Intro to Arthrology Flashcards
Arthrology
The science concerned with the anatomy, function, dysfunction, and treatment of joints
Joint
- AKA articulation or arthrosis
- Point of articulation between two or more bones, allowing motion
- Specialized structures made up of connective tissue that allow flexibility through specific movements meant to support our frame and give us mobility
- Point of contact between two or more bones, cartilage and bone, or teeth and bone
- Space between two bones
Functions of Joints (5)
1) Allows for physical movement and agility (fluidity of movement)
2) Structure and stability to the form of the skeleton
3) Point for absorption and transferring of compressive forces/shock
4) Provides a space for circulation of fluids and nutrients to the articulating cartilages of bone
5) Point of leverage for function of muscles
Naming joints
Taken from names of the bones that articulate with each other
Classification of Joints (2)
1) Function (movement)
2) Structure (composition)
Degrees of movement (based on function) (3)
1) Synarthrotic
2) Amphiarthrotic
3) Diarthrotic
Synarthrotic
Immoveable joints (sutures)
- May be fibrous or cartilaginous
*Axial skeleton
Ex skull sutures
Amphiarthrotic
Slightly moveable joints
- May be fibrous or cartilaginous
*Axial skeleton
Ex Pubic symphysis; fibrous connection; intervertebral discs
Diarthrotic
Freely moveable joints
- All synovial joints are diarthrotic
- Prominent in appendicular skeleton
Structure of the joint (3)
1) Fibrous
2) Cartilaginous
3) Synovial
“So F’in SAD”
Fibrous Joints
Bones connected by fibrous tissue
*No joint cavity
Types of Fibrous Joints (3)
1) Sutures (Ex skull sutures)
2) Syndesmosis (Ex between radius and ulna; distal tibiofibular joint)
3) Gomphoses (teeth)
Cartilaginous Joints
Bones are united by cartilage
*No joint cavity
Types of Cartilaginous Joints (2)
1) Synchondrosis (Ex 1st sternocostal joint)
2) Symphysis (Ex intervertebral joints; pubic symphysis joint)
Synovial Joints
- Facilitate movement and stability. Most moveable!
- Posses a joint cavity (synovial cavity with synovial fluid)
- Have articular cartilage (covers ends of opposing bones)
- Have an articular capsule (encloses joint cavity)
- Contain associated structures
Structures Associated with Joints (6)
1) Ligaments
2) Tendons
3) Articular discs/Menisci
4) Fat Pads
5) Bursae
6) Nerves and Blood Supply
Ligaments
- Attach bone to bone
- Joint capsule is continuous with the periosteum of the articulating bones
Accessory Ligaments
- Localized thickenings of joint capsule
- Reinforce and strengthen it; may also limit rotation
Sprain
When a ligament is stretched/injured to the point at which collagen fibers are torn and disrupted
Avulsion Fracture
When the attached bone breaks before the ligament. Ligaments are strong!
Types of Ligaments (2)
1) Intracapsular
2) Extracapsular
Intracapsular
Found INSIDE the capsule
Help prevent extreme movements (Ex’s PCL; ACL)
Extracapsular
OUTSIDE of the joint capsule (Ex’s MCL; LCL)
Tendons
- Attach muscle to bone
- Not part of the articulation itself
- May limit range of motion and provide mechanical support (Ex muscles of arm bracing for shoulder joint)
Strain
Injury to a muscle
Articular Discs or Menisci
- Fibrocartilage pads
- Stabilize joint by improving fit of articulating surfaces
- Contribute to joint movement and shock absorption
- A Meniscus (crescent shaped) sits within a synovial joint between opposing bones
- Both may subdivide a synovial cavity, channel the flow of synovial fluid, or allow for variations in the shapes of articular surfaces
Fat Pads
- Masses of adipose tissue surrounded by a synovial membrane
- Commonly superficial to a joint capsule
- Protect articular cartilages and act as packing material for joint
- Fat pads fill the spaces created when bones move as joint cavity changes shape
Bursae (bursa)
- Small, fluid-filled pockets in connective tissue
- Contain fluid (similar to synovial but NOT) and lined by a synovial membrane
- May be connected to joint capsule or separate
- Form where a tendon or ligament rub against other tissues
- Reduce friction and act as shock absorber
- Found around most synovial joints (Ex sub acromial bursa)
Nerves and Blood Supply
- Bones and joints are alive!
- Nerves that supply a joint are same as those that supply the skeletal muscles that move the joint
- Numerous arteries and veins supply joints and surrounding structures
- Joints also have specialized receptors for detecting where the body is in space so nervous system can coordinate muscular contractions for stability
