6.5+Nerves,+hormones+and+homeostasis

6 Physiology - 6.1 Digestion - 6.2 The transport system - 6.3 Defence against infectious disease - 6.4 Gas exchange - 6.5 Nerves, hormones and homeostasis - 6.6 Reproduction - Physiology Labs

6.5 Nerves, hormones and homeostasis

 * Assessment statements** (IBO notes added to some points to clearly indicate what needs to be understood and what does not)
 * 6.5.1 || State that the nervous system consists of the central nervous system (CNS) and peripheral nerves, and is composed of cells called neurons that can carry rapid electrical impulses. No other structural or functional divisions of the nervous system are required. ||
 * 6.5.2 || Draw and label a diagram of the structure of a motor neuron. Include dendrites, cell body with nucleus, axon, myelin sheath, nodes of Ranvier and motor end plates. ||
 * 6.5.3 || State that nerve impulses are conducted from receptors to the CNS by sensory neurons, within the CNS by relay neurons, and from the CNS to effectors by motor neurons. ||
 * 6.5.4 || Define resting potential and action potential (depolarization and repolarization). ||
 * 6.5.5 || Explain how a nerve impulse passes along a non-myelinated neuron. Include the movement of Na+ and K+ ions to create a resting potential and an action potential. ||
 * 6.5.6 || Explain the principles of synaptic transmission. Include the release, diffusion and binding of the neurotransmitter, initiation of an action potential in the post-synaptic membrane, and subsequent removal of the neurotransmitter. ||
 * 6.5.7 || State that the endocrine system consists of glands that release hormones that are transported in the blood. ||
 * 6.5.8 || State that homeostasis involves maintaining the internal environment between limits, including blood pH, carbon dioxide concentration, blood glucose concentration, body temperature and water balance. The internal environment consists of blood and tissue fluid. ||
 * 6.5.9 || Explain that homeostasis involves monitoring levels of variables and correcting changes in levels by negative feedback mechanisms. ||
 * 6.5.10 || Explain the control of body temperature, including the transfer of heat in blood, and the roles of the hypothalamus, sweat glands, skin arterioles and shivering. ||
 * 6.5.11 || Explain the control of blood glucose concentration, including the roles of glucagon, insulin and α and β cells in the pancreatic islets. ||
 * 6.5.12 || Distinguish between type I and type II diabetes. ||

Test your stretch reflex then look at the Get Body Smart animation to see what is happening (some of the terms are different to the ones we use, but the theory is the same) media type="custom" key="23684806"
 * Starter**

Visit the [|DCS bridge]and download the workbook for this topic. Word versions of workbooks available below for those unable to access the DCS Bridge. media type="custom" key="23684680"
 * Workbook and Worksheets**

Essential Biology [|6.5 Nerves, Hormones and Homeostasis] is an alternate set of notes

The [|i-Biology] presentation is a great starting point media type="custom" key="23684684"
 * Presentations and Tutorials**

[|Click4Biology]summarises nerves, hormones and homeostasis concisely.

McGraw-Hill Biology has some good narrated animations I recommend viewing:
 * [|Action potential] talks about how an impulse is generated
 * The active transport mechanism which restores the resting potential is explain in the [|sodium-potassium exchange pump]
 * [|Action potential propogation] explains how an impulse moves along the axon and only in a single direction
 * The [|chemical synapse] explains how neurotransmitters cause an impulse to be generated in adjacent neurons

[|G. Matthews] gives another good visual demonstration of how the impulse is passed along the axon. His animation of the [|action potential] has the benefit of directly comparing the movement on sodium and potassium ions to the action potential graph

Animations from Sumanas Inc. on the generation of an [|action potential] and [|synaptic transmission]

The [|MedMovie video on diabetes] is a good introduction to both diabetes I and II

Test your knowledge of the synapse using this interactive animation from the University of Tartu


 * Activities**

Test your understanding of synaptic transmission by completing the [|interactive simulation], click on the book icon for help reminders of the theory

__Display board wars__ In groups of 6-8 students decide who will take responsibility for developing a contribution to a display board for each of the following assessment statements: 6.5.1 - 6.5.3 (Nerves) 6.5.4 - 6.5.5 (Nerves - action potential and impulses) 6.5.6 (Nerves - the synapse) 6.5.7 - 6.5.9 (Hormones) 6.5.10 (Hormones - body temperature control) 6.5.11 - 6.5.12 (Hormones - blood sugar control and diabetes)
 * Approach**

For contributions to the board remember: - you need a title - the assessment statement should be a part of the display - this is a competition and there will be rewards for the winning group - for 6.5.4 - 6.5.5 and 6.5.5 the display board element should be in the form of a comic strip/story board.

During class time all students will get an opportunity for a seminar on their aspect of the display. Use this option well and make sure you are prepared to ask questions.

You will be given a deadline. During that last lesson your group will present their work. There is a twist to bear in mind: you do not present your own contribution. Those contributing to nerve assessment statements will present a hormones statement grouping and vice-versa. Make sure you are fully aware of what you will present as presentations count to the final score as well as the quality of the display board.

Neuroscience for kids has good summary information on the [|autonomic nervous system] Medmovie has a nice [|animation on diabetes]
 * Useful links**

This video made by students at Standford Uni has some clever lyrics about the nervous system (it's also good fun): media type="custom" key="23684686"

Here's another about synapses: media type="custom" key="23684688"