Biological Bases Vocab Flashcards
(121 cards)
a nerve cell; the basic building block of the nervous system
ex: tells your body to react to pain
Neuron
the part of a neuron that contains the nucleus; the cell’s life support center
Cell body (soma- cells that aren’t reproductive)
a neuron’s often bushy, branching extensions that receive and integrate messages, conducting impulses toward the cell body
Dendrites
the neuron extension that passes messages through its branches to other neurons or to muscles or glands
Axon
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
Myelin Sheath
cells in the nervous system that support, nourish, and protect neurons; they also play a role in learning, thinking, and memory
Glial Cells (glia)
a neural impulse; a brief electrical charge that travels down an axon
Action Potential
the level of stimulation required to trigger a neural impulse
ex: if excitatory signals exceed the inhibitory signals by a minimum intensity/threshold, the combined signals trigger an action potential
Threshold
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
ex: (a refractory period takes about a fraction of the time it takes to blink) if you were on the phone and it took you a slower amount of time to react to a car in front of you
Refractory Period
a neuron’s reaction of either firing (with a full strength response) or not firing
ex: (it’s like a gun, neurons either fire or they don’t) distinguishing a gentle touch from a big hug
All-or-none Response
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
ex: how the intention to move our arm translates to actually moving our arm
Synapse
chemical messengers that cross the synaptic gaps between neurons; when released by the sending neuron, these travel across the synapse and bind to receptor sites on the receiving neuron, thereby influencing whether that neuron will generate a neural impulse
ex: (they affect awareness, mood, and hunger) endorphins, dopamine, serotonin, etc
Neurotransmitters
a neurotransmitter’s reabsorption by the sending neuron
ex: some antidepressant medications work by partially blocking the reuptake of mood-enhancing neurotransmitters
Reuptake
“morphine within”-natural, opiate-like neurotransmitters linked to pain control and to pleasure
ex: chemicals produced doing pleasurable things such as exercise or laughing, but can also happen during pain
Endorphins
a molecule that increases a neurotransmitter’s action
ex: opiate drugs, heroine, morphine
Agonist
a molecule that inhibits or blocks a neurotransmitter’s action
ex: Botulin, a poison that can form in improperly canned food, causes paralysis by blocking ACh release (also used for botox)
Antagonist
the body’s speedy, electrochemical communication network, consisting of all the nerve cells of the peripheral and central nervous systems
ex: touching a hot plate, reflectively pulling back your hand, sending pain signals to your brain
Nervous System
the brain and spinal cord
Central Nervous System (CNS)
the sensory and motor neurons that connect the CNS to the rest of the body
ex: allows you to feel pain and other sensations
Peripheral Nervous System (PNS)
bundled axons that form neural cables connecting the CNS with the muscles, glands, and sense organs
ex: the optic nerve bundles a million axons into a single cable carrying the messages from the eye to the brain
Nerves
neurons that carry incoming information from the body’s tissues and sensory receptors to the brain and spinal cord
ex: touching a stove, these are what fire and sends signals to the nervous system
Sensory (afferent) Neurons
neurons that carry outgoing information from the brain and spinal cord to the muscles and glands
ex: optical nerves
Motor (efferent) Neurons
neurons within the brain and spinal cord; they communicate internally and process information between the sensory inputs and motor outputs
ex: (our nervous system has a few million sensory neurons and a few million motor neurons, but it has billions and billions of these) golgi cell found in cerebellum
Interneurons
the division of the peripheral nervous system that controls the body’s skeletal muscles; also called the skeletal nervous system
ex: cranial nerves carry information from the brain to the head and neck region
Somatic Nervous System