Tutorial 4 - Joints & Appendicular Skeleton Flashcards
Three functional categories of joints
Synarthrosis
Amphiarthrosis
Diarthrosis
Synarthrosis
no movement
- extremely strong joints are located where movement between the bones must be prevented
Amphiarthrosis
little movement
- permits more movement than synarthrosis but is much stronger than a freely movable joint
- connected by collagen fibers and cartilage
Diarthrosis
free movement
- permits the widest range of movement
What are the 4 structural categories/types of synarthrosis joints?
suture
gomphosis
synchondrosis
synostosis
What are the 2 structural categories/types of amphiarthrosis joints?
syndesmosis
symphysis
What is the one structural categories/types of diarthrosis joints?
synovial
Suture
- synarthrotic joint located only between bones of the skull
- interlocked and bound together at the suture by dense fibrous connective tissue
- fibrous joints
- occur only in the skull
- immovable joint
- joint with no movement
- serrated edges that lock together with fibers of connective tissue
- strong and fracture-resistant
- all skull joints are sutures except the joint connecting the mandible and the temporal bone, which is a movable synovial joint
ex: coronal suture is the suture connecting the parietal and frontal bones in the cranial
Gomphosis
- synarthrosis joint
- binds the teeth to bony sockets in the maxillae and mandible
- a periodontal ligament
- fibrous articulations between teeth and maxillae or teeth and mandible
ex: teeth to bony sockets
Synchondrosis
- synarthrosis joint
- a rigid, cartilaginous bridge between two articulating bones
- immovable cartilaginous joint
- first pair of ribs and sternum
ex: connect the ends of the first pair of ribs and the sternum
Synostosis
- synarthrosis joint
- a totally rigid, immovable joint formed when two bones fuse and the boundary between them disappears
ex: frontal suture of the frontal bone and epiphyseal lines of mature long bones are synostoses
Syndesmosis
- amphiarthrosis joint
- connect bones by a ligament
- ligament connecting two bones
- distal joint between tibia and fibula (tibiofibular ligament)
ex: distal joint between the tibia and fibula
Symphysis
- amphiarthrosis joint
- bones separated by a wedge or pad of fibrocartilage
- fibrocartilaginous pads between two bones
- vertebrae, intervertebral disc, etc.
ex: joint between the two pubic bones
Synovial
- diarthrosis joint
- greatest range of motion compared to other joints
- typically located at the ends of long bones
- 6 types
- presence of an articular capsule between two joined bones
- bone surfaces at synovial joints are covered in a coating of articular cartilage
ex: ends of long bones in the upper and lower limbs
What are the four components of a synovial joint?
- articular cartilage
- joint capsule
- synovial membrane
- joint cavity
What are the three functions of synovial fluid?
lubrication
nutrient distribution
shock absorption
Articular cartilage
like hyaline cartilage
wraps bones at joints
no perichondrium & its matrix contains more water
Joint capsule
sac enclosing the articulating ends of joints
Synovial membrane
lines interior of joint capsule and secretes synovial fluid
Joint cavity
contains synovial fluid
What are the four accessory structures supporting the knee?
- bursa
- fat pads
- meniscus
- accessory ligaments
Bursa
reduce friction and act as shock absorbers (connective tissue)
Fat pads
fill in spaces created as joint cavity changes shape when bones move (adipose tissue)
Meniscus
subdivide a synovial cavity, channel flow of synovial fluid, allow for shape variations of articular surfaces (fibrocartilage)