BIO222 Test 1 Ch 12
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63 terms
Terms | Definitions |
|---|---|
 CNS | what main division of the nervous system is composed of the brain and spinal cord? |
| PNS | what main division of the nervous system is composed of cranial nerves, spinal nerves, plexuses |
| sensory, integrative, motor | what are the three main functions of the nervous system? |
| cell body, axon, synapse | What are the three main regions of an axon? |
| dendrite | the extension of the neuron's cell body that receives signals and electrical impulses |
| trigger zone | when there is enough impulses, a signal is sent through the axon starting at this region of the cell body |
| multipolar, bipolar, unipolar | what are the three main classifications of neurons? |
| unipolar | of the three main classes of neurons, which one has the fastest nerve propagation and functions as sensory receptors? |
| meissner/pacinian corpuscle (filament), merkel cell, nociceptor | what are the four types of unipolar neurons? |
| pukinje (cerebellum), pyramidal (cerebral cortex) | what are the two types of neurons and where are they found? |
| sensory (info to CNS), motor (info away from CNS), interneurons (integrate and send response) | What are the three functional classifications of neurons? |
| astrocyte, oligodendrocyte, ependymal cell, microglial | what are the four types of neuroglia in the CNS? |
| astrocyte | Which type of neuroglia contains microfilaments which support neurons, secretes a blood-brain barrier, and maintains the environment for nerve impulses |
| fibrous (white matter, long/unbranched), protoplasmic (gray matter, short/unbranched) | What are the two types of astrocytes? |
| oligodendrocyte | which type of neuroglia is responsible for maintaining the myelin sheath around CNS axons? |
| microglial | which type of neuroglia functions as a phagocyte to help degrade worn out cells? |
| ependymal cell | which type of neuroglia lines ventricles of the brain and functions in absorption and the production/circulation of cerebrospinal fluid |
| schwann, satellite | what are the two types of neuroglial cells in the PNS? |
| schwann cell | which type of neuroglia is responsible for the myelination of a single axon in the PNS? |
| satellite cell | which neuroglia regulates exchange between neuronal cell bodies and interstitial fluid? |
| ganglion | the term for neuronal bodies in the PNS |
| nucleus | the term for neuronal bodies in the CNS |
| nerve | the term for a bundle of axons in the PNS |
| tract | the term for a bundle of axons in the CNS |
| white | which type of "matter" primarily consists of myelinated axons of many neurons? |
| gray | which type of "matter" primarily consists of neuron cell bodies, dendrites, unmyelinated axons, axon terminals, and neuroglia? |
| The central nervous system is composed of the brain and spinal cord. It receives information via sensory nerves, integrates, and sends response to motor neurons in the peripheral nervous system. The PNS is made up of the somatic nervous system (skeletal muscle, voluntary), autonomic nervous system (smooth muscle), and enteric nervous system (GI tract). | Describe the organization of the Nervous system |
| short | Graded potentials allow for communication over ____ distances |
| long | Action potentials allow for communication over ____ distances |
| graded potential in sensory receptor triggers action potential along sensory nerve to the CNS. Sensory nerve synapses with an interneuron then interneuron then interneuron... until interneurons in the cerebral cortex are activated and perception occurs. | Describe the process of perceiving that you are holding something |
| stimulus causes graded potential to form causing an action potential in an upper motor neuron. The upper motor neuron synapses with a lower motor neuron which forms a neuromuscular junction with skeletal muscle fibers. Neurotransmitter release stimulates muscle fibers to contract. | Describe the process of a stimulus in the brain causing muscle contraction |
| resting membrane potential, specific ion channels | Production of graded potentials and action potentials depend on what two basic features of the plasma membrane of excitable cells? |
| unequal distribution of ions, inability of most anions to leave cell, electromagnetic nature of Na+ / K+ATPase | What three factors are needed to maintain resting membrane potential? |
| hyperpolarizing, depolarizing (cause AP) | What are the two types of graded potentials? Which type can create an action potential if it meets threshold? |
| resting state, depolarization phase, repolarization phase | what are the three main phases of the axon's plasma membrane? |
| Voltage gated Na+ and K+ channels are closed and the plasma membrane potential is at -70mV. Negative inside, Positive outside. | Describe the resting state |
| voltage-gated Na+ channels open and Na rushes in to cause a buildup of positive charges inside the membrane. Membrane becomes depolarized (-55mV) | Describe the depolarization phase |
