Locomotor - joints Flashcards
What are synovial joints?
Most common type of joint as most moveable.
Consists of articulating bones separated by synovial fluid, contained in a synovial membrane, strengthened by a joint capsule.
What is hyaline cartilage?
Found at top of long bones. Made of chrondrocytes, collagen II, GAGs (chrondroitin sulphate) and mostly water.
Provides a smooth gliding surface, shock absorption and load transmission.
Avascular to has limited healing/repair ability, blood supply via epiphysis and joint capsule.
Has proprioceptior and free sensory fibres in the joint capsule.
What is synovial fluid?
Clear fluid with hyaluronic acid, a proteoglycan known for jelly consistency.
For lubrication, shock absorption and nutrient/waste transport
What is the synovial membrane?
Fibrous tissue for producing synovial fluid and phagocytosis, a bit leaky.
What are the menisci?
If bones have condyles, they sit in discs of fibrous cartilage called menisci to provide stability
What are bursa?
Fluid filled sacs to cushion the area and help movement
What are sheaths?
Wrap around tendons to ease gliding
What is a cartilaginous joint?
Resist compression and provide support/flexibility.
Contains chrondrocytes that undergo chondrogenesis to produce extracellular matrix.
Two types of cartilaginous joints?
Synchrondosis and immoveable - fibrocartilage between articulating surfaces e.g. ribs and sternum
Symphysis and slightly more moveable - hylaine between e.g. pelvis and mandibular
What are fibrous joints?
No joint cavity, bound by ligamentous/fibrous tissue so are largely immovable.
What are examples of fibrous joints?
Sutures - sites in the skull, close as species age
Gomphosis - joints holding teeth to dental alveoli
Syndesmosis - hold tibula and fibula together. In horses can ossify the metacarpals
Other types of joint?
Non-articular hyaline - in trachea
Elastic cartilage
What is a planar joint?
Bones with articulating surfaces that are flat or slightly curved.
V few true planar joints
What is an example of a planar joint?
Carpus/tarsus
Between cervical vertebra
What is a pivot joint?
Like a peg fitted within a ring, which rotates.
Whats an example of a pivot joint?
Proximal radioulnar joint
Atlantoaxial joint
What is a hinge joint?
One concave and one convex joint with a notch to limit side to side movement
What is an example of a hinge joint?
Humeroulnar
MCP
What is a condylar joint?
Ovoid convex surfaces with corresponding concavity. Movement at right angles with some rotation.
Think flexion/extension and adduction/abduction so biaxial but primarily uniaxial
What is an example of a condylar joint?
Femoro-tibial joint (stifle)
What is a saddle joint?
Two surfaces conves in one direction and concave at another, right angle to the first
What is an example of a saddle joint?
DIP joint of dog paw
What is a spheroidal joint?
Ball and socket joint with very versatile movement
What is an example of a spheroidal joint?
Hip
How else can joints be defined? 1/2
Range of motion;
Flexion/extension/hyperextension
Abduction/adduction
Circumduction
Pronation/supination
How else can joints be defined? 2/2
Linear > Gliding > Planar
Rotation
> Uniaxial > Pivot and Hinge
>Biaxial > Condyloid and saddle
>Multiaxial > ball and socket
What can provide a mechanical advantage?
Joint configuration.
If the point of lever (fulcrum), body can be crouched or mostly over it
