Nuerons
a nerve cell, the basic building block of the nervous system, generate/conduct electric impulses
Afferent (Sensory) Neurons
send information from senses to the CNS, A for arriving, ex: touch hot stove; send info to brain
Efferent (Motor) Neurons
send info from CNS to body, E for exit, ex: moves arm from hot stove
Interneurons
internal communication within the CNS, intervene between sensory inputs and motor outputs, I for internal
Cell Body (Soma)
the cell's life support center
Terminal Branches
form junctions with other cells
Dendrite
the bushy, branching extensions of a neuron that receive messages and conduct impulses toward the cell body
Axon
the extension of a neuron, ending in branching terminal fibers, through which messages pass to other neurons or to muscles or glands
Myelin Sheath
an insulating layer covering an axon that allows for faster neural impulses, if damaged, impulses slow down
Multiple Sclerosis
results when myelin sheath degenerates, communication to muscle slows, with eventual loss of muscle control
Action Potential
a neural impulse, a brief electric charge that travels through a neuron allowing a neurotransmitter, or messenger, to exit the neuron an go to another neuron
Resting Potential
each neuron sits, or rests at a, positive outside/negative inside state
Depolarization
a message from another neuron causes the inside of the neuron to become positive as sodium starts to enter
Selective Permeability
the membrane letting in/shutting out certain ions
Repolarization
occurs right after the action potential as potassium moves out of the inside of the cell restoring the inside back to a negative charge
Refractory Period
a brief period that the neuron CANNOT fire until
Excitatory Signal
produce action potentials, like pushing a neuron's accelerator
Inhibitory Signal
prevent action potentials, like pushing a neuron's brake
Reuptake
sending neuron reabsorbs remaining, neurotransmitters in synapse, like a vacuum
Threshold
the amount of neurotransmitters that need to be received to trigger an action potential
Synapse
the junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron, "meeting point"
Synaptic Gap
the tiny gap at the synapse, axon terminal of one neuron is seperated from the receiving neuron by this gap
Glial Cells
"housekeeper" cells of nervous system, hold neurons in place, supply nutrients and oxygen to neurons, insulate neurons from each other, destroy and remove dead neurons
Neurotransmitters
chemical messengers that cross the synaptic gaps between neurons
Receptor Sites
a region of specialized membrane on the surface of a neuron that contains receptor molecules that receive and react with neurotransmitters
Endorphins
blocks pain signals and causes pleasure (addiction), too much pain medication could lead to lack of natural endorphin supply, ex: opiates mimicking endorphins
Acetylcholine (ACh)
muscle action, learning, memory, messenger at every junction between a motor neuron and skeletal muscle, lack of it can lead to Alzheimer's disease; paralyzed without it
Dopamine
attention, emotion (pleasure), voluntary motion, ex: eat sugar, causes you to feel good, too much leads to schizophrenia, too little could lead to Parkinson's disease
Serotonin
mood, hunger, sleep, arousal, lack of is linked to depression and anxiety disorders
GABA (glutamate)
inhibitory neurotransmitter, slows down brain activity, lack of linked to seizures, tremors, and insomnia
Agonist
mimic effects of neurotransmitters
ex: morphine mimics endorphins
Antagonist
block neurotransmitters from receptor sites, ex: curare blocks ACh
Nervous System
the body's speedy, electrochemical communication network, consisting of all the nerve cells of the peripheral and central nervous systems
Nerves
bundled axons that form neural "cables" connecting the CNS with muscles, glands, and sense organs
ex: optic nerve bundles 1 million axon fibers into a single cable carrying the messages each eye sends to the brain
Peripheral Nervous System (PNS)
the sensory and motor neurons that connect the CNS to the rest of the body
Somatic Nervous System
the division of the PNS that controls the body's skeletal muscles (skeletal nervous system)
ex: as you reach the bottom of a page while reading, your SNS will report to your brain the current state of your skeletal muscles and carry instructions back, triggering your hand to turn the page
Automatic Nervous System
the part of the PNS that controls the glands and muscles of the internal organs (such as the heart), ex: autopilot (operates on its own)
Sympathetic Nervous System
