Neurons Types of Neurons Sensory Motor Interneurons 1

Neurons Types of Neurons Sensory Motor Interneurons 1

Target Goal: Students will know the basic structure and function of a neuron. Students will understand the impact of agonists & antagonists.

Sensory Neurons(Afferent) z INPUT From sensory organs to the brain and spinal cord. Vision, hearing, taste and smell nerves are cranial, not spinal Brain Sensory Neuron Spinal Cord 3

Motor Neurons ( efferent) z OUTPUT From the brain and spinal cord To the muscles and glands. Sensory Neuron Brain Spinal Cord Motor Neuron 4

Interneurons z Interneuron carry info between neurons z Brain and spinal cord. Brain Sensory Neuron Spinal Cord Motor Neuron 5

Structures of a neuron 6

The cell body (Soma) z Contains the cell’s Nucleus y Contains DNA 7

Dendrites z Receive inputs from adjacent neurons If enough inputs the cell’s AXON may generate an output Action Potential= Electrical message firing 8

Axon z The cell’s output structure z Tube like branches z Connect to dendrites of other cells 9

Myelin sheath z White fatty casing on axon z Increases the speed Myelin Sheath 1 0

Neuron to Neuron z A gap separates the axon terminals from dendrites z Gap is the Synapse (gap/cleft) Dendrite Axon Cell Body 1 1

Synapse Sending Neuron z Axon terminals contain small storage sacs called synaptic vesicles Axon Terminal Synapse y vesicles contain neurotransmitter molecules 1 2

Neurotransmission http: //learn. genetics. utah. edu/content/addictio n/crossingdivide/ (longer) 1 3

Locks and Keys z Neurotransmitter molecules have specific shapes z Receptor molecules have binding sites z When NT binds to receptor, ions enter z Excitatory NT z Inhibitory NT 1 4

Some Drugs work on receptors z Shaped like neurotransmitters z Agonists : fit receptor well and act like the NT (Excite) Antagonists : fit the receptor poorly Block the NT z (Inhibit) 1 5

Neuron Chemicals Serotonin- mood control -Excess (mania) or deficit can cause depression Dopamine=motor control & alertness -Excess-schizophrenia -Deficit-Parkinson's Acetylcholine-Motor - Deficit= Alzheimer's Endorphins= -Pain Control, involved in addictions Norepinephrine -deficit can lead to depression 1 6

Old Macdonald 1 7

Summary z 3 types of neurons z The cell membrane z Ion movements z Action potentials z Synapse z Neurotransmitters z Receptors and ions z Agonists and antagonists 1 8