Chapter 3 + 4 Flashcards
Structure of a Neuron
-Dendrites
-Cell Body (Soma)
-Axon
-Synapse
Dendrites
Receives information from other neurons and transmits towards the cell body
Cell Body (Soma)
Keeps neuron alive and determines whether it will fire
Axon
Extending fiber that conducts impulses away from the cell body and transmits to other cells
Parts of the Synapse
- Synaptic cleft
-Axon Terminals
-Synaptic vesicles
The 3 types of neurons
-Sensory
-Motor
-interneurons
Sensory neurons
Carry input messages from the sense organs to the spinal cord and brain
Motor neurons
Transmit impulses from the brain and spinal cord to the muscles and organs
Interneurons
Perform connective or associative functions in the nervous system
Glial Cells
-Surrounds neurons and hold them in place
-Manufacture nutrient chemicals neurons need
-Absorb toxins and waste materials
-Facilitates communication
-enhances memory and learning
Glial cells - Astrocyte
Neural communication, improved thought and memory
Glial Cells - Oligodendrocyte
-Neurogenesis
-myelin sheath
Action potential
If a neuron reaches threshold, an AP is triggered
-usually around -55mV
-Triggered by stimulus or neurotransmitters
-ALL OR NONE: They do not partially fire
During AP what happens?
Positive ions flood into the axon, triggering a wave or positive charge down the axon
-Reaches a charge of +40mV
What happens during the absolute refractory period?
Neurons will not fire
what do excitatory do?
increase the charge
what do Inhibitory do?
decrease the charge
Myelin sheath
-Insulation layer covers axons in the brain and spinal cord
-Allows for high-speed conduction
Neurotransmitter
Chemical substance released by a transmitting neurons at the synapse and capable of affecting the activity of a receiving neuron
Breakdown - Deactivation of neurotransmitters
Other chemicals in the synapse break down neuro-transmitters into their chemical components
Reuptake - Deactivation of neurotransmitters
Neurotransmitters are taken back into the presynaptic axon terminal
Glutamate
-Main excitatory
-relay of sensory input and learning
memory, cognition, and mood regulation
GABA (gamma-aminobutyric acid)
Main inhibitory neurotransmitter
Acetylcholine
-Muscle contraction (PNS)
-Cortical arousal, selective attention and memory (CNS)
Monoamine neurotransmitters
-Norepinephrine
-Dopamine
-Serotonin
Norepinephrine
Cortical arousal
Dopamine
Motor function and reward
Serotonin
-Mood regulation
-Circadian rhythms
-aggression
Endorphins
-Neuropeptide
-Reduction of pain sensation
-Opiates
Anandamide
-Pain reduction
-Appetite arousal
-Motivation memory sleep
Melatonin
-Hormone
-Regulates daily biological rhythms
Adrenal Hormones
-Involved in emotions and stress
- Cortisol, epinephrine and norepinephrine
Sex Hormones
regulates development and functioning of reproductive organs
-Androgens, estrogens and progesterone
Endocrine glands
Release hormones into the bloodstream
Central nervous system
Brain and spinal cord
Peripheral Nervous system
connects the CNS with the muscles, glands, and sensory receptors
Somatic nervous system
-Peripheral nervous system
-Consists of sensory and motor neurons the bind together to create nerves to transmit messages to sensory receptors
Autonomic nervous system:
-Peripheral nervous system
-Controls glands and smooth muscles in bodily organs
-Sympathetic and parasympathetic nervous system
Sympathetic nervous system
Arouses the body
Parasympathetic nervous system
Slows down body processes
The Cerebral cortex
-In charge of most sensory, motor and cognitive processes
-Upper (outer) part of the brain divided into two cerebral hemispheres
Corpus callosum
Connects the two cerebral hemispheres in the brain
-millions of myelinated axons connecting the brains hemispheres
-provides a pathway for communication between hemispheres
-if surgically severed to treat epilepsy, hemispheres cannot communicate directly
Frontal lobe
-Executive functions, motor, language production, memory
motor cortex
Controls voluntary muscular movements
- In the frontal lobe
Broca’s Area
Involved in speech production
-in the frontal lobe
Parietal lobe
Physical perception - Touch, pain, temperature, taste
-Spatial perception
-Body perception
-Sensory-motor integration
-shifting attention
-number concepts
Somatosensory cortex
Receives sensory input for heat, touch, cold, balance and body ,movement
- In the parietal lobe
Occipital Lobe
Sight-Processing visual information
Temporal lobe
-Hearing - understanding language
-Autobiographical memory and integration of sensory information
Wernicke’s Area
involved in speech comprehension
- In the temporal lobe
Basal Ganglia
- 2 sets of structures
- Aid in movement control
- Create a motor action plan and communicate this to the motor cortex
