MS System: Joints and muscles Flashcards
What is a joint?
Joints are where two or more bones meet
What is the function of joints?
Joints allow bones to grow and transmit forces (which allows us to move and weight bare)
What does arthro mean ?
joint
What is arthritis?
Inflammation of a joint
What is arthroscopy?
Sticking a camera into a joint
What age group has more joints and why?
Younger people as their bones will fuse together later on in development.
What is synarthroses and give an example of this?
Joints that are fixed together and immovable (e.g suture joints in skull)
What is amphiarthroses and give an example of this?
A joint that allows for a slight bit of movement (e.g vertebrae)
Diarthroses
A joint that is very moveable (e.g knee)
What are the 3 types of fibrous joints and where can they be found ?
1) . Sutures - joints between skull vault bones
2) . Syndesmosis - joints between radioulnar interosseous (between bones in forearm)
3) . Gomphosis - peg and socket joints that hold the teeth into the jaw
What is the proper term for a primary cartilaginous joint, its function, composition and give an example of this?
Synchondrosis - Very strong cartilaginous joint that doesn’t allow any movement. It is composed of bone joined to hyaline cartilage which is joined onto another bone.
e.g - 1st costosternal joint - costa (rib) on one side is connected by Hyaline cartilage to the sternum
What is the proper term for a secondary cartilaginous joint, its function, composition and give an example of this?
Symphysis - Fibrous discs between articular surfaces and allows for limited movement (Amphiarthroses). It is composed of bone joined to hyaline cartilage joined to Fibrocartilage which is joined onto Hyaline cartilage and then back onto another bone.
E.g - Sternum to vertebrae to pelvis (disks)
What kind of movement does synovial joints allow and what features do they contain?
Synovial joints allow for friction-free movements
They contain a fibrous capsule which allows for proprioception.
What is proprioception?
The body’s awareness for its position in space. Feedback from the muscle receptors and joints tells the body where the limbs are without having to visually see them
What do ligaments do?
They restrict movement and protect the joint from damage and dislocation.
What are intrinsic ligaments?
Ligaments that are inside and thicken the joint capsule and prevents dislocation
What are extrinsic ligaments?
Ligaments that are separate from the the joint capsule and prevents dislocation.
What is the medial collateral ligament?
The ligament that prevents the knee from bending medially (inwards) towards the body.
As you grow what happens to the collateral ligament?
It will undergo stress and thicken to become an intrinsic ligament
What is the term for when a ligament has been over stretched?
A sprain
Why is a sprain good?
As it prevents dislocation of the joint
What is articular cartilage, its function, what is its blood supply like and how does this affect the cartilage?
It is Hyaline cartilage in a joint that creates a frictionless surface between bones, preventing them from grinding against one another.
It has a very poor blood supply and is referred to as being avascular.
Due to the poor blood supply it cannot repair itself well and takes many years to.
It has no shock absorbance either
What is the articular capsule?
The space between two ends of bone
Where does the articular cartilage get its nutrients, oxygen and metabolites from?
The synovial fluid
What is the synovial membrane?
Collagenous tissue that lines the fibrous capsule and secrets synovial fluid
What is synovial fluid made up off and what is its function?
Synovial fluid contains Hyaluronic acid, lubricin and a small number of phagocytic cells.
It reduces friction between the articular surfaces, lubricates joints and alters its viscosity
Why does the synovial fluid alter its viscosity ?
As it decreases its viscosity to improve lubrication for exercise and it increases its viscosity to act as a shock absorber.
What do intra-articular discs do and what are they made from?
They are made of Fibrocartilage. The discs are found in joints where there are rotatory movements. They allow for a deeper joint cavity and make it more stable.
What are Bursae and what do they do?
Bursae are closed sacs lined with synovial membrane and lubricated with fluid.
Their function is to prevent rubbing and friction between skin, bones and tendons.
What are synovial sheaths and what are their function?
Synovial sheaths are as specialised type of Bursae that surround tendons where they are subject to pressure. They prevent rubbing.
What can potential space found in synovial sheaths cause?
Potential risk of a spread of infection
How many planes of movement does a ball and socket joint allow?
3 planes
How many planes of movement does a hinge joint allow?
1 plane
What are the 3 factors that influence stability?
1) . The shape of the bones (e.g deep or small socket)
2) . Strength and position of ligaments
3) . Tone of surrounding muscles
What is muscle tone?
Muscle tone is a continuous low level pull helping to keep a joint together (e.g shoulder)
Muscle bulk increases muscle tone
Where do joints go when dislocated?
Into other structures
What is Osteoarthritis and how is this caused?
A degenerative disease where the articular cartilage is being damaged and inflamed. This occurs on weight bearing joints and the inflammation causes bony changes
What is Rheumatoid arthritis and how is this caused?
An autoimmune disease that leads to changes in the synovium which leads to destruction of articular cartilage.
The antibodies attack the synovial membrane and creates an inflammatory structure knows as a panes which erodes bone and cartilage, inflaming this joint.
What are the characteristics of skeletal muscle?
They move voluntary and are striated
What are the characteristics of visceral muscle?
They move involuntary and smoothly
What are the characteristics of cardiac muscle?
They move involuntary and striated
What does deep facia do?
Divides parts of muscles into compartments
What are the 3 things found in a muscle function group and what is their function?
Prime mover - main participant in a movement
Synergists - the other muscles in the group
Antagonists - cause the opposite movement in contraction of muscles so muscle control is smoothed out
What are muscle fibres arranged in?
bundles or fasciculi
What is the endomysium?
they separate the muscle fibres
What is the perimysium?
lies between the fasciculi
What is the epimysium?
dense sheath on the surface
What is the function of deep fascia?
Deep facia allows muscles to slide over other muscles that are around it. They assist in movement and support nerves and blood vessels and act as a connective tissue holding them together.
What do deep fascias form at the end of the muscle?
a tendon to connect muscle to bone
What do tendons do?
Attach muscle to bone and allows movement of muscle
What does Myosatellite cells give arise too?
Myoblasts
What do myoblasts mature into?
Monocytes
What does myostatin do?
Inhibits the process if differentiation and prevents muscle growth
What happens when myostatin signalling is defective?
The body loses the ability to. inhibit muscle growth so the body will have a massive muscle cell growth
