Test Flashcards
The nervous system
A communication network consisting of the nerve cells(neurons) that carry messages both to and from the brain and spinal cord to other parts of the body
Neuroscientists
Study the Brian and the rest of the nervous system in hopes of gaining a better understanding of Normal and abnormal behavior ( consciousness, perception, memory, emotion, stress)
Nervous system functions
- gather and process information
- produce responses to stimuli
- coordinate the workings of the different cells
Central nervous system
- Brian (in the skull)
- spinal cord ( in the spine)
Peripheral nervous system (PNS)
- located outside of the skull and spine
- sensory and motor nerves
CNS
Receives, processes, interprets and stores incoming sensory info
Spinal cord
A collection of neurons and supportive tissue running from the base of the brain down the center of the back
Spinal reflexes
Automatic require no conscious effort ( touching a hot stove )
PSN
Brings sensory information into the CNS and carries motor signals out
Somatic nervous system
Voluntary control of body movements ( nerves connected to sensory receptors and skeletal muscles)
Autonomic nervous system
Involuntary control of visceral functions ( heart rate, digestion, breathing )
- ) sympathetic nervous system
- ) parasympathetic nervous system
Sympathetic nervous system
- Quick response, mobilizing system arousal
- flight or fight
- expend energy
- thoracic and lumbar
Parasympathetic nervous system
- Slowly activated dampening system relaxation
- rest and store
- conserve energy
- cranial and sacral
Neurons
Specialized cells for the receptor, conduction and transmission of electrochemical signals
Glia
Cells that provide support,nurture, and insulate neurons, remove debris when neurons die, enhance the formation and maintenance of neural connections, and modify neuronal functioning
Sensory neurons
Carry incoming information from the sense receptors to the CNS
Motor neurons
Carry outgoing information from the CNS to muscles, glands and organs
Interneurons
Connect the 2 neurons
Cell body
Life support center
Dendrites
Receives messages from other cells
Axon
Passes messages away from the cell body to other neurons, muscles, or glands
Neural impulse
Electrical signal traveling down the axon
Myelin sheath
Covers the axon of some neurons and helps speed neural impulses
Neurogenesis
Production of new neurons from immature stem cells
Stem cells
Immature cells that renew themselves and have the potential to develop into mature cells
Neural plasticity
The Brian’s ability to change and adapt in response to experience, through neurogenesis, or by reorganizing or growing new neural connections
- Brian can recover from damage
Threshold
When the excitatory signals minus the inhibitory signals exceed a minimum intensity(threshold) the neuron fires an action potential
Action potential
Brief change in electrical voltage that occurs between the inside and outside of an axon when a neuron is stimulated
-creates an electrical impulse
All or non response
Intensity of an action potential remains same along length of the axon
Neurotransmitter
Chemical substance released by a transmitting neuron at the synapse and that alters the activity of a receiving neuron
- neurotransmitter released by vesicles in the axon terminal
- neurotransmitter enters synapse
Neurons communicate by:
- Neurotransmitter binds to specific receptors on the post synaptic cell that it fits ( lock and key)
- depending on the type of neurotransmitter, once it binds to the receptor it can have either and excitatory effect or an inhibitory effect on the postsynaptic cell
Acetylcholine
Neurotransmitter used by the spinal cord neurons to control muscles and by many neurons in the Brian to regulate memory
Dopamine
Produces feelings of pleasure when released by the brain reward system
Gamma-aminobutyric (GABA)
Inhibitory neurotransmitter in the brain
Glutamate
Excitatory neurotransmitter in the Brian
Norepinephrine
Hormones, fight or flight response
Serotonin
Mood, appetite, and sensory perception, pain pathways ,sleepy
Endocrine system
Release hormones into the bloodstream
- secreted by glands that affect the functioning of other organs( regulating growth, metabolism, sexual development)
- long distance messengers
Melatonin
Regulates daily biological rhythms
Oxytocin
Secreted by the pituitary gland; enhances uterine contractions during childbirth, facilitates ejection of milk during nursing
Adrenal hormones
Involved in emotions and stress ( cortisol, epinephrine and norepinephrine
Sex hormones
Regulate development and functioning of reproductive organs ( androgens, estrogens and progesterone)
Pons
Involved in sleeping, waking and dreaming
Medulla
Responsible automatic functions ( breathing and heart rate )
Reticular activating system
- dense network of neurons
- arouses the cortex and screens incoming information
The cerebellum
- regulates movement and balance
