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AP Biology Chapter 48: Nervous System Flashcards

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9277087345Nervous System- Coordinates and controls bodily functions with nerves and electrical impulses - Composed of different types of nerve cells called neurons - Brain provides integrative power that underlies the complex behavior of vertebrates - The spinal cord integrates simple responses to certain kinds of stimuli and conveys information to and from the brain0
9277087346Information Processing- Sensory input, integration, motor output1
9277087347Central Nervous System- Integrates and processes information from the body2
9277087348Peripheral Nervous System- Transmits information to and from the Central Nervous System - Contains sensory and motor division3
9277087349Sensory Nervous System- Sends signals to the Central Nervous System from receptors4
9277087350Motor Nervous System- Sends signals away from the Central Nervous System to the parts of the body - Can be separated into the Somatic Nervous system and the Autonomic Nervous System5
9277087351Somatic Nervous System- Carries signals to skeletal muscles and is voluntarily controlled6
9277087352Autonomic Nervous System: Involuntarily regulates the internal environment : Carries signals to cardiac muscle, smooth muscle, and glands : Divides into the Parasympathetic and Sympathetic divisions7
9277087353Sympathetic Division: "Fight or flight" response : Brings the body into a state of arousal8
9277087354Parasympathetic Division: Promotes a return to self-maintenance functions and resting and digesting : Brings the body from a state of arousal back to normal9
9277087355Sensory Neurons: Transmit information from sensory receptors to the Central Nervous System : Detects external stimuli and internal conditions10
9277087356Interneurons: Integrate the information in the Central Nervous System : This can be in the spinal cord or connect up to the brain11
9277087357Motor Neurons: Transmit information away from the Central Nervous System : Neurons communicate with effector organ (muscles and glands)12
9277087358Reflex Arc: Body's automatic response to a stimuli : Pathway includes-receptor, sensory neuron, interneuron, motor neuron, effector organ : Much faster response compared to the typical stimulus-response transmission pathways ->does not involve the integration of the brain ->does not require conscious control13
9277087396Neuron14
9277087359Cell Body: Contains the organelles15
9277087360Dendrites: Highly branched extensions that receive signals from other neurons16
9277087361Axon: Cytoplasmic extension that transmits signals to other cells at synapses : May be covered with Schwann cells17
9277087362Schwann Cells: A fatty cell wrapped around the axon to form the myelin sheath18
9277087363Myelin Sheath: A fatty covering on the axon that insulates it and speeds up the conducting process19
9277087364Nodes of Ranvier: Space between the Schwann cells on the axon20
9277087365Axon terminals: Contains the vesicles of neurotransmitters21
9277087366Glia Cells: Essential for the structural integrity of the nervous system and for the normal funciotning of neurons22
9277087367Resting Membrane Potential: The electrical potential difference that polarizes the membranes of neurons : The inside of the cell is negative (K+) relative to the outside, which is more positive (Na+) : When a neuron is not transmitting a signal : -70 mV : Depends on the ionic gradients that exist across the membrane ->Ion pumps and ion channels maintain this potential : The diffusion of potassium and sodium through these channels leads to a separation of charges across the membrane, producing the resting potential23
9277087368Why is the charge -70 mV?: Because there are more potassium (K+) channels open compared to sodium (Na+) and there are negative proteins inside the cell24
9277087369Action Potential: Gated ion channels open or close in response to the binding of a specific ligand or a voltage change ->Changes the membrane potential : Two different responses, both graded potentials (because the change in potential varies with the strength of the stimulus) ->Hyperpolarization ->Depolarization25
9277087370Hyperpolarization: An increase in the magnitude of the membrane potential (larger negative difference from inside to outside)26
9277087371Depolarization: A reduction in the magnitude of the membrane potential (move towards a positive difference from outside to inside) : A stimulus strong enough to produce a depolarization that reaches the threshold will trigger and action potential27
9277087372Threshold: Membrane voltage amount needed to cause an action potential : -55 mV28
9277087373Action Potential Steps: A brief all-or-none depolarization of a neuron's plasma membrane that carries information along axons : Depolarization, Action Potential, Repolarization29
9277087374Action Potential Steps: Depolarization: Membrane sodium (Na+) channels open which allows sodium to diffuse into the cell : This causes the charge on the neuron membrane to change to positive inside and negative outside30
9277087375Action Potential Steps: Action Potential: Propagation of the signal is continued depolarization down the axon31
9277087376Action Potential Steps: Repolarization: As the action potential subsides, K+ channels open, and potassium flows out of the cell whcih changes the charge again on the membrane : Na/K pump restores the ion concentration differences with the use of ATP ->Returns to the resting membrane​ potential : A refractory period follows the action potential during which a second action potential cannot be initiated​32
9277087377Conduction of Action Potentials: An action potential can travel long distances by regenerating itself along the axon : The opening of Na+ channels triggers the opening of even more channels : The speed of an action potential increases with the diameter of an axon33
9277087378Saltatory Conduction: A process when action potentials in myelinated axons jump between the nodes of Ranvier : Allows the signal to travel faster down the axon34
9277087379Synapse: Electrical-electrical current flows directly from one cell to another via gap junction : Chemical-a presynaptic neuron releases chemical neurotransmitters, which are stored in the synaptic terminal ->Neurotransmitters will travel through the synaptic cleft to bind the post-synaptic neuron : Calcium forces the neurotransmitters across the gap35
9277087380Direct Synaptic Transmission: Involves the binding of neurotransmitters to ligand-gated ion channels : Causes the ion channels to open, generating a postsynaptic potential (either excitatory or inhibitory) : After its release, the neurotransmitter diffuses out of the synaptic cleft (either taken backup or degraded by enzymes)36
9277087381Neurotransmitters: Chemical messengers that act on cells to create a response : Can produce different effects in different types of cells : Acetylcholine, epinephrine and norepinephrine, dopamine and serotonin, GABA37
9277087382Acetylcholine: Stimulates muscle contractions38
9277087383Epinephrine and Norepinephrine: Fight or flight response39
9277087384Dopamine and Serotonin: Excitatory responses40
9277087385GABA: Represses neuron activity especially during fear or anxiety when neurons are overstimulated41
9277087386Gray Matter: No myelin sheath : Located outside in brain and inside in spinal cord42
9277087387White Matter: Has a myelin sheath : Located on outside in spinal cord and inside in brain43
9277087388Brainstem: Midbrain-contains centers for passing, ascending, and descending signals : Pons-controls breathing : Medulla oblongata-controls heart rate, breathing, swallowing, and vomiting44
9277087389Cerebellum: Important for coordination and balance : Also involved in earning and rememebering motor skills45
9277087390Diencephalon: Epithalamus-includes pineal gland (releases melatonin for sleep) : Thalamus-sends sensory and motor information to the cerebrum : Hypothalamus-regulates homeostasis (the four F's-feeding, fighting, fleeing, and reproducing)46
9277087391Cerebrum: Centers for planning and learning : Analyzes sensory information47
9277087392Limbic System- Attach emotional "feelings" to survival-related functions48

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