Ch.47 - Nervous SystemSee all chapters
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Ch.1 - Introduction to Biology
Ch.2 - Chemistry
Ch.3 - Water
Ch.4 - Carbon
Ch.5 - Biological Molecules
Ch.6 - Cells
Ch.7 - The Membrane
Ch.8 - Energy and Metabolism
Ch.9 - Respiration
Ch.10 - Photosynthesis
Ch.11 - Cell Signaling
Ch.12 - Cell Division
Ch.13 - Meiosis
Ch.14 - Mendelian Genetics
Ch.15 - Chromosomal Theory of Inheritance
Ch.16 - DNA Synthesis
Ch.17 - Gene Expression
Ch.18 - Regulation of Expression
Ch.19 - Viruses
Ch.20 - Biotechnology
Ch.21 - Genomics
Ch.22 - Development
Ch.23 - Evolution by Natural Selection
Ch.24 - Evolution of Populations
Ch.25 - Speciation
Ch.26 - History of Life on Earth
Ch.27 - Phylogeny
Ch.28 - Prokaryotes
Ch.29 - Protists
Ch.30 - Plants
Ch.31 - Fungi
Ch.32 - Overview of Animals
Ch.33 - Invertebrates
Ch.34 - Vertebrates
Ch.35 - Plant Anatomy
Ch.36 - Vascular Plant Transport
Ch.37 - Soil
Ch.38 - Plant Reproduction
Ch.39 - Plant Sensation and Response
Ch.40 - Animal Form and Function
Ch.41 - Digestive System
Ch.42 - Circulatory System
Ch.43 - Immune System
Ch.44 - Osmoregulation and Excretion
Ch.45 - Endocrine System
Ch.46 - Animal Reproduction
Ch.47 - Nervous System
Ch.48 - Sensory Systems
Ch.49 - Muscle Systems
Ch.50 - Ecology
Ch.51 - Animal Behavior
Ch.52 - Population Ecology
Ch.53 - Community Ecology
Ch.54 - Ecosystems
Ch.55 - Conservation Biology

Neurons and Action Potentials

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Additional Problems
The point of connection between two communicating neurons is called the ________.a. axon hillockb. dendritec. synapsed. cell body
The concentrations of ions are very different inside and outside a nerve cell due to ________. a. osmosis b. diffusion c. sodium-potassium pumps d. symports and antiports
Why do Na+ ions enter the cell when voltage-gated Na + channels are opened in neurons? a. because the Na+ concentration is much lower outside the cell than it is inside b. because the Na+ ions are actively transported by the sodium-potassium pump into the cell c. because the Na+ concentration is much higher outside the cell than it is inside, and the Na + ions are attracted to the negatively charged interior d. because the Na+ concentration is much higher outside the cell than it is inside, and the Na + ions are actively transported by the sodium-potassium pump into the cell
Neurotransmitters are released from axon terminals via ________. a. osmosis b. active transport c. diffusion d. exocytosis
An example of ligand-gated ion channels is ________. a. the spreading of action potentials in the heart b. acetylcholine receptors at the neuromuscular junction c. cAMP-dependent protein kinases d. action potentials on the axon
Neurotransmitters can affect postsynaptic cells by ________. I) initiating signal transduction pathways in the cells II) causing molecular changes in the cells III)altering ion channel proteins IV)altering the permeability of the cells a. I and III b. II and IV c. III and IV d. I, II, III, and IV
A common feature of action potentials is that theya. cause the membrane to hyperpolarize and then depolarize.b. can undergo temporal and spatial summation.c. are triggered by a depolarization that reaches threshold.d. move at the same speed along all axons.
