Unit 1: Biological Bases of Behavior pt.1

acetylcholine

A neurotransmitter involved in muscle activation, memory, and learning. Not enough of this neurotransmitter is associated with Alzheimer's. Myasthenia Gravis attacks the receptors for this neurotransmitter.

action potential

A brief electrical charge that travels down the axon of a neuron, generated by the movement of positively charged atoms in and out of channels in the neuron's membrane.

Activation-Synthesis Theory

A theory of dreaming that suggests dreams are the brain's attempt to make sense of random neural activity.

addiction

A complex condition characterized by compulsive drug use or behaviors despite harmful consequences.

agonist

A drug or chemical that enhances the activity of neurotransmitters by fitting into and activating receptors.

Alcohol

A depressant that slows down the central nervous system, impairing cognitive and motor functions.

all-or-nothing principle

The principle that a neuron either fires completely or does not fire at all.

amygdala

A limbic system structure involved in processing emotions, particularly fear and aggression.

antagonist

A drug or chemical that inhibits or blocks the action of neurotransmitters by blocking neurotransmitters from their receptors.

Aphasia

A condition characterized by the loss of ability to understand (Wernicke's) or express (Broca's) speech.

association areas

Areas of the cerebral cortex that are not involved in primary motor or sensory functions but are involved in higher mental functions such as learning, remembering, thinking, and speaking.

Auditory Cortex

The part of the brain that processes auditory information.

autonomic nervous system

The part of the peripheral nervous system that controls involuntary functions like heart rate, digestion, and glandular secretion.

axon

The extension of a neuron through which neural impulses are sent.

brainstem

The oldest part and central core of the brain, responsible for automatic survival functions.

Broca's Area

A region in the frontal lobe of the brain associated with speech production. Particularly present in the left hemisphere.

Caffeine

A stimulant found in coffee, tea, and many soft drinks that increases alertness and reduces fatigue.

central nervous system

The brain and spinal cord, responsible for processing and coordinating information.

cerebellum

A structure in the hindbrain that helps coordinate voluntary movement and balance.

cerebral cortex

The outer layer of the brain responsible for complex cognitive processes such as thinking, planning, and language.

circadian rhythm

The biological clock; regular bodily rhythms that occur on a 24-hour cycle.

Cocaine

A powerful stimulant drug that increases levels of dopamine in the brain, leading to intense euphoria and increased energy.

Consolidation Theory

The theory that sleep helps strengthen the neural connections that form our memories.

Contralateral Control

The principle that each hemisphere of the brain controls the opposite side of the body.

corpus callosum

The large band of neural fibers connecting the two brain hemispheres and carrying messages between them.

dendrites

Branchlike extensions of a neuron that receive messages and conduct impulses toward the cell body.

Depolarization

The process by which a neuron's membrane potential becomes less negative, leading to the firing of an action potential.

depressants

Drugs that reduce neural activity and slow body functions, such as alcohol.

Dopamine

A neurotransmitter involved in reward, motivation, and motor control. Too much of this neurotransmitter is associated with addictive behaviors. Not enough is associated with Parkinson's.

electroencephalogram (EEG)

A recording of the electrical waves sweeping across the brain's surface, measured by electrodes placed on the scalp. Indicates presence/absence of activity but not specific location.

endocrine system

The body's "slow" chemical communication system, consisting of glands that secrete hormones into the bloodstream.

endorphins

Neurotransmitters that are natural painkillers produced by the brain. Reduces pain and enhances mood.

Nurture (environment)

Every nongenetic influence, from family & friends, to our culture, education, & experiences

eugenics

A controversial and unethical movement aimed at "improving" the genetic quality of the human population, leading to discrimination against certain groups of people.

Excitatory Neurotransmitter

A neurotransmitter that promotes the firing of neurons.

fMRI

A technique for revealing blood flow and, therefore, brain activity by comparing successive MRI scans. Shows both presence/absence of activity as well as the specific location of the activity.

fraternal (dizygotic) twins

Twins who develop from separate eggs and are no more similar genetically than non-twin siblings.

frontal lobes

The portion of the cerebral cortex lying just behind the forehead, involved in planning and judgment.

GABA

The main inhibitory neurotransmitter in the brain.

glial cells

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

Glutamate

The main excitatory neurotransmitter in the brain.

hallucinogens

Drugs that alter perception and cause hallucinations or profound distortions in a person's perceptions of reality, such as marijuana.

Nature (heredity)

The genetic transmission of characteristics from parents to offspring.

Heroin

An opioid drug that produces intense euphoria and pain relief, highly addictive.

hippocampus

A neural center located in the limbic system that helps process explicit memories for storage.

hormones

Chemical messengers produced by the endocrine glands and circulated in the bloodstream, regulating the activity of target cells or organs.

hypnagogic sensations

Sensations experienced during the transition from wakefulness to sleep (Stage 1), including hallucinations, muscle jerks, and sensations of falling.

hypothalamus

A neural structure lying below the thalamus, regulating bodily functions such as hunger, thirst, body temperature, and sexual behavior, and controlling the pituitary gland.

identical (monozygotic) twins

Twins who develop from a single fertilized egg that splits in two, creating two genetically identical organisms.

Inhibitory Neurotransmitter

A neurotransmitter that inhibits the firing of neurons.

insomnia

Persistent problems falling asleep or staying asleep.

interneurons

Neurons within the brain and spinal cord that communicate internally and intervene between the sensory inputs and motor outputs.

