Key Terms

abduction

movement in the coronal plane that moves a limb laterally away from the body; spreading of the fingers

acetabular labrum

lip of fibrocartilage that surrounds outer margin of the acetabulum on the hip bone

adduction

movement in the coronal plane that moves a limb medially toward or across the midline of the body; bringing fingers together

amphiarthrosis

slightly mobile joint

annular ligament

intrinsic ligament of the elbow articular capsule that surrounds and supports the head of the radius at the proximal radioulnar joint

anterior cruciate ligament

intracapsular ligament of the knee; extends from anterior, superior surface of the tibia to the inner aspect of the lateral condyle of the femur; resists hyperextension of knee

anterior talofibular ligament

intrinsic ligament located on the lateral side of the ankle joint, between talus bone and lateral malleolus of fibula; supports talus at the talocrural joint and resists excess inversion of the foot

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

atlanto-occipital joint

articulation between the occipital condyles of the skull and the superior articular processes of the atlas (C1 vertebra)

atlantoaxial joint

series of three articulations between the atlas (C1) vertebra and the axis (C2) vertebra, consisting of the joints between the inferior articular processes of C1 and the superior articular processes of C2, and the articulation between the dens of C2 and the anterior arch of C1

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)

bursa

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

calcaneofibular ligament

intrinsic ligament located on the lateral side of the ankle joint, between the calcaneus bone and lateral malleolus of the fibula; supports the talus bone at the ankle joint and resists excess inversion of the foot

cartilaginous joint

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

circumduction

circular motion of the arm, thigh, hand, thumb, or finger that is produced by the sequential combination of flexion, abduction, extension, and adduction

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

coracohumeral ligament

intrinsic ligament of the shoulder joint; runs from the coracoid process of the scapula to the anterior humerus

deltoid ligament

broad intrinsic ligament located on the medial side of the ankle joint; supports the talus at the talocrural joint and resists excess eversion of the foot

depression

downward (inferior) motion of the scapula or mandible

diarthrosis

freely mobile joint

dorsiflexion

movement at the ankle that brings the top of the foot toward the anterior leg

elbow joint

humeroulnar joint

elevation

upward (superior) motion of the scapula or mandible

eversion

foot movement involving the intertarsal joints of the foot in which the bottom of the foot is turned laterally, away from the midline

extension

movement in the sagittal plane that increases the angle of a joint (straightens the joint); motion involving posterior bending of the vertebral column or returning to the upright position from a flexed position

extrinsic ligament

ligament located outside of the articular capsule of a synovial joint

femoropatellar joint

portion of the knee joint consisting of the articulation between the distal femur and the patella

fibrous joint

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

fibular collateral ligament

extrinsic ligament of the knee joint that spans from the lateral epicondyle of the femur to the head of the fibula; resists hyperextension and rotation of the extended knee

flexion

movement in the sagittal plane that decreases the angle of a joint (bends the joint); motion involving anterior bending of the vertebral column

fontanelles

expanded areas of fibrous connective tissue that separate the braincase bones of the skull prior to birth and during the first year after birth

glenohumeral joint

shoulder joint; articulation between the glenoid cavity of the scapula and head of the humerus; multiaxial ball-and-socket joint that allows for flexion/extension, abduction/adduction, circumduction, and medial/lateral rotation of the humerus

glenohumeral ligament

one of the three intrinsic ligaments of the shoulder joint that strengthen the anterior articular capsule

glenoid labrum

lip of fibrocartilage located around the outside margin of the glenoid cavity of the scapula

gomphosis

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

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

humeroradial joint

articulation between the capitulum of the humerus and head of the radius

humeroulnar joint

articulation between the trochlea of humerus and the trochlear notch of the ulna; uniaxial hinge joint that allows for flexion/extension of the forearm

hyperextension

excessive extension of joint, beyond the normal range of movement

hyperflexion

excessive flexion of joint, beyond the normal range of movement

iliofemoral ligament

intrinsic ligament spanning from the ilium of the hip bone to the femur, on the superior-anterior aspect of the hip joint

inferior rotation

movement of the scapula during upper limb adduction in which the glenoid cavity of the scapula moves in a downward direction as the medial end of the scapular spine moves in an upward direction

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

intracapsular ligament

ligament that is located within the articular capsule of a synovial joint

intrinsic ligament

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

inversion

foot movement involving the intertarsal joints of the foot in which the bottom of the foot is turned toward the midline

ischiofemoral ligament

intrinsic ligament spanning from the ischium of the hip bone to the femur, on the posterior aspect of the hip joint