Thalamus
Routes sensory information to higher brain structures
Limbic system
-Thalamus
-Includes all sensory messages except those from olfactory bulb
-Hypothalamus
Hypothalamus
-Major role in motivation and emotions
-connects with the endocrine system
-involved in pain/pleasure
Hypothalamus and pituitary gland
-Involved in emotions and drives vital to survival
- Fear, hunger thirst and reproduction
-Regulates autonomic nervous system
Pituitary gland
small endocrine gland which releases hormones and regulates other endocrine glands
Amygdala
Organizes emotional responses
what is Amygdala responsible for
-Arousal
-regulation of emotion
-the initial emotional response to sensory information
Amygdala plays an important role in
-Fear and fear recognition
-mediating anxiety and depression
-emotional memory
Cingulate cortex
-The limbic system
-Active during emotional expression
-contributes to social behavior
-Damage results in lack of empathy
Hippocampus
-The limbic system
-involved in forming memories
-spatial memories and navigation
-Plays a role in trauma (the integration of emotional significant and fearful memories)
What is the hippocampus responsible for?
-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
Cerebellum
Concerned with muscular movement, learning and memory
-regulates movement and balance
-involved in remembering simple skills and acquired reflexes
Cerebellum plays a part in
-analyzing sensory information
-solving problems
-understanding words
The midbrain
Reticular activating system
- Involved in brain arousal, sleep, and attention
Ascending - Reticular activating system
sends information to and alerts higher brain regions
Descending - Reticular activating system
Higher brain centers can admit or block sensory input
Medulla
-Plays role in vital body functions such as heart rate and breathing
-brain death
Pons
Carries nerve impulses from cortex to cerebellum and other lower parts of nervous system
Electroencephalogram (EEG)
A recording of neural activity detected by electrodes
Positron Emission Tomography (PET)
-Active areas have increased blood flow
-sensors detect radioactivity
-different tasks show distinct activity patterns
Chromosomes
rod-shaped structures within cells that carry genes
Genes
Functional units of heredity which are composed of DNA and specify the structure of proteins
Genotype
-Genetic makeup of an individual
- XX or XY
Phenotype
-Observable characteristics produced by genes
-Female or male
Dominant genes
if a person receives a dominant gene, he or she will display the characteristic the gene controls
Recessive genes
if the gene is recessive the characteristic will not be displayed unless its partner gene inherited from the other parent is also recessive
Adaption - Genetic
physical factors that results in increased ability to survive and breed
-shell, opposable thumb, long neck, physical attractiveness
Behavioral - Adaption
behaviors that result in increased ability to survive and breed
- Aggression, sociability
Heritability
-degree to which genes contribute to trait differences among individuals
- Expressed as a %
Heritability misunderstood
Heritability does NOT apply to individuals
-Differences among individuals
- Heights has heritability of 70 or 80 %, Your height does not
Traits with high heritability DO change
-Plants
Sensation
-The detection of physical energy emitted or reflected by physical objects
-it occurs when energy in the external environment or the body stimulates receptors in the sense organs
Perception
The process by which the brain organizes and interprets sensory information
Attention - Perception
-focusing on certain stimuli
-filtering out other information
Stimulus factors in attention
-Intensity
-Novelty
-repetition
-Contrast
-movement
Personal factors in attention
-Motives
-interests
Psychological and cultural influences on perception
-we are more likely to perceive something when we need it
-what we believe can affect what we perceive
- Emotions, such as fear can influence perception of sensory information
-Expectation based on our previous experiences influence how we perceive the world
-All are influenced by our culture
Perceptual set
What you see originally you’ll continue to see
EX: face vs woman (center image)
Sensory Adaptation
-The reduction of disappearance of sensory responsiveness when stimulation is unchanging or repetitious
-prevent us from having to continuously respond to unimportant information
Sensory deprivation
The absence of normal levels of sensory stimulation
Sensory overload
-Overstimulation of the sense
-can use selective attention to reduce sensory overload
Sclera
whites of the eye
Cornea
-protects eye and bends light towards lens
Lens
