Unit 1.3a Neural Communication + the Endocrine System -- AP Psych

Neuron

a nerve cell; the basic building block of the nervous system

→ transmits via electrical and chemical signals

Cell Body (soma)

the part of a neuron that contains nucleus

Dendrites

A neurons often bushy, branching extensions that receive and integrate messages

Axon

the segmented neuron extensions passes messages through its branches to other neurons or to other muscles or glands

Myelin Sheath

a fatty tissue layer that segmentally encases the axons of some neurons

Terminal Branches

ends of the axon containing terminal buttons which hold synaptic vesicles that store neurotransmitters

Glial Cells

Cells in the nervous system that support, nourish, and protect neurons

• may also play a role in learning, thinking, and memory

Neural Impulse

A neuron sends a message by firing an impulse — action potential

Action Potential

a neural impulse; a brief electrical charge down an axon

Threshold

the level of stimulation required to trigger a neural impulse

Refractory Period

a brief resting pause that occurs after a neuron has fired

All-or-none response

a neurons reaction of either firing at full strength or not firing at all

Synapse

The junction between the axon tip of the sending neuron and the dendrite or cell body of the recieving neuron

Neurotransmitters

chemical messengers that cross the synaptic gap between neurons

• when released by the sending neuron, neurotransmitters travel across the synapse and bind to receptor sites on the receiving end

  • influences whether the neuron will generate neural impulses

Acetylcholine (ACl)

_{- neurotransmitter -}

• muscle action

• learning

• memory

Malfunction examples: Alzheimer’s, Myasthenia Gavis

Dopamine

_{- neurotransmitter -}

• feelings of pleasure

→ positive feelings

Examples of malfunction: Schizophrenia, Parkinsons

Serotonin

_{- neurotransmitter -}

• mood

• sleep

• arousal

Examples: Undersupply → depression

Norepinephrine

_{- neurotransmitter -}

• alertness

• arousal

Gaba

_{- neurotransmitter -}

• slows down brain activity

  • feel calm

  • less stress and anxiety

  • relaxation

Glutamate

_{- neurotransmitter -}

• overstimulation

• migraines

• seizures

Endorphins

_{- neurotransmitter -}

natural opiates — pain killer

Substance P

_{- neurotransmitter -}

more chronic pain

Reuptake

a neurotransmitters reabsorption by the sending neuron

Endorphins

natural opioid-like neurotransmitters linked to pain control + pleasure

Agonist

a molecule that increases a neurotransmitters action

Antagonist

a molecule that decreases a neurotransmitters action

Endocrine System

the body’s slow chemical communication system

• a set of glands + fat tissue that secrete hormones into the bloodstream

Hormones

chemical messengers that are manufactured by the endocrine glands, travel through bloodstream, affect other tissues