Chapter 1 of Physiological Psychology

Membrane

The surface of a cell that separates the inside from the outside.

Nucleus

Structure that contains the chromosomes.

Mitochondrion

Structure that performs metabolic activities by providing energy.

Ribosomes

The sites within a cell that synthesize new protein molecules.

Endoplasmic reticulum

A network of thin tubes that transport newly synthesized proteins to other locations.

Dendrite

Receives information from other neurons via neurotransmitters.

Cell body/Soma

The major powerhouse of the cell, containing the nucleus, ribosomes, and mitochondria; responsible for metabolic work of the neuron.

Axons

A thin fiber that transports information from the dendrites to the presynaptic terminals.

Myelin sheath

Insulating material that covers the axon and increases the speed of information transmission.

Nodes of Ranvier

Interruptions in the myelin sheath.

Presynaptic terminal

Terminals at the end of axons that release information to neighboring cells.

Astrocytes

Synchronize the activity of surrounding axons by taking ions and transmitters; dilate blood vessels to bring more nutrients to active brain areas.

Oligodendrocytes and Schwann cells

Build the myelin sheath.

Radial glia

Guide the migration of neurons and their axons and dendrites during embryonic development.

Microglia

Acts as part of the immune system by removing viruses and fungi from the brain.

Blood-brain barrier

Surrounds the brain and keeps select chemicals outside; provides extra protection since neurons generally do not regenerate.

Active transport system

Expends energy to pump chemicals from the blood into the brain; transports glucose, certain hormones, amino acids, and a few vitamins.

Sodium-potassium pump

Maintains the electrical gradient by pumping 3 sodium ions out and 2 potassium ions in to maintain resting potential.

Absolute refractory period

The membrane cannot produce another action potential because it recently produced one.

Relative refractory period

A stronger than usual stimulus is needed to initiate an action potential because the cell is still resting after the previous one.

Saltatory conduction

The process by which action potentials jump from node to node along the axon, increasing the speed of transmission.

Motor Neuron

A type of neuron that transmits signals from the central nervous system to muscles, causing movement. Soma is in the spinal cord.

Sensory Neuron

Carries sensory information to the central nervous system.

action potential

A rapid change in membrane potential that propagates along the axon, allowing for the transmission of electrical signals in neurons.

resting membrane potential

-70 mv

polarized

more potassium ions are inside the cell, and more sodium ions are outside of the cell

blood-brain barrier

A selective permeability barrier that protects the brain from harmful substances in the bloodstream while allowing essential nutrients to pass through.