Chapter 8, 8.1

joints (articulations)

functional connections between bones, bind parts of skeletal system together

what makes bone growth possible, permits skeleton to change shape during childbirth, and enables body to move in response to skeletal muscle contractions

joints

structural classifications of joints

fibrous, cartilaginous, synovial

fibrous joints

held together by dense connective tissue containing many collagen fibers

synovial joints

have a complex structure

functional classifications of joints

synarthrotic, amphiarthrotic, and diarthrotic

synarthrotic joints

immovable

amphiarthrotic joints

slightly movable

diarthrotic joints

freely movable

where are fibrous joints found

in bones in close contact

3 types of fibrous joints

syndesmosis, suture, gomphosis

syndesmosis

bones bound by a sheet of dense connective tissue (interosseous membrane) or a bundle of dense connective tissue (interosseous ligament)

are syndesmosis amphiarthrotic (flexible, may twist)

yes

where are syndesmosis found

between tibia and fibula

suture

thin layer of connective tissue (sutural ligament) connects to bones, and synarthrotic (immovable) between flat bones of skull

gomphosis

cone-shaped bony process in a socket, synarthrotic

example of gomphosis

root of a tooth in maxilla or mandible held in place by periodontal ligament

cartilaginous joints

connected by hyaline cartilage or fibrocartilage

2 types of cartilaginous joints

synchondrosis and symphysis

synchondrosis

bands of hyaline cartilage unite bones, synarthrotic

example of temporary synchondrosis

epiphyseal plate (ossification converts this to a synostosis)

example of permanent synchondrosis

between manubrium and the first rib (costal cartilages)

symphysis

pad of fibrocartilage between bones, articular surfaces covered by hyaline cartilages

example of symphysis

pubic symphysis, joint between bodies of adjacent vertebrae (intervertebral discs)

synovial joints

diarthrotic, have a more complex structure

what kind are most joints

synovial

structure of a synovial joint

articular cartilage covers articular ends of bones

2 layers of joint capsule in synovial joint

outer fibrous layer and inner layer

outer fibrous layer of joint capsule in synovial joint

composed of ligaments

inner layer of joint capsule in synovial joint

synovial membrane, which secretes synovial fluid

synovial joints parts

Articular cartilage

• Joint capsule

• Ligaments

• Synovial membrane

• Synovial cavity

• Synovial fluid

• Meniscus (-i) in some joints

• Bursa (-ae) in some joints

6 types of synovial joints

saddle, pivot, hinge, plane, ball-and-socket, condylar

ball-and-socket joint (spheroidal)

round head in cup-shaped cavity, multiaxial, plus rotation

examples of ball-and-socket joints

hip and shoulder

which synovial joint has the widest range of motion

ball and socket

condylar joint

oval condyle fits into elliptical cavity

movement of condylar joint

back and forth, side to side, biaxial, no rotation

example of condylar joint

joints between metacarpals and phalanges

plane joint

almost flat, or slightly curved

plane joint movement

back-and-forth and twisting, nonaxial

plane joint example

wrist and ankle joints

hinge joint

convex surface fits into concave surface of other bone

hinge joint movement

uniaxial

hinge joint example

elbow, joints between phalanges

pivot joint

cylindrical surface rotates within ring of other bone

pivot joint movement

uniaxial, rotation only

pivot joint example

atlas (C1) and dens of axis (C2)

saddle joint

both bones have concave and convex surfaces

saddle joint movement

biaxial

saddle joint example

carpal and metacarpal of thumb