Module 2: Structures and Functions

"-[...]: A glial cell that controls chemical environment around neurons, ""housekeeping"" -Provides nutrients to the neurons by wrapping around neurons and blood vessels -Convert glucose from bloodstream to [...], which is then used by neurons and store glycogen to convert to glucose later -Surround and isolate [...], limiting the dispersion of neurotransmitters that are released by the terminal buttons. -Remove debris via [...] -Act as ""glue"" by holding neurons in place"

"-Astrocyte: A glial cell that controls chemical environment around neurons, ""housekeeping"" -Provides nutrients to the neurons by wrapping around neurons and blood vessels -Convert glucose from bloodstream to lactate, which is then used by neurons and store glycogen to convert to glucose later -Surround and isolate synapses, limiting the dispersion of neurotransmitters that are released by the terminal buttons. -Remove debris via phagocytes -Act as ""glue"" by holding neurons in place"

"Steps from action potential to release of NTs 1)[...] ""dock"" against membrane via proteins on vesicle binding with proteins on presynaptic membrane 2)AP results in opening of voltage-dependent [...] channels 3)[...] the cells 4)Binds with docking proteins on presynaptic membrane and [...] (thereby forming the fusion pore) 5)Neurotransmitter released to [...]"

"Steps from action potential to release of NTs 1)Vesicles ""dock"" against membrane via proteins on vesicle binding with proteins on presynaptic membrane 2)AP results in opening of voltage-dependent Calcium (Ca++) channels 3)Ca++ enters the cells 4)Binds with docking proteins on presynaptic membrane and causes them to separate (thereby forming the fusion pore) 5)Neurotransmitter released to synaptic cleft"

Resting Potential

-70mV

-A neuron receives info from the [...] of axons of other neurons and the [...] of its axons form synapses with other neurons -A neuron may receive info from other neurons, each can form a large # of synaptic connections -[...] can form synapses on the membrane of the dendrites or the soma

-A neuron receives info from the Terminal Buttons of axons of other neurons and the Terminal Buttons of its axons form synapses with other neurons -A neuron may receive info from other neurons, each can form a large # of synaptic connections -Terminal Buttons can form synapses on the membrane of the dendrites or the soma Neuron connections

Compare neural communication in a withdrawal reflex with and without inhibition of the reflex

-A simple withdrawal reflex is made up of a sensory neuron that detects the stimulus, a spinal interneuron that excites a motor neuron, and a motor neuron that causes the withdrawal behavior -This reflex can be inhibited by input from the brain that can prevent the withdrawal behavior by inhibiting the motor neuron

-Activation of G protein may: 1) Opens [...] 2) Activate [...] causing biochemical changes in other parts of the cell 3) Turns [...] on and off

-Activation of G protein may: 1) Opens ion channel 2) Activate second messenger causing biochemical changes in other parts of the cell 3) Turns genes on and off

-In the CNS the oligodendrocytes support axons and produce myelin, In the PNS the [...] cells perform the same functions -The myelin sheath occurs in segments; each consists of a [...] Schwann cell wrapped around the axon -Provides myelin for 1 axon, and the entire cell -If damage occurs to a nerve, they aid in the [...] of the dead and dying axons -Then arrange themselves in a series of cylinders that act as guides for [...] of the axons -The distal portions of the severed axons die, but the [...] of each severed axon grows sprouts -If one of these sprouts encounters a [...] provided by the cell, the sprout will grow through the tube quickly, while the other, nonproductive sprouts wither away

-In the CNS the oligodendrocytes support axons and produce myelin, In the PNS the Schwann cells perform the same functions -The myelin sheath occurs in segments; each consists of a single Schwann cell wrapped around the axon -Provides myelin for 1 axon, and the entire cell -If damage occurs to a nerve, they aid in the digestion of the dead and dying axons -Then arrange themselves in a series of cylinders that act as guides for regrowth of the axons -The distal portions of the severed axons die, but the stump of each severed axon grows sprouts -If one of these sprouts encounters a cylinder provided by the cell, the sprout will grow through the tube quickly, while the other, nonproductive sprouts wither away

Differentiate functions of supporting cells of the central and peripheral nervous systems

-In the CNS, astrocytes, oligodendrocytes, and microglia support neurons by creating an environment conducive to neuronal function, providing a myelin sheath, and activating immune responses -In the PNS, Schwann cells provide myelin and assist with neural regeneration.