the division of the automatic nervous system that arouses the body, mobilizing its energy in stressful situations, ex: if something alarms, enrages, or challenges you, your sympathetic nervous system accelerates heart rate, raises blood pressure, slows digestion, raises blood sugar, and cools you with precipitation, making you alert and ready for action
Parasympathetic Nervous System
the division of the automatic nervous system that calms the body, conserving its energy, ex: decreases heart rate, lowers blood sugar, and so forth
Central Nervous System
the brain and spinal cord, communicates with the body's sensory receptors, muscles, and glands via PNS
Spinal Cord
an info highway connecting the PNS to the brain
ascending neural fibers send up sensory info, and descending fibers send back motor
control info
Reflexes
a simple, automatic response to a sensory stimulus
ex: knee jerk response
a simple spinal reflex pathway is composed of a single sensory neuron and a single motor neuron; often communicate through an interneuron
Endocrine System
the body's "slow" chemical communication system; a set of glands that secrete hormones into the bloodstream
Hormones
chemical messengers that are manufactured by the endocrine glands, travel through the bloodstream, and affect other tissues
ex: when they act on the brain, they influence our interest in sex, food, and aggression
Adrenal Glands
a pair of endocrine glands that sit just above the kidneys and secrete hormones (epinephrine and norepinephrine) that help arouse the body in times of stress.
Epinepherine
hormone that increases heart rate, blood pressure, and blood sugar, providing us with a surge of energy
Pituitary Gland
the endocrine system's most influential gland
ex: under brain's influence, the pituitary triggers your sex glands to release sex hormones; these in turn influence your brain and behavior
under the influence of the hypothalamus, the pituitary regulates growth and controls other endocrine glands, located in core of brain; controlled by hypothalamus
Lesion
tissue destruction; a brain lesion is a naturally or experimentally caused destruction of brain tissue
ex: scientists can selectively lesion (destroy) tiny clusters of normal or defective brain cells, leaving the surrounding tissue unharmed
Computerized Axial Tomography (CAT) Scan
creates an image of the brain using x ray
quick and cheap; grainy
Electroencephalogram (EEG)
detects general electrical brain waves emanating from the brain, ex: like humming of a car (you can tell if it doesn't sound right, but don't get info about individual parts)
used in sleep studies
Positron Emission Tomography (PET) Scan
shows neurons' consumption of radioactive glucose (contained in blood), areas of high consumption = high activity, shows function, but not structure
Magnetic Resonance Imaging (MRI)
uses magnetic field to determine density and location of brain material
structure of brain's soft tissue, not function, costly and timely; more detailed than CAT scan
Functional MRI (fMRI)
combines blood flow (PET) with structure (MRI)
shows us brain activity (function)
3D model
Brainstem
the oldest part and central core of the brain, beginning where the spinal cord swells as it enters the skull, responsible for automatic survival functions
Medulla
the base of the brainstem
controls heartbeat and breathing
Pons
just above the medulla
helps coordinate movements
Reticular Formation
a nerve network in the brainstem that plays an important role in controlling arousal
network of neurons that extends from spinal cord to thalamus
Thalamus
the brain's sensory switchboard, located ontop of brainstem, directs messages to the sensory receiving areas in the cortex and transmits replies to cerebellum and medulla, receives info from all senses except smell
Cerebellum
the "little brain" at the rear of the brainstem, functions include processing sensory input and coordinating movement output and balance, functions occur without any conscious effort
Limbic System
neural system, located below the cerebral hemispheres associated with emotions and drives
Hippocampus
processes memory
if we lose hippocampus, we are unable to process new memories of facts and episodes
Amygdala
two lima bean
linked to emotion, influence aggression and fear
Hypothalamus
a neural structure lying below the thalamus, directs several maintenence activities (eating, drinking, body temp), helps govern the endocrine system via the pituitary gland
"reward center" or "pleasure center"
linked to emotion and reward
Cerebral Cortex
thin gray
carries on thinking and perceiving
Lobes
each hemisphere is divided into 4 lobes which are geographic subdivision separated by fissures, or folds
