Unit 1A: Biological Bases of Behavior

75 vocabulary flashcards covering key concepts, neuroanatomy, neurotransmitters, and sleep states from Unit 1A: Biological Bases of Behavior.

Heredity

The biological transmission of genetic traits and characteristics from parents to their offspring.

Evolutionary perspective

A psychological approach that focuses on how natural selection of traits has promoted the survival and adaptation of genes and behaviors over time.

Natural selection

The process by which inherited traits that provide a survival or reproductive advantage are more likely to be passed on to subsequent generations.

Eugenics

A set of beliefs and practices aimed at improving the genetic quality of a human population through selective breeding.

Central nervous system

The primary division of the nervous system consisting of the brain and spinal cord, responsible for processing sensory information and directing responses.

Peripheral nervous system

The sensory and motor neurons that connect the central nervous system to the rest of the body, including organs, muscles, and glands.

Autonomic nervous system

The part of the peripheral nervous system that controls involuntary bodily functions such as heart rate, digestion, and glandular activity.

Somatic nervous system

The division of the peripheral nervous system that controls voluntary movements of skeletal muscles and transmits sensory input to the central nervous system.

Sympathetic nervous system

The division of the autonomic nervous system that arouses the body and mobilizes its energy during stressful or emergency situations (fight-or-flight response).

Parasympathetic nervous system

The division of the autonomic nervous system that calms the body and conserves its energy during restful states (rest-and-digest response).

Glial cells

Non-neuronal cells in the nervous system that support, nourish, protect neurons, and produce the myelin sheath.

Reflex arc

A neural pathway that mediates an automatic reflex action, typically involving a sensory neuron, an interneuron in the spinal cord, and a motor neuron without initial brain involvement.

Sensory neurons

Afferent neurons that carry incoming sensory information from sensory receptors toward the central nervous system.

Motor neurons

Efferent neurons that carry outgoing information from the central nervous system to muscles and glands to execute movement or action.

Interneurons

Neurons located within the central nervous system that process information and communicate internally between sensory inputs and motor outputs.

All-or Nothing principle

The neurophysiological principle stating that a neuron either fires an action potential completely at maximum strength or does not fire at all.

Depolarization

The change within a neuron's membrane potential during an action potential, where positively charged sodium ions flow into the cell, making the internal charge less negative.

Refractory period

A brief resting pause after a neuron has fired, during which it cannot generate another action potential until it resets to resting potential.

Resting potential

The stable, negative electrical charge of a neuron's membrane when it is inactive, typically around $-70\text{ mV}$.

Reuptake

The process by which neurotransmitters released into the synaptic cleft are reabsorbed back into the sending presynaptic neuron.

Multiple sclerosis

A chronic autoimmune disease in which the immune system degrades the myelin sheath of neurons in the central nervous system, impairing signal transmission.

Myasthenia gravis

A chronic autoimmune neuromuscular disorder characterized by muscle weakness and rapid fatigue due to the breakdown of communication between nerves and muscles at acetylcholine receptor sites.

Dopamine

A key neurotransmitter associated with reward, motivation, pleasure, motor control, and reinforcement learning.

Serotonin

A neurotransmitter that influences mood, sleep, appetite, arousal, and emotional regulation.

Norepinephrine

A neurotransmitter and stress hormone that helps control alertness, arousal, and the body's fight-or-flight response.

Glutamate

The major excitatory neurotransmitter in the brain, essential for learning, memory, and synaptic plasticity.

GABA

Gamma-aminobutyric acid, the primary inhibitory neurotransmitter in the brain that reduces neuronal excitability.

Endorphins

Opiate-like neurotransmitters naturally produced by the brain to reduce perception of pain and elevate mood.

Acetylcholine

A major neurotransmitter involved in voluntary muscle contraction, memory formation, and attention.

Substance P

A neuropeptide involved in transmitting pain signals from peripheral nerves to the central nervous system.

Leptin

A protein hormone secreted by fat cells that acts on the hypothalamus to decrease hunger and signal satiety.

Ghrelin

A hunger-arousing hormone secreted by an empty stomach that signals the hypothalamus to stimulate appetite.

Melatonin

A hormone released by the pineal gland that regulates sleep-wake cycles and circadian rhythms in response to light and darkness.

Oxytocin

A hormone and neurotransmitter involved in social bonding, trust, maternal attachment, and uterine contractions during childbirth.

Agonist

A chemical or drug that binds to a receptor site of a neuron and mimics or increases the effects of a neurotransmitter.

Antagonist

A chemical or drug that binds to a receptor site and blocks or inhibits the normal action of a neurotransmitter.

Stimulants

Psychoactive drugs (such as caffeine, nicotine, and amphetamines) that excite neural activity and speed up body functions.