The Organic Anion (A-)

-Inside cell -Unable to pass through the membrane of the axon

Contrast the changes in electrical potential within a neuron when it is experiencing resting potential, hyperpolarization, depolarization, and an action potential

-Resting potential in neurons is -70 mV, more negative inside the neuron compared to outside it -Hyperpolarization occurs when the inside of the neuron becomes more negative (-100mV) -Depolarization occurs when the inside of the cell becomes more positive (+20mV) -An AP occurs when a neuron is depolarized beyond its threshold of excitation -An AP is a burst of depolarization followed by hyperpolarization that proceeds like a wave along the axon, starting at the point where the axon meets the soma and proceeding to the terminal buttons

Electrostatic Pressure

-The attractive force between atomic particles charged with opposite signs or the repulsive force between atomic particles charged with the same sign -Moves ions from place to place: Cations are pushed away from regions with an excess of cations, and anions are pushed away from regions with an excess of anions

-The [...] fluid and the [...] fluid contain different ions -Membrane potential is produced by a balance between the forces of diffusion and electrostatic pressures -Ions include: [...] -Organic anions, negatively charged are found only in the [...] fluid - K+ is found in the [...] fluid -Na+ and Cl- are found in the [...] fluid

-The intracellular fluid and the extracellular fluid contain different ions -Membrane potential is produced by a balance between the forces of diffusion and electrostatic pressures -Ions include: 1. Organic anions (A-) 2. Chloride ions (Cl-) 3. Sodium ions (Na+) 4. Potassium ions (K+) -Organic anions, negatively charged are found only in the intracellular fluid - K+ is found in the intracellular fluid -Na+ and Cl- are found in the extracellular fluid

-Two types of synaptic vesicles: 1) Large, produced only in the [...] and are transported through the axoplasm to the terminal buttons. 2) Small, (found in all terminal buttons) contain [...]. Are produced in the [...] located in the soma and are carried by fast axoplasmic transport to the terminal button. -Vesicular transporter proteins fill vesicles with the neurotransmitter

-Two types of synaptic vesicles: 1) Large, produced only in the soma and are transported through the axoplasm to the terminal buttons. 2) Small, (found in all terminal buttons) contain molecules of the neurotransmitter. Are produced in the Golgi apparatus located in the soma and are carried by fast axoplasmic transport to the terminal button. -Vesicular transporter proteins fill vesicles with the neurotransmitter

-Two types of synaptic vesicles: 1) Large, produced only in the soma and are transported through the axoplasm to the terminal buttons. 2) Small, (found in all terminal buttons) contain molecules of the neurotransmitter. Are produced in the Golgi apparatus located in the soma and are carried by fast axoplasmic transport to the terminal button. -[...] fill vesicles with the neurotransmitter

-Two types of synaptic vesicles: 1) Large, produced only in the soma and are transported through the axoplasm to the terminal buttons. 2) Small, (found in all terminal buttons) contain molecules of the neurotransmitter. Are produced in the Golgi apparatus located in the soma and are carried by fast axoplasmic transport to the terminal button. -Vesicular transporter proteins fill vesicles with the neurotransmitter

Neurotransmitters open Ion Channels by at least 2 different Methods

1) Direct (simpler) 2) Indirect

Postsynaptic potentials are brief depolarizations or hyperpolarizations caused by the activation of postsynaptic receptors with molecules of a neurotransmitter. They are kept brief by 2 mechanisms

1) Reuptake 2) Enzymatic Deactivation.

4 Types of Neurotransmitter-Dependent Ion Channels found in the Postsynaptic Membrane

1) Sodium 2) Potassium 3) Chloride 4) Calcium

Postsynaptic Potentials can be either

1. Excitatory postsynaptic potential (EPSP): depolarization 2. Inhibitory postsynaptic potential (IPSP): hyperpolarization

Protein Production: Two-step process 1) ?: Info from DNA is transcribed into a portable form, mRNA. mRNA takes this info to the ribosomes for the 2nd step 2) ?: The ribosomes use the info from the mRNA and create proteins.

