Muscle structure

Question 1

What are three types of muscle?

Answer 1

Cardiac
Smooth
Skeletal

Question 2

What is cardiac muscle?

Answer 2

Contracts without conscious control but only found in heart

Question 3

What is smooth muscle?

Answer 3

Contracts without conscious control and found in the walls of internal organs

Question 4

What is skeletal muscle?

Answer 4

Type of muscle you use to move

Question 5

What attaches skeletal muscle to bones?

Answer 5

Tendons

Question 6

What attaches bones to other bones?

Answer 6

Ligaments

Question 7

What moves bones at a joint?

Answer 7

Pairs of skeletal muscle that contract and relax as the bones of the skeleton are incompressible so they act as levers, giving the muscle something to pull against

Question 8

What are antagonistic pairs?

Answer 8

Muscles that work together to move a bone

Question 9

In an antagonistic pair, what is the contracting muscle?

Answer 9

Agonist

Question 10

In an antagonistic pair, what is the relaxing muscle?

Answer 10

Antagonist

Question 11

What happens when the biceps contract?

Answer 11

The triceps relax
Pulls the bone so your arm bends at the elbow
Bicep is agonist
Tricep is antagonist

Question 12

What happens when the triceps contract?

Answer 12

The biceps relax
Pulls the bone so your arm straightens at the elbow
Tricep is agonist
Bicep is antagonist

Question 13

What is skeletal muscle made up of?

Answer 13

Large bundles of long cells, called muscle fibres

Question 14

What is the membrane of a muscle fibre called?

Answer 14

Sarcolemma

Question 15

What is a sarcoplasm?

Answer 15

A muscle cell’s cytoplasm

Question 16

What are transverse (T) tubules?

Answer 16

Folds of the sarcolemma which go into the sarcoplasm

Question 17

What do T tubules do?

Answer 17

They help to spread electrical impulses throughout the sarcoplasm so they reach all parts of the muscle fibre

Question 18

What is the sarcoplasmic reticulum?

Answer 18

Network of internal membranes

Question 19

What does the sarcoplasmic reticulum do?

Answer 19

Stores and releases calcium ions that are needed for muscle contraction

Question 20

What do muscle fibres have a lot of to provide the ATP for muscle contraction?

Answer 20

Mitochondria

Question 21

What are myofibrils?

Answer 21

long, cylindrical organelles found in muscle fibres

Question 22

What are myofibrils made up of?

Answer 22

Proteins

Question 23

What do myofibrils contain?

Answer 23

Thick and thin myofilaments that move past each other to make muscles contract

Question 24

What are thick myofilaments made up of?

Answer 24

Myosin

Question 25

What are thin myofilaments made up of?

Answer 25

Actin

Question 26

What are A bands?

Answer 26

Dark bands of thick myosin filaments and some overlapping thin actin filaments

Question 27

What does the I band contain?

Answer 27

only contains thin actin filaments

Question 28

What is a sarcomere?

Answer 28

A short unit which lots make up myofibril

Question 29

What is the Z-line?

Answer 29

Marks the end of a sarcomere

Question 30

What is the M-line?

Answer 30

The middle of the sarcomere which is also the middle of the thick myosin filaments

Question 31

What is the H-zone?

Answer 31

only contains thick myosin filaments

Question 32

What is the sliding filament theory?

Answer 32

Myosin and actin filaments slide over one another to make sarcomeres contract

Question 33

In the sliding filament theory, what causes the myofibrils and muscle fibres to contract?

Answer 33

The simultaneous contraction of lots of sarcomeres

Question 34

What happens to the structure of a sarcomere during contraction?

Answer 34

A-Bands stay the same length
I-band gets shorter
H-zones get shorter
The distance between the two Z-lines becomes shorter