Depressants

Psychoactive drugs (such as alcohol, barbiturates, and opiates) that reduce neural activity and slow down bodily functions.

Hallucinogens

Psychoactive drugs (such as LSD and psilocybin) that distort perceptions and evoke sensory images in the absence of real sensory input.

Medulla

The base of the brainstem that controls essential involuntary survival functions, including heart rate and breathing.

Reticular activating system

A network of nerve pathways in the brainstem that regulates sleep, arousal, alertness, and attention.

Cerebellum

The structure at the back of the brainstem that coordinates voluntary muscle movements, balance, posture, and procedural motor memory.

Cerebral cortex

The intricate outer layer of interconnected neural tissue covering the cerebral hemispheres, responsible for ultimate control and information-processing functions.

Limbic system

A neural structure group surrounding the brainstem (including hippocampus, amygdala, and hypothalamus) associated with emotions, drives, and memory processing.

Thalamus

The brain's sensory control center located on top of the brainstem, routing incoming sensory signals (except smell) to specific cerebral cortex regions.

Hypothalamus

A limbic structure lying below the thalamus that directs maintenance activities (eating, drinking, body temperature) and governs the endocrine system via the pituitary gland.

Pituitary gland

The endocrine system's most influential gland, controlled by the hypothalamus, which regulates growth and secretes hormones affecting other glands.

Hippocampus

A limbic structure crucial for processing explicit, declarative memories for long-term storage.

Amygdala

Two almond-shaped neural clusters in the limbic system linked to emotional processing, particularly fear and aggression.

Corpus callosum

The large band of neural axon fibers connecting the left and right cerebral hemispheres, enabling communication between them.

Occipital lobes

The lobes situated at the rear of the head containing the primary visual cortex, responsible for receiving and processing visual information.

Parietal lobes

The lobes located at the top and rear of the head containing the somatosensory cortex, responsible for processing bodily sensations like touch and position.

Temporal lobes

The lobes located above the ears containing the primary auditory cortex, involved in processing auditory information, speech comprehension, and memory.

Frontal lobes

The lobes behind the forehead involved in executive functions, reasoning, planning, judgment, movement, and emotional control.

Association areas

Areas of the cerebral cortex that connect sensory and motor areas to process information.

Somatosensory cortex

A region at the front of the parietal lobes that registers and processes bodily touch and movement sensations.

Motor cortex

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

Broca’s area/aphasia

Broca's area is a left frontal lobe region controlling language expression through speech production; Broca's aphasia involves difficulty producing spoken language while maintaining comprehension.

Wernicke’s area/aphasia

Wernicke's area is a left temporal lobe region involved in language comprehension; Wernicke's aphasia involves impaired language understanding and fluent but nonsensical speech production.

Brain plasticity

The brain's capacity to modify its neural connections and reorganize following experience, learning, or damage.

EEG

Electroencephalogram; an amplified recording of the waves of electrical activity sweeping across the brain's surface, measured by scalp electrodes.

fMRI

Functional magnetic resonance imaging; a technique for revealing blood flow and brain activity by comparing successive MRI scans to show brain function.

Left hemisphere

The cerebral hemisphere specialized in verbal tasks, sequential logic, mathematical calculations, and analytical thinking.

Right hemisphere

The cerebral hemisphere specialized in spatial perception, facial recognition, artistic creativity, and emotional interpretation.

N-REM 1-3

Non-rapid eye movement sleep stages ranging from stage $1$ light sleep to stage $3$ deep slow-wave sleep dominated by delta waves.

REM

Rapid eye movement sleep; a recurrent sleep stage characterized by vivid dreams, high brain activity, rapid eye movements, and physiological muscle paralysis.

Circadian rhythm

The biological clock that regulates bodily functions and behaviors on a repeating cycle of approximately $24\text{ hours}$.

Hypnogogic sensations

Involuntary, bizarre sensory experiences (such as feeling like falling or floating) occurring during the transition into stage $1$ N-REM sleep.

REM rebound

The observed increase in the proportion of REM sleep following periods of sleep deprivation.

Insomnia

A sleep disorder characterized by persistent problems in falling or staying asleep.

REM sleep behavior disorder

A sleep disorder in which the normal muscle paralysis accompanying REM sleep is absent, causing individuals to physically act out their dreams.

Sleep apnea

A sleep disorder characterized by temporary cessations of breathing during sleep and repeated momentary awakenings.

Narcolepsy

A neurological sleep disorder marked by uncontrollable daytime sleep attacks, where a person lapses directly into REM sleep.

Somnambulism

Sleepwalking; a sleep disorder occurring during deep stage $3$ N-REM sleep where individuals walk or perform complex behaviors while asleep.

Activation synthesis theory

The theory that dreams represent the brain's effort to synthesize and make sense of random neural activation originating from the brainstem during REM sleep.