Unit 3 Flashcards
Neuron
A nerve cell, the basic building block of the nervous system
Cell body
The part of a neuron that contains the nucleus; the cells life-support center
Dendrites
A neuron’s often bushy, branching extensions that receive and integrate messages, conducting the impulses toward the cell body
Axon
The neuron extension that passes messages through its branches to other neurons or to muscles or glands
Myelin Sheeth
A fatty tissue layer segmentally encasing the axons of some neurons; enables vastly greater transmission speed as neural impulses hop from one node to the next
Glial Cells
Cells in the nervous system that support, nourish, and protect neurons; they also play a role in learning, thinking, and memory
Action Potential
A neural impulse; a brief electrical charge that travels down an axon
Threshold
The level of stimulation requires to trigger a neural impulse
Refractory period
In neural processing, a brief resting pause that occurs after a neuron has fired; subsequent action potentials cannot occur until the axon returns to its resting state.
All-or-none response
Neurons reaction of either firing (with a full-strength response) or not firing
Synapse
The junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron. The tiny gap at this junction is called the synaptic gap or the synaptic cleft
Neurotransmitters
Chemical messengers that cross the synaptic gaps between neurons. when released by the sending neuron, neurotransmitters travel across the synapse and bind to receptor sites on the receiving neuron, thereby influencing whether that neuron will generate a neural impulse.
Reuptake
A neurotransmitter’s reabsorption by the sending neuron
Endorphins
“Morphine within” - natural opiate like neurotransmitters linked to pain control and to pleasure
Agonist
A molecule that increases a neurotransmitter’s action
Antagonist
A molecule that inhibits or blocks a neurotransmitter’s action
Nervous system
The body’s speedy, electrochemical, communication network, consisting of all the nerve cells of the peripheral and central nervous systems.
Central nervous system (CNS)
The brain and the spinal chord
Peripheral Nervous system (PNS)
Th sensory and motor neurons that connect to the central nervous system (CNS) to the rest of the body
Nerves
Bundled axons that form neural cables connecting the central nervous system with muscles, glands, and sense organs
Sensory (afferent) neurons
Neurons that carry incoming information from the body’s tissues and sensory receptors to the brain and spinal chord
Motor (efferent) neurons
Neurons that carry outgoing information from the brain and spinal cord to the muscles and glands
Interneurons
Neurons within the brain and spinal cord; they communicate internally and process information between the sensory inputs and motor outputs
Somatic Nervous System
The division of the peripheral nervous system that controls the body’s skeletal muscles also called the skeletal nervous system
Autonomic nervous system
The part of the peripheral nervous system (PNS) that controls the glands and the muscles of the internal organs (heart) its sympathetic divisions arouses; its parasympathetic division calms
Sympathetic Nervous System
The division of the autonomic nervous system that arouses the body, mobilizing its energy
Parasympathetic Nervous System
The division of the autonomic nervous system that calms the body, conserving its energy
Reflex
A simple, autonomic response to a sensory stimulus, such as the knee-jerk response
Endocrine system
The body’s “slow” chemical communication system; a set of glands that secrete hormones into the bloodstream
Lesion
Tissue destruction. A brain lesion is a naturally or experimentally caused destruction of brain tissue
EEG (electroencephalogram)
An amplified recording of the waves of electrical activity sweeping across the brain’s surface. These waves are measured by the electrodes placed on the scalp
MEG (magnetoencephalography)
A brain imaging technique that measures magnetic fields from the brain’s neural electrical activity
CT (computed tomography scan)
A series of x-ray photographs taken from different angels and combined by computer into a composite representation of a slice of the brain’s structure (also called CAT scan)
PET (positron emission tomography scan)
A visual display of brain activity that detects where a radioactive form of glucose goes while the brain performs a given task
MRI (magnetic resonance imaging)
A technique that uses magnetic fields and radio waves to produce computer-generated images of soft tissue. MRI scans show brain anatomy
Hormones
Chemical messengers that are manufactured by the endocrine glands, travel through the bloodstream and affect other tissues
Adrenal glands
A pair of endocrine glands that sit just above the kidneys and secrete hormones (epinephrine) (norepinephrine) that helps rouse the body in times of stress
Pituitary gland
The endocrine system’s most influential gland. Under the influence of the hypothalamus, the pituitary regulates growth and controls other endocrine glands.
