Week 5 - Joints Flashcards
What are joints
Joints also known as articulation are structures where 2 bones meet, providing mobility, flexibility and structure.
Joints are the sites where 2 skeletal elements come together.
What are the different types of joints
- Fibrous
- Cartilaginous
- Synovial
What are fibrous joints
Bones - Fibrous tissue - Bone
Provides little to no movement
Examples of Fibrous Joints
- sutures e.g. the “seams” that only occur in the skull
- gomphoses - attach the teeth to their sockets in the jaws
- syndesmoses
What are syndesmoses
Type of fibrous joint
Where bones are connected by longer fibres, and the amount of movement dependent on fiber length
e.g. proximal tibiofibular joint and the distal tibiofibular joint (they are the joints in between the radius and ulnar which are connected by interosseous membrane)
What are examples of syndesmoses joints
proximal tibiofibular joint and the distal tibiofibular joint (they are the joints in between the radius and ulnar which are connected by interosseous membrane)
What are the different types of cartilaginous joints
- Primary cartilaginous (Synchondrosis)
- Secondary cartilaginous (Symphysis)
What are synchondrosis joints
Primary cartilaginous
Bone - Cartilage - Bone
Provides little movement, protection (shock absorbers)
What are symphysis joints
Secondary Cartilaginous joints
Bone - Cartilage - Fibrocartilage - cartilage - Bone
The fibrocartilage is compressible/resilient and acts as a shock absorber
*All secondary lie in the mid line - the middle of the body e.g. vertebra column
Example of synchondrosis joints
- Epiphyseal plate
- Joint between first rib and sternum (immovable)
Example of Symphysis joint (singlular:symphysis) (secondary cartilaginous joints)
- Fibrocartilaginous intervertebral disc
- Pubic symphysis (between the 2 pubic bones)
What are synovial joints
Bone - Cartilage - Synovial cavity - cartilage - bone
Synovial joints are connections between skeletal components where the elements involved are separated by a narrow articular cavity
- Most joints are in this category
- Articular bones separated by a fluid filled cavity
- Allow sliding, rolling and twisting movements
Articular capsule
Hyaline cartilage - covers the articulating surfaces of the bone
joint cavity (contains synovial fluid)
Ligament
What are the different classes of synovial joints (3)
- Uniaxial (around 1 axis)
- Biaxial (around 2 axes at 90 degrees to one another)
- Multiaxial (around many axes)
What are the different types of uniaxial synovial joints
- Hinge joint
- Pivot joint
What are the different types of Biaxial synovial joints
- Condyloid joint
- saddle joint
What are the different types of Multiaxial synovial joints
- Ball and Socket joint
- Plane/gliding joint
What are hinge joints
- uniaxial synovial joint
- Allows flexion and extension
e.g. elbow, ankle
Example of hinge joints
elbow
ankle
What are pivot joints
- uniaxial synovial joint
- allows rotation movement
- Cylindrical process in ring of bone/ligament
e.g. superior radio-ulnar, atlanto-axial
Example of pivot joints
Atlanto-axial - the rotating movement from the first 2 vertebra (allows head shacking ‘no’)
What are Condyloid Joints
- Biaxial synovial joints
- allows flexion, extension, abduction and adduction movements
- convex face in concave depression
- “egg in spoon”
e.g. knuckle joints, wrist joint
Example of condyloid joints
wrist
knuckle joints
What are Saddle joints
- Biaxial synovial joints
- Allows flexion and extension, abduction and adduction and circumduction (circular)
- 2 convex and concave surfaces
e.g. between carpal and metacarpal at thumb
Example of Saddle joints
between carpal and metacarpal at the thumb
What are Ball and Socket Joints
- Multiaxial synovial joints
- allows flexion, extension, abduction, adduction, external rotation, internal rotation and circumduction
- round head + cup-shaped depression
e.g. shoulder, hip joint
Example of ball and socket joints
shoulder joints
hip joints
What are plane/gliding joints
- Multiaxial synovial joints
- Allow sliding r gliding movements when one bone moves across the surface of another
- flattened/slightly curved surfaces
e.g. carpals, tarsals
Example of plane/gliding joints
Carpal bones in the hand
tarsal bones of the foot
In between vertebrae
What controls the stability of a joint
- The more mobility a joint provides the less stable it is
- ligaments limit movements
- muscles and tendons - stabilize
