Biological Psychology Key Point for this Unit: Everything psychological is simultaneously biological!!

NEURON Dendrites Dendrites – The bushy, branching extensions that receive messages from other cells and conduct impulses toward the cell body

Cell Body – the cell’s life-support center NEURON Dendrites Cell Body Cell Body – the cell’s life-support center

NEURON Dendrites Cell Body Axon Axon – the extension of a neuron through which messages are sent to other neurons or to muscles or glands

NEURON Dendrites Cell Body Axon Myelin Sheath Myelin Sheath – a layer of fatty cells covering the axon, helps speed neural impulses

Terminal branches of axon – form junctions with other cells NEURON Dendrites Terminal branches of axon Cell Body Axon Myelin Sheath Terminal branches of axon – form junctions with other cells

Neural Communication Synapse [SIN-aps] Neurotransmitters junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron tiny gap at this junction is called the synaptic gap or cleft Neurotransmitters chemical messengers that traverse the synaptic gaps between neurons when released by the sending neuron, neuro-transmitters travel across the synapse and bind to receptor sites on the receiving neuron, thereby influencing whether it will generate a neural impulse

Biological Psychology It is all about the body!!!! Concerned with the links between biology and behavior (also called Neuroscience)

The Nervous System It starts with a NEURON: an individual nerve cell; the basic building block of the nervous system

How does a Neuron fire? Resting Potential: slightly negative charge. Reach the threshold when enough neurotransmitters reach dendrites. Threshold: level of stimulation required to trigger a neural impulse; excitatory signals minus inhibitory signals must equal a minimum intensity Go into Action Potential; a neural impulse (brief electrical charge) that travels down an axon. All-or-none response.

Types of Neurons Sensory Neurons – sends receptors to CNS Interneurons – internal communication neurons Motor Neurons – CNS to muscle and glands