AP Psych 24/25 course Unit 2
Neuron
The types of cells that make up the brain and nervous system. The gray matter of the brain.
Cell body
What contains the nucleus. It produces energy for neuron activity.
Dendrites
Fibers that stick out and receive impulses/signals from other neurons on it’s receptor sites.
Axon
Carries impulses from one neuron to another. Can be several feet in length.
Axon terminal/Terminal buttons
Branch out at the end of the neuron. They contain vesicles that hold neurotransmitters.
Myelin Sheath
Insulates/protects the axon.
How do neurons generate activity?
Fluids inside and outside of the neuron contain positive and negative ions. The semipermeable gates open and close, allowing the ions to move back and forth. When they move back and forth, energy is created.
Positive ions
Sodium and potassium
Negative ions
Chlorine
Resting potential
The neuron is negatively charged on the inside and positively charged on the outside. This is a polarized state.
Depolarization
The ion channels allow positive ions to go through the semipermeable gates into the neuron.
All-or-Nothing Principal
When the electrical impulse reaches its threshold at a certain level of intensity, the impulse must fire. It moves down the axon without losing its intensity.
Action Potential
The wave of electrical charge. It lasts 1/1000 of a second.
Repolarization
Returning to a polarized state. Positive ions leave the neuron, and the neurons become negative again.
Refractory Period
The period of time before a neural impulse can be fired again. Also known as hyperpolarization.
Reuptake
When transporter proteins carry neurotransmitters back to the pre-synaptic neuron.
Excitatory
A type of neurotransmitter that makes it more likely for the post-synaptic neuron to fire an action potential.
Inhibitory
A type of neurotransmitter that decreases the likelihood of the post-synaptic neuron to fire an action potential.
Agonist
A type of chemical that mimics the action of a neurotransmitter.
ex: opioids mimic endorphins
Antagonist
A type of chemical that blocks the action of a neurotransmitter.
ex: Haldol blocks dopamine receptors.
SSRI
Serotonin supply uptake inhibitor.
Acetylcholine (ACh)
Excitatory (stimulates neurons)
Muscle action
Learning and memory
When ACh neurons deteriorate = alzheimers
GABA
Major inhibitory neuron
The brain’s break pedal
Calms down the brain
Undersupply = anxiety, seizures, tremors, insomnia
Glutamate
A major excitatory neurotransmitter.
The brain’s accelerator
Learning and memory
Most prevalent neurotransmitter
Oversupply overstimulates the brain
Oversupply = Headaches, migraines, seizures
Norepinephrine
Inhibitory to neurons in the nervous system
Excites heart muscles and intestines
Alertness and arousal
Undersupply = depressed mood
Dopamine
Voluntary movement
Learning and reward
Affects sleep
Attention
Emotion
Addiction
Oversupply = Schizophrenia
Undersupply = Tremors, decreased mobility in Parkinson’s
Serotonin
Mood
Hunger
Sleep
Arousal
Learning
Attention
Undersupply = depression
Drugs can raise serotonin to treat depression
Endorphins
Perception of pain or pleasure
Natural opiates
Depress the immune system
Eliminate pain
Oversupply with opioid drugs = suppress body’s natural supply
Substance P
Pain perception and immune response
Oversupply = chronic pain
Neural networks
Connected pathways of nerves that produce motor output from sensory input.
Structure
A part of the brain that carries out a specific function
Lobe
A section of the brain that seems to be involved in specific functions
There are 4
Cortex
The brain’s surface area
Midbrain structures
Reticular Formation
Recticular Formation
Tells the brain a signal is coming
Forebrain structures
Amygdala
Hypothalamus
Hippocampus
Thalamus
Limbic system (not a structure, but in the forebrain)
Cerebral cortex and cerebrum
Limbic System
Motivation, memory, and regulating emotions
Cerebral Cortex and Cerebrum
Learn and store complex info
Reading
Understanding language
Amygdala
Handles intense emotions like fear and aggresion
Differentiation of things essential for survival like food and mates
Hypothalamus
Keeps the body in homeostasis (inner state regulation, body temperature)
Hunger
Thirst
Fight or flight reflex
Hippocampus
Recalling information by ‘waking up’ parts of the brain
Creating memories
Thalamus
Sensory input
Sends sensory signals to the correct part of the brain that handles them
All senses except smell
Hindbrain structures
Cerebellum
Medulla
Pons
Cerebellum
Motor coordination
Medulla
Essential life functions
Breathing, heart rate, reflexes
Pons
Sleep and arousal
Corpus Callosum
Fibers that connect the left and right hemispheres, allowing them to communicate with each other
Frontal Lobe
Personality
Intelligence
Control of voluntary movements
Pre-frontal cortex
Higher cognitive functions
Planning, reasoning, self control
Motor Cortex
Body movement
Parietal Lobe
Spatial reasoning
Attention
Motor control
Occipital Lobe
Visual signals (interpretation)
Temporal Lobe
Hearing
Memory
Emotion
Speaking
Connects to limbic system
Association cortexes
Cortexes that integrate outside information into newly processed information
Broca’s Area
Production of speech, in the left hemisphere
Wernicke’s Area
Comprehension of speech, in the left hemisphere
Nervous system
Electrochemical communication circuitry
Plasticity
The brain’s adaptablility
It’s special ability to change and adapt
Central Nervous System
The brain and spinal cord
Peripheral Nervous System
Smaller nerve branches that reach all over the body
Somatic Nervous System
Voluntary activities
Autonomic Nervous System
Involuntary activities
Sympathetic Nervous System
Arouses the body, mobilizing it for action
‘fight or flight’
Parasympathetic Nervous System
Calms down the body
‘rest and digest’
Reflex arc
Afferent neurons conducting signals from receptors (PNS) → interneurons (confined to CNS) → Efference neurons conduct signals to effectors (muscles and glands)
Afferent Neurons
Sensory Neurons
Efferent Neurons
Motor Neurons
Endocrine System
Made up of glands that secrete hormones
Pituitary Gland
The ‘mastergland’ of the endocrine system
Releases hormones = stimulate actions of other endocrine glands
Hormones
Melatonin
Adrenaline
Oxytocin
Ghrelin
Leptin
Melatonin
Sleep/waking up
Adrenaline
Actviates the sympathetic nervous system
Fight or flight
Oxytocin
Social bonding (child/parent bond)
Ghrelin
Stomach contractions (growling)
Promotes hunger
Leptin
Decreases hunger by providing info to the hypothalamus
Rodger Sperry
Taught cats with a severed corpus callosum to solve a puzzle
Mike Gazzaniga
Performed split brain operation
Can be used to treat epilepsy by stopping spread of electrical activity
Lateralization
The specialization of the different hemispheres of the brain
Epigenetics
The study of environmental influences of gene expression that occur without a gene change
Twin Studies
Comparing identical twins to fraternal twins
Adoption Studies
Examining the resemblance between adopted children with both their biological and adoptive parents
How do scientists study the brain?
Recording
Stimulation
Lesions
Accidentals
TMS
Images
EEG
Recording
Electrodes on the scalp detect brain wave activity
Lesions
Scientists cut or destroy part of an animals brain
TMS
Magnets send brief electrical currents to the brain to trigger action potential
CT scan
Image
Produces 3D image from x-rays
PET scan
Positron emission typography
Metabolic changes in the brain related to activity
Image
MRI
Image
Magnetic field around the person
Radiowaves construct images of tissue and biochemical activity
FMRI is similar (functional, person is doing something)