front 1 What are the functions of the nervous system? | back 1 Integration, sensory input, and motor output |
front 2 integration (brain) | back 2 processes sensory info, controls all body responses and activities, stores info |
front 3 sensory input (eyes) | back 3 detecting and monitoring internal and external stimuli |
front 4 motor output (movement) | back 4 causes a response in muscles and glands |
front 5 The nervous system is divided into what parts? | back 5 central nervous system (CNS) and peripheral nervous system (PNS) |
front 6 The CNS is made up of | back 6 the brain and spinal cord |
front 7 The PNS is made up of | back 7 the cranial and spinal nerves and sensory receptors |
front 8 What subdivisions is the PNS further divided into based on the direction impulses travel? | back 8 sensory (afferent) pathway and motor (efferent) pathway |
front 9 sensory (afferent) pathway | back 9 receptors that detect stimuli and the neurons that carry info TO the CNS (incoming) |
front 10 motor (efferent) pathway | back 10 neurons that carry impulses FROM the CNS (outgoing) |
front 11 What are the two parts of the efferent pathway? | back 11 somatic nervous system (SNS) and the autonomic nervous system (ANS) |
front 12 SNS | back 12 mostly voluntary- includes the neurons sending info to the skeletal muscles |
front 13 ANS | back 13 always involuntary- includes sending info to smooth and cardiac muscles. Divided into sympathetic and parasympathetic divisions. |
front 14 What are the two main parts of the cells in the nervous system? | back 14 a)neurons
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front 15 neurons | back 15 the functional unit of the nervous system, excitable cells that produce and conduct electrical signals and release chemicals for regulation and communication called neurotransmitters. |
front 16 neurotransmitters (NT) | back 16 chemicals used to regulate and communicate |
front 17 neuroglia | back 17 (glial cells) support neurons |
front 18 The structure of a neuron includes: | back 18 a)cell body
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front 19 cell body | back 19 has one nucleus, rough ER, and ribosomes to make proteins |
front 20 axon hillock | back 20 thick base of the cell body |
front 21 dendrites | back 21 carry impulses TO the cell body, often branched |
front 22 axons | back 22 carry impulses AWAY from the cell body. a single long process that starts at the axon hillock. branches at its end to form axon terminals whose tips are filled with NT. |
front 23 How are neurons classified by function? | back 23 a)afferent neutons
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front 24 interneurons | back 24 make up about 90% of all neurons in the body, connect sensory and motor neurons |
front 25 How are neurons classified by structure? | back 25 ![]() |
front 26 multipolar | back 26 several dendrites and one axon; most common |
front 27 bipolar | back 27 has one dendrite and one axon |
front 28 unipolar | back 28 has one process that splits into an axon and dendrite; rare |
front 29 Which glial cells are in the CNS? | back 29 astrocytes, oligodendrocytes, microglia, and ependymal |
front 30 Which glial cells are found in the PNS? | back 30 Schwann and satellite |
front 31 astrocytes (CNS) | back 31 star shaped cells that form the blood-brain barrier by covering brain capillaries in the brain. |
front 32 oligodendrocytes (CNS) | back 32 form a myelin sheath around multiple axons which send signals faster |
front 33 microglia (CNS) | back 33 found near blood vessels and are phagocytic |
front 34 ependymal cells (CNS) | back 34 line the inside of the spinal cord and produce cerebrospinal fluid |
front 35 satellite cells (PNS) | back 35 flat cells that surround cell bodies in ganglia to provide support |
front 36 Schwann cells (PNS) | back 36 wrap around axons of PNS neurons and produce a myelin sheath |
front 37 myelination | back 37 most PNS axons are myelinated, only some are in the CNS |
front 38 nodes of Ranvier | back 38 unmyelinated gaps along an axon; nodes are in contact with the extra cellular fluid (ECF) |
front 39 white matter | back 39 made up of myelinated axons |
front 40 gray matter | back 40 made up of everything else (cell bodies, dendrites, axon terminals, unmyelinated axons, and neuroglia) |
front 41 excitable cells | back 41 change their membrane potential when they are stimulated which creates an electrical signal |
front 42 resting membrane potential (RPM) | back 42 occurs when all ions inside and outside of the membrane are in equilibrium; RPM = -70 in neurons |
front 43 Na+ is high _____ the cell and the membrane is ________ permeable to Na+. | back 43 outside, barely |
front 44 K+ is high ______ the cell and the membrane is ________ permeable to K+. | back 44 inside, highly |
