T3 L4: The principles of articulation Flashcards
What is a fibrous joint?
It has no synovial cavity and is held together by fibrous connective tissue
It permits little or no movement (synarthrosis/amphiarthrosis)
What does Synarthrosis mean?
Immovable
What does Amphiarthrosis mean?
Partially moveable
What does Diarthrosis mean?
Freely moveable
What are the 3 types of fibrous joint?
- Suture
- irregular thin layer of connective tissue Eg. cranial bones - Syndesmosis
- more connective tissue than in a suture joint
- Typically permit slight movement Eg. anterior tibiofibular ligament, dentoalveolar - Interosseous membrane
- Sheet of dense connective tissue that binds adjacent bones Eg. tibia and fibula
What is a synostosis?
Ossification at a suture
What is a cartilaginous joint?
A joint with no synovial cavity that is held together by fibrocartilage of hyaline cartilage
It permits little or no movement
What are the 2 types of cartilaginous joint?
- Synchondrosis
- Hyaline cartilage Eg. epiphyseal plate - Symphysis
- Fibrocartilage
- They only occur in the midline of the body Eg. Pubis, sternum, and intervertebral joints
What is the difference between hyaline cartilage and fibrocartilage?
Hyaline is softer and contains less fibres
What is a synovial joint?
A cavity between articulating bones
Freely moveable (diarthosis)
Contain a later of hyaline cartilage called articular cartilage
What is the articular cartilage composed of?
Collagen and proteoglycan
The orientation of collagen structure causes resistance to compression
What are the 2 layers of a articular capsule?
Outer fibrous membrane: connects to the periosteum
- Flexibly permits movement
- Fibres are arranged into fibres which allows for high tensile strength
Inner layer (synovial membrane): Areolar connective tissue rich in elastic fibres -It occasionally contains structural articular fat pads
What forms the synovial fluid?
Rich in hyaluronic acid secreted by fibroblast-like cells and interstitial fluid from blood plasma
What is the function of synovial fluid?
- Lubricates the articular surface to reduce friction
- Shock-absorbing properties
- Phagocytes remove microbes and debris
What are the 2 accessory ligaments of synovial joints?
-Intracapsular ligaments lie within the capsule
Eg. Anterior and posterior cruciate ligaments of the knee
-Extrascapular ligaments lie outside the joint capsule
Eg. Fibular and tibial collateral ligaments of the knee
What is the function of accessory articular discs?
Fibrocartilage pads lie between articular cartilage of some synovial joints Eg. meniscus of the knee
- Called menisci or articular discs
- Help with joint stability
- Direct the flow of synovial fluid
In what people are meniscal tears common?
Athletes that use their joints a lot
What is the nerve and blood supply to synovial joints?
Same nerve endings that supply associated muscles
Many components of joints are avascular but those that aren’t rely on numerous branching arteries and veins supplying the associated areas
What are bursae and what is their function?
Fluid filled sacs lined with synovial-like membrane that cushion movement between body parts
What are tendon sheaths and what is their function?
They are specialised membranes that wrap around tendons especially where many tendons come together
They protect against damage
What are the 6 types of synovial joints?
Planer Hinge Pivot Condyloid Saddle Ball and socket
What are planer joints?
A type of synovial joint between flat or slightly curved surfaces
Permit back and forth, and side to side movements
Eg. intercarpal joints or intertarsal joints
What are hinge joints?
When a rounded surface fits a curved surface
Permits movement in a single axis
Eg. knee joint, elbow joint
What is a pivot joint?
When a rounded or pointed surface of one bone pivots inside a ring of another bone
It permits rotation on it’s longitudinal axis
Eg. radioulnar joints, atlanto-axial joint
What is the dens of the axis bone?
The bit that sticks up and allows pivoting of the atlas bone above it
What is a condyloid joint?
A convex oval projection of one bone fits into an oval depression of another
Permits movement around 2 axis: biaxial flexion and extension, and adduction and abduction
Eg. Wrist joint, metacarpophalangeal joint
What is a saddle joint?
A specialised form of saddle joint where one bone fits into a saddle shaped bone is opposes
Allows movement in 2 axis: flexion and extension, and abduction and adduction
Eg. Carpometacarpal joint of the thumb
What is a ball and socket joint?
A ball-like surface of one bone fits into a cup-like depression of another
Allows triaxial movement: flexion and extension, abduction and adduction, and rotation
Eg. Shoulder joint, hip joint
What is the glenoid labrum?
A narrow rim of fibrocartilage that deepens the glenoid joint
What are the 3 ligament that stabilise the glenohumeral joint?
Glenohumeral
coracohumeral
transverse humeral
And has 4 associated bursae
Which 3 ligaments stabilise the acromioclavicular joint?
Acromioclavicular
Coracoacromial
Coracoclavicular
