Unit 2: Neurons and Research Methods Flashcards
Lesioning
destruction of brain tissue; victims of severe brain injury, Parkinson’s/schizophrenic/OCD patients
Electroencephalograph (EEG)
monitors brainwave pattern produced by electrical activity of brain; sleep stages, tumors, seizure disorders
Electrical stimulation of brain (ESB)
process where a weak electrical current is sent into brain structure to stimulate it; animal research
Computer tomography (CT)
brain imaging method that utilizes computer-controlled x-rays of brain; gives composite representation (,ap) of brain slices; stroke damage, blood clots, tumors, injuries
Positron Emission Tomography (PET)
brain-imaging method where radioactive glucose is injected into subject; can monitor brain activity like sleep cycles
Magnetic Resonance Imaging (MRI)
technique uses magnetic fields and radioactive waves to produce computer generated images that distinguish among different types of soft tissue; allows to see smaller details and structures within brain
Functional MRI (fMRI)
new variation on MRI technology that monitors blood flow and oxygen consumption in brain to identify areas of high activity
CT vs MRI
CTs are less expensive; CTs are less sensitive to patient movement; CT scans can be performed in presence of implanted medical device
Central nervous system (CNS)
contains spine and brain
Peripheral nervous system (PNS)
sensory and motor neurons that connect CNS with rest of body; contains Autonomic and Somatic nervous systems
Autonomic nervous system
controls involuntary functions or items that happen automatically within body; contains Sympathetic and Parasympathetic nervous systems
Somatic nervous system
controls voluntary movements and communication to and from the sense organs
Sympathetic nervous system
physically arouses body, preparing it to act/react in stressful situations, expends energy; initiates fight-or-flight; inhibits digestion, dilates pupils, increases breathing and heartrate to oxygenate blood, stimulates release of epinephrine and norepinephrine by adrenal gland
Parasympathetic nervous system
calms body, conserving its energy and helping keep a constant internal state; returns body to homeostasis; initiates rest and digest; stimulates digestion, contracts pupils, slows breathing and heartrate
Sensory neurons
afferent neurons; carries incoming messages/information from sense receptors to CNS
Motor neurons
efferent neurons; carries outgoing information from CNS to the peripheral nervous system and muscles
Resting potential
when neuron is not firing, and has a negative charge with mostly potassium ions inside and mostly sodium ions outside
Polarization
at resting potential, when NA is outside and K is inside; at this state, neuron is at homeostasis; should strive to obtain this regularly
Action potential
nerve impulse; electrical pulse or message that travels length of axon
All or nothing principle
when nucleus decides to fire, it fires down axon completely (all the way) or not at all; maintains same intensity the entire length of axon regardless of strength of intent
Depolarization
Sodium and positive ions rush in, causing potassium and negative ions to rush out; takes longer for potassium channels to open, so neurons struggle to fire; action potential
Refractory period
period of time after firing that neuron is focused on resetting, and therefore unable to fire again
Neurotransmitters
chemical substance that crosses synapse to carry on message to next neuron
Synapse
open space between two neurons where neurotransmitters cross
Receptor sites
specific points on dendrites of neurons that receive specific types of neurotransmitters
Agonist
external substance that somehow interact with neurotransmitters at receptor sites on dendrites of neuron; mimics neurotransmitter activity; anesthesia (morphine mimics endorphins)
Antagonist
external substance that somehow interact with neurotransmitters at receptor sites on dendrites of neuron; blocks neurotransmitter activity; prevents neurotransmitter from getting to receptor site; botox
Reuptake
process where neurotransmitter molecules that have been released by synapse are reabsorbed by presynaptic neuron that released them
axon
part of neuron that carries nerve impulse away from cell body
dendrite
part of neuron that increases receptive surface of neuron; receives communications from other cells
Interneurons
only neurons in CNS; act as messengers between sensory and motor neurons
