Musculoskeletal system Flashcards
What does the term ‘lateral’ mean?
Further or furthest from the midline.
What does the term ‘medial’ mean?
Close or clostest to the midline.
What does the term ‘anterior’ mean?
Towards front of body
What does the term ‘posterior’ mean?
Towards back of the body.
Give the different types of joints.
Fibrous
Cartilaginous
Synovial
What are fibrous joints?
Bones that are fused together to create structure. E.g. the skull
What are cartilaginous joints?
Bones connected by flexible cartilage that allows for some movement.
What are synovial joints?
Flexible and moveable joints.
What does the synovial capsule contain and why?
The synovial capsule contains synovial fluid that helps lubricate the joint to allow for easier movement.
What do ligaments do?
Connect bone to bone.
What do tendons do?
Connects muscle to bone.
What do muscle fibres contain and why?
Muscle fibres contain myofibrils that are responsible for muslce contraction.
What are muscle fibres held together by?
Bundles of sheath of connective tissue.
Give the functions of the skeleton.
Provides support for the body
Protects organs
Blood production
Mineral storage
State the difference types of bone.
Long
Short
Flat
Irregular
Sesamoid
What two proteins do muscle contain?
Actin and myosin.
What protein is contained within thick filament?
Myosin
What protein is contained with thin filament?
Actin, troponin, tropomyosin.
How are the filaments arranged?
They are arranged in myofibrils in a repeating pattern called sarcomeres.
What happens to the sarcomere when the muscles contract?
The sarcomere shortens.
Outline the process of sliding filament theory.
- Thin filaments consist of long chains of actin molecule.
- Thick filaments are a bundle of myosin molecules so that the ‘head’ groups protrude around the bundle.
- The ‘head’ group binds to actin molecules
- When this occurs, a change in shape of the myosin head pulls the filament towards the center of the sarcomere.
- Myosin head then deatches and energy is transfered from hydrolysis to Adenine Triphosphate (ATP) and the myosin head returns to it’s orginal position.
What is the first step in the process of muscle contraction?
In resting state, ADP and inorganic phophate bind to myosin head. Each actin molecule has a binding site for myosin that is covered in tropomyosin that prevents myosin head from binding to actin filaments.
What is the second step in the process of muscle contraction?
Calcium ions are stored in the sarcoplasmic recticulum. When a nerve impulse arrives, the calcium ions are released from the sarcoplasmic recticulum to the sarcoplasm.
What is the third step in the process of muscle contraction?
Calcium ions will bind to troponin and changes shape causing the tropomyosin to move and expose the binding site of actin.
What is the fourth step in the process of muscle contraction?
When the myosin binding site on action is exposed, myosin head binds to actin forming a cross-bridge.
What is the fifth step in the process of muscle contraction?
ADP and inorganic phosphate are released from the myosin head causing it to bend that pulls the actin towards the centre of the sarcomere.
What is the sixth step in the process of muscle contraction?
As ADP and inorganic phosphate are released from the myosin head, ATP can now bind in their place. This breaks the cross-bridge so the myosin deatches from actin.
What is the seventh step in the process of muscle contraction?
Myosin head acts as ATPase, converting the bond ATP to ADP and inorganic phosphate. Energy is released and turns the myosin head back to it’s orginal position.
what is ATPase?
An enzyme that catalysts the hydrolysis of ATP, releasing energy.
What is a sarcoplasmic recticulum?
Specialised form of endoplasmic recticulum found in muscle fibres.
what is rheumatoid arthritis?
A chronic inflammatory disease that is autoimmune.
Give the cause of RA
When the body produces antibodies against antigens in the joints e.g. synovial membrane and cartliage of synovial joints.
Although it is not clear what causes the immune system to attack its own cells, what does some evidence suggest that could contribute to this?
That RA could be a genetic component
How does RA impact physically?
It causes soreness and redness because the antibodies attack the synovial membrane that causes these symptoms as chemicals are released that cause damage to nearby bones.
If RA is not treated, what may happen?
Joints may become stiff and painful as well as lose shape and alignment.
What must patients learn to do because there is no cure?
Take responsibility for their own health
Taking prescribed medications
Low-impact exercise
Being vaccinated against flu and pneumonia.
How can RA impact mentally?
As flare-ups are unpredictable, RA can make people feel depressed, frustrated, anger, fear and resentment.
What are the four treatment options avaliable for RA?
DMARDS
Biological medicines
Physiotherapy
Surgery
Explain how DMARDS work
DMARDS supress the immune system so the cells do not attack it’s own cells
What is muscular dystrophy?
MD is a gradual weakening of the muscles that leads to increased levels of disability over time.
Who does Duchenne’s muscular dystrophy impact?
Affects boys in early childhood and often shortens life expectancy.
Give the cause of muscular dystrophy.
It is caused by mutations in genes for muscle proteins. The protein targeted is dystrophin that helps stregthen muscle fibres and protects from injury.
What does the term ‘dominant inherited disorder’ mean?
Mutuation is inherited from one parent.
What does the term recessive inherited disorder mean?
Mutuation that is inherited from both parents.
How can steroids help MD?
Improves muscle strength and function for 6 months up to two years.
How can low-impact exercise help?
it can help stregthen muscles and keep flexibilty.
