Unit 2 Flashcards
Neuron
A nerve cell; a basic building block of the nervous system.
Cell body
Part of a neuron; contains the nucleus.
Dendrites
Neuron’s bushy, branching extensions that receive and integrate messages.
Axon
Neuron extension; passes messages through branches to other neurons/muscles/glands.
Myelin Sheath
The fatty tissue layer encasing axons; enables greater transmission speed (looks like hotdog buns).
Multiple Sclerosis
XXXXXXXXX
Myelin sheath degenerates; communication to muscle slows and eventual loss of muscle control.
Glial Cells
Cells in the nervous system that support, nourish, and protect neurons.
Action potential
A neural impulse; a brief electrical charge travels down an axon.
Threshold
Level of stimulation required to trigger a neural impulse.
Refractory period
A brief resting period that occurs after a neuron has fired (goes down like a chain).
All-Or-None response
XXXXXXX
Neuron’s reaction of either firing (with full strength) or not firing.
Synapse
The junction between the axon tip of the sending neuron and the dendrite/cell body of the receiving neuron.
Neurotransmitter
Chemical messengers that cross synaptic gaps between neurons.
Reuptake
Neurotransmitter reabsorption by sending neurons.
Acetylcholine (ACh)
Enables muscle action, learning, and memory (Increased secretions, memory, and muscle contractions. Decreased heart rate).
Dopamine
Influences movement, learning, attention, and emotion (Increased alertness and happiness. Decreased hunger).
Serotonin
Affects mood, hunger, sleep, and arousal (Increased happiness and fullness. Decreased pain).
Norepinephrine
Helps control alertness and arousal (Increased heart rate, alertness, happiness. Decreased blood circulation and pain).
GABA (gamma-aminobutyric acid)
A major inhibitory neurotransmitter (Increased sleepiness. Decreased anxiety, alertness, memory, muscle tension).
Glutamate
A major excitatory neurotransmitter is involved in memory (most common).
Endorphins
Natural opiates - Neurotransmitters that influence the perception of pain and pleasure.
Agonist
A molecule that increases a neurotransmitter’s action
3 ways agonists can work
- Increase neurotransmitter action.
- Increase production/release neurotransmitters, or block reuptake in synapse.
- May be similar enough to neurotransmitters to bind to its receptor and mimic its ex/in effects.
Antagonist
A molecule that inhibits/blocks the action of a neurotransmitter (causes paralysis by blocking ACh release).
Nervous System
The body’s speedy, electrochemical communication network.
Central Nervous system (CNS)
Brain and spinal cord.
Peripheral Nervous System (PNS)
Sensory and motor neurons connect the CNS to the rest of the body.
Nerves
Bundles of axons form cables connecting the CNS with muscles, glands, and sense organs.
Sensory (aff.) Neurons
carry messages from tissue/sensory receptors inward to the brain/spinal cord for processing.
Motor (eff.) Neurons
carry instructions from CNS outward to muscles/glands.
Somatic Nervous System
Enables VOLUNTARY control of our skeletal muscles.
Autonomic Nervous System (ANS)
AUTOMATICALLY controls our glands and our internal organs.
Sympathetic Nervous System
Arouses and expands energy (fight or flight)
Parasympathetic Nervous System
Conserves energy as it calms you (rest and digest).
Spinal cord
XXXXXX
The body’s decision maker -> runs along the spine (2-way info highway connecting ParaNS and brain.
Reflexes
Simple, automatic response to a sensory stimulus (The brain doesn’t have time to respond; Spinal cord does the response).
Oxytocin
XXXXX
Enables contractions associated with birthing, milk flow during nursing, and orgasm.
Cortisol
XXXXX
Stress hormone that increases blood sugar.
Lesion
Tissue destruction
Stimulate
XXXXX
Electrically, chemically, and magnetically excite the body (variable).
EEG (electroencephalogram)
Records electrical ACTIVITY; electrodes placed on the scalp to measure activity.
MEG (magnetoencephalography)
Records magnetic fields from the brain’s natural electrical currents.
CT (computed tomography)
Can only show structure; an X-ray of the head generates images that may locate brain damage
PET (positron emission tomography)
Identifies what parts are active during certain tasks; tracks where a temporarily radioactive form of glucose goes while the brain performs tasks.
MRI (magnetic resonance imaging)
Detailed picture of structure; people sit/lie down in a chamber that uses magnetic fields and radio waves to provide a map of brain structure.
fMRI (functional MRI)
Shows structure and activity; measures blood flow to brain regions by comparing continuous MRI scans.
Brainstem
The oldest part and the central core of the brain begins at the spinal cord and ends at the brain. Responsible for automatic survival functions.
Medulla
The base of the brainstem; controls heartbeat and breathing.
