1. Module 4 Responding to the environment
2.4.7 Coordinated movement

2. Learning Objectives Success Criteria
To understand how movement is coordinated
Identify parts of a joint
(Grade E - D)
Describe how coordinated movement requires action of skeletal muscle about joints, with reference to the elbow joint
(Grade C –B)
Compare and contrast synapses and neuromuscular junction (Grade B – A) 2

3. Starter
Describe the differences between the CNS and the peripheral nervous system (4 marks)

4. Coordinated movement
CNS coordinates muscle movement, receives sensory info. and decides what responses is required. If a response is needed, the CNS sends impulses along the motor neurones to let the skeletal muscles contract.
Skeletal muscles are attached to bones by tendons. Ligaments attach bones to other bones, to hold them together. The structure of joints between bones determines movement
Ball and socket – allow movement in all directions
Gliding joints – wide range of movement
Hinge joints – movement in one plane only – elbow. The elbow is an example of a synovial joint. Synovial fluid is a lubricant, to ease this movement.

5. Antagonistic muscles
The best-known example of antagonistic muscles are the biceps and triceps muscles, which articulate the elbow joint. Movement of bones at many joints require a range of actions and is under control of groups of muscles called synergists
Muscles cannot push, only pull  work in pairs which oppose each other. Muscles must be attached to incompressible skeleton, which they move.

6. Control of contraction

7. Key terms
Neuromuscular junction – a specialised synapse occurring at the end of a neurone where it meets the muscle fibre. Acetylcholine is released after depolarisation stimulating contraction of the muscle fibre.
Sarcolemma – muscle fibre cell membrane
Sarcoplasm – muscle cell cytoplasm
Transverse (T) tubules – invaginated sections of sarcolemma sticking into the sarcoplasm. Spread electrical impulses through the sarcoplasm.
Sarcoplasmic Reticulum – network of internal menbranes running through sarcoplasm . Stores and releases calcium ions for muscle contraction.

8. A muscle fibre is made up of many myofibrils.
Myofibrils are themselves made up of contractile proteins
There are two types
Thick myofilament is myosin
Thin myofilament is actin.

9. Neuromuscular Junction
Impulse from motor neurone causes ACh vesicles to be released into the gap
ACh binds to sarcolemma (muscle fibre membrane)
Depolarisation travels down tubules
Calcium ions released from sarcoplasmic reticulum
Calcium ions bind to proteins in muscles causing contraction
Acetylcholinesterase breaks down ACh in gap and stops the contraction

13. Plenary - Compare and Contrast Neuromuscular Junction & Synapse
Similarities
Differences
Neuromuscular Junction
Synapse

14. Compare and Contrast Neuromuscular Junction & Synapse
Similarities
Differences
Neuromuscular Junction
Synapse
Neurotransmitter in vesicles
Vesicles release neurotransmitter into cleft
Neurotransmitter diffuses across gap & binds to receptor
Neurotransmitter results in depolarisation
Enzymes degrade neurotransmitter
Neurone to sarcomere
Postsynaptic simulation leads to depolarisation of sarcolemma
End plate has appearance of microvilli
Neurone to neurone
Postsynaptic simulation leads to AP in postsynaptic neurone
Synaptic knob is smooth and rounded

15. Learning Objectives Success Criteria
To understand how movement is coordinated
Identify parts of a joint
(Grade E - D)
Describe how coordinated movement requires action of skeletal muscle about joints, with reference to the elbow joint
(Grade C –B)
Compare and contrast synapses and neuromuscular junction (Grade B – A) 15