Exam #2 Terms (Nature vs. Nurture) Flashcards
What is a neuron?
A nerve cell; the basic building block of the nervous system.
What is the cell body?
The part of a neuron that contains the nucleus; the cell’s life-support center.
What are dendrites?
A neuron’s often bushy; branching extensions that receive and integrate messages, conducting impulses toward the cell body.
What is an axon?
The neural extension that passes messages through its branches to other neurons or to muscles or glands.
What is the myelin sheath?
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.
What are glial cells?
Cells in the nervous system that support, nourish, and protect neurons; they also play a role in learning, thinking, and memory.
What is action potential?
A neural impulse; a brief electrical charge that travels down an axon.
What is the threshold?
The level of stimulation required to trigger a neural impulse.
What is the 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.
What is an all-or-none response?
A neuron’s reaction of either firing (with a full-strength response) or not firing.
What are ions?
An atom or molecule with a net electric charge due to the loss or gain of one or more electrons.
What is a selectively permeable membrane?
A type of biological or synthetic, polymeric membrane that will allow certain molecules or ions to pass through it by osmosis.
What is resting potential?
The imbalance of electrical charge that exists between the interior of electrically excitable neurons (nerve cells) and their surroundings.
What are excitatory neurotransmitters?
Has excitatory effects on the neuron; increases the likelihood that the neuron will fire an action potential.
What are inhibitory neurotransmitters?
Has inhibitory effects on the neuron; decreases the likelihood that the neuron will fire an action potential.
What is the 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 synaptic cleft.
What are 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.
What is reuptake?
A neurotransmitter’s reabsorption by the sending neuron.
What is the function of acetylcholine?
Enables muscle action, learning, and memory; linked to Alzheimer’s disease, where ACh-producing neurons deteriorate.
What is the function of dopamine?
Influences movement, learning, attention, and emotion; oversupply linked to schizophrenia, while undersupply is linked to tremors and decreased mobility in Parkinson’s disease.
What is the function of serotonin?
Affects mood, hunger, sleep, and arousal; undersupply linked to depression.
What is the function of norepinephrine?
Helps control alertness and arousal; undersupply can depress mood.
What is the function of GABA (gamma-aminobutyric acid)?
A major inhibitory neurotransmitter; undersupply linked to seizures, tremors, and insomnia.
What is the function of glutamate?
A major excitatory neurotransmitter involved in memory; oversupply can overstimulate the brain, producing migraines or seizures.
What is the function of endorphins?
Neurotransmitters that influence the perception of pain or pleasure; oversupply with opiate drugs can suppress the body’s natural endorphin supply.
What is an agonist?
A molecule that increases a neurotransmitter’s action.
What is an antagonist?
A molecule that inhibits or blocks a neurotransmitter’s action.
What is the nervous system?
The body’s speedy, electrochemical communication network, consisting of all the nerve cells of the peripheral and central nervous systems.
What is the central nervous system?
The brain and spinal cord.
What is the peripheral nervous system?
The sensory and motor neurons that connect the central nervous system to the rest of the body.
What are nerves?
Bundled axons that form neural cables connecting the central nervous system with muscles, glands, and sense organs.
What are sensory (afferent) neurons?
Neurons that carry incoming information from the body’s tissues and sensory receptors to the brain and spinal cord.
What are motor (efferent) neurons?
Neurons that carry outgoing information from the brain and spinal cord to the muscles and glands.
What are interneurons?
Neurons within the brain and spinal cord; they communicate internally and process information between the sensory inputs and motor outputs.
What is the somatic nervous system?
The division of the peripheral nervous system that controls the body’s skeletal muscles.
What is the autonomic nervous system?
The part of the peripheral nervous system that controls the glands and the muscles of the internal organs (such as the heart).
What is the sympathetic nervous system?
The division of the autonomic nervous system that arouses the body, mobilizing its energy.
What is the parasympathetic nervous system?
The division of the autonomic nervous system that calms the body, conserving its energy.
What is a reflex?
A simple, automatic response to a sensory stimulus.
What is the endocrine system?
The body’s “slow” chemical communication system; a set of glands that secrete hormones into the bloodstream.
What are hormones?
Chemical messengers that are manufactured by the endocrine glands, travel through the bloodstream, and affect other tissues.
What are 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.
What is the pituitary gland?
Regulates growth and controls other endocrine glands under the control of the hypothalamus.
What is lesion?
Tissue destruction.