Biological Bases of Behavior – PSY 301 Lecture Notes (UT Austin)

Biological Bases of Behavior
1. Neurons

●​ Definition: Basic building blocks of the nervous system; specialized cells that transmit
information.​

●​ Parts of a neuron:​

○​ Dendrites: Receive messages from other neurons.​

○​ Cell body (soma): Processes incoming signals; contains the nucleus.​

○​ Axon: Sends electrical impulses away from the cell body.​

○​ Myelin sheath: Insulates axon; speeds up transmission.​

○​ Axon terminals: Release neurotransmitters to communicate with other neurons.​

●​ Types of neurons:​

○​ Sensory neurons: Carry information from body to CNS.​

○​ Motor neurons: Carry instructions from CNS to muscles/glands.​

○​ Interneurons: Connect neurons within the CNS; process info.​

●​ Action potential: Electrical signal that travels down the axon.​

●​ Resting potential: Neuron’s baseline electrical charge.​




2. Neurotransmitters

●​ Definition: Chemical messengers that transmit signals across synapses.​

●​ Major neurotransmitters:​

○​ Acetylcholine (ACh): Muscle movement, learning, memory.​