1.)Transcription 2.) Translation

3 Distinct Pools of Synaptic Vesicles 1)[...], are docked against the inside of the presynaptic membrane, ready to release their contents when an AP arrives, less than 1% 2) [...], 10-15% 3) [...] 85-90% -If the axon fires at a low rate, only vesicles from the release-ready pool will be called on -If the rate of firing increases, vesicles from the recycling pool and finally from the reserve pool will release their contents

3 Distinct Pools of Synaptic Vesicles 1)Release-ready vesicles, are docked against the inside of the presynaptic membrane, ready to release their contents when an AP arrives, less than 1% 2) Recycling pool vesicles, 10-15% 3) Reserve pool vesicles 85-90% -If the axon fires at a low rate, only vesicles from the release-ready pool will be called on -If the rate of firing increases, vesicles from the recycling pool and finally from the reserve pool will release their contents

A) The membrane potential must reach the [...] B) [...] channels in the membrane open, Na+ rushes in, propelled by the forces of [...], the Na+ channels are called [...] ion channels because they are only opened by changes in the membrane potential C) The interior of the cell becomes more [...] D) Voltage-dependent K+ channels open, allowing K+ to leave the cell. These K+ channels are less sensitive than voltage-dependent sodium channels, they require a greater level of depolarization before they begin to open, and they begin to open later than the Na+ channels D) After they open, the Na+ channels become [...], the channels become blocked and cannot open again until the membrane once more reaches the resting potential (-70 mV)

A) The membrane potential must reach the threshold of excitation B) Sodium channels in the membrane open, Na+ rushes in, propelled by the forces of diffusion and electrostatic pressure, the Na+ channels are called voltage-dependent ion channels because they are only opened by changes in the membrane potential C) The interior of the cell becomes more positive D) Voltage-dependent K+ channels open, allowing K+ to leave the cell. These K+ channels are less sensitive than voltage-dependent sodium channels, they require a greater level of depolarization before they begin to open, and they begin to open later than the Na+ channels D) After they open, the Na+ channels become refractory, the channels become blocked and cannot open again until the membrane once more reaches the resting potential (-70 mV) Action Potential and Ion Channels

The purpose of the blood-brain barrier is to: A) block the entrance of some substances into the brain. B) block neurotransmitters from being released. C) protect the brain from accidental impacts. D) provide a cushion for the brain.

A) block the entrance of some substances into the brain.

For Na+ ions, __________ pushes them into a cell. A) both electrostatic pressure and diffusion B) electrostatic pressure C) neither electrostatic pressure or diffision D) diffusion

A) both electrostatic pressure and diffusion

A neuron first receives a message in a _______ and passes the message along a long, thin portion of the cell called the _____. A) dendrite; axon B) dendrite; soma C) axon; dendrite D) soma; axon

A) dendrite; axon

A scan shows that a particular substance has spread throughout the body via the bloodstream but has not entered the brain. This finding demonstrates the existence of: A) the blood-brain barrier. B) medicine effects. C) the doctrine of specific nerve energies. D) blood efficacy.

A) the blood-brain barrier.

Ca2+ enters the cell when an action potential is generated. Diffision and electrostatic pressures push Ca2+ into the cell. Ca2+ channels are: A) voltage-gated. B) chemically-gated and voltage-gated. C) chemically-gated. D) passive.

A) voltage-gated.

ACh is released at every synapse at which a [...] terminates at a (skeletal) muscle fiber, and activates the motor neurons that control and [...] the (skeletal) muscles.

ACh is released at every synapse at which a motor neuron terminates at a (skeletal) muscle fiber, and activates the motor neurons that control and contract the (skeletal) muscles.

-A neurotransmitter found in the CNS and parts of the PNS -Responsible for muscular contraction

Acetylcholine (ACh)

-The enzyme that destroys acetylcholine after it is liberated by the terminal buttons, terminating the postsynaptic potential

Acetylcholinesterase (AChE)

-A brief electrical event of an axon -Act of depolarization followed by hyperpolarization, triggered by threshold of excitement

Action Potential

A molecule of prime importance to cellular energy metabolism

Adenosine Triphosphate (ATP)

An action potential either occurs or does not occur, once triggered, it is transmitted down the axon to its end

All-or-none Law

An AP is a burst of depolarization followed by hyperpolarization that proceeds like a wave along the axon, starting at the point where the [...] and proceeding to t[...]

An AP is a burst of depolarization followed by hyperpolarization that proceeds like a wave along the axon, starting at the point where the axon meets the soma and proceeding to the terminal buttons

[...] axoplasmic transport: movement from soma to terminal buttons; faster -through the protein [...] -supplied by ATP produced by mitochondria Faster than retrograde axoplasmic transport

Anterograde axoplasmic transport: movement from soma to terminal buttons; faster -through the protein kinesin -supplied by ATP produced by mitochondria Faster than retrograde axoplasmic transport

-Blood-brain area that is more permeable -Responsible for vomiting -Poisons that enter the circulatory system from the stomach can be detected there and can initiate vomiting

Area Postrema

-Located on a presynaptic neuron -Responds to neurotransmitters that they released -Metabotropic receptors with generally inhibitory effects -Help regulate the amount of neurotransmitter released and available for use

