IntroductionThis GLS comprises a number of activities designed to help with your understanding of key concepts about nerve structure and function, neurotransmission, nerve reflexes and the different organisational subdivisions of the brain and nervous system. You are required to work through a series of practical activities and workbook questions, and participate in class presentations and clicker quizzes.

Part A – Workbook Questions / ActivitiesThese questions are designed to explore important concepts in detail and allow you to test your understanding. You will also perform some simple reflex tests to demonstrate concepts of nerve function.

Part B – Human AnimationStudents will conduct a real-life simulation of the processes of synaptic neurotransmission by themselves taking on the roles of the various components, molecules and messengers involved. This will be organised by your lecturer during the session – no preparation required.

Part C - Student PresentationsEach home group will give a 3 minute presentation on their allocated topic. Home groups 9-24 will present this week.

Part D – Clicker QuestionsHome groups will compete to answer a series of “exam-style” MCQs on this week’s content.

PreparationPlease read over and bring your notes from the Introductory Sessions and your textbook. Bring these resources to the GLS.

OrganisationAll activities will take place in the 010 Quad rooms.

MD1010 WEEK 8 – The Nervous SystemGUIDED LEARNING SESSION WORKBOOK

Part A Work book Questions

Q1. Compare A, B and C type nerve fibres and relate their properties to their function.

Q2. Name the division of the nervous system that best corresponds to the following description:

a) Division that is composed of the brain and spinal cord.

b) Division composed of cranial nerves, spinal nerves and ganglia.

c) Subdivision that regulates the activity of the heart, smooth muscle and glands.

d) Subdivision that controls voluntary activities such as the activation of skeletal muscles.

e) Subdivision that carries information from the body towards the central nervous system.

Q3. From the table below, select the brain region that best matches the description:

a) The main neural regulator of body temperature, autonomic function and fluid balance b) contains the brain centres involved in regulation of cardiac and respiratory function c) responsible for control of equilibrium, posture and motor learningd) the largest part of the brain in humans e) can be divided into the temporal lobe, occipital lobe, parietal lobe and frontal lobe f) contains the substantia nigra, a brain nucleus implicated in Parkinson’s disease midbrain

cerebrum thalamus cerebellumcerebral cortex hypothalamus midbraindiencephalon brainstem pons

Spinal cord

Effector tissue Ganglion

(near effector tissue)

Ganglion (in paravertebral chain)

Q4. Below is a diagrammatic representation of the efferent nerve pathways in the peripheral nervous system. Complete the diagram by adding the following information:

- the name of each nervous system pathway- the types of neurons in each pathway- the neurotransmitters at each synapse- the type of receptor at each synapse- an example of an effector tissue for each pathway- a functional effect that pathway activation would have on that tissue

Q4. Which division of the ANS causes the following effects:

a) Dilation of pupils

b) Increased smooth muscle activity in the digestive tract

c) Stimulation and co-ordination of defaecation

d) Constriction of respiratory passages

e) Increase of heart rate and force of contraction

Q6. Define a reflex. What are the two main functional types of reflexes?

Q7. What are the anatomical components of a reflex arc?

Q8. What would it mean if a reflex was classified as a monosynaptic, ipsilateral reflex?

Exercise 1 - The knee jerk reflex (patellar reflex)

1. Ask the subject to sit on the bench and relax.

2. Test the knee jerk response several times using a percussion hammer to assess the average response amplitude.

3. Ask the subject to concentrate on trying to inhibit the reflex response. While he/she is doing this, reassess the amplitude of the reflex response.

4. Ask the subject to clasp both hands together tightly and pull hard. While he/she is doing this, reassess the amplitude of the reflex response. This is called the Jendrassik’s manoeuvre.

Q9. What effect did the alterations in Steps 4 and 5 have on the amplitude of the reflex. Why do you think this occurred?

Q10. What is the clinical role of reflex testing?

Exercise 2 - Pupillary Reflexes

1. Conduct the reflex testing in an area where the lighting is relatively dim. Before beginning, obtain a metric ruler to measure and record the size of the subject's pupils as best you can.

2. Stand to the left of the subject to conduct the testing. The subject should shield his or her right eye by holding a hand vertically between the eye and the right side of the nose.

3. Shine a flashlight into the subject's left eye. Note the pupillary response. Without moving the flashlight, observe the right pupil. Note if any change has occurred.

Q11. What did you observe and why do you think these changes occurred?

Q12. What would be the receptor and the effector in this reflex?

Part B Human Animation - neurotransmission

To help consolidation and summarise our learning over weeks 7-8, students will conduct a real-life simulation of the processes of synaptic neurotransmission by themselves taking on the roles of the various components, molecules and messengers involved. This will be organised by your lecturer during the session – no preparation required. With the aid of props, students will volunteer to play the roles of : action potentials myelin neurotransmitters G protein-coupled receptor ligand-gated ion channel Na+ channel Ca++ channels EPSPs, IPSPs

The animation will be filmed and uploaded to YouTube to help you revise.

Part C Student Presentations

HG 9 Drug treatment for Alzheimer’s disease

HG 10 Sarin gas

HG 11 Atropa Belladonna

HG 12 Emperor scorpion

HG 13 Funnel Web spiders

HG 14 Fampridine

HG 15 Digitalis

HG 16 Mamba

HG 17 Valium 

HG 18 Endocannabinoids

HG 19 The knee-jerk reflex

HG 20 The sensory homunculus

HG 21 Frontal lobotomy

HG 22 MSG poisoning

HG 23 and HG 24 Debate – The nervous System is more important than the Endocrine SystemNS (HG23) v ENDO (HG24)