Jet Lag

A temporary sleep disorder that occurs when a person's internal body clock (circadian rhythm) is out of sync with the time zone they are in.

limbic system

A set of structures in the brain, including the amygdala, hypothalamus, and hippocampus, involved in emotion, motivation, and memory.

Marijuana

A drug containing THC that alters mood, perception, and cognitive function. Example of a hallucinogen.

medulla

The base of the brainstem, controlling heartbeat and breathing.

motor neurons

Neurons that carry outgoing information from the brain and spinal cord to the muscles and glands.

motor cortex

An area at the rear of the frontal lobes that controls voluntary movements.

Multiple Sclerosis

A disease in which the immune system attacks the protective covering of nerves (myelin), leading to communication problems (slowed or blocked transmission) between the brain and the rest of the body.

Myasthenia Gravis

An autoimmune disorder that affects communication between nerves and muscles, leading to muscle weakness. Attacks acetylcholine receptors.

myelin

A fatty tissue layer that encases the axons of some neurons, speeding up the neural impulses.

narcolepsy

A sleep disorder characterized by uncontrollable sleep attacks, often triggered by strong emotions.

natural selection

The principle that heritable traits that better enable an organism to survive and reproduce in a particular environment will most likely be passed on to succeeding generations.

nature-nurture issue

The debate over the relative contributions of genetic inheritance and environmental factors to human development.

nervous system

The body's speedy, electrochemical communication network, consisting of all the nerve cells of the peripheral and central nervous systems.

neurogenesis

The formation of new neurons.

neuron

A nerve cell; the basic building block of the nervous system.

Brain Plasticity (neuroplasticity)

The brain's ability to reorganize itself by forming new neural connections throughout life, particularly in response to learning, experience, or injury.

neurotransmitters

Chemical messengers that transmit signals across the synaptic gap between neurons.

Norepinephrine

A neurotransmitter involved in arousal and alertness (fight or flight response).

NREM sleep

Non-Rapid Eye Movement sleep; the sleep stages (1-3) characterized by slow brain waves, relaxed muscles, and decreased heart rate and breathing.

occipital lobes

Regions of the cerebral cortex located at the back of the brain, responsible for processing visual information.

opioids

A class of drugs that act on opioid receptors to produce morphine-like effects, including pain relief and feelings of euphoria.

parasympathetic nervous system

The division of the autonomic nervous system that calms the body, conserving its energy and promoting rest and digestion.

parietal lobes

Regions of the cerebral cortex located at the top of the brain, responsible for processing sensory information such as touch and spatial awareness.

peripheral nervous system

The sensory and motor neurons that connect the central nervous system to the rest of the body, transmitting information to and from the brain and spinal cord.

Pituitary Gland

The "master gland" of the endocrine system that regulates other glands and controls various bodily functions. Controlled by the hypothalamus.

Plasticity

The brain's ability to change and adapt as a result of experience.

psychoactive drug

A chemical substance that alters perception, mood, consciousness, cognition, or behavior.

Reflex Arc

The neural pathway that controls an instant reflex action. Simple example of relationship between sensory neurons, interneurons, and motor neurons.

refractory period

A brief period after a neuron has fired during which it cannot generate another action potential.

REM rebound

The tendency for REM sleep to increase following REM sleep deprivation.

REM sleep

Rapid Eye Movement sleep; a stage of sleep characterized by rapid eye movements, vivid dreams, and muscle paralysis. Also known as paradoxical sleep.

REM sleep behavior disorder

A sleep disorder characterized by the acting out of violent or dramatic dreams during REM sleep (body is not paralyzed like its supposed to be).

Resting Potential

The electrical charge of a neuron when it is not active.

reticular formation

A network of neurons running through the core of the brainstem, involved in controlling arousal and attention. Contains the Reticular Activating System.

reuptake

The reabsorption of neurotransmitters by the sending neuron after they have been released into the synaptic gap.

Reuptake Inhibitors

Medications that block the reabsorption of neurotransmitters into neurons, increasing their levels in the brain by keeping them in the synapse.

sensory neurons

Neurons that carry incoming information from the sensory receptors to the brain and spinal cord.

Serotonin

A neurotransmitter that affects mood (well-being & happiness), appetite, and sleep. Not enough of this neurotransmitter is associated with depression.

sleep

A natural state of rest for the body and mind, characterized by altered consciousness, reduced sensory activity, and inactivity of nearly all voluntary muscles.

sleep apnea

A sleep disorder characterized by pauses in breathing or shallow breaths during sleep, leading to disrupted sleep and daytime fatigue.

somatic nervous system

The division of the peripheral nervous system that controls the body's skeletal muscles (voluntary movement)

somatosensory cortex

A brain region located in the parietal lobe that processes sensory information from the skin and internal body receptors for touch, temperature, and body position.

Somnambulism

A disorder in which a person walks or performs other complex behaviors while asleep (occurs during NREM 3).

split brain procedure

A surgical procedure that involves severing the corpus callosum, the bundle of nerve fibers connecting the brain's hemispheres, typically done to treat severe epilepsy.

stimulants

Drugs that excite neural activity and speed up body functions, such as caffeine & cocaine

Substance P

A neurotransmitter involved in the transmission of pain signals. Too much of this neurotransmitter is associated with chronic pain.

suprachiasmatic nucleus

A tiny region of the hypothalamus that acts as the body's internal clock, regulating circadian rhythms such as the sleep-wake cycle.

sympathetic nervous system

The division of the autonomic nervous system that mobilizes the body's resources during stress and emergencies, preparing the body for "fight or flight" responses.