Chapter 9 joints Flashcards
Joint Classification
- joints are classified structurally based on their anatomical
characteristics - joints are classified functionally based on the kind of movement
they permit
Fibrous Joints
- do not have a synovial cavity and the articulating bones are held together with Fibrous connective tissue
- these allow little to no movement
Sutures
a thin layer of dense fibrous connective tissue connects the
bones of the skull
- functionally, this kind of joint is called a synarthrosis, i.e.
an immovable joint (these joints tend to ossify with age to form a
synostosis)
Syndesmoses:
a fibrous joint which has a greater distance between articulating
bones than sutures and more fibrous connective tissue
- ex. the sheen of connective tissue that connects the Tibia and
Fibula
- these joints are slightly moveable, i.e. amphiarthrosis
Gomphosis:
- where a cone shaped peg fits into a socket
- ex. connecting the jaw to teeth
- synarthrosis
Cartilaginous Joints
- do not have a synovial cavity and the articulating bones are connected with cartilage
- these allow little to no movement
Synchondroses is
- Joins by cartilage
- contains Hyaline Cartilage
- ex. the Epiphyseal plates closes
Symphyses
-a broad, flat disk of fibrocartilage connects the bones
- ex. Intervertebral Disks and Symphysis Pubis
- are amphiarthroses
Synovial Joints
a space called the Synovial Cavity lies between the articulating
bones
- these are considered to be freely moveable
- functionally, freely moveable joint is called a diarthrosis
- the bone ends of these joints are covered with Articular
(Hyaline) Cartilage
- other components of Synovial Joints:
Articular Capsule
surrounds the synovial joint to form the Synovial Cavity
- two layers
a. outer layer is the Fibrous Capsule, often contains Ligaments
b. inner layer is the Synovial Membrane
Synovial Fluid
secreted by the Synovial Membrane
- a viscous fluid that lubricates and nourishes joint surfaces
Accessory Ligaments:
some joints contain ligaments inside or outside the joint cavity
Meniscus = Articular disc is
a pad of fibrocartilage that lies between certain articulating
bones
- ex. knee joint
Bursae:
tiny, fluid-filled, saclike structures around certain joints that
help reduce friction caused by movement
- Bursitis = inflammation of a bursa
Tendon Sheaths:
- a tube like bursa that wraps around certain tendons
- these help reduce friction where tendons pass through synovial cavities
Flexion
a decrease in the angle between articulating bones
Extension:
an increasesin the angle between articulating bones, or
to restore a body part to the Anatomical Position
Hyperextension
a continuation of extension beyond the Anatomical Position
Abduction
the movement of a bone away from the midline
- the midline for the hand is the middle finger
- the midline for the foot is the second toe
Adduction
movement of a bone towards the midlin
Circumduction
movement of the distal end of a body part in a circle
- requires movement in more than one plane of motion
Rotation
when a bone revolves around its own longitudinal axis
Opposition
the movement of the thumb at the carpometacarpal joint in which
the thumb moves across the palm to touch the tips of the fingers of the same hand
Sprain
damage to a joint that tears ligaments, but does not dislocate bones can cause significant damage to surrounding tissues
Dislocation
a displacement of a bone from a joint
- this results in the tearing of the articular capsule and adjacent
tissues
Osteoarthritis (O.A.) = Degenerative Joint Disease (D.J.D.
a degenerative disorder of synovial joints where the articular
cartilage is gradually lost
- associated with the normal “wear and tear” on joints
- calcium deposits around the joint to create “spurs”
Rheumatoid Arthritis (R.A.
an autoimmune disorder (the body attacks its own tissues)
- this disorder usually occurs bilaterally (vs. R.A.)
- often leads to joint fusion
Gouty Arthritis (Gout)
a disorder associated with the build-up of Uric Acid (a waste
product of Nucleic Acid metabolism)
- as Uric Acid build up it forms crystals which are deposited in
soft tissues of joints, these crystals irritate and inflame joints
eroding away articulating surfaces _
