Joints Classifications

Structural classification of joints

(fibrous, cartilaginous, synovial) based on amount of space bw our joints, type of CT within/surrounding the joint-3 categories in this classification system, more precise system

Functional Classification of joints

(synarthrosis-nonmoveable, amphiarthrosis-slightly moveable, diarthrosis-freely moveable). Classified based on motion.

Ball and Socket Joint

- most moveable joint of body -spherical surface that articulates with a concave depression (socket)

Sutures

- these areas allow for flexibility of skull during childbirth (membranous area bw these are called fontanels) - wider spaces bw them in childhood

Sutures

- type of fibrous joint - dense regular collagenous CT - seams within the bones of the skull joined by the CT - interlocking bony edges that help provide extra strength to the joints

periodontal ligaments

-are bundles of CT (regular collagenous) that hold teeth in sockets -allows small amount of movement for chewing

Fibrous joints

-bones united by fibrous connective tissue -no joint cavity -no movement (in most cases, sometimes very small amount) -3 types

Synovial joint

-classified based on shape of articular surfaces

Synovial Joints

-contain synovial fluid--hyaluronic acid -allow a great degree of motion -makeup most of moveable joints in body (esp. those with append. skeleton).

Synchondrosis

-joined by hyaline cartilage -no movement -often temporary joints and end up being ossified into a bone as we age

Saddle joint

-joint that has two saddle shaped surfaces at right angles to each other -biaxial joint -ex. carpal metacarpals policies joint

Ellipsoid joint

-modified ball and socket joint --oval concave articulating with oval convex -can't undergo rotation, biaxial.

Gomphoses

-peg and socket -bundles of regular collagenous -joints between teeth and sockets -specific to the teeth

Gomphosis of tooth

-root of tooth=peg -alveolar process=maxillary bones -mandible=sockets

Symphysis

-two or more bones united by fibrocartilage -somewhat flexible

Hinge Joint

-uniaxial -ex. elbow -concave bony surface articulating with convex bony surface (cylinder on a concave surface)

Pivot joint

-unique joint -cylindrical process on one bone rotating on a ring comprised of bone must also of ligament -unaxial, rotates around one axis -allows for pronation and supination of forearm -ex. head of radius with surface of ulna.

Coronal Suture

Frontal bone is connected to parietal bones through this suture.

Lambdoid Suture

Occipital bones is attached to the parietal bones through the lambdoid suture.

Sagittal Suture

Two parietal bones are connected to each other with this.

Plane Joints

aka gliding joint bc gliding movement -uniaxial -two flat surfaces articulating -slight amount of movement bc held tight by ligaments -ex. bw process of the vertebrae

monoaxial movement

aka uniaxial, movement in one plane only

cartilaginous joints

bones united by hyaline or fibrocartilage -two types: synchondrosis and symphysis

bursa

extension of joint cavity

root of tooth

f

periosteum

fibrous and cellular layer (outside to in)

joint cavity

filled with synovial fluid

Crown of tooth

green arrow

gingiva (gum)

image h

tendon

inside tendon sheath

joint capsule

made up of synovial fluid, fibrous capsule, and bone

biaxial movement

movement in two planes

multiaxial

movements or joints are usually symmetrically shaped joints that allow for movement in a variety of directions

alveolar bone

spongy stuff

Joint bw intervertebral disks, junction bw manubrium and body on sternum

symphysis joint

Joint for coxal bones- that join ilium ischium and pubis

synchondrosis joint

joint between epiphyseal plate before fusion

synchondrosis joint

Ball and Socket Joint

these joints are at hip and shoulder and their respective girdles -can have circumduction, multi axial. -degree of movement depends on movement on deepness of socket and how spherical the ball is.

Syndesmosis

this is the second type of fibrous joints. -bones are further apart that in a suture -joined by ligaments -some movement (bc of the small space bw the bones and the flexibility of the ligaments holding the bones together). Ex. occurs at the midpoint of ulna and radius

Joint/articulation

where there's a union of two or more bones (can be classified based on shape of bony surfaces, types of CT within the joints and degrees and types of movements that are possible at our joints).