found in the early stages of intramembranous ossification

osteoblast cell responsible for forming new bone

osteoclast cell responsible for resorbing bone

osteocyte primary cell in mature bone; responsible for maintaining the matrix

osteogenic cell undifferentiated cell with high mitotic activity; the only bone cells that divide; they differentiate and develop into osteoblasts

osteoid uncalcified bone matrix secreted by osteoblasts

osteon (also, Haversian system) basic structural unit of compact bone; made of concentric layers of calcified matrix

perichondrium membrane that covers cartilage

periosteum fibrous membrane covering the outer surface of bone and continuous with ligaments

pivot joint synovial joint at which the rounded portion of a bone rotates within a ring formed by a ligament and an articulating bone; functionally classified as uniaxial joint

plane joint synovial joint formed between the flattened articulating surfaces of adjacent bones; functionally classified as a multiaxial joint

primary ossification center region, deep in the periosteal collar, where bone development starts during endochondral ossification

proximal radioulnar joint articulation between head of radius and radial notch of ulna; uniaxial pivot joint that allows for rotation of radius during pronation/supination of forearm

remodeling process by which osteoclasts resorb old or damaged bone at the same time as and on the same surface where osteoblasts form new bone to replace that which is resorbed

red marrow connective tissue in the interior cavity of a bone where hematopoiesis takes place

saddle joint synovial joint in which the articulating ends of both bones are convex and concave in shape, such as at the first carpometacarpal joint at the base of the thumb; functionally classified as a biaxial joint

secondary ossification center region of bone development in the epiphyses

sesamoid bone small, round bone embedded in a tendon; protects the tendon from compressive forces

short bone cube-shaped bone that is approximately equal in length, width, and thickness; provides limited motion

spongy bone (also, cancellous bone) trabeculated osseous tissue that supports shifts in weight distribution

suture fibrous joint that connects the bones of the skull (except the mandible); an immobile joint (synarthrosis)

symphysis type of cartilaginous joint where the bones are joined by fibrocartilage

synarthrosis immobile or nearly immobile joint

synchondrosis type of cartilaginous joint where the bones are joined by hyaline cartilage

syndesmosis type of fibrous joint in which two separated, parallel bones are connected by an interosseous membrane

synovial fluid thick, lubricating fluid that fills the interior of a synovial joint

synovial joint joint at which the articulating surfaces of the bones are located within a joint cavity formed by an articular capsule

synovial membrane thin layer that lines the inner surface of the joint cavity at a synovial joint; produces the synovial fluid

tendon dense connective tissue structure that anchors a muscle to bone

tendon sheath connective tissue that surrounds a tendon at places where the tendon crosses a joint; contains a lubricating fluid to prevent friction and allow smooth movements of the tendon

trabeculae (singular = trabecula) spikes or sections of the lattice-like matrix in spongy bone

uniaxial joint type of diarthrosis; joint that allows for motion within only one plane (one axis)

yellow marrow connective tissue in the interior cavity of a bone where fat is stored