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

joint interzone

site within a growing embryonic limb bud that will become a synovial joint

lateral (external) rotation

movement of the arm at the shoulder joint or the thigh at the hip joint that moves the anterior surface of the limb away from the midline of the body

lateral excursion

side-to-side movement of the mandible away from the midline, toward either the right or left side

lateral flexion

bending of the neck or body toward the right or left side

lateral meniscus

C-shaped fibrocartilage articular disc located at the knee, between the lateral condyle of the femur and the lateral condyle of the tibia

lateral tibiofemoral joint

portion of the knee consisting of the articulation between the lateral condyle of the tibia and the lateral condyle of the femur; allows for flexion/extension at the knee

ligament

strong band of dense connective tissue spanning between bones

ligament of the head of the femur

intracapsular ligament that runs from the acetabulum of the hip bone to the head of the femur

medial (internal) rotation

movement of the arm at the shoulder joint or the thigh at the hip joint that brings the anterior surface of the limb toward the midline of the body

medial excursion

side-to-side movement that returns the mandible to the midline

medial meniscus

C-shaped fibrocartilage articular disc located at the knee, between the medial condyle of the femur and medial condyle of the tibia

medial tibiofemoral joint

portion of the knee consisting of the articulation between the medial condyle of the tibia and the medial condyle of the femur; allows for flexion/extension at the knee

meniscus

articular disc

multiaxial joint

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

opposition

thumb movement that brings the tip of the thumb in contact with the tip of a finger

patellar ligament

ligament spanning from the patella to the anterior tibia; serves as the final attachment for the quadriceps femoris muscle

periodontal ligament

band of dense connective tissue that anchors the root of a tooth into the bony jaw socket

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

plantar flexion

foot movement at the ankle in which the heel is lifted off of the ground

posterior cruciate ligament

intracapsular ligament of the knee; extends from the posterior, superior surface of the tibia to the inner aspect of the medial condyle of the femur; prevents anterior displacement of the femur when the knee is flexed and weight bearing

posterior talofibular ligament

intrinsic ligament located on the lateral side of the ankle joint, between the talus bone and lateral malleolus of the fibula; supports the talus at the talocrural joint and resists excess inversion of the foot

pronated position

forearm position in which the palm faces backward

pronation

forearm motion that moves the palm of the hand from the palm forward to the palm backward position

protraction

anterior motion of the scapula or mandible

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

pubofemoral ligament

intrinsic ligament spanning from the pubis of the hip bone to the femur, on the anterior-inferior aspect of the hip joint

radial collateral ligament

intrinsic ligament on the lateral side of the elbow joint; runs from the lateral epicondyle of humerus to merge with the annular ligament

reposition

movement of the thumb from opposition back to the anatomical position (next to index finger)

retraction

posterior motion of the scapula or mandible

rotation

movement of a bone around a central axis (atlantoaxial joint) or around its long axis (proximal radioulnar joint; shoulder or hip joint); twisting of the vertebral column resulting from the summation of small motions between adjacent vertebrae

rotator cuff

strong connective tissue structure formed by the fusion of four rotator cuff muscle tendons to the articular capsule of the shoulder joint; surrounds and supports superior, anterior, lateral, and posterior sides of the humeral head

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

subacromial bursa

bursa that protects the supraspinatus muscle tendon and superior end of the humerus from rubbing against the acromion of the scapula

subcutaneous bursa

bursa that prevents friction between skin and an underlying bone

submuscular bursa

bursa that prevents friction between bone and a muscle or between adjacent muscles

subscapular bursa

bursa that prevents rubbing of the subscapularis muscle tendon against the scapula

subtalar joint

articulation between the talus and calcaneus bones of the foot; allows motions that contribute to inversion/eversion of the foot

subtendinous bursa

bursa that prevents friction between bone and a muscle tendon

superior rotation

movement of the scapula during upper limb abduction in which the glenoid cavity of the scapula moves in an upward direction as the medial end of the scapular spine moves in a downward direction

supinated position

forearm position in which the palm faces anteriorly (anatomical position)

supination

forearm motion that moves the palm of the hand from the palm backward to the palm forward position

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

synostosis

site at which adjacent bones or bony components have fused together

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

talocrural joint

ankle joint; articulation between the talus bone of the foot and medial malleolus of the tibia, distal tibia, and lateral malleolus of the fibula; a uniaxial hinge joint that allows only for dorsiflexion and plantar flexion of the foot

temporomandibular joint (TMJ)

articulation between the condyle of the mandible and the mandibular fossa and articular tubercle of the temporal bone of the skull; allows for depression/elevation (opening/closing of mouth), protraction/retraction, and side-to-side motions of the mandible

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

tibial collateral ligament

extrinsic ligament of knee joint that spans from the medial epicondyle of the femur to the medial tibia; resists hyperextension and rotation of extended knee

ulnar collateral ligament

intrinsic ligament on the medial side of the elbow joint; spans from the medial epicondyle of the humerus to the medial ulna

uniaxial joint

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

zygapophysial joints

facet joints; plane joints between the superior and inferior articular processes of adjacent vertebrae that provide for only limited motions between the vertebrae