Where are neurotransmitter receptors located? a. the nuclear membrane b. the nodes of Ranvier c. the postsynaptic membrane d. synaptic vesicle membranes
What is the most abundant intracellular cation?a. Na+b. K+c. HPO42-d. Cl-
The rate with which an action potential travels along an axon _______.a. is called the conduction velocityb. is measured in meters/secc. is measured in volts/secd. is called the conduction velocity and is measured in meters/sece. is called the conduction velocity and is measured in volts/sec
Which of the following describes a B fiber?a. large diameter, lightly myelinatedb. medium diameter, lightly myelinatedc. small diameter, lightly myelinatedd. small diameter, unmyelinated
An enzyme known as acetylcholinesterase is present in the synaptic cleft. What is its role?a. to pump Ca2+ back out of the axon terminalb. to facilitated transport of acetylcholine across the cleftc. to break down acetylcholined. to facilitate the entrance of acetylcholine into the muscle cell 
List and explain all things that contribute the resting membrane potential of excitable cells (e.g., neurons, muscle).
If Ca+2 concentrations inside and outside a cell are 10-7 M and 10-3 M, respectively, then ECa+2 will be:a. +61.5 mVb. +246 mVc. +123 mVd. -61.5mV
Why is a neuron unable to fire an action potential during the absolute refractory period?
The neurotransmitter acetylcholine:A. enters muscle cells through acetylcholine receptorB. released from nerve cells through the acetylcholine receptor C. once bound to the acetylcholine receptor will trigger an electrical event in the muscle cell membraneD. more than one ofthe above are true
The effects of acetylcholine can be either excitatory or inhibitory. The effect depends on A. The type of calcium channels in the presynaptic neuron.B. The type of acetylcholine-activated channel in the post-synaptic membrane.C. The presence or absence of acetylcholinesterase in the synaptic cleft.D. whether the presynaptic cell is excitatory or inhibitory.E. whether calcium flows through the acetylcholine-activated channel.
Astrocytes often serve as support cells that provide fuel for the neurons. Describe briefly the processes carried out by astrocytes to feed the neurons. 
Explain the sequence of events that allows a pre-synaptic cell to communicate with a post-synaptic cell.
What causes a neuron to "fire?" How does this happen? In your own words, do your best to explain this process.
What factors contribute to the -70mV resting membrane potential? (select all that apply)A. Na+ leak channels allow Na+ to leak in.B. Cl- enters the cell making the inside very negative.C. K+ leak channels allow K+ to enter the cell down its concentration gradient.D. Na+/K+ pump generates a high concentration of K+ on the outside of the cell, making the inside more negative.
How does signal conduction in myelinated axons differ from signal conduction in unmyelinated axons?
Why are neurons long and branched? Why are neutrophils so small?
The plasma membrane of a neuron is more permeable to potassium ions than to sodium ions because the membrane has:A. more ligand-gated potassium ion channels.B. more voltage-gated sodium ion channels.C. more carrier molecules for potassium ions.D. more potassium leakage channels.E. fewer voltage-gated sodium ion channels.
Describe the properties of a voltage gated potassium channel. What is its' role in an ? Is there any effect of the inactivating particle?
What are the three different possible electrical currents in the post synaptic membrane?
The absolute refractory period is the timeA. between injury to an axon and recovery of function.B. it takes a neurotransmitter to diffuse across a synaptic cleft.C. following an action potential during which a second action potential cannot be initiated regardless of stimulus strength.D. following birth when neurons can still reproduce.E. it takes to reach threshold via temporal summation.
The Na+/K+ ATPase  (Na+/K+ pump) maintains the concentration gradients for sodium and potassium ions by moving two sodium ions out of the cell and three potassium ions into the cell.A. TrueB. False
Why does the width of the action potential affect synaptic release?
Describe the sequence of events at a typical fast chemical sysnapse.
If Ca+2 concentrations inside and outside a cell are 10-7 and 10-3 M, respectively, then ECa+2 will be: a. +61.5 mVb. +246 mVc. +123mVd. -61.5mV
What does it mean that a part of the membrane is refractory? Select all that apply.A. It is insensitive to another depolarizing stimulus.B. It means that voltage-gated K+ channels and voltage-gated Na+ channels are closed.C. It is ready to have another action potential.D. It means that Na+ is coming into the cell.