1. Higher Human Biology Nerve cells and neural pathways Part 1

2. What is the structure (three parts) and function of neurons? Draw a sensory, motor and inter neuron, show direction of transmission in your diagram. What is the function of myelin sheath? When does myelination occur and what is its effect? Certain diseases destroy the myelin sheath causing a loss of coordination, give three examples What is the function of glial cells? What can you remember from reading?

3. Function and Types of Neurone Neurones provide the body with rapid communication and control They conduct nerve impulses from on one part of the body to another 3 types of neurones – sensory – inter (relay) – motor

4. Structure of a Neuron Each neuron consists of a – Cell body – Axon – Dendrites

5. NEURONES  SENSORY NEURONES  From sense organs to CNS  MOTOR NEURONES  From CNS to effectors  INTER NEURONES  From sensory neurones to motor neurones.  Are in CNS

6. SENSORY NEURONE DIRECTION OF IMPULSE

7. MOTOR NEURONE DIRECTION OF IMPULSE

8. INTER NEURONE

9. The Function of Parts of a Neuron Control metabolism, contains ribosomes for the production of neurotransmitters

10. Myelin Sheath  Is a fatty material that insulates the axon  The small gaps are called nodes  The presence of the myelin sheath greatly increases the speed of transmission of the impulse from node to node

11. Myelination  Is the development of myelin around the axon fibres  It is not complete at birth  Continues into adolescence  As a result responses to stimuli in the first two years of life are not as rapid or coordinated as those of an older child or adult.  Certain diseases destroy the myelin sheath causing a loss of coordination.

12. Diseases  Diseases such as multiple sclerosis and poliomyelitis  Cause the myelin sheath to become damaged or destroyed  Resulting in loss of muscular coordination

13. Glial Cells Provide physical support to neurons  (Oligodendrocytes) form the myelin sheath around axons.  (Astrocytes) provide nutrients to neurons, maintain their extracellular environment, and provide structural support. (homeostatic environment)  (Microglia) scavenge pathogens and dead cells by phagocytosis

14.  Testing your knowledge Qs p256 No’s 1 and 2  Homework read textbook p252 - 256 Activity

15. What is the structure (three parts) and function of neurons? Draw (briefly) a sensory, motor and inter neuron, show direction of transmission in your diagram. What is the function of myelin sheath? When does myelination occur and what is its effect? Certain diseases destroy the myelin sheath causing a loss of coordination, give two examples What is the function of glial cells? What have I learned?