Key Notes Terms

Pivot joints

rounded end of one bone protrudes into a sleeve or ring composed of bone or

ligament; uniaxial (proximal radio-ulnar joint, the dens of the axis to atlas).

Hinge joints

cylindrical projection of one bone fits into a trough-shaped surface on another bone; uniaxial (elbow joint, knee joint, ankle joint, and interphalangeal joints).

Saddle joints

articular surfaces have a concave area on one that fits with the convex area of

the other; biaxial (first carpometacarpal joint in the thumb).

Plane joints

also known as gliding joints; articular surfaces are flat and only allow for short gliding movements; multi-axial (intercarpal and intertarsal joints, sacro-iliac joint, vertebrocostal joint, acromioclavicular and sternoclavicular joints, and between the superior and inferior articulating processes of the vertebrae).

Condyloid joints

also known as ellipsoid joint, oval articular surface of one bone fits into a

complementary depression in another; biaxial (metacarpophalanges 2-5 or knuckles, radiocarpal joints, and metatarsophalangeal joints).

Ball and socket joints

the spherical end of one bone articulates with a cuplike socket of another bone; multi-axial (shoulder joint and hip joints).

Synarthosis

no movement is permitted; the bony edges are quite close together and may even interlock. These extremely strong joints are located where movement between bones must be prevented.

Amphiarthosis

only slight movement is permitted; permits more movement than a synarthrotic joint, but is much stronger than freely moveable joints.

Diarthosis

freely moveable joints, provide a wide range of motion as typical in the joints of our appendages.

Fibrous joints

held together by fibrous connective tissues but lack cartilage and possess no cavity between the bones: are either synarthrotic or amphiarthrotic.

Cartilaginous joints

held together by fibrous connective tissues such as ligaments but they also possess either hyaline cartilage or fibrocartilage; lack a joint cavity and are either synarthrotic or amphiarthrotic.

Synovial joints

held together by fibrous connective tissues, hyaline cartilage and/or fibrocartilage, and possess a joint cavity; all are diarthrotic; quite complex in structure, are the most numerous type of joint in the body, and permit the greatest range of motion.

Interosseous membrane

membrane that connected two parallel bones in the forearm and the lower leg

Anterior cranial fossa

the most anterior and the shallowest of the three cranial fossae. It overlies the orbits and contains the frontal lobes of the brain.

Middle cranial fossa

deeper and situated posterior to the anterior fossa. It extends from the lesser wings of the sphenoid bone anteriorly, to the petrous ridges (petrous portion of the temporal bones) posteriorly.

Posterior cranial fossa

the most posterior and deepest portion of the cranial cavity. It contains the cerebellum of the brain.

Coronal suture

between frontal and anterior border of the parietal bones.

Sagittal suture

between the two parietal bones.

Squamous suture

between parietals and squamous of temporal

Lambdoid suture

between posterior parietal bones and occipital bone

Hyoid bone

only bone that does not articulate with other bones

Kyphosis

an excessive posterior curvature of the thoracic region

Lordosis

an excessive anterior curvature of the lumbar region

Scoliosis

an abnormal, lateral curvature, accompanied by twisting of the vertebral column

Herniated disc

is a condition where part of the soft, jelly-like center of an intervertebral disc (spinal disc) pushes through its tough outer layer (annulus) and into the spinal canal.

True ribs (1-7)

connected directly to the sternum by way of a costal cartilage

False ribs (8-12)

connected to the sternum indirectly

Achondroplasia

results from abnormal hyaline cartilage development. Because hyaline cartilage forms the model for long bone formation, the individual will have short, stocky limbs but the torso and head are of normal size.

Acromegaly

result from too much growth hormone after the epiphyseal plates close so that the

bones do not grow longer but instead get thicker (especially the bones of the face, hands, and jaw). This leads to changes in their physical appearance.

Articular cartilage

covers portions of the epiphysis that articulate with other bones. The cartilage is avascular, hyaline cartilage that reduces friction and acts as a shock absorber.

Endosteum

internal membrane of bone made of connective tissue where bone growth, repair, and remodeling occur. Also lines the many canals that pass-through bone to supply blood and nerves to the bone.

Periosteum

outermost covering of bone made primarily of dense irregular tissue and held on by collagen fibers; contains blood vessels, nerves, and lymphatic vessels that nourish compact bone. Tendons and ligaments also attach to bones here; covers the entire outer surface except where the epiphyses meet other bones to form joints