Physiological Psychology 41363



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Physiological Psychology 41363
Outline 1

I. Introduction


II. Physiological Psychology - Definition and History
III. The Neuron - structure and function

What is physiological psychology?

neuroscience = study of the nervous system

physiological psychology - taking a biological approach to the


study of psychology

History of Biopsychology

-Plato and early Greek philosophers - dualists

-Rene Descartes

-British empiricists (Locke, Berkely, Hume)

-Pierre Flourens - experimental ablation



Localization of function doctrine

-Broca and Wernicke - autopsies of brain damaged patients

-Golgi - neuron is the basic unit of the nervous system

NS
/ \

CNS PNS

brain and spinal cord nerves in periphery

Nervous system contains two types of cells

1. Neuron


2. Supporting cells

I. Neurons


A. Structure
1. Almost all neurons contain:

a. Cell body or soma

b. Dendrites

c. Axon


d. Terminal buttons

B. 3 types of neurons based on structure

1. Unipolar

2. Bipolar

3. Multipolar

C. 3 types depending on function

1. Sensory

2. Motor

both sensory and motor are part of the PNS

3. Interneuron

D. Inside neurons

1. membrane

2. cytoplasm

3. nucleus - control center

4. mitochondria - provide cell with energy

5. neurofilaments - support and shape cell

6. microtubules - transport substances from place to place
within the cell

7. endoplasmic reticulum

8. Golgi apparatus

9. Lysosomes

II. Supporting cells

1. Glial cells - located in the CNS

A. Astrocytes - provide physical support: destroy dead neurons (phagocytosis)

B. Oligodendrocytes - provide support: produce myelin sheath - insulates and


speeds transmission down the axon - nodes of Ranvier

2. Schwann cells - exist only in PNS - also support axons and produce myelin:

also aid in digestion of dead axons and arrange themselves to support and guide new
growth and regeneration

III. Neural Communication

2 types of communication
1. Within neurons
2. Between neurons

A. Within neurons - through action potentials (APs)

- resting membrane potential is -70mV

2 types of ions: cations (+) and anions (-)

2 forces on ions
1. Diffusion

2. Electrostatic pressure


A- membrane impermeable
K+ balances: diffusion out, electrostatic in
Cl- balances: diffusion in, electrostatic out
Na+ diffusion in and electrostatic in
Na+K+ pump maintains membrane potential : 3 Na+ out for 2 K+ in

Action Potential

A. Brief drop in membrane resistance to Na+

B. Characteristics of AP

1. All or none law

2. AP remains constant in size

3. Rate law - differences in strength of muscle contraction not


due to differences in size of AP but to differences in rate of
firing

4. saltatory conduction in myelinated axons


-saves energy
-faster

B. Between neurons (Synaptic Transmission)

1. neurons communicate with each other through synapses

-presynaptic membrane

-postsynaptic membrane

-synaptic cleft - gap

-synaptic vesicles

-when depolarize, terminal buttons depolarize, Ca++ channels open and Ca++ rushes in and opens fusion pore. This releases neurotransmitter which travels across synapse and produces


IPSP or EPSP

-process occurs by two means

1. Direct (Ionotropic)

2. Indirect (Metabotropic)

How do we get rid of excess neurotransmitter?

1. reuptake - presynaptic takes it back



2. enzymatic deactivation - enzymes destroy neurotransmitter


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