Biological Bases of Behavior and Brain Function

Flashcards based on the biological bases of behavior, brain structure and function, hormones, neurotransmitters, and sensory perception.

Nature

Genetics and biology’s role in shaping behavior and traits.

Nurture

The environment and experience shaping behavior, not biological inheritance.

Central nervous system (CNS)

Brain and spinal cord; the body's command center.

Peripheral nervous system (PNS)

Connects CNS to limbs and organs; controls input and output.

Somatic nervous system

Controls voluntary muscle movement and sensory information processing.

Autonomic nervous system

Regulates involuntary functions like heartbeat, breathing, and digestion.

Action potential

Neural impulse firing; electrical signal traveling down the axon.

All or nothing principle

Neuron either fires completely or doesn’t fire at all.

Depolarization

Positive ions rush in, making the neuron more likely to fire.

Refractory period

After firing, a neuron briefly cannot fire again immediately.

Resting potential

State of a polarized neuron; ready to fire when stimulated.

Threshold

Minimum stimulation needed for a neuron to fire.

Acetylcholine

Neurotransmitter for muscle movement, memory, and learning; linked with Alzheimer’s.

Dopamine

Neurotransmitter involved in pleasure, movement, and attention; linked with Parkinson’s.

Serotonin

Affects mood, hunger, and sleep; low levels linked to depression.

Norepinephrine

Controls alertness and arousal; linked to the fight-or-flight response.

GABA

Inhibitory neurotransmitter that calms activity; low levels can cause seizures.

Glutamate

Excitatory neurotransmitter involved in memory; excess can cause migraines.

Endorphins

Natural painkillers that reduce pain and increase pleasure during stress.

Substance P

Neurotransmitter involved in pain perception and transmission.

Frontal lobe

Controls thinking, planning, speaking, movement, and decision-making.

Parietal lobe

Processes touch, spatial awareness, and sensory information.

Temporal lobe

Processes sound, language comprehension, memory, and auditory information.

Occipital lobe

Visual processing center located at the back of the brain.

Cerebellum

Coordinates balance, movement, and motor control.

Thalamus

Sensory relay station between the body and the cerebral cortex.

Pituitary gland

Master gland controlling hormones and activities of other glands.

Hypothalamus

Regulates hunger, thirst, temperature, and the endocrine system.

Pons

Relays information, regulates sleep, and controls facial expressions.

Medulla

Controls heartbeat, breathing, and other vital involuntary functions.

Cerebral cortex

Outer layer of the brain; handles thinking, sensation, and decisions.

Corpus callosum

Connects the right and left brain hemispheres, allowing communication.

Adrenaline

Hormone that increases heart rate and energy during stress.

Melatonin

Hormone that regulates sleep-wake cycles and drowsiness.

Oxytocin

Promotes bonding, love, trust, and social connections.

Split brain

Condition resulting from a severed corpus callosum limiting hemispheres’ communication.

Brain plasticity

The brain’s ability to reorganize and adapt after injury.

Narcolepsy

Sleep disorder causing sudden, uncontrollable sleep attacks.

Sleep apnea

Breathing stops during sleep, causing repeated awakenings.

Insomnia

Persistent difficulty falling or staying asleep.

Somnambulism

Sleepwalking, occurring during deep NREM sleep.

REM sleep behavior disorder

Condition where individuals act out their dreams during REM sleep.

Absolute threshold

Minimum stimulus needed to detect a sensation 50% of the time.

Difference threshold

Smallest detectable difference between two stimuli.

Cornea

The eye’s outer layer; protects and bends incoming light.

Pupil

Opening controlling how much light enters the eye.

Lens

Focuses light onto the retina for clear vision.

Retina

Light-sensitive layer in the eye where images are processed.

Fovea

Central point of the retina; responsible for sharpest visual focus.

Optic nerve

Carries visual information from the eye to the brain.

Bipolar cells

Relay signals from rods and cones to ganglion cells.

Ganglion cells

Receive signals and send information to the optic nerve.

Rods

Photoreceptors that detect black, white, and low light; peripheral vision.

Cones

Photoreceptors that detect color and fine detail in bright light.

Sensory adaptation

Reduced sensitivity to a stimulus after constant exposure.

Habituation

Decreased response to a stimulus after repeated exposure.

Opponent process theory

Theory explaining afterimages and color vision through opposing retinal processes.

Trichromatic theory

Theory proposing three types of cones for red, green, and blue perception.

Dichromatism

Color blindness involving two functioning cone types.

Monochromatism

Complete color blindness; only one cone type is functional.

Monocular cues

Depth cues using one eye, such as size and interposition.

Binocular cues

Depth perception utilizing both eyes, such as retinal disparity.

Place theory

Theory stating pitch is perceived based on the location of vibration on the cochlea.

Frequency theory

Theory suggesting pitch is based on the speed of neural impulses matching frequency.

Volley theory

Theory stating neurons fire in alternating groups to encode high-frequency sounds.

Olfaction

Sense of smell; processed in the olfactory bulb.

Pheromones

Chemical signals that unconsciously affect others’ behavior.

Gate control theory

Theory suggesting the spinal cord blocks or allows pain signals to pass.

Sensory interaction

Concept where senses influence each other’s perception and experience.

Semicircular canals

Inner ear structures that help maintain balance.

Vestibular system

System that regulates sense of balance, position, and spatial orientation.