musculoskeletal system

Question 1

what is the function of the musculoskeletal system (3)

Answer 1

1. supports the body and gives it shape
2. protection of underlying tissues.
3. movement by contraction of muscles across a joint.

Question 2

what are the 2 bone classifications

Answer 2

1. Long bones (e.g. Femur, Radius)
2. Short bones(e.g. Patella, Tarsal)

Question 3

what is the function of bones (5)

Answer 3

S = Stability/Support
P = Protection
A = Attachment (for muscles)
S = Storage
M = Manufacture of blood cells

Question 4

what is the vertebral column and its function (6)

Answer 4

1. 26 individual bones
2. gives protection
3. gives support
4. maintains posture
5. provides points of attachment

The intervertebral disc is made up of cartilage.

Question 5

what are the tissues of the skeleton (3)

Answer 5

1. Cartilage
2. Ligaments - made out of tough connective tissue, collagen and elastin. They attach bone to bone and hold the joint in place.
3. Tendons - made up of tough connective tissue, collagen and elastin. They connect muscle to bone.

Question 6

what is soft tissue damage and the 2 types

Answer 6

This is damage to the skeletal tissues: Ligaments and Tendons

1. Dislocation: damages the ligaments
2. Sprains: can cause ligament damage although not sufficient to dislocate the joint but can cause damage.

Question 7

what is the difference between a sprain and a strain

Answer 7

1. Sprain - injures the band of tissue that connects two bones
2. Strain - injury to a muscle or the band of tissue that attaches a muscle to a bone.

Question 8

what are the 4 treatments for sprains

Answer 8

R = rest

I = ice

C = compression

E = elevation

These aim to reduce inflammation.

Question 9

what causes ligament tears

Answer 9

These are possibly a result of over-stretching.

Question 10

what is osteoporosis

Answer 10

This is due to a loss of calcium from the bone resulting in weakness. Bones are easily fractured and crumble

Question 11

what factors affect osteoporosis (6)

Answer 11

1. Genetics - can be a genetic condition
2. Age tends to affect individuals as they get older. The bone naturally loses calcium over time.
3. Sex - women are more prone post menopause probably due to lack of oestrogen.
4. Hormone regulation (thyroid problems)
5. Smoking
6. Diet (low calcium diet)

Question 12

what are muscles made up of (4) and how do they contract (3)

Answer 12

• Consists of bundles of muscle fibres surrounded by connective tissue.
  -Two ends of each muscle extend into tendons which anchor the muscle onto bone.
  -The tendon at the static end is called the point or origin.
  -the tendon at the moving end is called the point of insertion.

-Muscles only contact with force, they relax passively. So they operate in antagonistic pairs.
-The flexor contracts to bend the joint.
-The extensor contracts to straighten the joint.

Question 13

what is muscular dystrophy

Answer 13

This is when a protein called dystrophin is missing therefore muscle cells do not work properly. This leads to muscle weakness.

Question 14

what is the muscle structure (3)

Answer 14

Inside each muscle, there are sarcoplasm and myofibrils.

Not all muscle fibres are the same, they are dependent on the type of respiration carried out by the cell.

Some muscle fibres are designed to respire anaerobically whilst others aerobically. We have approximately an equal mixture of both.

Question 15

what happens during anaerobic respiration (2)

Answer 15

this only involves glycolysis and therefore is a fast process.

Lactic acid is produced which causes muscle fatigue.

Question 16

what happens during aerobic respiration (2)

Answer 16

Involves all 3 respiratory stages and is much slower.

Muscles that are required to contract for a long period where stamina and endurance are a priority prefer this type of respiration.

Question 17

what are sarcomeres (2)

Answer 17

sarcomeres are repeating units of myofibrils. they provide the striated appearance to the skeletal and cardiac muscles.

The repeating pattern of the sarcomeres changes its appearance slightly in contracting muscles. they are now known to bring about shortening in a muscle cell.

Question 18

what happens to the Z lines and A bands during contraction

Answer 18

During contraction, the Z lines move closer together. The A band remains the same size.

Question 19

what is the filament sliding theory (6)

Answer 19

Produced to try and explain the banding pattern and mechanism of contraction following the identification of muscle proteins actin and myosin.

when the muscle contracts the filaments stay the same size but are pulled past each other giving rise to the idea that the filaments slide.

Cross bridges are where the thin actin and thick myosin filaments overlap in the A band.

the cross bridges attach to the actin filaments pulling on them to create movement.

Each flexion of a cross bridge produces a very small movement in the actin filament so many cross bridges throughout the muscle must flex repeatedly and rapidly for any measurable movement to occur.

ATP is used by the cross bridges to make the filaments slide past each other during muscle contraction.