Ch 3: Biopsychology - Cells of the Nervous System

Nervou system

composed of glial cells and neurons

Glial Cells

scaffolding which nervous system is built

The Function of Glial Cells

helps neurons line up close to each other for communication, provides insulation to neurons, transports nutrients and waist, mediates immune responses

Neurons

interconnected info processers essential for all tasks in the nervous system

Semipermeable Membrane

makes up a neuron’s outer surface

Semipermeable Membrane Function

allows smaller molecules and ones without electrical charge to pass through and stop larger ones or highly charged ones

A neuron’s nucleolus is located in…

the cell body aka soma

Dendrites

receives signals from other neurons

Terminal Buttons

contain synaptic vesicles that house neurotransmitters aka the chemical messengers of the nervous system

Myelin Sheath

coats the axon and acts as an insulator increasing the speed the signal travels

Nodes of Ranvier

gaps in the myelin sheath

Synaptic Cleft

small space between two neurons where communication occurs

Receptors

proteins on the cell surface where neurotransmitters attach

Membrane Potential

the difference in charges across membrane, provide energy for signal

Resting Potential

Ions line up on either side of the neuron ready to go

Threshold of Excitation

when the charge of a neuron reaches a certain level, the neuron becomes active and the action potential begins

Action Potential

electric signal that moves from the cell body, down the axon to the axon terminals

All or None Phenomenon

an incoming signal from another neuron is either sufficient or insufficient

Reuptake

when a signal fails, neurotransmitters get pumped back into the neuron in order to clear the synapse

Psyochotropic Medication

drugs that treat psychiatric symptoms by restoring the balance of neurotransmitters

Agonists

chemicals that mimic neurotransmitters at the receptor site

Antagonists

blocks the normal activity of a neurotransmitter at the receptor

Peripheral Nervous System

carries messages between CNS, muscles, organs, and senses in the periphery body

Somatic Nervous System

voluntary, relays sensory and motor info to and from CNS

Motor Neurons

carries instructions from the CNS to the muscles (efferent fibers)

Sensory Neurons

carries sensory info to the CNS (afferent fibers)

Autonomic Nervous System

involuntary, controls internal organs

Sympathetic Nervous System

prepares the body for stress related activities

Parasympathetic Nervous System

associated with returning the body to its normal routine

Homeostasis

state of balance which biological conditions are maintained at optimal levels