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| * Another word for "nerve cell" is _____. | neuron p782 |
| * Communication by neurons largely consists of long-distance ______ signals and short-distance ____ signals | electrical, chemical p782 |
| * Communication by neurons largely consists of _____-distance chemical signals, and _____-distance electrical signals. | short, long p782 |
| * The part of the neuron that contains the nucleus and other organelles is called the _____. | cell body p783,  |
| * The extensions of the neuron that receive incoming messages are the _____. | dendrites p783,  |
| * The extension of the neuron that transmits a signal to another cell is called the _____. | axon p783, |
| * The small space between the terminal axon branch of one neuron and the dendrite of the post-synaptic cell is called a(n) _____. | synapse p783,  |
| * The cytoplasm at the end of an axon contains many small vesicles. What's in those vesicles? | neurotransmitters p783,  |
| * _____-neurons transmit information about external stimuli, such as light, touch, or smell, or internal conditions, such as blood pressure or muscle tension. | Sensory p784 |
| * ____-neurons form the local circuits connecting neurons in the brain or ganglia and are responsible for the integration (analysis and interpretation) of sensory input. | Inter p784 |
| * _______ -neurons transmit signals to muscle cells, causing them to contract. | Motor p784 |
| * The vertebrate nervous system can be broken down into two parts. What are they? | Central Nervous System (CNS) and Peripheral Nervous System (PNS) p784,  |
| * The inside of a nerve cell is _____ charged relative to the outside. | negatively p785 |
| * For most neurons, the concentration of ___ is higher inside the cell, while the concentration of is higher outside. | K+, Na+ p785,  |
| * For most neurons, the concentration of K+ is higher _____ the cell, while the concentration of Na+ is higher ___. | inside, outside p785, |
| * The gradient of sodium and potassium ions across the membrane of neuron is maintained by the ____. | sodium-potassium pump p785,  |
| * The sodium-potassium pump uses the energy from ____ to actively transport sodium and potassium ions across the nerve cell membrane against their concentration gradients. | ATP p785, |
| * The sodium-potassium pump pumps sodium ions ____ the nerve cell and potassium ions ___ the nerve cell. | out of, into p785, |
| * The sodium-potassium pump pumps potassium ions ____ the nerve cell and sodium ions ___ the nerve cell. | into, out of p785, |
| * The sodium-potassium pump transports ___ sodium ions out of the cell for every ___ potassium ions that it transports simultaneously into the cell. | 3, 2 p785, |
| * The resting potential of a neuron is between ___ and ___ millivolts. | -60 to -80 (The negative represents the charge inside the cell which is negative) p785,  |
| * In a resting neuron, _______ results from any stimulus that increases the outflow of positive ions or the inflow of negative ions. | hyperpolarization p788, |
| * In a resting neuron, _______ results from any stimulus that increases the inflow of positive ions or the outflow of negative ions. | depolarization (In neurons, depolarization often involves the opening of gated Na+ channels) p788, |
| * In neurons, depolarization often involves the opening of gated ____ channels (The answer is not "ion." Be more specific) | sodium (Na+) p788 |
| * If an axon is stimulated, sodium channels will briefly open to allow the neuron to become slightly _______. If the stimulation is great enough, the membrane potential will exceed the threshold potential (-55 mV) to initiate the _______ potential. | depolarized, action potential p789, |
| * If an axon is stimulated, sodium channels will briefly open to allow the neuron to become slightly depolarized. If the stimulation is great enough, the membrane potential will exceed the _____ potential (____) to initiate the action potential. | threshold, -55 mV p789, |
| * TRUE OR FALSE: Once initiated, the action potential has a magnitude that is dependent on the strength of the triggering stimulus. | FALSE (An action potential is an "all-or-none" response. As long as the stimulus is sufficient to decrease the membrane potential past -55mV, the action potential will proceed the same way no matter how strong the stimulus was that triggered the action potential) p789, |
| * Which type of voltage-gated ion channel opens first at the start of an action potential? | sodium p789,  |
* What is "A" referring to in the diagram below?,  | dendrites p783, |
| * What is "C" referring to in the diagram below?, | axon (it extends from the cell body to the end of the neuron) p783, |
* The strong rapid depolarization seen in part B of the graph is caused by the ___ of ____ voltage-gated channels.,  | opening, sodium 789, |
| * The change in membrane potential seen in part C of the graph is caused by, | closing of sodium channels and the opening of potassium channels p789, |
| * It's the ___ of action potentials, not their ____, that conveys information about the stimuli that are being received. | frequency, strength (All action potentials have the same strength. How frequently they are triggered matters. In hearing, for example, louder sounds trigger more frequent action potentials in neurons linking the ear to the brain.) p791 |
| * What is "D" referring to in the diagram below?, | myelin sheath p792, |
| * What does the myelin sheath do to nerve impulses? | speed them up (the action potential jumps from one node of ranvier to the next, speeding up the impulse over what it would have been if the depolarization had to occur along the whole length of the axon. This jumping impulse is called saltatory conduction) p792,  |
| * The entrance of _____ through gated channels in the presynaptic membrane stimulates vesicles to fuse with the presynaptic membrane, releasing neurotransmitters into the synapse. | calcium ions (Ca++) p793, |
| * Once in the synapse, neurotransmitters bond with ______ embedded in the postsynaptic membrane. | receptors (usually a ligand gated channel that allows ions to flow into the postsynaptic neuron and stimulate an action potential) p793 |
| * Neurotransmitters in the synapse are either destroyed by _____ in the synapse, taken back into the presynaptic neuron (reuptake) by active transport, or diffuses out of the synapse. | enzymes (Many drugs and poisons work by interfering with enzymes meant to degrade neurotransmitters or by interfering with the re-uptake of neurotransmitters back into the pre-synaptic neuron. Both of these events lead to higher than normal amounts of neurotransmitter in the synapse) p793 |
| * TRUE or FALSE: The input from a single action potential coming from a pre-synaptic neuron is typically not strong enough to cause the post-synaptic neuron to fire off. | TRUE (It usually takes the input of axons from several different pre-synaptic neurons to cause the post-synaptic neuron to fire off. It can also be triggered to fire off by the rapid arrival of several action potentials in succession coming from the same pre-synaptic neuron.This cumulative effect of multiple excitatory stimuli is called summation) p794 |
| * TRUE or FALSE: Stimulation from a pre-synaptic neuron can inhibit the firing off of a post-synaptic neuron. | * TRUE (If the stimulus causes only K+ ions to enter the post-synaptic neuron, the post-synaptic neuron will hyperpolarize, causing it to have a harder time firing off) p794 |
| * If the sum of both the excitatory (positive) and inhibitory (negative) post-synaptic potentials causes the membrane potential in the post-synaptic neuron to reach the threshold of -55mV, it will lead to a(n) ______ potential in the post-synaptic neuron. | action (The purple stimulus is inhibitory and the green ones are excitatory in the graphic below) pp794&795,  |
