Psych key terms (overview)

what does the CNS do and what makes it up

• process information received and activate as appropriate

• spinal cord and brain

what are the two major functions of the spinal cord

• receive sensory information from the body and send to the brain for processing

• receive motor (movement) information from the brain and send it to the relevant parts of the body

define the PNS (peripheral nervous system) and describe the movement of information

the entire network of nerves located outside the CNS

• carriers info from internal (muscles, organs, glands) and external environment (sensory organs) → to CNS

• carriers info from CNS → to the body’s muscles, glands and organs

define somatic nervous sytem

receives sensory info from skin, muscles, joints and sends it sends motor information for movement to the skeletal muscles (Voluntary)

define autonomic nervous system (ANS)

a subdivision of the PNS that connects the CNS to the bodies internal organs and glands, providing feedback to the brain about their activities (involuntary)

define the sympathetic nervous system

activates internal muscles, organs and glands to prepare the body for vigorous activity or to deal with a stressful or threatening situation

define parasympathetic nervous system

helps maintain the internal body environment in a steady, balanced state of normal functioning

define and describe the enteric nervous system

embedded in the walls of the gastrointestinal tract

• detects physiological condition of the gastrointestinal tract and controls relevant functions ; muscle contractions, nutrient management

conscious vs. unconscious responses

conscious

• a response to a sensory stimulus which involves awareness - individual will have paid attention to the stimulus and voluntarily, intentionally react to it.

unconscious

• a response to a sensory stimulus which does not involve awareness. It is involuntary, unintentional automatic and cannot be controlled (responses by the Autonomic NS are unconscious)

define spinal reflex/ reflex arc

unconscious, involuntary and automatically occurring response to the stimuli initiated within the spinal cord without and involvement from the brain (a survival mechanism)

steps involved in spinal reflex/ reflex arc

1. sensory receptors on the skin receive sensation and send it along sensory neural pathways to the spinal cord

2. interneurons in the spinal cord receive and initiate a response as a survival mechanism

3. the message is sent along motor pathways to the point of need (to withdraw hand ect)

4. the message completes its journey to the brain which then registers pain and can initiate further action if required

define neurotransmitter

a chemical substance produced by a neuron that carries a message to other neurons or cells in muscles, organs or other tissues

describe reuptake

any neurotransmitter that doesn’t bind to the receptor is reabsorbed by the pre-synaptic neuron

differ from excitatory and inhibitory

excitatory

• stimulates and activates postsynaptic neurons to perform their function

inhibitory

• blocking or preventing postsynaptic neurons from firing

define glutamate

the primary excitatory neurotransmitter, enhances information transmission by making postsynaptic neurons more likely to fire (post synapse action potential more likely)

define gaba

primary inhibitory neurotransmitter, making postsynaptic neurons less likely to fire

define neuromodulators

type of neurotransmitter that can influence the effect of other neurotransmitters ; also called modulator neurotransmitter

what is dopamine

a neuromodulator with multiple functions depending on where it acts, functions include; important role to voluntary movements, the experience of pleasure, motivation, appetite, reward based learning and memory

• can either an excitatory effect at one location or an inhibitory effect at another, depending on the type of receptors that are present

identify and describe the 3 main pathways which dopamine is involved in the brain

1. nigrostriatal,

• a pathway stemming from the substantia nigra (nigrostiantal) is invloved in coordinating smooth and coordinated movement - disease in this area increases rigidity or stiffness such as those symptoms of parkinson’s disease

2. mesolimbic, mesocorital,

• overlap and are strongly associated with the experience of pleasure and its role in rewarding behaviour - linked to schizophrenia

defie serotonin

neuromodulator with multiple functions depending on where it acts; functions include mood, emotional processing, sleep inset, appetite, and pain perception

• only has inhibitory effects, does not stimulate the brain

define learning

the acquisition of new information, behaviour or abilities that occurs as a result of experience

define synaptic plasticity/neural plasticity

the ability of the brains neural structure or function to be changed of the synapses due to experience

identify the two types of plasticity and how they occur

developmental plasticity

• occurs due to learning

adaptive plasticity

• occurs due to damage

define sprouting, rerouting and pruning

sprouting

• the creation of new extensions on a neuron to allow it to make new connections with other neurons

rerouting

• when new connections are made between neurons to create alternate neural pathways

pruning

• the elimination of weak, ineffective or unused synapses

describe the hebbian theory

neurotransmitter is repeatedly sent across the synaptic gap, the presynaptic neuron and the postsynaptic neuron are repeatedly activated at the same time. Having the effect of actually changing the chemistry of the synapses, this leads to a strengthening of connections between neurons at the synapse

→ stronger connection, more likely to fire together and transmit their signals forcibly in the future

→ neurons that fire together, wire together