unit 1 (biological bases of behavior)

glial cells

nervous-system cells that support neurons: provide structural integrity, insulate (myelin), supply nutrients, and manage waste

central nervous system (CNS)

the body’s decision maker, composed of the brain and spinal cord, and acting as the control center of the body

sensory neurons

carry messages from the body’s tissues and sensory receptors toward the brain/spinal cord for processing, called afferent nerves

motor neurons

carry instructions from the CNS toward the body’s muscles and glands, called efferent nerves

inter neurons

process and transmit information throughout the body, between motor neurons and sensory neurons

peripheral nervous system (PNS)

gathers information and transmits CNS messages throughout the body

somatic nervous system (SNS)

enables voluntary control of skeletal muscles and relays information to the brain from the body, utilizing efferent and afferent nerves

autonomic nervous system (ANS)

controls involuntary processes (heart rate, respiration, etc.), and it consists of the sympathetic nervous system and parasympathetic nervous system

sympathetic nervous system

arouses and expends energy (eccelerates heart rate, raises blood pressure, etc.), creating the fight-or-flight response

parasympathetic nervous system

conserves energy and calms the body (“rest-and-digest” functions)

neurons

specialized nervous-system cells that send and receive information through electrochemical signals

soma

the body of a neuron, responsible for maintaining the cell and keeping it functional

dendrites

“branch-like” extensions that receive messages from other neurons via the receptor sites found on the extensions; attached to the soma

axon

a long fiber extending from the neuron’s soma; responsible for carrying electrical impulses to other cells

myelin sheath

a fatty protective layer, produced by glial cells, surrounding the neuron’s axon

benefits of a myelin sheath

protects the nerve fiber from damage, insulates the axon, and speeds up neural messages

axon terminals

end of the axon branches, and they are also the parts of the neuron that meet with teh dendrites of another neuron

action potential

a brief electric charge that travels down the axon, and allows for the temporary inflow of positive ions into an axon’s fluid interior

threshold

a minimum requirement for the excitatory singal sent by a neuron in order for an action potential to be triggered

refractory period

a period of time when action potentials cannot occur until the axon is recharged and in resting potential

synapse

the meeting point between neurons

synaptic cleft

a microscopic space between the axon terminal of one neuron and the dendrite receptors of another neuron

neurotransmitters

chemicals released, when an action potential is triggered, that transmit messages between neurons and influence thoughts, emotions, and behaviors

excitatory neurotransmitter

makes an action potential more likely

inhibitory neurotransmitter

reduces the likelihood of an action potential

reuptake

the reabsorption of neurotransmitters by the sending neuron, after the electrochemical message is sent

glutamate

the main excitatory neurotransmitter that is essential for learning and memory

gamma-aminobutyric acid (GABA)

the primary inhibitory neurotransmitter, reducing CNS activity

dopamine

involved in reward, motivation, and motor control, impacting pleasure, attention, and movement

serotonin

regulates mood, appetite, and sleep, influencing emotional well-being and mental balance

norepinephrine

helps regulate altertness, arousal, and stress responses, aiding in focus and readiness

endorphins

natural painkillers and mood enchancers, reducing pain perception and promoting pleasure

subtance p

transmits pain signals, enhancing the perception of pain in response to injury or inflamation

acetylcholine

involved in learning, memory, and muscle activation, affecting both the brain and the body

hindbrain

the lowest section of the brain, where vital life functions are preferred; includes the brainstem (medulla and pons) and the cerebellum

medulla

controls the essential life-sustaining processes like breathing, heart rate, and blood pressure.

pons

regulation of breathing, involuntary actions, chewing, swallowing, secretion of salive, and tears

cerebellum

coordinates muscle movements, maintains balance, and supports procedural learning (i.e. riding a bike); located at the back of the brain

midbrain

responsible for motor control, sensory procressing, and wakefullness; is a connector between the hindbrain and the forebrain

reticular formation

the brain’s reward center that controls some voluntary movement and eye movement

forebrain

largest and most complex section of the brain; deals with advanced processing of sensory information, reasoning emotion, memory, voluntary, and planned movement

limbic system

loosely connected network of structures involved in emotions, motivations, memories, and other aspects of behavior

amygdala

enables aggression and fear

hypothalamus

directs maintanence activites (eating, drinking, and body temperature), helps govern the endocrine system, and is linked to emotion and reward

hippocampus

helps process conscious, explicit memories of facts and events for storage

thalamus

receives information from all the senses except smell, and routes that information to its corresponding brain regions; located atop the brainstem

cerebrum

the largest part of the brain, responsible for complex cognitive functions

cerebral cortex

the outer layer of the brain, what is considered to be the “wrinkles” in the brian

