AP Psych Unit 7 Part 1

Sensory Afferent Neurons

Sensory Afferent Neurons

Neurons that send incoming sensory information detected by receptors to the brain/spinal cord for processing

(feeling squeeze on shoulder)

Interneurons

Neurons within the brain and spinal cord that enable communication between sensory/motor neurons

Motor Efferent Neurons

Neurons that activate effectors such as muscles to enable motor movements

(Lifting up arm)

Dendrites

Receives information from other neurons at receptor sites

Receptor Sites

Surface of dendrites that activate due to neurotransmitters

Axon

Sends messages received by the dendrites to the terminal for communication with other neurons

Myelin Sheath

Fatty casing around the axon that quickens the velocity/speed of communication along the neuron

Axon Terminals/Terminal Buttons

Branches at the end of the axon that contain neurotransmitters in the synaptic vesicles

Synaptic Vesicles

Sacs in the terminal that store neurotransmitters until messages from the axon trigger release

Resting Potential/Polarization

When a neuron is not transmitting or receiving a message because the interior of the neuron is more negative than the outside

(Neurons are Normally Negative)

Action Potential/Neuron Impulse

Brief electrical charge that occurs when a neuron is stimulated (fires) by another neuron

Threshold of Extinction

Amount of stimulation needed for a neuron to fire (go from “resting potential” to “action potential”)

All-or-None Response

Once threshold is reached - the neuron fully fires - same magnitude of intensity every time

Refractory Period/Hyperpolarization

Short time period after a neuron fires - when a neuron returns to resting potential and cannot fire again

RE-factory period

RE-set period/Resting

Action Potential Graph

1. Stimulus intensity reaches threshold while neuron is polarized (resting)

2. Depolarization - sodium (+) enters the neuron (becomes positive)

3. Repolarization- potassium (+) exits the neuron (REturning to negative)

4. Hyperpolarization - refractory period

Synapse

Location of neural communication between two neurons

1. Terminal of the presynaptic neuron

2. Synaptic cleft/gap (literal space)

3. Receptor sites on dendrites of the postsynaptic neuron

Neurotransmitters

Chemicals held in the synaptic vesicles of the axon terminal

During action potential they are released from those vesicles into the synaptic cleft causing the stimulation of other neurons

Reuptake

Absorption of neurotransmitters in the synapse back to the sending neuron after stimulating the receiving neuron

Long-term Potential

The process of neural communication strengthening (faster) after repeated patterns

• The literal reason you study (improves remembering)

Excitatory

Type of neurotransmitter

Causes more action potential

Inhibitory

Type of neurotransmitter

Stops action potential

Serotonin

Mood regulation

Linked with depression

Acetylcholine

Enables muscle movements and linked with memory

Difficulty with movement and memory (Alzheimer’s)

Dopamine

Brains pleasure reward system

High levels linked to schizophrenia

Low levels linked to parkisons disease

Norepinephrine

Regulation of alertness and arousal

Endorphins

Body’s natural pain killer/stress maintenance

“Runners high” - Euphoric experience after workout

Glutamate

Most common excitatory neurotransmitter - active for most normal cognitive functioning (thinking)

GABA

Most common inhibitory neurotransmitter - reduces brain activity

Low levels linked with insomnia

Depressants

Slows the activity of neurons and body functions (alcohol, morphine)

Stimulants

Stimulate activity of neurons (caffeine, nicotine, cocaine)

Hallucinogens

Vivid and distorted visual/auditory perception not based on sensory input (ecstasy, LSD)

Withdrawal

Physical discomfort when the substance is stopped

Tolerance

Declining psychological effects of a drug after substained use

Dependence

Relying on a drug to avoid withdrawal

Addiction

Uncontrollable cravings to use a drug or do a behavior

Central Nervous System

Brain and spinal cord

Pons + Reticular Formation

Regulation of arousal, alertness, wakeness, dreaming

Damage could cause a coma

Location: Brain stem

Medulla

Controls vital automatic functions (heartbeat, swallowing, breathing)

Location: Brain stem

Cerebellum

Coordinates smooth voluntary movement and balance

Thalamus

Relays sensory signals (except smell) to the corresponding cortex

Limbic System

Network of brain structures responsible for memory, emotion, and motivation

Contains: Hippocampus, Amygdala, Hypothalamus

Amygdala

Emotions such as through facial expressions and “fight or flight” response (fear + aggression)

Hypothalamus

“Maintenence activites” since it links to nervous system to endocrine systems (horomones)

(Hunger, thirst, sex drive, body temp)

Hippocampus

Formation of long-term memory

Corpus Callosum

Collection of neuron axons that connect both hemispheres

Severed to stop epileptic seizures

Association Areas

Areas not associated with receiving sensory information/muscle movements

Temporal Lobes

Auditory sensory processing and memory

Contains: Wernicke’s Area, Hippocampus

Wernicke’s Area

Understanding written/spoken speech

When damaged: Cannot understand language

Occipital Lobes

Visual sensory processing

Contains: Visual cortex

Parietal Lobes

Processes sense of touch at the somatosensory cortex aka “sensory cortex”

Larger regions for areas with higher sensitivity

Frontal Lobes

Enables movement, high level cognition and language production

1. Motor cortex

2. Prefrontal cortex (make + carry out plans/judgement/reasoning)

3. Broca’s Area

Broca’s Area

Muscle movements controlling speech

When damaged: Broca’s Aphasia (cannot perform muscle movements necessary to speak

Spinal Cord

Series of inter neurons that connect the brain to the rest of the body

1. Carries motor movement messages from the brain

2. Carries messages from sensory neurons (ex. touch) to the brain

3. Enables spinal reflexes - without the brain - due to inter neurons in the spinal cord

Peripheral Nervous System

Sensory/motor neurons outside of the brain

Automatic Nervous System

Responsible for enabling bodily activities via effectors (ex. stomach) that are not knowingly controlled

(Heartbeat, digestion)

Polygraph Test (Lie Detector)

Measures autonomic arousal, however, “guilt” measures the same as many emotions

Very unreliable

Sympathetic Nervous System

Active when you are aroused by expending energy (ex. fear response)

When activated: Dialates pupils, heartbeat goes up, digestion goes down, relaxes bladder, high adrenaline

Parasympathetic Nervous System

Active when you are relaxing and saving energy

When activated: Constricts pupils, heartbeat goes down, digestion goes up, contracts bladder, salvation goes up

Somatic Nervous System

Enables movement of effectors (muscles) you can control via motor neurons (thus producing voluntary movement)