Frontal Lobes
portion of the cerebral cortex lying just behind the forehead, involved in speaking and muscle movements, and in making plans and judgements, prefrontal cortex and motor cortex
Prefrontal Cortex
the cerebral cortex covering the front part of the frontal lobe, functions: focusing one's attention, predicting consequences of one's actions, impulse control, and planning for the future
Parietal Lobes
portion of the cerebral cortex lying at the top of the head
somatosensory cortex
toward the rear; receives sensory input for touch and body position
Occipital Lobes
portion of the cerebral cortex lying at the back of head, includes areas that receive info from the visual field, visual cortex
Temporal Lobes
portion of the cerebral cortex lying roughly above the ears, includes the auditory areas, each receiving info primarily from the opposite ear, auditory cortex
Cortical Areas
motor and sensory cortex
Motor Cortex
controls body movements, motor cortex in each hemisphere controls opposite side of body, located at rear of frontal lobes
Sensory Cortex
located at front of parietal lobes, processes body touch and movement sensations, parallel and just behind motor cortex
Association Areas
areas of the cerebral cortex that aren't involved in primary motor or sensory functions
involved in higher neural functions such as learning, remembering, thinking, and speaking
found in all 4 lobes
frontal: enable judgement, planning, and processing of new memories
parietal: enable mathematical and spatial reasoning
temporal: enables us to recognize faces
Neuroplasticity
brain's ability to change and reorganize itself in response to damage, brain "rewiring" itself, brain can't create new cells when damaged, but it can rewire
Neurogenesis
formation of new neurons
Hemispheric Specialization (lateralization)
brain's 2 sides serve differing functions
Corpus Callosum
the large band of neural fibers connecting the 2 brain hemispheres and carrying messages between them
Split Brain
a condition in which the two hemispheres of the brain are isolated by cutting the connecting fibers (mainly those of the corpus callosum) between them
Right Hemisphere
intuition, "reading" emotions, visual and spatial reasoning, creativity, motor control for left side, processes left side of visual field
Left Hemisphere
speech and language, logical reasoning, math skills, motor control for right sideprocesses right side of visual field
Chromosomes
threadlike structures made of DNA molecules that contain the genes, 23 from each parent
Genes
the biochemical units of heredity that make up the chromosomes, a segment of DNA capable of synthesizing a protein
can be active (expressed) or inactive
Genome
the complete instructions for making an organism, consisting of all the genetic material in that organism's chromosomes
Monoxygotic (Identical) Twins
twins who develop from a single fertilized egg that splits in 2, creating genetically identical organism
Fraternal Twins
twins who develop from separate fertilized eggs
they are genetically no closer than brothers and sisters, but they share a fetal environment
Temperament
a person's characteristic emotional reactivity and intensity, ex: infant's emotional excitability; whether reactive, intense, and fidgety, or easygoing, quiet, and placid
Heritability
the proportion of variation among individuals that we can attribute to genes the heritability of a trait may vary, depending of the range of populations and environments studied
Molecular Genetics
the subfield of biology that studies the molecular structure and function of genes
goal is to find some of the many genes that influence normal human traits, such as body weight, sexual orientation, and extraversion
explores the mechanisms that control gene expression
Evolutionary Psychology
the study of evolution of behavior and the mind, using principles of natural selection
focus on what makes us so alike as humans
Natural Selection
the principle that, among the range of inherited trait variations, those that lead to increased reproduction and survival will most likely be passed on to succeeding generations
Mutations
a random error in gene replication that leads to a change
X Chromosome
the sex chromosome found in both men and women
females have 2; males have 1
Y Chromosome
the sex chromosome found in only males
Testosterone
the most important of the male sex hormones, both males and females have it, but the additional testosterone in males stimulates the growth of the male sex organs in the fetus and the development of the male sex characteristics during puberty