Psychology 1000 Chapter Notes - Chapter 3: Homeostasis, Sensory System, Peripheral Nervous System

• School: Western University
• Department: Psychology
• Course: Psychology 1000
• Professor: Laura Fazakas- De Hoog

Document Summary

Blood-brain barrier: prevents many substances (ex: toxins, etc) from entering brain. Neurons do 2 important things: generate electricity that creates nerve impulses, release chemicals that allow them to communicate with other neurons & muscles & glands. Nerve activation (three steps: at rest, neuron has electrical resting potential due to distribution of. In salty fluid outside neuron: +ve charged sodium ions (na+) and ve charged chloride ions (ci-) Inside neuron: large ve charged protein molecules (anions or a-) and +ve charged potassium ions (k+) Resting potential: interior of cell ve compared to outside by difference of 70 millivolts: at rest, neuron in state of polarization. Action potential: sudden reversal in neuron"s membrane voltage; membrane voltage momentarily moves rom -70 millivolts (inside) to +40 millivolts. Absolute refractory period: a time of recovery during which a cell membrane is not excitable and cannot generate another action potential. Damage to myelin sheath results in nervous, jerky movements and paralysis.