Biology in Focus (AP) Chapter 37 Flashcards

9448054827	neuron	A nerve cell; the fundamental unit of the nervous system, having structure and properties that allow it to conduct signals by taking advantage of the electrical charge across its plasma membrane.	0
9448054828	brain	Organ of the central nervous system where information is processed and integrated.	1
9448054829	ganglion	A cluster (functional group) of nerve cell bodies in a centralized nervous system.	2
9448054830	cell body	The part of a neuron that houses the nucleus and most other organelles.	3
9448054831	dendrite	One of usually numerous, short, highly branched extensions of a neuron that receive signals from other neurons.	4
9448054832	axon	A typically long extension, or process, of a neuron that carries nerve impulses away from the cell body toward target cells.	5
9448054833	axon hillock	The cone-shaped base of an axon, where signals that travel down the axon are generated.	6
9448054834	synapse	The junction where a neuron communicates with another cell across a narrow gap via a neurotransmitter or an electrical coupling.	7
9448054835	synaptic terminal	The part of each axon branch that forms a synapse.	8
9448054836	neurotransmitter	A molecule that is released from the synaptic terminal of a neuron at a chemical synapse, diffuses across the synaptic cleft, and binds to the postsynaptic cell, triggering a response.	9
9448054837	presynaptic neuron	The neuron that transmits a signal to another cell.	10
9448054838	postsynaptic cell	The neuron, muscle, or gland cell that receives a signal from a neuron.	11
9448054839	glia	Cells of the nervous system that support, regulate, and augment the functions of neurons.	12
9448054840	sensory neuron	A nerve cell that receives information from the internal or external environment and transmits signals to the central nervous system.	13
9448054841	interneuron	An association neuron; a nerve cell within the central nervous system that forms synapses with sensory and/or motor neurons and integrates sensory input and motor output.	14
9448054842	motor neuron	A nerve cell that transmits signals from the brain or spinal cord to muscles or glands.	15
9448054843	central nervous system	The portion of the nervous system where signal integration occurs, in vertebrate animals, the brain and spinal cord.	16
9448054844	peripheral nervous system	The sensory and motor neurons that connect to the central nervous system.	17
9448054845	nerve	A fiber composed primarily of the bundled axons of neurons.	18
9448054846	membrane potential	The difference in electrical charge (voltage) across a cell's plasma membrane due to the differential distribution of ions.	19
9448054847	resting potential	The membrane potential characteristic of a nonconducting excitable cell, with the inside of the cell more negative than the outside.	20
9448054848	sodium-potassium pump	A transport protein in the plasma membrane of animal cells that actively transports sodium out of the cell and potassium into the cell.	21
9448054849	ion channel	A transmembrane protein channel that allows a specific ion to diffuse across the membrane down its concentration or electrochemical gradient.	22
9448054850	selective permeability	Property of ion channels that allows only certain ions to pass through to the other side of the membrane.	23
9448054851	equilibrium potential	The magnitude of a cell's membrane voltage at equilibrium, calculated using the Nernst equation.	24
9448054852	gated ion channel	A gated channel for a specific ion. The opening or closing of such channels may alter a cell's membrane potential.	25
9448054853	hyperpolarization	A change in a cell's membrane potential such that the inside of the membrane becomes more negative relative to the outside. Reduces the chance that a neuron will transmit a nerve impulse.	26
9448054854	depolarization	A change in a cell's membrane potential such that the inside of the membrane is made less negative relative to the outside.	27
9448054855	graded potential	In a neuron, a shift in the membrane potential that has an amplitude proportional to signal strength and that decays as it spreads.	28
9448054856	action potential	An electrical signal that propagates (travels) along the membrane of a neuron or other excitable cell as a nongraded (all-or-none) depolarization.	29
9448054857	voltage-gated ion channel	A specialized ion channel that opens or closes in response to changes in membrane potential.	30