front 45 One pump cycle moves ____ Na+ out and ____ K+ in. | back 45 3, 2 |
front 46 Ion channels | back 46 Allow ions to pass thorough the membrane
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front 47 Leakage channels | back 47 are always open and create a slow leak |
front 48 Gated channels | back 48 must be stimulated in order to open and close |
front 49 Chemically-gated channels | back 49 channel has ligands bound to it which cause the gate to open. The gate closes when there is no ligand present. |
front 50 Voltage-gated channels | back 50 open and close when there is a nearby change in membrane potential (voltage) |
front 51 Depolarization | back 51 the potential is making the inside of the cell less negative than the RMP ex. -60 |
front 52 Repolarization | back 52 the potential is making the inside of the cell more negative |
front 53 Hyperpolarization | back 53 the potential is making the inside of the cell more negative than RMP ex. -80 |
front 54 stimulus | back 54 starts activity by moving neuron away from its RMP and creates a new potential
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front 55 Name the types of potentials. | back 55 a)graded
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front 56 Graded potentials | back 56 initiated by a stimulus to either the dendrites or cell body. they can be weak or strong depending on the stimulus. transmitted along the membrane of dendrites/cell body towards the axon hillock. |
front 57 Action potentials | back 57 initiated ONLY if a STRONG graded potential makes it to the axon hillock; spreads along the length of an axon to the axon terminals |
front 58 Graded potentials _____ as they travel. | back 58 weaken |
front 59 Strong enough graded potentials reach a ___________ which is located on the axon hillock. | back 59 trigger zone |
front 60 Trigger zone | back 60 is only activated if the graded potential is strong enough (if GP hits a threshold voltage, TV, of -55mV) |
front 61 GP < TV, then | back 61 there is no response |
front 62 GP > or = TP, then | back 62 the neuron hits threshold and an AP is generated in the axon |
front 63 In the trigger zone | back 63 there is a high concentration of Na+ voltage-gated channels. if threshold is reached: channels open and Na+ rush into cell which causes depolarization and initiates the AP |
front 64 Action potentials are based on | back 64 if the threshold is reached or not; the activity of voltage-gated Na+ and K+ channels |
front 65 What are the steps of an action potential? | back 65 1.resting state
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front 66 1.Resting State | back 66 neuron is at RMP and Na+ and K+ channels are closed |
front 67 2.Depolarization | back 67 stimulus depolarizes the membrane IF stimulus is strong enough, then the AP starts. Many Na+ channels open causing Na+ to rush in (causes depolarization). Few K+ channels open causing a little K+ to leak out. At the peak of depolarization, a second gate on Na+ channels closes (stops depolarization) |
front 68 3.Repolarization | back 68 many K+ channels open and K+ leaves the cell |
front 69 4.Hyperpolarization | back 69 some K+ channels are still open after repolarization and the membrane over shoots RMP (hyperpolarization). Then all K+ channels are closed, Na/K+ pumps restore ions to original position (Na+ out and K+ in). Membrane returns to RMP. |
front 70 Energy | back 70 ATP is needed to fuel Na+/K+ pumps but is not needed to generate an AP (done by diffusion) |
front 71 How does a neuron respond to stimuli of different intensities? | back 71 a stronger stimulus means an increase in the frequency of AP |
front 72 Refractory Period | back 72 recovery period for the neuron after an AP |
front 73 Absolute refractory period | back 73 axon membrane can produce another AP, but requires a STRONGER stimulus than before |
front 74 Conduction of APs | back 74 one AP doesn't occur across the entire axon, only across a small distance (< 1mm). One AP stimulates a new one in the next region of the axon membrane and conduct along the axon to it's end. (Domino Effect) |
front 75 Saltatory Conduction in myelinated axons | back 75 where there is myelin on an axon, channels don't open or close. APs jump from one Node of Ranvier to another; conducts APs 10-50x faster |
front 76 Synapse | back 76 occurs when an AP reaches the end of the axon; allows communication between a neuron and another cell (neuron to neuron or neuron to effector) |
front 77 Which direction is the transmission of synapse information? | back 77 the presynaptic neuron sends info to the postsynaptic neuron or cell |
front 78 Synaptic cleft | back 78 space between presynaptic and postsynaptic neurons |
front 79 Steps to release a NT | back 79 1. an AP arrives at axon terminal
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