Unit 2 Flashcards
Central Nervous System (CNS)
The brain and spinal cord
Peripheral Nervous System (PNS)
Connects to CNS to the limbs and organs, essentially serving as a communication relay going back and forth between the brain and the extremities
Somatic Nervous System
The division of the PNS that controls the body’s skeletal muscles. Also known as the skeletal nervous system.
Autonomic Nervous System
The part of the PNS that controls the glands and the muscles of the internal organs. Controls the sympathetic and parasympathetic nervous systems
Sympathetic Nervous System
“Fight or flight or freeze” the division of the autonomic nervous system that arouses the body, mobilizing its energy in stressful situations
Parasympathetic Nervous System
“Rest and digest” the division of the autonomic nervous system that calms the body, conserving its energy
Sensory neurons
Neurons that carry incoming information from the sensory receptors to the brain and spinal cord
Interneurons
neurons within the brain and spinal cord that communicate internally and intervene between the sensory inputs and the motor outputs
Motor neurons
Neurons that carry outgoing information from the brain and spinal cord to the muscles and glands
Soma (cell body)
The neuron’s life support center that also produces neurotransmitters
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, muscles, or glands
Myelin sheath
A layer of fatty tissue that covers the axon which aides in the speed of neural impulses; the thicker the myelin sheath, the faster the impulse
Nodes of Ranvier
Spaces between the myelin
Schwann Cell
Produces myelin
Action potential
A neural impulse; a brief electrical charge that travels down an axon
Ions
Electrically charged atoms
Resting potential
A fluid interior of a resting axon has an excess of negatively charged ions, while the fluid outside the axon membrane has more positively charged ions
Selectively permeable
The axon’s surface is very selective about what it allows in
Polarized
During the resting state of a neuron when the outside is now positively charged and the inside is now negatively charged
Depolarized
Axon is no longer at resting potential; outside is now negatively charged and inside is now positively charged
Refractory period
Resting state after firing in which the neuron goes back to its polarized resting state
Excitatory
Accelerates neuron’s firing speed
Inhibitory
Slows neuron’s firing speed
Threshold
A level of stimulation required to trigger a neural impulse
Synapse
The junction between the terminal branch of the synaptic cleft
Synaptic gap/cleft
The tiny gap at the synapse in which neurotransmitters cross
Neurotransmitters
Chemical messengers that cross the synaptic gaps between neurons. When released by the sending neurons, neurotransmitters travel across the synapse and bind the 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
Acetylcholine
Enables muscle action, learning, and memory
With Alzheimer’s disease, Acetylcholine deteriorates
Dopamine
Movement, learning, attention, and emotion
Too much=schizophrenia
Too little=Parkinson’s
Serotonin
Mood, hunger, sleep, arousal
Too little=depression
Antidepressants raise serotonin
Norepinephrine
controls alertness and arousal
Too little=depress mood
GABA
A major inhibitory neurotransmitter
Too little=seizures, insomnia, tremors
Glutamate
A major excitatory neurotransmitters
Too much= migraines and seizures
Endorphins
Natural, opiate-like neurotransmitters linked to pain control and pleasure
Agonist
A molecule that may be similar enough to a neurotransmitter to bind its receptor and mimic its effects (blocks the original neurotransmitters)
Antagonist
A molecule that binds to receptors but blocks a neurotransmitter’s functioning
Adrenal glands
A pair of endocrine glands that sit just above the kidneys and secrete hormones that help Arouse 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
Lesion
Tissue destruction that is naturally or experimentally caused to help study regions and functions of the brain
Plasticity
The brain’s ability to modify itself after tissue damage
EEG
An amplified recording of the waves of electrical activity that sweep across the brain’s surface
CT/CAT
A series of x-ray photographs of the brain taken from different angles and combined by computer to create an image that represents a slice through the brain
PET
Measures the different levels of activity in the brain by detecting where a radioactive form of glucose goes while the brain is performing a given task
fMRI
A technique for revealing bloodflow and, therefore, brain activity by comparing successive MRI scans. Shows brain functions.
Brainstem
The oldest and innermost region of the brain that is responsible for autonomic survival functions. It begins where the spinal cord swells and enters the skulls
Thalamus
The brain’s sensory switchboard located on the top of the brainstem. Directs messages to the sensory receiving areas in the cortex. Transmits replies to the cerebellum and medulla. Smell, olfaction, does not go through the thalamus.
Medulla
Part of the brainstem that controls heartbeat and breathing
Reticular formation
A nerve network in the brainstem that plays an important role in controlling arousal
Cerebellum
“Little brain” attached to the rear of the brainstem that assists in balance and voluntary movements.
Limbic system
Associated with emotions (fear and aggression) and drives (food and sex)
Hippocampus
Learning and memory
Pituitary gland
Master endocrine gland in limbic system
Cerebral cortex
Body’s ultimate control and info processing center
Glial cells
“Glue cells” in the cortex that guide neural connections, provide nutrients and insulating myelin, and mop up ions and neurotransmitters
Frontal lobes
Speaking, muscle movements, making plans, and making judgements
Motor cortex
The area at the back of the frontal lobes that controls voluntary movements
Parietal lobes
Body’s sensations. Includes sensory cortex
Sensory cortex
Registers and processes body sensations
Occipital lobes
Visual cortex
Temporal lobes
Auditory cortex for hearing
Auditory cortex
Receives auditory info from the ears
Association areas
Higher mental functions such as learning, remembering, thinking, and speaking
Broca’s area
Damage impairs speaking
Wernicke’s Area
Language comprehension. Damage impairs understanding
Aphasia
Impairment of language usually caused by damage to the Broca’s or Wernicke’s area
Neurogenesis
The formation of new neurons
Corpus callosum
How the two (right and left) hemispheres communicate.
Split Brain
When the two hemispheres cannot communicate. Severing of the corpus callosum
alien hand syndrome
Disorder that causes hand movement without the person being aware of what is happening or having control over the action
Cognitive neuroscience
Study of the brain activity linked with cognition (perception, thinking, memory, and language)
Superchiasmatic Nucleus (SCN)
Cell clusters in the hypothalamus that helps in waking up a person when it is activated by light-sensitive retinal proteins
Melatonin
A sleep inducing hormone
Adenosine
Causing drowsiness and the slowing of nerve cells. Caffeine is an antagonist that blocks the transmission of adenosine keeping us awake
Types of Waves
Beta, Alpha, Theta, Delta
Stage 1
Lasts about 5 mins, emits theta waves, experience hallucinations and hynagogic senations (falling or floating)
Stage 2
Lasts for 20 mins, experience sleep spindles (random bursts of activity
Stage 3
Transition into stage four, first emission of delta waves
Stage 4
Deepest sleep, 30 mins, delta waves, sleep walking, bed wetting
REM Sleep
Vivid dreams. Paradoxical sleep bc the muscles are relaxed
NREM
All sleep stages except REM
Insomnia
Recurring problems in falling or staying asleep
Narcolepsy
Sleep attacks usually caused by excitements
Sleep apnea
Temporary cessations of breathing during sleep and repeated momentary awakenings
Night terrors
Occur during stage 4, high arousal and an appearance of being terrified
Manifest content
The remembered story line of dream
Latent content
The underlying meaning of a dream
