15. Coordination and control

15.1 Control and coordination in mammals

Learning outcomes Candidates should be able to:

1. describe the features of the endocrine system with reference to the hormones ADH, glucagon and insulin (see 14.1.8, 14.1.9 and 14.1.10)

2. compare the features of the nervous system and the endocrine system

3. describe the structure and function of a sensory neurone and a motor neurone and state that intermediate neurones connect sensory neurones and motor neurones

4. outline the role of sensory receptor cells in detecting stimuli and stimulating the transmission of impulses in sensory neurones

5. describe the sequence of events that results in an action potential in a sensory neurone, using a chemoreceptor cell in a human taste bud as an example

6. describe and explain changes to the membrane potential of neurones, including:

• how the resting potential is maintained

• the events that occur during an action potential

• how the resting potential is restored during the refractory period

7. describe and explain the rapid transmission of an impulse in a myelinated neurone with reference to saltatory conduction

8. explain the importance of the refractory period in determining the frequency of impulses

9. describe the structure of a cholinergic synapse and explain how it functions, including the role of calcium ions

10. describe the roles of neuromuscular junctions, the T-tubule system and sarcoplasmic reticulum in stimulating contraction in striated muscle

11. describe the ultrastructure of striated muscle with reference to sarcomere structure using electron micrographs and diagrams

12. explain the sliding filament model of muscular contraction including the roles of troponin, tropomyosin, calcium ions and ATP

15.1 Control and coordination in mammals...

10. describe the roles of neuromuscular junctions, the T-tubule system and sarcoplasmic reticulum in stimulating contraction in striated muscle

11. describe the ultrastructure of striated muscle with reference to sarcomere structure using electron micrographs and diagrams

12. explain the sliding filament model of muscular contraction including the roles of troponin, tropomyosin, calcium ions and ATP

15.2 Control and coordination in plants

Learning outcomes Candidates should be able to:

1. describe the rapid response of the Venus fly trap to stimulation of hairs on the lobes of modified leaves and explain how the closure of the trap is achieved

2. explain the role of auxin in elongation growth by stimulating proton pumping to acidify cell walls

3. describe the role of gibberellin in the germination of barley (see 16.3.4)