frontal lobes

enable linguistic processing, muscle movements, higher-order thinking, and executive functioning; located in the top of the brain, just behind the forehead

parietal lobes

receives sensory input for touch, pressure, temperature, pain, and body position; located on the top of the head towards the rear of the brain

temporal lobes

responsible for the sense of hearing, visual memory, emotion association, and language comprehension

occipital lobes

receive information from the visual fields; located in the rear of the brain towards the bottom of the head

motor cortex

controls voluntary skeletal movement; located at the rear of the frontal lobes

somatosensory cortex

registers and processes body, touch, and movement sensations; located at the front of the parietal lobes

prefrontal cortex

involved in the executive functions of the brain; located at the front of the frontal lobes

split brain research

achieved by severing the corpus callosum, and reveals that the right and left hemispheres of the brain specialize in different functions

left hemisphere of the brain

affects langauge comprehension (wernicke’s area) and speech production (broca’s area)

adrenaline

increases heart rate, blood pressure, and blood sugar

oxytocin

enables orgasm and provides social support in specific situations

ghrelin

arouses hunger in the body

leptin

suppresses hunger in the body

melatonin

induces sleep; found in the hypothalamus

NREM sleep

3 stages of sleep that decreases in duration throughout the cycle; however, the further into the stages that one is, the larger and slower the delta waves are in EEG scans

REM sleep

a period of sleep after stage 3 of NREM sleep where brain activity replicates that of a waking person, and rapid eye movements indicate the beginning of a dream

activation-synthesis theory

the belief that dreams are the brain’s way of making sense of random electrical signals created during REM sleep

consolidation theory

the theory that dreams are influenced by the consolidation of memories, storage into the brain for long-term use, that occurs during sleep

insomnia

recurring problems in falling or staying asleep

narcolepsy

sudden attacks of overwhelming sleepiness

REM sleep behavior disorder

acting out the content of dreams while asleep, including vocalizing or motor behaviors such as kicking or punching

sleep apnea

stopping breathing repeatedly while sleeping

somnambulism

repeated episodes of complex motor behavior, such as walking, while asleep (during stage 3 of NREM sleep)

weber’s law

two stimuli must differ by a constant minimum percentage in order for an average person to perceive a difference

hue

the color that humans experience, determined by light’s wavelength

intensity

the brightness of the color experienced, influenced by a light wave’s amplitude

cornea

the eye’s clear, protective outer layer, which bends light to help provide focus

pupil

an adjustable opening in the center of the eye through which light enters

iris

the colored muscle in the eye that controls the pupil’s size

lens

a transparent structure behind the pupil that changes shape to focus images on the retina

retina

a multilayered tissue lining the back inner surface of the eyeball

accommodation

the process by which the eye’s lens changes shape to focus images of near or far objects on the retina; when altered it produces nearsightedness and farsightedness

rods

detect black white, and gray and are sensitive to shapes and movement; mainly activated in low-light environments

cones

concentrated near the center of the retina (fovea) and detect fine detail and give rise to color sensations

trichromatic theory

the retina contains three different types (red, green, blue) of color receptors that, when stimulated in combination, can produce the perception of any color

opponent-process theory

the theory that opposing retinal processes enable color vison; impulses travel to the visual cortex and some neurons are turned on and off by opposing colors, thus the opposing colors will not “mix”, but the non-opposing colors can

pitch

a tone’s perceived highness or lowness, determined by a sound wave’s frequency

loudness

the perceived volume of a tone, determined by a sound wave’s amplitude

place theory

different pitches are determined because sound waves trigger activity at different places along the cochlea’s basilar membrane, thus determining a sound’s pitch by recognizing the specific place that is generating the neural signal

frequency theory

pitch is read by the brain’s monitoring of the frequency of neural impulses traveling via the auditory nerve

volley theory

neural cells alternate firing impulses in rapid sucession, promoting their ability to have a combined frequency above 1000 waves per second; an extention of the frequency theory

sound localization

sound waves stike one ear sooner and more intensely than the other, and the brain analyzes these differences to understand where the source of the sound is

conduction deafness

damage to the mechanical system that confucts sound waves to the choclea, causing hearing loss

sensoineural deafness

damage to the cochlea’s receptor cells or auditory nerve that causes hearing loss

pain

a biopsychosocial phenonmen that can vary widely throughout the world

gate control theory

small spinal cord nerve fibers conduct most pain signals, and an injury activates the small fibers and opens the gate. Thus, the pain signals can travel to your brain, but large-fiber activity can close the pain gate by blocking signals

phantom limb sensation

occurs when people who have lost limbs report sensation or pain where the limb used to be