Pons
These help coordinate movement and controls sleep.
Thalamus
The brain’s sensory control center; sends messages to receiving areas in the cortex and transmits replies to the cerebellum and medulla. (Located at the top of the brainstem)
Reticular formation
The nerve network that travels through the brainstem into the thalamus plays an important role in controlling arousal.
Cerebellum
The “little brain” is at the rear of the brainstem; the functions include processing sensory input, coordinating movement output and balance, and enabling nonverbal learning and memory.
Limbic system
The neural system is located below the cerebral hemispheres; associated with emotions and drives.
Amygdala
Two lima-bean-sized neural clusters in the limbic system; are linked to emotion (fight or flight) + (fear and anger).
HYPOthalamus
The neural structure lying below (HYPO) the thalamus; directs several maintenance activities (eating), helps govern the endocrine system via the pituitary gland, linked to emotion and reward (drinking/body temp).
HIPPOcampus
The neural center located in the limbic system; helps process for storage of explicit (conscious) memories of facts and events.
Cerebral cortex
The intricate fabric of interconnected neural cells covering cerebral hemispheres; is the body’s ultimate control and info-processing center.
Frontal Lobe
The portion of the cerebral cortex lying just behind the forehead; is involved in speaking and muscle movements and in making plans/judgements/decision-making.
Parietal Lobes
The portion of the cerebral cortex lies on top of the head and towards the rear; this receives sensory input for touch and body positions.
Occipital Lobes
The portion of the cerebral cortex lying at the back of the head; includes areas that receive info from visual fields.
Temporal Lobes
The portion of the cerebral cortex lying roughly above the ears; includes auditory areas, each receiving info primarily from the opposite ear.
Fissures
XXXXX
The lobes are separated by these.
Motor cortex
An area at the rear of teh 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 are NOT included in primary motor/sensory functions; they ARE involved in higher mental functions (learning, remembering, thinking, speaking).
Prefrontal cortex
XXXXX
The forward part of the frontal lobe; controls judgements, planning, and processing new memories.
Phineas Gage
XXXXX
25-year-old railroad worker who got a rod shot through his left cheek and skull; his personality changed and his moral judgments were unrestrained.
Broca’s area
Disrupts speaking
Wernicke’s area
Disrupts understanding
Plasticity
The brain’s ability to change, especially during childhood, by reorganizing after damage/by building new pathways based on experience.
Neurogenesis
The formation of new neurons.
Corpus Callosum
A large band of neural fibers connects the two brain hemispheres and carries messages between them.
Split brain
The condition results from surgery that isolates the brain’s two hemispheres by cutting fibers that connect them.
Consciousness
Subjective awarness of ourselves and our environmant
Sleep
Periodic, Natural loss of consciousness.
Circadian Rhythm
Biological Clock, regular bodily rhythms that occur on a 24 hour cycle.
REM Sleep
Rapid Eye Movement. Sleep stage in which vivid dream commonly occur.
Alpha Waves
Relatively slow brain waves of a relaxed, awake state.
NREM Sleep
Non-Rapid Eye Movement. Encompasses all sleep stages except REM Sleep.
Hallucinations
False sensory experiences, such as seeing something in absence of an external visual stimulus.
Hypnagogic Sensations
Bizarre experiences while falling asleep, such as jerking, feeling of falling, floating.
Delta Waves
Large, slow brain waves associated with deep sleep.
Suprachiasmatic Nucleus (SCN)
Pair of cell clusters in Hypothalamus that controls circadian rhythm and adjusts melatonin production.
Insomnia
Reoccurring problems falling or staying asleep.
Narcolepsy
Sleep disorder known as sleep attacks. Falls into REM Sleep often at inopportune times.
Sleep Apnea
Sleep disorder characterized by temporary cessations of breathing during sleep and repeated momentary awakenings (mask like pump to sleep).
Night Terrors
Sleep disorder characterized by high arousal and an appearance of being terrified, occur during NREM-3 sleep.
Dream
Sequence of images, emotions, and thoughts passing through a sleeping person’s mind.
Manifest Content
The remembered story line of the dream (Literal).
Latent Content
The underlying meaning of a dream (interpretation).
REM Rebound
Tendency for REM sleep to increase following REM sleep deprivation.
Psychoactive Drug
Chemical substance that alters perceptions and moods.
Substance Use Disorder
Continued substance craving and use despite significant life disruption and/or physical risk.
Tolerance
Diminishing effect with regular use of the same dose of a drug, requiring the user to take larger and larger doses.
Withdrawal
Discomfort or distress that follow discontinuing an additive drug.
Alcohol Use Disorder
Marked by tolerance, withdrawal, and a drive to continue problematic use.
Near-death Experience
