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