- involved in remembering simple skills and acquired reflexes
- problem solving and understanding words
Thalamus
-relays sensory messages to the cerebral cortex-includes all sensory messages except those from olfactory bulb
Limbic system
A group of brain areas involved in emotional reaction and motivated behavior
- hypothalamus
- hippocampus
- amygdala
Hypothalamus
- involved in emotions and drives vital to survival (hunger, thirst)
- regulates autonomic nervous system
- helps govern endocrine system (pituitary gland)
Amygdala
- responsible for arousal
- regulation of emotion, initial emotional response to sensory information
- plays important role in mediating anxiety , depression, and emotional memory
Hippopotamus
- storage of new information in memory
- comparing sensory Information with what the brain expects about the world
- enabling us to form spatial memories for navigating the environment
Cerebrum
- largest Brian structure; 2 cerebral hemispheres connected by the corpus callosum( bunde of nerve fibers connecting the 2 cerebral hemisphere)
- in charge of most sensory, motor , and cognitive processes
- surrounded by cerebral cortex and collection of several thin layers of cells (gray matter)
Occipital lobes ( contain visual cortex)
Contains visuals cortex
Parietal lobes (somatosensory cortex)
Pressure , pain, touch, and temperature
Temporal lobes ( auditory cortex)
- memory , perception, and emotion
- left Kobe : wernicke’s area ( language comprehension)
Frontal lobes ( motor cortex)
- emotion, planning , creative thinking, and take initiative
- left lobe: Broca’s area ( speech production)
Consciousness
Our awareness of ourselves and the environment
- learning , reading , watching tv
Biological rhythms
Periodic somewhat regular fluctuations in biological systems
Internal rhythms
Endogenous
External rhythms
Exogenous
Circadian rhythms
- once about every 24 hours
- sleep-wake cycle
Infradian rhythms
- occurs less frequently than once a day ( more than 24 hours )
- women’s period
Ultradian rhythms
- occurs more frequently than once a day( shorter than 24 hours)
- hormone fluctuations
The body’s clock
• cicadian rhythm controlled by biological clock in Suprachiasmatic Nucleus (SCN)
- cluster of cells located in the hypothalamus
-regulates levels of melatonin secreted by pineal glad
~ melatonin induces sleep and helps biological clock keep phase with light and dark cycle
Internal desynchronization
- a state in which biological rhythms are not in phase with one another
- changes in your normal routines can cause desynchronization
- may occur in response to jet lag, rotating shift work
Seasonal affective disorder (SAD)
- controversial disorder in which a person experiences depression during winter and an improvement of mood in the spring
- treatments may involve phototherapy or exposure to fluorescent light
Premenstrual syndrome (PMS)
Vague cluster of physical or emotional symptoms associated with the days preceding menstruation that was labeled as an illness
- cramps
- irritability
Unconsciousness
Lack of awareness of one’s surroundings or loss of consciousness ( sleeping and dreaming )
Deep unconsciousness
Complete loss of consciousness
- anesthesia
Altered states of consciousness
State of awareness that differ from one’s usual waking state ( hypnosis, drug use)
Rapid eye movement
Characterized by eye movement, loss of muscle tone , and dreaming
Non -rem sleep
Characterized by fewer eye movements than in REM
- divided into 4 stages with different brain waves
- relaxed brain associated with aloha waves
Stage 1:
Feel on the edge of consciousness (alpha waves) light sleep
Stage 2:
Presence of sleep spindles; minor noises won’t disturb you
Stage 3:
Delta waves begin; breathing and pulse have slowed down; hard to be awaken
Stage 4:
Delta waves predominant; deep sleep ; most likely stage for sleepwalking ( 30-40 min to reach)
REM:
Increased eye movement, increased respiration and heart rate, loss of muscle tone , dreaming ( last on average of 20 mins)
Why we sleep
• exact function of sleep unclear but allows for certain processes to occur
- body eliminates waste products from muscles
- repairs cells
- conserves and replenishes energy stores
- strengthens immune system
- recovers abilities lost during the day
- necessary for normal mental functioning
Chronic sleep deprivation
Increased cortisol levels which can impair neurons involved in learning and memory
Chronic insomnia
Difficulty falling asleep or staying asleep; about 10% of adults have this
Sleep apnea
Disorder in which breathing briefly stops during sleep, causing person to choke and gasp and momentarily awaken
Narcolepsy
Disorder involving sudden and unpredictable day time attacks of sleepiness or lapses into REM sleep ( can last 5-30mins)
-maybe caused by degeneration of neurons in the hypothalamus
REM behavior disorder
Muscle paralysis associated with REM sleep does not occur , sleep (mostly males ) may “act out” their dreams
