Unit 1a unit test

Heredity

The genetic transmission of traits, characteristics, and behaviors from biological parents to offspring

Environment

All external, non-genetic conditions, surroundings, and experiences that influence an individual’s development and behavior

Genome

The complete set of genetic instructions contained within an organism’s DNA

Epigenetics

The study of environmental influences on gene expression (if genes are turned on or off)

Gene-environmental interaction

The dynamic process where genetic predispositions influence how an individual responds to their environment, and environmental factors that influence how genes are expressed

Central nervous system (CNS)

Composed of the brian and spinal chord, acts as the body’s primary control and processing center

Peripheral nervous system (PNS)

All nerves connecting the CNS to the rest of the body, responsible for gathering sensory information and sending motor commands

Sensory (afferent) neurons

Carry incoming sensory information from body tissues and sensory receptors toward the CNS

Motor (efferent) neurons

Carry outgoing instructions from the CNS away to muscles and glands

Interneurons

Neurons residing strictly within the CNS that process information internally between sensory input and motor output

Somatic nervous system

Division of the PNS controlling voluntary movements and conscious sensory input

Autonomic Nervous system (ANS)

Division of the PNS controlling involuntary internal organ and gland functions (heart rate, digestion)

Sympathetic nervous system

Fight or flight branch of the ANS, accelerates heart rate, sweaty palms, etc

Parasympathetic Nervous system

Rest and digest branch of the ANS, conserves body energy and returns body to a calm baseline, slows heart rate

Neuron

The basic building block of the nervous system, specialized for transmitting electrical and chemical messages across dendrites, the cell body, and the axon

Action potential

A brief electrical charge/impulse that travels down the axon of a neuron when triggered

Threshold

The minimal level of stimulation required to trigger an action potential (all or none)

Refractory period

A resting pause after a neuron fires, during which another action potential cannot occur until the neuron resets

Neurotransmitters

Chemical messengers that cross the synaptic gap between neurons to bind to receptor sites on the receiving neuron

Reuptake

The reabsorption of excess neurotransmitter molecules by the sending neurons terminal buttons after signal transmission

Endorphins

Endogenous (natural) opiate-like neurotransmitters linked to pain control and pleasure

Agonist

A chemical or drug that binds to a receptor and mimics or enhances the action of a neurotransmitter

Antagonist

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

Endocrine system

The body’s slow chemical communication system consisting of glands that secrete hormones into the bloodstream

Hormones

Chemical messengers manufactured by endocrine glands that travel through the blood and affect other tissues

Psychoactive drugs

Chemical substances that alter perception, mood, conciousness, or behavior

Depressants

Drugs that reduce neural activity and slow body functions

Barbiturates

Subcategory of depressants that decrease central nervous system activity, impairing memory and judgement

Opioids

Depressant drugs that relieve pain and depress neural activity

Stimulants

Drugs that excite neural activity and speed up bodily functions (caffeine, nicotine)

Hallucinogens

Psychedelic drugs that distort perceptions and evoke sensory images in the absence of sensory input

Twin studies

Research comparing identical twins (who share all DNA) and fraternal twins (who share half DNA) to estimate the relative influence of genes v.s environment

Family studies

Research examining family members to see how traits run in biological families v.s non-biological environments

Reflex arc

A fast, involuntary response pathway that bypasses the brain, carrying sensory input directly to the spinal chord interneurons

Glial Cells

Support cells in nervous system that nourish, protect, insulate myelin

Resting potential

The baseline electrical state of a neuron when it is not firing

Excitatory neurotransmitter

A chemical signal that increases the likelihood that the receiving neuron will fire an action potential

Inhibitory Neurotransmitter

A chemical signal that decreases the likelihood that the receiving neuron will fire an action potential

Biopsychosocial approach

explains human behavior and mental processes by analyzing the interaction of biological, psychological, and social-cultural factors

Neuroplasticity

The brain’s ability to adapt, reorganize, and form new neural connections in response to learning, experience, or recovery from injury

EEG

Measures electrical activity across the scalp using electrodes

MEG

Measures magnetic fields produced b y the brain’s natural electrical currents

Hindbrain

Oldest, lowest part managing basic survival functions like breathing, heart rate, and motor coordination

Midbrain

central segment that routes sensory inputs and aids in visual and auditory reflexes

Forebrain

largest, highest region controlling cognitive processing, emotions, sensory integration

Brainstem

Consisting of medulla and pons, responsible for automatic survival functions like heartbeat, respiration, and sleep regulation

Thalamus

The brain’s sensory control center located atop the brainstem, routing sensory (except smell) to cortical areas

Reticular formation

Nerve network running through the brainstem controlling arousal, alertness, and filtering sensory stimuli

Cerebellum

“little brain” rear of brainstem, responsible for coordinating voluntary movement, balance, memory, fine motor skills

Limbic system

Located below cerebral hemispheres associated with emotions, drives, and memory formation

Amygdala

processing emotions; fear and aggression

Hypothalamus

Below thalamus, regulates bodily maintenance drives (eating, drinking, body temp)

Hippocampus

Processing and consolidating memories

cerebral cortex

Neural tissue covering the cerebral hemispheres, serving as body’s ultimate control and info processing center

frontal lobes

involved in speaking, muscle movements, planning, judgement

motor cortex

controlling voluntary movements

Prefrontal cortex

high-level executive functions, decision making, personality expression

parietal lobes

top rear of head, houses somatosensory cortex to process touch, body position, and spatial awareness

occipital lobes

back of cerebral cortex containing visual cortex, receives and processes visual stimuli

temporal lobes

Above ears, containing auditory cortex, responsible for hearing, language comprehension, and memory retrieval

corpus callosum

large band of neural fibers connecting the left and right cerebral hemishperes, enabling communication between the,

Split brain

condition resulting from surgical severing of the corpus callosum, isolating the two hemispheres from communicating directly

conciousness

personal awareness of ourselves and external environment

dual processing

principle that info is simultaneously processed on separate conscious and unconscious tracks

parallel processing

processing many aspects of a problem or visual scene simultaneously

sequential processing

processing info one item or step at a time

sleep

periodic, natural, reversible state of altered consciousness characterized by reduced sensory activity and body movement.

circadian rhythm

body's internal biological clock that regulates physical and behavioral changes over a roughly 24-hour cycle.

REM

Rapid Eye Movement sleep, a stage marked by vivid dreaming, high brain activity, and muscle paralysis.

NREM

encompassing stages 1 through 3, marked by slowing brain waves, physical relaxation, and restorative physiological processes.

narcolepsy

uncontrollable, sudden sleep attacks directly into REM sleep during waking hours.

sleep apnea

A sleep disorder involving repeated, temporary pauses in breathing during sleep that cause frequent brief awakenings.

insomnia

A persistent difficulty in falling asleep, staying asleep, or achieving restful sleep.