Autoreceptors

-Do not contribute directly to neural integration -Alter amount of neurotransmitter released by the terminal buttons of the postsynaptic axon -Can produce presynaptic modulation: 1) Presynaptic inhibition 2) Presynaptic facilitation

Axoaxonic synapses

-A long, thin, slender tube that conveys info from the soma of a neuron to its terminal buttons, often covered by a myelin sheath. -The outer surface of the axon carries info from the cell body to the terminal buttons

Axon

Axons 2 Modes of Growth during Development 1) The first mode causes them to [...] so that they reach their target, which could be as far away as the other end of the brain or spinal cord. [...] cells provide this signal to injured axons 2)The second mode causes axons to stop elongating and begin [...] because they have reached their target

Axons 2 Modes of Growth during Development 1) The first mode causes them to elongate so that they reach their target, which could be as far away as the other end of the brain or spinal cord. Schwann cells provide this signal to injured axons 2)The second mode causes axons to stop elongating and begin sprouting terminal buttons because they have reached their target

[...] transport: An active process that propels substances along microtubule "tracks" that run inside the axon.

Axoplasmic transport: An active process that propels substances along microtubule "tracks" that run inside the axon.

Influx of ____ or _____ ions result in EPSPs. A) Ca+; K+ B) Na+; Ca2+ C) Cl-; Na+ D) Ca2+; Cl-

B) Na+; Ca2+

As you study for your neuroscience exam, you feel a tickle on your arm. You look and see a large spider and you jerk your arm automatically. What might be the neural path for this action? A) Sensory neuron - motor neuron - interneuron - muscle B) Sensory neuron - interneuron - motor neuron - muscle C) Motor neuron - sensory neuron - interneuron - muscle D) Interneuron - sensory neuron - motor neuron - muscle

B) Sensory neuron - interneuron - motor neuron - muscle

When students enter a class, they tend to spread themselves out (provided there are enough desks to do so). In biological terms, this effect would be: A) ionic movement. B) diffusion. C) electrostatic pressure. D) antisocialism.

B) diffusion.

Susie takes a huge drink of her coffee, assuming that it is tolerable and the heat sears her mouth. Although the pain is so great that her reflex is to spit out the coffee, she does not do so. The reflex to spit out the coffee is inhibited at the __________________. A) Interneuron B) motor neuron C) glial cell D) sensory neuron

B) motor neuron

If a bowling ball fell on your foot, the action potentials would differ from a feather falling on your foot. The action potentials for the bowling ball would be: A) larger in size and faster in occurrence. B) the same size as for the feather but they would be faster in occurrence. C) the same size as for the feather but they would be slower in occurrence. D) larger in size and slower in occurrence.

B) the same size as for the feather but they would be faster in occurrence.

Hormones and neuromodulators differ from neurotransmitters in that: A) they disperse more narrowly than neurotransmitters. B) they disperse more widely than neurotransmitters. C) they are chemicals and neurotransmitters are not. D) they are fast acting compared to neurotransmitters.

B) they disperse more widely than neurotransmitters.

-The location on a receptor protein to which a ligand binds -Neurotransmitters exert their effects on cells by attaching to a particular region of a receptor molecule -The shape of the binding site and the shape of the molecule of the neurotransmitter are complementary

Binding Site

-A semipermeable barrier between the blood and the brain produced by the cells in the walls of the brain's capillaries -Responsible to avoid disruption of brain activity by controlling the neuron environment composition of what goes in and out of the neurons -Molecules are ferried in by active transport -More permeable at the area postrema, region of the brain responsible for vomiting

Blood-brain Barrier

The resting membrane potential is: A) -80 mV. B) 55 mV. C) -70 mV. D) 10 mV.

C) -70 mV.

______________ refers to the process of EPSPs and IPSPs interacting to have either an end result of excitation or inhibition. A) Immigration B) Innervation C) Integration D) Importation

C) Integration

A cation would be attracted to: A) a sodium ion. B) another cation. C) an anion. D) a potassium ion.

C) an anion.