fMRI (functional MRI)
A technique for revealing blood flow and therefore, brain activity by comparing successive MRI scans. fMRI scans show brain function & structure
Medulla
The base of the brainstem, controls heartbeat & breathing
Brainstem
The oldest part & central core of the brain, beginning where the spinal cord swells as it enters the skull; the brain stem is responsible for automatic survival functions
Reticular formulation
A nerve network that travels through the brainstem into the thalamus and plays an important role in controlling arousal
Thalamus
The brain’s sensory control center, located on top of the brainstem, it directs messages to the sensory receiving areas in the cortex and transmits reply’s to the cerebellum and medulla
Cerebellum
The “little brain” at the rear of the brainstem; functions include processing sensory input, coordinating movement output and balance, and enabling nonverbal learning & memory
Limbic system
Neural system located below the cerebral hemispheres; associated w/ emotions & drives
Amygdala
Two lima-bean sized neural clusters in the limbic system; linked to intense emotion
Hypothalamus
A neural structure lying below the thalamus, it directs several maintenance activities, helps govern the endocrine system via the pituitary gland, and is linked to emotion & reward
Hippocampus
A neural center located in the limbic system; helps process for storage explicit (conscious) memories of facts & events
Cerebral Cortex
The intricate fabric of interconnected neural cells covering the cerebral hemispheres; the body’s ultimate control & information - processing center
Frontal lobes
The portion of the cerebral cortex lying just behind the forehead; involved in speaking & muscle movements and in making plans and judgements
Parietal lobes
The portion of the cerebral cortex lying at the top of the head and toward the rear; receives sensory input for touch and body position
Occipital lobes
The portion of the cerebral cortex lying at the back of the head; includes an rea’s that receive info from the visual fields
Temporal lobes
A portion of the cerebral cortex lying roughly above the ears; this includes the auditory areas, each receiving information primarily from the opposite ear
Motor cortex
An area at the rear of the frontal lobes that controls voluntary movements
Somatosensory cortex
An area at the front of the parietal lobes that registers and processes body touch and movement sensations
Association areas
Areas of the cerebral cortex that aren’t involved in primary motor or sensory functions, rather they are involved in higher mental functions such as learning, remembering, thinking, and speaking
Plasticity
The brain’s ability to change, especially during the childhood, by reorganizing after damage or by building new pathways based on experience
Neurogenesis
The formation of new neurons
Corpus callosum
The large band of neural fibers connecting the two brain hemispheres and carrying messages between them
Split brain
A condition resulting from surgery that isolates the brain’s two hemispheres by cutting the fibers (mainly those of the corpus callosum) connecting them
Consciousness
Our subjective awareness of ourselves and our environment
Cognitive neuroscience
The interdisciplinary study of the brain including activity linked w/ cognition (including perception, thinking, memory, & language)
Dual processing
The principle that information is often simultaneously processed on separate conscious & unconscious tracks
Blindsight
A condition in which a person can respond to a visual stimulus without consciously experiencing it
parallel processing
Processing many aspects of a problem simultaneously; generally used to process well-learned information or to solve easy problems
Sequential processing
Processing one aspect of a problem at a time; generally used to process new information or to solve difficult problems
Behavior genetics
The study of the relative power and limits of genetic & environmental influences on behavior
Heredity
The genetic transfer of characteristics from parents to offspring
Environment
Every nongenetic influence, from prenatal nutrition to the people and things around us
Chromosomes
Threadlike structure made of DNA molecules that contain the genes
DNA (deoxyribonucleic acid)
A complex molecule containing the genetic information that makes up the chromosomes
Genes
The biochemical units of heredity that make up the chromosomes; segments of DNA capable of synthesizing proteins
Genome
The complete instructions for making an organism; consisting of all the genetic material in the organism’s chromosomes
Identical (monozygotic) twins
Develop from single fertilized egg which splits into two, creating two genetically identical eggs twins
Fraternal (dizygotic) twins
Develop from separate fertilized eggs. They are genetically no closer than ordinary brothers and sisters, but they share a prenatal environment
Heritability
The proportion of variation among individuals in a group that we can attribute to genes. The heritability of a trait may vary, depending on the range of populations and environments studied
Interaction
The interplay that occurs when the effect of one factor (such as environment) depends on another factor (such as heredity)
Molecular genetics
The subfield of biology that studies the molecular structure and function of genes
Molecular behavior genetics
The study of how the structure and function of genes interact w/ our environment to influence behavior
Epigenetics
“above” or “in addition to” (epi) genetics; the study of environmental influences on gene expression that occur without a DNA change
Evolutionary psychology
The study of the evolution of behavior and the mind, using principles of natural selection
Natural selection
The principle that inherited traits that better enable an organism to survive and reproduce in a particular environment will (in competition w/ other trait variations) most likely be passed on to succeeding generations
Mutation
A random error in gene replication that leads to a change in
Social script
A culturally modeled guide for how to a act in various situations
GABA
a neurotransmitter that slows down CNS by blocking certain signals; known to have calming effect. Inhibitory neurotransmitter. Undersupply linked to seizures, tremors, and insomnia
Acetylcholine (ACh)
Neurotransmitter that enables muscle action, learning, and memory. Undersupply linked to Alzheimer’s.