Benefits of sleep: memory consolidation
Process by which the synaptic changes associated with the recently stored memories become durable and stable, causing memory to become more reliable
Psychoactive drug
A substance that alters perception, mood, thinking, memory , or behavior by changing the body’s biochemistry
1.) stimulants
•drugs that speed up activity in the CNS
-feelings of excitement, confidence , euphoria
- increased doses can result in jittering , anxiety, hyper-alertness, convulsions, heart failure , and death
Ex: nicotine, caffeine
2.) depressants
-drugs that slow down activity in the CNS
• feel calm and drowsy, reduce guilt , anxiety and tension
•enhance activity of GABA
•very kings can result in irregular heartbeats, convulsions, death
EX: alcohol, tranquilizer)
3.) opiates
- drugs , derived from opium poopy , that relieve pain and commonly produce euphoria
• can enhance transmission of dopamine
EX: heroin, morphine
4.) psychedelic drugs
Drugs that produce hallucinations, change thought processes or disrupt the normal perception of time and space
Ex: LSD , mescaline
Anabolic steroids
Synthetic derivatives of testosterone that are taken by pill or injection; used to increase muscle mass and strength
Marijuana
Contains tetrahydrocannabinol (THC) related to mild euphoria , relaxation, intense sensations and reduced pain and various cognitive deficits - used medically to reduce nausea for chemo and seizures
Physiology of drug effects
•psychoactive drugs produce their effects by acting on brain neurotransmitter
- increased/ decrease release of NT
- prevent reabsorption of excess NT
- block effects of NT on receiving cells
- bind to receptors that would ordinarily be triggered by NT
Sensation
The detection, by sense organs, of physical energy emitted or reflected by physical objects
- Brian receives input from the sensory organs
Perception
The process by which the brain organizes and interprets sensory information
- the brain makes sense out of the input from sensory organs
Reception
Stimulation of sensory receptors by energy
Transduction
Transforming physical energy into electrical energy
Transmission
Delivering neural information to the brain
Physical stimulus
•energy that produces a response in a sense organ
-light , sound , texture , odor
Sensory receptors
Specialized cells that detect and convert physical energy in the environment or the body to electrical energy that can be transmitted as nerve impulses to the brain
Photoreceptors
Light
Chemoreceptors
Taste and smell
Mechanoreceptors
Touch and pressure
Thermoreceptors
Temperatures
Nociceptors
Pain
Electroreceptors
Electrical currents
Magneto receptors
Magnetic fields
Anatomical coding
Doctrine of specific nerve energies statuses that different sensory modalities exist because signals received by the sense organs stimulate different nerve pathways leading to different areas of the brain
Functional coding
- particular receptors fore or are inhibited in the presence of certain stimuli
- codes relate to which cells , how many and the rate and pattern of firing
Bottom - up processing
Taking sensory information, integrating it, and sending it to the brain for interpretation
Top- down processing
Using models ideas and expectations to interpret sensory information
Sensory adaptation
The reduction or disappearance of sensory responsiveness when stimulation is unchanging or repetitious
Sensory overload
Overstimulation of the senses
Selective attention
The focusing of attention on selected aspects of the environment and the blocking out of others
Inattentional blindness
-failure to consciously perceive something you are looking at because you are not attending to it
Hue
Dimension of visual experience specified by color names and related to the wavelength of light 400 nm- 700 nm
Brightness
Lightness or luminance; dimension of visual experience related to the amount (intensity) of light emitted from or reflected by an object
Saturation
Vividness or purity of color; dimension of visual experience related to the complexity of light waves
Cornea
Protects the eye and bends incoming light rays toward a lens
Lens
Becomes more of less curved to focus light on objects
Iris
Gives eye it’s color
Pupil
I round opening of the eye
Fovea
Center of retina ( vision is sharpest here)
Retina
Neural tissues lining the back of the eyeball’s interior , which contains the receptors for vision
Rods
Visual receptors that respond to dim light
Comes
Visual receptors involved in color vision
Ganglion cells
Neurons in the retina , which gather information from receptor cells ( bipolar cells)
Trichromatic theory ( young -helmholtz)
•theory of color perception that processes 3 mechanisms in the visual system , each sensitive to a certain range of wavelengths
Opponent - process theory
A theory of color perception that assumes that the visual system treats pair of color as opposing or antagonistic