| voltage-gated Na+channels close and K+ channels open. The membrane becomes repolarized as K+ ions leave the inside causing negative charges to build up. | Describe the repolarizing phase |
| the period of time after an action potential begins during which an excitable cell cannot generate another action potential to a normal threshold stimulus. Coincides with Na+ channel activation - inactivation. | Describe the refractory period |
| continuous | the type of conduction that occurs in non-myelinated axons. Opening of Na+ channels causes current that prompts adjacent Na+ channel to open |
| saltatory | the type of conduction that occurs in myelinated axons. Na+ channels are located in the nodes of ranvier and an Ionic current surrounds myelinated portions. Action potentials "leap" from one node to the next. |
| electrical, chemical | What are the two types of synapses? |
| An action potential is conducted directly between adjacent cells through gap junctions. Connexons are tunnels connecting the cytosol of two cells directly. Faster communication allows for synchronization | Describe electrical synapses |
| Action potential reaches the synaptic end bulb and triggers the opening of calcium gates. Calcium binds to vesicles containing neurotransmitters which merge to the plasmamembrane and exocytose contents. Neurotransmitters diffuse across synaptic cleft and bind to receptors on the plasma membrane of the postsynaptic neuron, opening Na channels. Influx of sodium creates a graded potential which creates an action potential | Describe chemical synapses |
| ionotropic, metabotropic | What are the two types of receptors? |
| ionotropic | the type of receptor that contains a neurotransmitter binding site and an ion channel as part of the same protein. It is a type of ligand-gated channel (binding causes immediate opening of channel) |
| metabotropic | the type of receptor that contains a neurotransmitter binding site and is coupled to a separate ion channel by a type of membrane protein (G protein). No direct action since the neurotransmitter and ion channel are components of different proteins. |
| diffusion, enzymatic degradation, uptake by cells | what are the three ways neurotransmitters may be removed from a synapse? |
| a | what type of nerve fiber has the largest diameter, is myelinated, has a brief absolute refractory period and the fastest impulse propagation? Examples include sensory neurons associated with pain, touch, and pressure and motor neurons that conduct impulses to skeletal muscles |
| b | what type of nerve fiber is myelinated and has a longer refractory period. Examples include sensory impulses from viscera to brain and spinal cord and autonomic motor neurons |
| c | what type of nerve fiber is unmyelinated, has the smallest diameter, slowest propagation, and longest refractory periods? Examples include some sensory impulses from skin and anutonomic motor fibers that stimulate heart, smooth muscle, and glands. |
| summation of postsynaptic potentials in response to stimuli that occur from different presynaptic neurons at different location in the postsynaptic membrane, but at the same time. Summation of total excitatory versus inhibitory signals. | Describe spatial summation of postynaptic potentials |
| summation of postsynaptic potentials in response to stimuli that occur at the same location in the membrane of the postsynaptic cell but at different times. Action potential results from the buildup of neurotransmitter released by a single presynaptic end bulb two or more times in rapid succession. | Describe temporal summation of postsynaptic potentials |
| acetylcholine, amino acids, biogenic amines, nitric oxide, neuropeptides | What are the five main categories of neurotransmitters? |
| excitatory at some synapses and inhibitory at others. commonly found in the CNS and PNS | Describe the neurotransmitter acetylcholine |
| Includes glutamate (EPSP), Aspartate, and GABA (IPSP). Located in CNS | Describe the amino acid neurotransmitters |
| includes norepinephrine (awakening), epinephrine, dopamine (emotional responses, addictive behaviors, pleasure), and serotonin (sensory perception, temp regulation, mood, appetite, sleep) | Describe the biogenic amine nuerotransmitters |
| not synthesized in advance; formed on demand and acts immediately. Affects memory and learning. Causes vasodilation | Describe the neurotransmitter nitric oxide |
| composed of three to forty amino acids. In the CNS and PNS. Function as the body's natural painkillers (enkephalins), memory, learning, pleasure, control of body temperature, regulate puberty hormones, sexual drive, reproduction, depression | Describe the neuropeptide neurotransmitters |
| diverging | what type of neural circuit corresponds to sensory signals? |
| converging | what type of neural circuit corresponds to motor neurons? |
| reverberating | what type of neural circuit is associated with waking up? |
| parallel after-discharge | what type of neural circuit is associated with concentration? |
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