Joints and Muscles Flashcards
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.
Explain rheumatoid arthritis
An autoimmune disease due to reaction to the synovial membrane. Inflammation causes changes in the synovium resulting in destruction of articular cartilage
Function of deep fascia?
Separates the limbs into compartments
What are the roles in a functional group of muscles?
Prime mover: Main participant in movement
Synergists: Assists prime mover
Antagonists: Group of muscles apposing the movement
Arrangement and function of muscle fibres?
Arranged in fasciculi, supports nerves and capillaries
What is the function of the endomysium?
Separates muscle fibres
Where is the perimysium?
Between fasciculi
What is the epimysium?
Dense sheet of connective tissue on the surface of the muscle
What is a tendon?
Connects muscle to bone
Explain skeletal muscle differentiation?
Myosatellite cells produce myoblasts that mature into multi-nucleated myocytes. Myosatin inhibits differentiaion
Where are primary cartilaginous joints found?
Epiphyseal plate
