Chapter 2 Nerve Cells and Behavior & Chapter 4 The Cytology of Neurons
25 nm 7 nm 25 nm Neuronal cytoskeleton
4. Transmit information to target cell (neuron, muscle, gland) Four functions of neurons 1. Receive and integrate inputs 2. Generate a nerve impulse (action potential) 3. Conduct the action potential dendrites, soma axon hillock axon nerve terminals
Dendrites and cell body Receive and integrate inputs Axon hillock and initial segment Generate action potentials Axon Conducts action potential Terminals Synaptic transmission
Eccles, J.C. (1964) The Physiology of Synapses. N.Y.: Springer
Classifications of Neurons 1. Function a. sensory neurons b. motoneurons c. interneurons
Classifications of Neurons 1. Function 2. Structure a. unipolar b. bipolar c. multipolar
Classifications of Neurons 1. Function 2. Structure 3. Shape e.g., pyramidal, stellate, basket, granule, etc.
100μm B A
Classifications of Neurons 1. Function 2. Structure 3. Shape 4. Effect a. excitatory neurons b. inhibitory neurons
Classifications of Neurons 1. Function 2. Structure 3. Shape 4. Effect 5. Axon length a. projection neurons (Golgi Type I) b. local neurons (Golgi Type II)
Classifications of Neurons 1. Function 2. Structure 3. Shape 4. Effect 5. Axon length 6. Neurochemical identity e.g., cholinergic, dopaminergic, GABAergic, etc.
Classifications of Neurons 1. Function 2. Structure 3. Shape 4. Effect 5. Axon length 6. Neurochemical identity
Types of glial cells 1.Astrocytes 2.Microglia 3.Oligodendroglia 4. Schwann cells
Types of glial cells 1.Astrocytes a. mechanical support b. metabolic support transport nutrients and wastes c. encapsulate synapses d. regulate chemical and ionic environment e. form scar tissue f. act as phagocytes
Types of glial cells 1.Astrocytes 2.Microglia a. act as phagocytes b. part of brain’s immune system
Types of glial cells 1.Astrocytes 2.Microglia 3.Oligodendroglia myelinate axons of central nervous system
Types of glial cells 1.Astrocytes 2.Microglia 3.Oligodendroglia 4. Schwann cells myelinate axons of peripheral nervous system