Nervous and hormonal control (Edexcel A-level Biology A)

This fully resourced lesson describes how coordination is brought about through nervous and hormonal control in animals. The detailed PowerPoint and accompanying resources have been primarily designed to cover point 8.7 of the Pearson Edexcel A-level Biology A (Salters Nuffield) specification but it can also be used as a revision lesson as there are numerous prior knowledge checks of the nervous system, muscle contraction, protein structure and the control of gene expression.

The lesson begins by challenging the students to recall that a control system contains sensory receptors, a coordination centre and effectors. The students will learn that the communication between these components is by cell signalling and that the effectors can be muscles which contract or glands that release chemicals. The next part of the lesson looks at the differing responses from the nervous and hormonal systems and discusses how this can be governed by the need for a rapid response or more of a long term effect. In terms of nervous control, the students are challenged on their recall of the sliding filament theory of muscle contraction as covered in topic 7. Moving forwards, the students will learn that hormones can be either peptide or steroid hormones and their action at a target cell differs based on their form. Students are tested on their knowledge of protein structure by a series of exam-style questions on insulin and glucagon. They are reminded that steroid hormones can pass directly through the cell membrane and their knowledge of the control of gene expression by transcription factors is tested through a task involving oestrogen and the ER receptor. The lesson concludes by reminding students that the control of heart rate, as covered in topic 7, is a coordinated response that involves both nervous and hormonal control.