Anatomy Joint unit

What are the two classifications of joints?

Classification of joint that relies on anatomy of the joint

Classification of joint that is based on the amount of movement possible (range of motion)

types of structural joints

types of functional joints

an immovable joint which can be fibrous or cartilaginous depending on the connection of the bones formed by the joint

a slightly moveable joint which can be fibrous or cartilaginous depending on the connection formed by the bone

a freely movable joint which is subdivided functionally according to their planes of movement

(fibrous synarthrosis) joint located between the bones of the skull. The edges of bones are interlocked at the suture

(fibrous synarthrosis) binds teeth to bony sockets in the maxilla and mandible

(cartilaginous synarthrosis) a bridge between two articulating bones

(bony synarthrosis) an immovable joint created when two bones fuse and the boundary between them disappears

(fibrous amphiarthrosis) bones connected by a ligament

(cartilaginous amphiarthrosis) bones connected by a wedge of fibrocartilage

(diarthrosis) permits a wider range of motion than other joints do

a two layered joint capsule that surrounds a synovial joint

what two things are in an articular capsule

• cartilage that covers articulating surfaces

• has no periochondrium and watery matrix

• surface is slick & smooth

clear, viscous solution with an egg yolk like consistency

3 functions of synovial fluid

when cartilage is compressed synovial fluid goes into the space between surfaces to reduce friction between moving surfaces. when compression stops the fluid is pulled back

the synovial fluid circulates continuously to provide nutrients and act as a waste removal route for the chondrocytes of cartilage.

synovial fluid cushions joints that are subjected to compression from shocks and sudden impacts (fluid amount increases as pressure increases)

fibrocartilage pad located between opposing bones w/ synovial joints function: subdivide a synovial cavity, channel flow of fluid, and allow variation of shapes.

localized masses of adipose tissue covered by a layer of synovial membrane function: protect articular cartilage and act as packing material for the joint

localized thickenings that support, strengthen, and reinforce synovial joints

2 types of ligaments

ligament located inside the joint capsule

ligament located outside the joint capsule

not part of the joint but connect the fleshy part of muscle to the bones that make up a joint

small, thin, fluid-filled pockets in connective tissue that reduce friction and act as shock absorbers, they contain synovial fluid and lined by synovial membrane

tubular bursae that surround tendons where they cross bony surfaces

bursae that develop in abnormal locations because of abnormal stresses

• collagen fibers of the joint capsule and any accessory

• shapes of the articulating surfaces and menisci which prevent movement

• the presence of other bones, skeletal muscles or fat pads around the joint

• tensions in tendons attached to the articulating bones