AP Psych Biological Bases

Peripheral Nervous System (PNS)

the sensory and motor neurons that connect the CNS to the rest of the body

Central Nervous System (CNS)

contains the spine and brain; in the center of the body

Autonomic 

part of the PNS that controls involuntary functions or things that happen automatically within the body (digestion, breathing)

Somatic

part of the PNS that controls voluntary movements and communication to and from the sensory organs 

Sympathetic

part of the autonomic system that physically arouses the body to respond to stress (“fight or flight”)

Parasympathetic

part of the autonomic system that calms the body, conserving  its energy and helping keep a constant internal state/return to homeostasis (“rest and digest”)

Brain

part of the CNS; neural center of the body; body’s control center

Spinal Cord

part of the CNS; super highway of nerves; the body’s means of transmitting messages to and from the brain

Interneurons

the only neurons in the CNS, acting as messenger between sensory and motor neurons

Sensory (afferent) neurons

carries incoming messages/information from the sense receptors to the CNS (approaches brain)

Motor (efferent) neurons

carries outgoing information from the CNS to the PNS and muscles (exits the brain)

Reflex

involuntary response to a specific stimulus that does not involve conscious thought

Reflex Arc 

reflexes are processed by the spinal cord, not the brain, which allows us to react more quickly. They serve a protective function, helping the body respond to potentially harmful stimuli

Sympathetic nervous system functions

inhibits digestion, stimulates glucose release by liver, stimulates release of epinephrine and norepinephrine by adrenal gland, dilates pupils, increases respiration rate

Parasympathetic nervous system functions

stimulates digestion, promotes energy storage, contracts pupils, slows heart rate and lowers blood sugar

Dendrites

receive incoming information and symbols

Cell Body/Soma

contains the nucleus

Nucleus

control center; determines whether the neuron should fire

Axon

longest part of the neuron; electrical message travels the length of this 

Myelin Sheath

fatty tissue that insulates the axon; speeds up transmission of the message

Axon terminals

endings of the axon; store neurotransmitters; ready to be released when the neuron fires

Mirror neurons

activated when we watch others complete an activity and we start to do it

Glial cells

provides protection, nutrients, and waste removal (Schwann cells)

Action potential

“nerve impulse”; electrical pulse or message that travels the length of the axon

The All or Nothing Principle

nucleus decides to fire, it fires down the axon completely or not at all, maintaining the same intensity for the whole axon

Resting potential 

the fluid inside the neuron is negatively charged, while the fluid outside is mostly positive; threshold is reached when there is enough of a charge to trigger an action potential

Depolarization

positive ions rush into the axon, flipping the charge. Action potential travels the length of the axon to the axon terminals. Neurotransmitters are released into the synapse

Refractory period

the neuron repolarizes so it will be prepared to fire again

Neurotransmitter

chemical substance that crosses the synapses to carry message to the next neuron

Synapse

small, fluid-filled gap between neurons

Receptor Sites

specific points on dendrites of neurons that receive specific types of neurotransmitters 

Reuptake

excess neurotransmitters are reabsorbed by the neuron that released them 

Multiple Sclerosis

immune system disorder that attacks the myelin sheath; slows communication between brain + muscles; causes muscle weakness, fatigue, and loss of coordination

Myasthenia Gravis

antibodies block or destroy receptor sites for ACh; results in muscle weakness and difficultly contolling voluntary muscles

Serotonin

NT that causes happiness, feeling good, mood regulation and calmness; it is used in depression and anxiety treatment; too much: hallucinations; too little: depression, OCD

Dopamine

NT that is associated with pleasure and rewards, motivation, satisfaction, and excitement. it is responsible for addiction; too much: addiction, schizophrenia; too little: Parkinson’s, depression

Norepinephrine

NT associated with fight or flight, increase in heart rate, blood pressure, and increase in breathing; too much: anxiety; too little: depression, mood disorders 

Gaba

NT associated with calming and relaxation, increasing sleepiness and decrease in anxiety. calms the CNS and decreases heart rate, blood pressure, and breathing rate; too much: too sleepy + sedated, normal functions are impaired; too little: anxiety, insomnia

