Joints and Muscles Flashcards
(34 cards)
What are joints?
The location where 2 or more bones meet
What do joints do?
Facilitate growth and are responsible for transmitting forces to allow movement and weight-bearing
What are the ways that joints can be classified according to their movement?
Synarthroses
Amphiarthroses
Diarthoses
What are synarthroses?
Suture joints, they are fixed together and are immovable
What are amphiarthroses?
Slightly movable and found between vertebrae
What are diarthroses?
Very movable and are found in the knee
What are the ways that joints can be classified according to the composition of their soft tissue?
Fibrous
Cartilaginous
Synovial
Explain the 3 types of fibrous joints
There are 3 types:
- Sutures: between skull vault bones
- Syndesmosis: fibrous membrane between bones and the radioulnar interosseous membrane
- Gomphosis: peg and socket
Explain cartilaginous joints
There are 2 types:
- Primary (synchondrosis): bone-hyaline cartilage- bone: great strength, no movement
- Secondary (symphysis): bone-hyaline cartilage-fibrocartilage- hyaline cartilage- bone: limited movement, found in midline of axial skeleton
Explain synovial joints
Allows movement without friction, contains a fibrous capsule made up of collagen fibres which unites bones, has a rich nerve supply and gives the joint structure. Also forms ligaments by widening itself where there are lines of stress
Different kinds of ligaments?
Intrinsic: forms thickening of the joint capsule
Extrinsic: located outside the capsule
How are sprains caused?
By over-stretching the ligaments, it prevents dislocation of the joint
What creates the frictionless surface of synovial joints?
The presence of articular hyaline cartilage
How does the avascular nature of synovial joints affect it?
It is poor at repairing itself as it cannot get rid of metabolites
Collagenous tissue (synovial membrane) secretes synovial fluid, what is in synovial fluid?
Hyaluronic acid
lubricin
phagocytic cells
How does exercise improve shock absorption of joints?
Exercise decreases the viscosity of the synovial fluid improving the lubrication to provide shock absorption. glycoproteins transfer metabolites to and from the articular cartilage dissolved in synovial fluid
Alternate name for intra-articular disc found in synovial joints?
Meniscus
Purpose of meniscus
Can deepen the joint and provides support and stability. Found in areas of rotary movement
Purpose of bursae in synovial joints?
Reduces friction between tendons and bones
What are synovial sheaths?
Specialised bursae that encloses tendons and are subject to pressure, potential route for infection
Range of movement in ball and socket joint?
3 planes
Range of movement in hinge joints?
1 plane
What variables is the stability of a joint dependent on?
Shape of bone
Strength and position of ligaments
Tone of muscle surrounding the joint
Explain Osteoarthritis
A degenerative disease affecting the articular cartilage and the weight-bearing joints. Inflammation of joints. The bone begins to grow and change shape.
