Unit 3: Biological Bases of Behavior Flashcards
neuron
a nerve cell that is the basic building block of the nervous system
cell body/soma
the part of the neuron that contains the nucleus, the cell’s life-support center
dendrites
bushy, branching extensions that receive and integrate messages, conducting impulses toward the cell body
axon
attached to the soma, the neuron extension that passes messages through its messages
terminal branches
located at the end of the soma, these hold synaptic vessels that store neurotransmitters
myelin sheath
the fatty tissue layer segmentally encasing the axons of some neurons; increases transmission speed and provides insulation, and play a role in motor skills
gilal cells
cells that support, nourish, and protect neurons; they play a role in learning, thinking, and memory
action potential
an electrical signal that neurons communicate through, based on movement of ions between the outside and inside of the cell
threshold
the level of stimulation required to trigger a neural impulse
refractory period
a resting pause the neuron must take in between communications, until the axon returns to its resting state
all-or-none response
more stimulation does NOT produce a more intense neural response: instead, the neuron’s reaction is all-or-none, meaning they fire or they don’t
synapse
the junction between the axon and tip of the sending neuron and the dendrite or cell body of the receiving neuron; the tiny gap is called the synaptic gap or synaptic cleft
acetylcholine (ACh)
enables muscle action, learning, and memory
What happens with ACh in Alzhemiers’ disease?
ACh-producing neurons deteriorate
dopamine
the neurotransmitter that influences movement, learning, attention, and emotion
What does an oversupply/undersupply of dopamine lead to?
an oversupply of dopamine is linked to schizophrenia; an undersupply of dopamine is linked to tremors and decreased mobility in Parkinson’s disease
serotonin
the neurotransmitter that affects mood, hunger, sleep, and arousal
What does an undersupply of serotonin lead to?
an undersupply of serotonin is linked to depression; some drugs that raise serotonin levels are used to treat depression
norepinephrine
the neurotransmitter that helps control alertness and arousal; an undersupply of norepinephrine is linked to a depressed mood
GABA (gamma-aminobutyric acid)
a major inhibitory neurotransmitter
glutamate
a major memor and excitatory neurotransmitter
What does an undersupply of GABA lead to?
an undersupply of GABA is linked to seizures, tremors, and insomnia
What does an oversupply of glutamate lead to?
an oversupply of glutamate leads to overstimulation of the brain, producing migranes or seizures (which is why some people avoid MSG, monosodium gluamate, in their food)
endorphins
neurotransmitters that influence the perception of pain or pleasure
reuptake
a neurotransmitter’s reabsorption by the sending neuron
agonist
a drug that excites neuron firing by increasing a neurotransmitter’s action
antagonist
a drug that inhibits or blocks neuron firing, and can also work by blocking reputake
nervous system
the body’s electrochemical communication network, consisting of all the nerve cells of the peripheral and central nervous systems
Central Nervous System (CNS)
made up of the brain and the spinal cord, the CNS is the decision-maker, responsible for coordinating incoming sensory messages and outgoing motor messages
Peripheral Nervous System (PNS)
made up of sensory and motor neurons, the peripheral nervous system connects the body to the CNS by gathering information from the senses and transmitting messages from the CNS
nerves
bundled axons that form neural cables connecting the CNS with muscles, glands, and sense organs
sensory (afferent) neurons
these enter the brain, contain afferent nerve fibers, and carry information from the sense organs to the CNS
motor (efferent) neurons
these leave the brain, contain efferent neurons, and carry information from the CNS to our muscles and glands
interneurons
transmits impulses and enables communication between the sensory and the motor neurons
somatic nervous system
controls the body’s skeletal muscles, also called the skeletal nervous system
autonomic nervous system
controls the glands and the muscles of the internal organs (such as the heart), functions automatically
sympathetic nervous system
arouses the body, mobilizing its energy, [fight, flight, or freeze] –> accelerates heartbeat, raises blood pressure, slows digestion, raises blood sugar, and cools the body off
parasympathetic nervous system
calms the body, conserving its energy [rest or digest] –> decelerates heartbeat, lowers blood pressure, stimulates digestion, and processes waste,
reflex
a simple, automatic response to a sensory stimulus, such as the knee-jerk reaction
endocrine system
the body’s “slow” chemical communication network: 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
adrenal glands
these glands release epinephrine and norepinephrine to energize the body when the sympathetic nervous sytem is activated
pituitary gland
the endocrine system’s most influential gland –> the hypothalamus directs the pituitary gland to regulate growth and control other endocrine glands
lesion
brain tissue is destroyed and researchers study the impact on functioning
EEG
a recording of the waves of electrical activity across the brain’s surface measured by electrodes placed on the scalp
MEG
a brain imaging technique that measures magnetic fields from the brain’s natural electrical activity
CT scan
x-ray photographs taken from different angles and combined by a computer to show a slice of the brain’s structure; show structural damage
PET scan
a visual display of brain activity that detects where one radioactive glucose goes while the brain performs a given task; shows activity
MRI
a technique that uses magnetic fields and radio waves to produce computer-generated images of brain anatomy –> performs the same function as a CT scan but an MRI is more detailed
fMRI
a measure of blood flow and brain activity by comparing successive MRI scans to show brain function and structure; shows damage
brainstem
the primitive brain with simple structures, like motor skills
medulla
at the base of the brainstem, controls heartbeat and breathing
thalamus
at the tip of the brainstem, the relay station for incoming and outcoming sensory information (except smell)
reticular formation
nerve network that travels through the brainstem into the thalamus; helps control arousal and filters incoming sensory stimuli
cerebellum
at the rear of the brainstem, processes sensory input, coordinating movement and balance, nonverbal learning, and implicit memory
limbic system
mammal brain with complex structures like motion, memory, and instinctual responses; the human reward system
amygdala
two lima-bean-sized neural clusters linked to emotion, fear, and aggression; fight-or-flight response
hypothalamus
below the thalamus; directs eating, drinking, and body temperatures, and helps govern the endocrine system via the pituitary gland, linked to emotion and reward; both a part of the CNS and the endocrine system
cerebral cortex
the intricate fabric of interconnected neural cells covering the cerebral hemispheres; the body’s ultimate control and information-processing center –> 20-23 billion nerve cells & 300 trillion synaptic connections, divided into four regions called lobes
frontal lobes
involved in speaking, motor movements, judgment, and decision-making, emotional regulation
parietal lobes
receives and processes sensory input for touch and body position; our sensory cortex and motor cortex are located here
occipital lobes
each lobe receives visual information, primarily from the opposite visual field –> visual cortex
temporal lobes
each lobe receives auditory information, primarily from the opposite ear; reading lips to understand what another person is saying –> auditory cortex
motor cortex
controls voluntary movements from the opposite side
somatosensory cortex
registers information from the skin senses and body movement for the opposite side
association areas
most of the brain’s cortex which integrates information involved in learning, remembering, thinking, and other high-level functions; attention is shifted, and planning occurs; these are not specifically devoted to motor or sensory cortex functions, and are difficult to map
plasticity
the brain’s ability to change, especially during childhood, by reorganizing itself after damage or by building new pathways based on experience
neurogenesis
the brain producing new neurons in order to mend itself
