Joints and muscles

Question 1

how do antagonistic pairs bring about movement

Answer 1

the flexor muscle flexes the joint shortening and causes the angle of the joint to become smaller and the extensor muscle muscle extends the joint by shortening and pulling the joint to create a larger angle

Question 2

what is a joint

Answer 2

where two or more bones meet and are held together by ligaments

Question 3

tendons

Answer 3

a strong strip of connective tissue that connects muscle to bone.
made out of collagen so is strong, flexible and and isn’t elastic

Question 4

ligaments

Answer 4

a strong strip of connective tissue which attaches bone to bone.
made out of collagen so are strong but also contain the protein elastin so can stretch

Question 5

components of a joint

Answer 5

cartilage - acts as a shock absorber and reduces friction
fibrous capsule - encloses the joint and stops synovial fluid leaking out
synovial membrane - makes and secretes synovial fluid
synovial fluid - lubricates the joint

Question 6

muscle fibre structure

Answer 6

• multinucleate
• has striations
• cell membrane is called the sarcolemma
• cytoplasm is called the sarcoplasm
• lots of mitochondria
• many myofibrils made up of actin and myosin

Question 7

muscle tissue structure

Answer 7

• bundles of muscle fibres bound together by connective tissue

Question 8

changes in muscle fibres during contaction

Answer 8

I band becomes shorter
A band stays the same
sarcomere shortens
H zone shortens