Topic 7: Muscles And Joints

Question 1

Define joint

Answer 1

Structures at which two or more bones are held together

Question 2

Define muscle

Answer 2

An effective which contacts to bring about movement

Question 3

What is the only thing muscles can do?

Answer 3

Pull (contract), never push

Question 4

Define tendons

Answer 4

Strip of connective tissue that connects muscle to bone

Question 5

Describe the structure of tendons

Answer 5

Made of protein (collagen) fibres that are strong and flexible but do not stretch

Question 6

Define ligaments

Answer 6

Strong strip of connective tissue that attaches bone to bone.

Question 7

Describe the structure of ligaments

Answer 7

Protein elastin to allow some stretching

Question 8

What are antagonistic muscles?

Answer 8

A pair of muscles that allows a joint to be moved back an forth

Question 9

What is an extensor

Answer 9

A muscle that contracts to cause the extension of a joint

Question 10

What is a flexor

Answer 10

A muscle that contracts to cause the flexion of a joint

Question 11

What are moveable joints called

Answer 11

Synovial Joints

Question 12

What are the 5 features of a synovial joint

Answer 12

1) Cartilage
2) fibrous capsule
3) synovial membrane
4) synovial fluid
5) ligament

Question 13

Function of cartilage in synovial joints

Answer 13

On end of bone, acts a shock absorber and reduces friction between bones

Question 14

Function of Fibrous capsule in synovial joints

Answer 14

Encloses joint and stops synovial fluid leaking

Question 15

Function of synovial fluid

Answer 15

Lubricates joint

Question 16

Function of Ligament

Answer 16

Joins bone to bone, holding in correct position

Question 17

Describe the structure of an individual muscle

Answer 17

Made up of lots of MUSCLE FIBRES held together by CONNECTIVE TISSUE. They are grouped to fork bundles that group to form the muscle

Question 18

What attaches skeletal muscles to bones

Answer 18

Connective tissue called tendons

Question 19

What type of muscles are used to move

Answer 19

Skeletal muscles

Question 20

What’s the cell membrane of a muscle fibre called?

Answer 20

Sarcolemma

Question 21

What is a muscle cells cytoplasm called

Answer 21

Sarcoplasm

Question 22

What is the name of the internal membranes that run through the sarcoplasm

Answer 22

Sarcoplasmic reticulum

Question 23

What is the function of the sarcoplasmic reticulum

Answer 23

Stores and releases calcium ions, needed for muscle contraction

Question 24

What do muscle fibres have more of than normal body cells

Answer 24

Contain lots of mitochondria

Question 25

Why do muscle fibres have lots of mitochondria

Answer 25

To provide the ATP needed for muscle contraction

Question 26

What are myofibrils

Answer 26

Long, cylindrical organelles made up of proteins. Highly specialised for contraction

Question 27

Describe the structure of myofibrils

Answer 27

Contain bundles of thick and thin myofilaments that move past each other to make muscles contract

Question 28

Thick filaments are made of protein...

Answer 28

Myosin

Question 29

Thin filaments are made of protein...

Answer 29

Actin

Question 30

Dark bands are: Light bands are:

Answer 30

Dark: thick myosin filaments with some overlapping thin actin (called A bands) Light: thin actin filaments only (I bands)

Question 31

What are the short units that make up a myofibril

Answer 31

Sarcomeres

Question 32

What are the Z lines

Answer 32

Ends of each sarcomere

Question 33

What is the M line

Answer 33

Middle of Myosin filaments

Question 34

What is the H zone?

Answer 34

Where there is ONLY myosin filaments

Question 35

What theory explains muscle contraction

Answer 35

Sliding filament theory

Question 36

Describe how a muscle contracts in terms of filaments

Answer 36

Myosin and actin filaments slide over each other to make sarcomeres contract- myofilaments themselves don’t contract and myosin and actin molecules stay the same length

Question 37

What gets shorter as the muscle contracts in terms of bands

Answer 37

H zone I band The scaromere

Question 38

What are skeletal muscles made up of

Answer 38

Large bundles of long cells (muscle fibres)

Question 39

What makes the muscle fibre contract

Answer 39

Simultaneous contraction of lots of sarcomeres means myofibrils contract

Question 40

What’s the binding site on actin filaments called?

Answer 40

Actin-myosin binding site

Question 41

Way do calcium ions do?

Answer 41

Active ATPase to brew down ATP for energy for muscle contraction and also breaking actin myosin cross bridge

Question 42

What are the two types of muscle fibres

Answer 42

Slow and fast twitch

Question 43

What’s the main differences between slow and fast twitch

Answer 43

``` Slow: contract slowly Slow: used for posture so in back Slow: endurance > get tired Slow: airobic so lots of mitochondria and blood vessels > quick release through anaerobic using glycogen (few blood vessels or mitochondria Slow: red because lots of myglobin ```