Textbook Notes (368,432)
Canada (161,877)
Psychology (528)
PSYCO104 (73)
All (1)
Chapter 3

Chapter 3 Notes

8 Pages
Unlock Document

All Professors

Chapter 3 Neurons Dendrite – Recieves information from other neurons and relays it to cell body Cell Body – coordinates information processing tasks and keeps cell alive Axon – transmits information to other neurons, muscles or glands Myelin Sheath – insulating layer of material made up of glial cells (some digest dead neurons, others provide physical and nutritional support, others form myelin) Synapse – Area between axon terminal and dendrite Types of neurons • Sensory Neuron o Receive information from the external world and convey information to brain via spinal cord • Motor Neuron o Neurons that carry signals from spinal cord to the muscles • Interneuron o Most neurons are these neurons which connect motor and sensory neurons and performs a variety of information-processing functions. Purkinje cells • Neuron that carries information from cerebellum to the rest of brain and spinal cord • Hippocampal Pyramidal cell • Found in cerebral cortex, they have a triangular cell body and one long dendrite along with other small ones • Bipolar Neuron • Sensory neuron found in the retina • Have a single axon and dendrite Electrochemical Action • Resting Potential o -70mV o Due to high concentration of Na+ outside cell and high concentration K+ inside cell. During resting potential K+ can flow freely in and out of cell membrane • Threshold Potential o An all or none voltage that must be reached to produce and action potential. o About +40mV o When this is reached the K+ channels shut down and the Na+ channels open causing lots of Na+ to come into the axon raising the potential. • Action Potential o When the Na+ ions flood in they spread down the axon until the reach the next node of Ranvier and create another action potential there (salutatory conduction) • Refractory Period o A time following action potential when another impulse cannot be sent because the excess Na+ ions must be moved outside the axon by an active chemical pump and K+ must be moved back in Transmission Between Neurons • Axons end in terminal buttons filled with vesicles of neurotransmitters • Dendrites have receptors for these neurotransmitters. • When an axon is undergoing action potential, as it reaches the terminal button it stimulates the release of neurotransmitters into the synapse which then start a new signal in the postsynaptic neuron • Destroying Neurotransmitters o Reuptake – when neurotransmitters absorbed by terminal buttons o Enzyme deactivation – Enzymes in Synaptic gap break down neurotransmitters o Autoreceptors – neurotransmitters bind to autoreceptors on presynaptic neuron and signal it to stop releasing the neurotransmitter. • Acetylcholine (Ach) o Involved in a number of functions, including voluntary motor control. Initiates motor behaviour • Dopamine o Regulates motor behavior, motivation, pleasure and emotional arousal. Seeking pleasure or associating actions with rewards (drugs) • Glutamate o Major excitatory neurotransmitter involved in information transmission throughout the brain. Too much can cause seizures • GABA (gamma-aminobutyric acid) o Primary inhibitory neurotransmitter in the brain. Stops the firing of neurons and too little can cause neurons to be overactive • Norepinephrine o Influences mood and arousal, especially states of vigilance or heightened awareness • Serotonin o Involved in regulation of sleep and wakefulness, eating and aggressive behaviour • Endorphins o Are chemicals that act within the pain pathways and emotion centers of the brain. Ie. Releasing endorphins when you have been running a long, long time. Drgus……. Agonist – Increase the action of a neurotransmitter Antagonists – block the function of a neurotransmitter Organization of the Nervous System • Central Nervous System o Composed of Brain and Spinal Cord  Spinal reflexes can occur so information does not need to travel all the way up to your brain.  Damage to the spinal cord is devastating • Peripheral Nervous System  Connects the central nervous system to the body’s organs and muscles o Autonomic • Carries involuntary and automatic information  Sympathetic • Prepares the body for threatening situations • Dilates eyes, increases heart rate, starts sweat glands, inhibits salivation and bowel movements, supresses immunity
More Less

Related notes for PSYCO104

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.