Endorphins

NT associated with alleviating pain, lowering stress, and mood improvement. enhances well being and released in pleasure; too much: ignores signals of pain; too little: significant pain

Glutamate

excitatory NT that has several types of receptors in the CNS. its metabolism is important to maintaining optimal levels within the extracellular; too much: overstimulates the brain, migraines, epileptic seizures; too little: insomnia, concentration problems, mental exhaustion

Acetylcholine (ACh)

NT associated with motivation, arousal, attention, learning, and memory. promotes rem sleep. regulates cardiac contraction and muscle action; too much: severe muscle spasms; too little: Alzheimer’s, dementia

Substance P

NT that plays a key role in transmitting pain signals to the brain, released by brain cells to send pain messages; too much: chronic pain; too little: reduced sensitivity to pain 

Endocrine System

network of glands that release hormones; works along the nervous system to regulate body functions

Hormones

chemical messengers released by glands that travel through the bloodstream; slower, longer lasting effects

Adrenaline

produced by the adrenal glands and released in stressful or exciting situations. prepares for “fight or flight” and mobilizes energy by increasing glucose availability 

Ghrelin

produced by stomach to signal hunger

Leptin

produced by adipose to signal satiety

Melatonin

produced by the pineal gland; regulates sleep wake cycles (circadium rhythm)

Oxytocin

produced by the hypothalamus and released by the pituitary gland; primary roles: bonding, trust, social connection, childbirth, lactation

Medulla

in the brain stem; autonomic processes- heartbeat, breathing, and blood pressure

Reticular Formation

in the brain stem; involved with alertness and arousal; filters incoming stimuli and selectively relays information 

Pons

in the brain stem; helps coordinate movement; involved with sleep

Cerebellum (little brain)

in the brain stem; involved with fine motor control, coordination, balance, and posture; processes sensory input

Thalamus (sensory switch board)

part of the limbic system; directs information from our sensory organs to the sensory receiving areas in the cortex

Hypothalamus (below the thalamus)

part of the limbic system; directs maintenance activity and survival drives; hunger, thirst, sex, body temp. regulation

Pituitary Gland (master gland)

part of the limbic system; directs the endocrine system and sends signals to other glands; stress, growth, reproduction

Amygdala (fear center)

part of the limbic system; involved in processing emotion and survival responses; linked to fear, aggression, and other emotions

Hippocampus (seahorse)

part of the limbic system; plays an important role in turning information into long term memories and recalling facts and events 

Corpus Callosum

bundle of nerve fibers that connect the two hemispheres and allow for communication between them

Cerebral cortex

wrinkled outer surface of the brain; involved in higher level functions and information processing 

Frontal lobe

controls executive functions: judgment, decision making, reasoning, planning, problem solving, personality/temperment, regulation of emotion, motivation + willpower

Motor cortex

largely responsible for voluntary movement, part of the frontal lobe

Parietal lobe 

involved with: processing certain sensory signals (touch, pressure, temperature, pain), body position, spatial reasoning 

Sensory cortex

largely responsible for perceiving touch and pressure on parts of the body, in the parietal lobe 

Temporal lobe

involved with processing auditory information (primary auditory cortex), storing long term memories, speech and language comprehension

Occipital lobe

processing visual signals and coordinating carious aspects of vison, contains the visual cortex

Broca’s area

located in the left frontal lobe, responsible for directing motor movement involved in speech

Wernicke’s area

located in the left temporal lobe, responsible for language comprehension and expression 

Brain lateralization

each hemispher has unique strengths; some are stronger or more efficient on one side (right- spatial skills, facial recognition, emotional expression, creative processing; left- speech and language, analysis, math and science reasonign, grammar

Neuroplasticity

the brain’s ability to change its structure and function in response ot experience, learning, or injury 

Corpus callostomy

treats severe epilpesy pby severing corpus callosum

Contralateral Organiztion

each hemisphere controls and receivs information from the opposite part of the body (right-left, left-right)