PSYC 1000U Lecture Notes - Lecture 3: Peripheral Nervous System, Autonomic Nervous System, Central Nervous System
Document Summary
Franz gall (1758-1828)- phrenology: mapping the bumps on skulls, bumps on skull this indicates abilities/traits. Mind is made up of neurons group. Together make who we are/ predict how we interact. Neurons- building blocks: complex from to a simple form, 40 billion in brain. Key components: cell body- life support, dendrites- receive messages, axon- passes messages, myelin sheath- insulates and speeds messages, action potential- electrical signal through axon. Action potential- signal tells other cells (chemical reactions) Electrical from chemical: exchange + and -ions. It have to reach its threshold: excitatory (accelerate) + inhibitory (brake, all-or-none response (gi(cid:448)es a response or it doesn"t gi(cid:448)e response at all) Resting potential: (+) ions outside & (-) ions inside. Selectively permeable: very selective about what goes in and out of it gates. Depolarization: loss of inside/ outside difference (+) ions goes outside & (-) comes inside. Excitatory signals inhibitory signal which lowers the intensity of threshold.