focuses on objects by changing shape
Iris
Controls amount of light that gets into the eye
Pupil
Widens or dilates to let in more light
Retina
-neural tissue at back of eye
-site or transduction
-rods and cones
Fovea
-Center of focus
-most cones
Blind spots
-Optic nerve leaves
-no rods or cones
Rods
Visual receptors that respond to dim light
-Black and white receptors
-more located on edge of retina
-sensitive to dim light
-less detail
Cones
Visual receptors involved in color vision
-color receptors
-located in Fovea
-More detailed
Transduction - vision
Absorption of light by photopigments produces a chemical reaction changing the rate of neurotransmitter release at the receptors synapse
-The greater the change in release, the stronger the signal passed into the optic nerve
Dark adaption
Photopigment molecules are regenerated increasing receptor sensitivity
-cones reach maximum sensitivity in 5 mins, rods take 30 mins
Trichromatic theory
-how we see color theory
-The eye detects 3 primary colors
-All other colors can be derived by combining these three
Opponent-process theory
-how we see color theory
-The visual system treats pairs of colors as opposing or antagonistic
-cells are inhibited by a color, and have a burst of activity when it is removed
Constructing the visual world
-Form perception
-depth and distance perception
-visual constancies
-visual illusions
visual constancies
-when seeing is believing
-The accurate perception of objects as stable or unchanged despite changes in the sensory patterns they produce
-shape constancy
-location constancy
-size constancy
-brightness constancy
-color constancy
Visual illusions
when seeing is misleading
Gestalt principle
-form perception
-describes the brains organization of sensory building blocks into meaningful units and patterns
-Proximity
-similarity
-closure (subjective contours)
-common movement
-figure ground relations
-continuity
Binocular cues
-Visual cues to depth or distance that require the use of both eyes
-convergence
-Retinal disparity
Convergence
-Binocular cue
Turning inward of the eyes, which occurs when they focus on a nearby object
Retinal Disparity
-Binocular cues
the slight difference in lateral separation between two objects as seen by the left eye and right eye
Monocular Cues
Visual cues to depth or distance that can be used by one eye alone
Color context
-the way you perceive a color depends on the color that surrounds it
Pitch
The dimension of auditory experience related to the frequency of a pressure wave
-the slower the wave the lower the pitch
-20Hz to 20 000 Hz is audible
Loudness
-the dimension of auditory experience related to the intensity of a pressure wave
-50 dB comfortable - normal conversation
-90 dB starts to do permanent effect on hearing
Timbre (TAM-bur)
the distinguishing quality of sound; the dimension auditory experience related to the complexity of the pressure wave
Outer Ear
-funnels sound
-Pinna
-Ear canal
-tympanic membrane
Middle ear
transmit sound
-ossicles
-hammer - anvil - stirrup
Inner ear
Converts vibration to neural signal
-cochlea
-basilar membrane
-organ of corti
-hair cells
Pitch perception
different tones excite different areas of the basilar membrane and primary auditory cortex
-high tones - place theory
-low tones -frequency theory, volley theory
Auditory localization
-sounds from different directions are not identical as they arrive at left and right ears
-loudness
-timing
-phase
-the brain calculates a sounds location by using these differences
Papillae
Knoblike elevations on the tongue, containing the taste buds
(singular: papilla)
Taste buds
nest of taste-receptors cells
What are the 5 basic tastes
salty
sour
bitter
sweet
umami (meaty)
reasons for different taste in different people
-genetics
-culture
-learning
-food attractiveness
smell
airborne chemical molecules enter the nose and circulate through the nasal cavity
- vapors can also enter through the mouth and pass into nasal cavity
-receptors on the roof of the nasal cavity detect the molecules
Pheromones
odorless chemicals that serve a social signal to members of one species
taste and smell - emotions
facial expressions when eating etc
Touch
specialized nerve endings
-identify specific sensation
-mechanoreceptors
-light touch
-deep pressure
-Identify several sensation
-pain
-touch
-temperature
kinesthesis
the sense of body position and movement of body parts
Equilibrium
The sense of balance
Proprioceptors
-muscle sketch receptors
-tendon force detectors
-info travels to somatosensory and motor cortices
Semicircular canal (inner ear)
-3 fluid-filled canals responsible for our sense of balance
-Otoliths
-info travels to brain stem and cerebellum
Otoliths
tiny crystals sense linear movement and gravity
