Essential Biology 11.2: Muscles and Movement (AHL)
Muscles and Movement
When a nerve impulse reaches the terminal end of a motor neuron, it intitiates muscle contraction,
causing movement in the body.
1. What are the roles of the following components in movement in the body?
Nerves
Muscles
Bones
Joints
Tendons
Ligaments
Synovial fluid
Cartilage
2. In the space below, draw and label a simple diagram of a human elbow joint.
Include the radius, ulna, humerus, biceps and triceps. Label and state the functions of the joint capsule,
synovial fluid and cartilage.
3. Outline how the biceps and triceps work antagonisticallyto ‘bend’ and ‘extend’ the arm.
Stephen Taylor
Bandung International School
http://sciencevideos.wordpress.com
Essential Biology 11.2: Muscles and Movement (AHL)
4. Compare these types of joints:
Elbow
Type of joint
Range of movement
Knee
Shoulder/ Hip
hinge
Hinge movement with
some pivoting possible
5. Label this section of a striated muscle cell with the names and functions of each structure.
6. Which part of the muscle cell is depolarized when an action potential reaches the
neuromuscular junction?
7. Why are there so many mitochondria in a muscle cell?
Stephen Taylor
Bandung International School
http://sciencevideos.wordpress.com
Essential Biology 11.2: Muscles and Movement (AHL)
8. The electron micrograph below shows a section of a myofibril.
a. Label the dark and light bands and z-lines.
b. How many full sarcomeres are shown in this image?
c. Draw a simple diagram of the corresponding sarcomeres, showing the actin and myosin
fibres (with myosin heads)
9. Annotate the diagrams below to show how muscle
contraction occurs in a sarcomere.
Include the roles of sarcolemma, sarcoplasmic reticulum, Ca2+, actin binding
sites, cross bridges, myosin heads, ATP.
Stephen Taylor
Bandung International School
http://sciencevideos.wordpress.com
Essential Biology 11.2: Muscles and Movement (AHL)
10. Compare these two electron micrographs of a skeletal muscle sarcomere.
Contracted or
relaxed?
Sarcomere length
Shorter
Z-bands
Closer
H-bands
No change
Light bands
Dark bands
No change
11. What can be deduced from this in terms of relative roles of actin and myosin fibres?
Stephen Taylor
Bandung International School
http://sciencevideos.wordpress.com