AP Biology Chapter 48: Nervous System Flashcards

9277087345	Nervous 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 brain	0
9277087346	Information Processing	- Sensory input, integration, motor output	1
9277087347	Central Nervous System	- Integrates and processes information from the body	2
9277087348	Peripheral Nervous System	- Transmits information to and from the Central Nervous System - Contains sensory and motor division	3
9277087349	Sensory Nervous System	- Sends signals to the Central Nervous System from receptors	4
9277087350	Motor 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 System	5
9277087351	Somatic Nervous System	- Carries signals to skeletal muscles and is voluntarily controlled	6
9277087352	Autonomic Nervous System	: Involuntarily regulates the internal environment : Carries signals to cardiac muscle, smooth muscle, and glands : Divides into the Parasympathetic and Sympathetic divisions	7
9277087353	Sympathetic Division	: "Fight or flight" response : Brings the body into a state of arousal	8
9277087354	Parasympathetic Division	: Promotes a return to self-maintenance functions and resting and digesting : Brings the body from a state of arousal back to normal	9
9277087355	Sensory Neurons	: Transmit information from sensory receptors to the Central Nervous System : Detects external stimuli and internal conditions	10
9277087356	Interneurons	: Integrate the information in the Central Nervous System : This can be in the spinal cord or connect up to the brain	11
9277087357	Motor Neurons	: Transmit information away from the Central Nervous System : Neurons communicate with effector organ (muscles and glands)	12
9277087358	Reflex 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 control	13
9277087396	Neuron		14
9277087359	Cell Body	: Contains the organelles	15
9277087360	Dendrites	: Highly branched extensions that receive signals from other neurons	16
9277087361	Axon	: Cytoplasmic extension that transmits signals to other cells at synapses : May be covered with Schwann cells	17
9277087362	Schwann Cells	: A fatty cell wrapped around the axon to form the myelin sheath	18
9277087363	Myelin Sheath	: A fatty covering on the axon that insulates it and speeds up the conducting process	19
9277087364	Nodes of Ranvier	: Space between the Schwann cells on the axon	20
9277087365	Axon terminals	: Contains the vesicles of neurotransmitters	21
9277087366	Glia Cells	: Essential for the structural integrity of the nervous system and for the normal funciotning of neurons	22
9277087367	Resting 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 potential	23
9277087368	Why is the charge -70 mV?	: Because there are more potassium (K+) channels open compared to sodium (Na+) and there are negative proteins inside the cell	24
9277087369	Action 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 ->Depolarization	25
9277087370	Hyperpolarization	: An increase in the magnitude of the membrane potential (larger negative difference from inside to outside)	26
9277087371	Depolarization	: 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 potential	27
9277087372	Threshold	: Membrane voltage amount needed to cause an action potential : -55 mV	28
9277087373	Action Potential Steps	: A brief all-or-none depolarization of a neuron's plasma membrane that carries information along axons : Depolarization, Action Potential, Repolarization	29
9277087374	Action 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 outside	30
9277087375	Action Potential Steps: Action Potential	: Propagation of the signal is continued depolarization down the axon	31
9277087376	Action 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
9277087377	Conduction 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 axon	33
9277087378	Saltatory Conduction	: A process when action potentials in myelinated axons jump between the nodes of Ranvier : Allows the signal to travel faster down the axon	34
9277087379	Synapse	: 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 gap	35
9277087380	Direct 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
9277087381	Neurotransmitters	: 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, GABA	37
9277087382	Acetylcholine	: Stimulates muscle contractions	38
9277087383	Epinephrine and Norepinephrine	: Fight or flight response	39
9277087384	Dopamine and Serotonin	: Excitatory responses	40
9277087385	GABA	: Represses neuron activity especially during fear or anxiety when neurons are overstimulated	41
9277087386	Gray Matter	: No myelin sheath : Located outside in brain and inside in spinal cord	42
9277087387	White Matter	: Has a myelin sheath : Located on outside in spinal cord and inside in brain	43
9277087388	Brainstem	: Midbrain-contains centers for passing, ascending, and descending signals : Pons-controls breathing : Medulla oblongata-controls heart rate, breathing, swallowing, and vomiting	44
9277087389	Cerebellum	: Important for coordination and balance : Also involved in earning and rememebering motor skills	45
9277087390	Diencephalon	: 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
9277087391	Cerebrum	: Centers for planning and learning : Analyzes sensory information	47
9277087392	Limbic System	- Attach emotional "feelings" to survival-related functions	48