9448054858	threshold	The potential that an excitable cell membrane must reach for an action potential to be initiated.	31
9448054859	refractory period	The short time immediately after an action potential in which the neuron cannot respond to another stimulus, owing to the inactivation of voltage-gated sodium channels.	32
9448054860	myelin sheath	Wrapped around the axon of a neuron, an insulating coat of cell membranes from Schwann cells or oligodendrocytes. It is interrupted by nodes of Ranvier, where action potentials are generated.	33
9448054861	oligodendrocyte	A type of glial cell that forms insulating myelin sheaths around the axons of neurons in the central nervous system.	34
9448054862	Schwann cell	A type of glial cell that forms insulating myelin sheaths around the axons of neurons in the peripheral nervous system.	35
9448054863	node of Ranvier	Gap in the myelin sheath of certain axons where an action potential may be generated.	36
9448054864	saltatory conduction	Rapid transmission of a nerve impulse along an axon, resulting from the action potential jumping from one node of Ranvier to another, skipping the myelin-sheathed regions of membrane.	37
9448054865	synaptic vesicle	Membrane-enclosed compartment at the terminal of a presynaptic neuron that contains neurotransmitter.	38
9448054866	synaptic cleft	The gap that separates the presynaptic neuron from the postsynaptic cell.	39
9448054867	ligand-gated ion channel	A transmembrane protein containing a pore that opens or closes as it changes shape in response to a signaling molecule (ligand), allowing or blocking the flow of specific ions.	40
9448054868	ionotropic receptor	A ligand-gated ion channel..	41
9448054869	postsynaptic potential	A graded potential in a postsynaptic cell.	42
9448054870	excitatory postsynaptic potential	An electrical change (depolarization) in the membrane of a postsynaptic cell caused by the binding of an excitatory neurotransmitter from a presynaptic cell to a postsynaptic receptor; makes it more likely for a postsynaptic cell to generate an action potential.	43
9448054871	inhibitory postsynaptic potential	An electrical change (usually hyperpolarization) in the membrane of a postsynaptic neuron caused by the binding of an inhibitory neurotransmitter from a presynaptic cell to a postsynaptic receptor; makes it more difficult for a postsynaptic neuron to generate an action potential.	44
9448054872	temporal summation	A phenomenon of neural integration in which the membrane potential of the postsynaptic cell in a chemical synapse is determined by the combined effect of EPSPs or IPSPs produced in rapid succession.	45
9448054873	spatial summation	A phenomenon of neural integration in which the membrane potential of the postsynaptic cell is determined by the combined effect of EPSPs or IPSPs produced nearly simultaneously by different synapses.	46
9448054874	metabotropic receptor	Binds a neurotransmitter and activates a signal transduction pathway that opens or closes an ion channel after one or more metabolic steps.	47
9448054875	acetylcholine	One of the most common neurotransmitters; functions by binding to receptors and altering the permeability of the postsynaptic membrane to specific ions, either depolarizing or hyperpolarizing the membrane.	48
9448054876	neuromuscular junction	The site where a motor neuron forms a synapse with a skeletal muscle cell.	49
9448054877	glutamate	An amino acid that functions as a neurotransmitter in the central nervous system and has a role in long term memory.	50
9448054878	GABA	An amino acid that functions as a neurotransmitter in the central nervous system of vertebrates where it is found at most inhibitory synapses in the brain.	51
9448054879	biogenic amines	A neurotransmitter derived from an amino acid.	52
9448054880	norepinephrine	A catecholamine that is chemically and functionally similar to epinephrine and that acts as a hormone or neurotransmitter; also known as noradrenaline.	53
9448054881	dopamine	A neurotransmitter that is a catecholamine, like epinephrine and norepinephrine.	54
9448054882	serotonin	A neurotransmitter, synthesized from the amino acid tryptophan, that functions in the central nervous system.	55
9448054883	neuropeptide	A relatively short chain of amino acids that serves as a neurotransmitter.	56
9448054884	endorphin	Any of several hormones produced in the brain and anterior pituitary that inhibit pain perception.	57