Chapter 8: Joints Flashcards
What are the two ways in which joints are classified? What are the three divisions within each system of classification?
Structural vs Functional
Structural:
- Fibrous
- Cartilaginous
- Synovial
Functional:
- Synarthroses
- Amphiarthroses
- Diarthroses
What defines a fibrous joint? Where
are examples of each found in the body?
Fibrous joints are mostly immovable joints with no cavity that are held together by collagen fibers. They are found in the skull, the mouth, between the tibia and fibia, and between the radius and ulna.
What are the differences in location, mobility, and examples of a suture, syndesmosis and a gomphosis?
Suture:
- Located in Skull
- Immovable (synarthrosis)
- Example: Coronal Suture between frontal and parietal bones
Syndesmosis:
- Located between long bones (i.e. radius & ulna, tibia & fibia)
- Slightly movable (amphiarthrosis)
- Example: Interosseous membrane of the forearm
Gomphosis:
- Located in the mouth as teeth in their sockets
- Immovable (synthrosis)
- Example: Tooth in the alveolar socket (jaw)
What defines a cartilaginous joint? What is the differences between a synchondrosis and symphysis?
Cartilagenous joints are not highly movable, have no cavity, and unite bones by cartilage.
Synchrondrosis: A joint where HYALINE cartilage unites bones and are immovable. i.e. epiphyseal plate, articular cartilage
Symphysis: A joint where FIBROCARTILAGE unites bones and are slightly movable. i.e. pubic symphysis of pelvis, intervertebral joints between the bodies of vertebrae
What defines a synovial joint?
Synovial joints are freely movable and contain a cavity known as the joint cavity filled with synovial fluid and surrounded by an articular capsule.
Name the 6 main features of a synovial joint and their roles.
- Articular (joint) capsule: Encloses synovial joint and unites bone.
- Role: Protects the joint. Outer layer provides structural support and inner synovial membrane produces synovial fluid. - Synovial cavity: Space between the bones within the joint capsule.
- Role: Allows free movement and contains synovial fluid for lubrication. - Articular cartilage: Smooth layer of HYALINE cartilage on long bone surfaces.
- Role: Reduces friction and absorbs shock during movement. - Synovial fluid: Thick fluid produced by the synovial membrane.
- Role: Lubricates the joint, supplies nutrients to cartilage, acts as a shock absorber. - Reinforcing ligaments: Dense, fibrous tissue connecting bone to bone
— Capsular: thickened part of fibrous layer
— Extracapsular: outside of the capsule
— Intracapsular: deep to capsule, covered by synovial membrane
- Role: Provide joint stability, limit excessive movements - Nerves and blood vessels
- Role: Nerves detect pain, monitor joint position and stretch. Capillary beds supply filtrate for synovial fluid.
What 5 accessory structures can be found in synovial joints?
- Menisci
- Fat Pads
- Ligaments
- Tendons
- Bursae
Describe the structure and function of the accessory structure found in synovial joints: Menisci
Menisci
- Structure: C-shaped fibrocartilage
- Function: Improve joint fit, absorb shock, distribute weight
Describe the structure and function of the accessory structure found in synovial joints: Fat pads
Fat Pads:
- Structure: Soft masses of adipose tissue
- Function: Cushion joints, reduce friction, fill spaces
Describe the structure and function of the accessory structure found in synovial joints: Ligaments
Ligaments:
- Structure: Dense, fibrous tissue connecting bone to bone
- Function: Provide joint stability, limit excessive movements
Describe the structure and function of the accessory structure found in synovial joints: Tendons
Tendons:
- Structure: Strong, fibrous tissue connecting muscle to bone
- Function: Stabilizes joints, transmits forces for movement
Describe the structure and function of the accessory structure found in synovial joints: Bursae
Bursae:
- Structure: Small, fluid-filled sacs lined with synovial membrane that form between tendon and bone. Some wrap around tendon sheath to reduce friction.
- Function: Reduce friction and cushion joints between moving structures
Name three factors that influence stability of synovial joints to prevent dislocations.
- Muscle tone: Keeps tendons taut as they cross joints, important in sholder and knee joints, and arches of foot
- Ligament Number and Location: The more ligaments, the stronger the joint
- Articular surface shape: Shallow surfaces less stable than ball-and-socket.
Label the appropriate parts of a synovial joint.
(image)
What are the 3 categories of movement allowed by synovial joints?
- Gliding: flat, or nearly flat, bone surface glides or slips over another. i.e. back-and-forth and side-to-side
- Angular: increase or decrease the angle between two bones. i.e. flexion, extension, hyperextension, abduction, adduction, and circumduction
3: Rotational: turning of a bone around its own long axis. i.e. protation and supination