If the inner voltage of a cell is -70 mV and application of stimulation results in a -95 mV charge, the stimulation had a ____________ effect. On the other hand, a resultant charge of +40 mV would be a ___________ effect. A) depolarizing; hyperpolarizing B) repolarizing; hyperpolarizing C) hyperpolarizing; depolarizing D) repolarizing; depolarizing

C) hyperpolarizing; depolarizing

Autoreceptors are located on the ___________. A) golgi apparatus B) post-synaptic cell C) pre-synaptic cell D) endoplasmic reticulum

C) pre-synaptic cell

When substances are transported from the terminal buttons at the end of the axon back to the soma, this process is referred to as ____________. A) systemic axoplasmic transport B) peripheral axoplasmic transport C) retrograde axoplasmic transport D) anterograde axoplasmic transport

C) retrograde axoplasmic transport

After release of the neurotransmitter serotonin, the neurotransmitter is transported back into the cell to be reused. This process is called: A) degradation. B) release-ready. C) reuptake. D) exocytosis.

C) reuptake.

In order to cross the synapse between two cells, a substance called ___________ is released from the first cell (pre-synapse) to activate or inhibit the second cell (post-synapse). A) dynein B) protein C) neurotransmitter D) kinesin

C)neurotransmitter

Calcium Ions -Some that enter the terminal button bind with the clusters of protein molecules that [...] -This event makes the segments of the [...], producing a fusion pore, a hole through both membranes that enables them to fuse together

Calcium Ions -Some that enter the terminal button bind with the clusters of protein molecules that join the membrane of the synaptic vesicles with the presynaptic membrane -This event makes the segments of the clusters of protein molecules move apart, producing a fusion pore, a hole through both membranes that enables them to fuse together

-Defines the boundary of the neuron -Consists of a double layer of lipid protein molecules -Proteins act as transporters, actively carrying certain molecules into or out of the cell

Cell Membrane

Brain and spinal cord, controls the body by processing and responding to sensory input from the PNS

Central Nervous System (CNS)

-Consists of long strands of DNA, with associated proteins, found in the nucleus -Carries genetic info -When active genes produce mRNA which leaves nucleus and attaches to ribosomes to code for proteins or enzymes

Chromosomes

Compare the functions of EPSPs and IPSPs in postsynaptic cells -EPSP is a depolarization resulting from the [...] through a neurotransmitter-dependent ion channel -In the [...], calcium can also bind with enzymes that have a variety of effects -IPSP is a hyperpolarization resulting from the [...] through a neurotransmitter-dependent ion channel

Compare the functions of EPSPs and IPSPs in postsynaptic cells -EPSP is a depolarization resulting from the entry of sodium or calcium ions into the cell through a neurotransmitter-dependent ion channel -In the dendrites of the postsynaptic cell, calcium can also bind with enzymes that have a variety of effects -IPSP is a hyperpolarization resulting from the exit of potassium ions from or the entry of chloride ions into the cell through a neurotransmitter-dependent ion channel

Contrast ionotropic and metabotropic receptors -Ionotropic receptors open ion channels in [...] to the binding of a ligand -Metabotropic receptors can indirectly open ion channels through the use of a [...] that can travel to the nucleus or other regions of the neuron and initiate biochemical changes that affect the functions of the cell -[...] can also turn specific genes on or off, initiating or terminating production of particular proteins

Contrast ionotropic and metabotropic receptors -Ionotropic receptors open ion channels in direct response to the binding of a ligand -Metabotropic receptors can indirectly open ion channels through the use of a G protein and activate a second messenger system that can travel to the nucleus or other regions of the neuron and initiate biochemical changes that affect the functions of the cell -Second messengers can also turn specific genes on or off, initiating or terminating production of particular proteins

-Jellylike, semiliquid substance contained in the interior of the cell -Contains all of the organelles

Cytoplasm

Formed of microtubules and other protein fibers, linked to each other and forming a cohesive mass that gives a cell its shape

Cytoskeleton

The Na+/K+ pump removes ______ Na+ ions and adds _______ K+ ions. A) 2; 3 B) 3; 4 C) 2; 4 D) 3; 2

D) 3; 2

___________ are multi-function glial cells that participate in phagocytosis, provide lactate for cells, and structurally support neurons in the brain. A) Schwann cells B) Microglia C) Oligodendrocytes D) Astrocytes

D) Astrocytes

____________ are supporting cells that can provide myelination to multiple axons at once. A) Schwann cells B) Microglia C) Astrocytes D) Oligodendrocytes

D) Oligodendrocytes

Sally's stomach begins to rumble, reminding her that she skipped breakfast this morning. This hunger signal is sent to the brain which is part of the __________ nervous system. A) autonomic B) sympathetic C) peripheral D) central

D) central

In comparison to ionotropic receptors, metabotropic receptors A) have effects that occur quicker. B) have effects that last for a limited duration. C) act directly on ion channels. D) have effects that occur slower

D) have effects that occur slower

You reach out and touch a piece of cloth, feeling its texture. The cells that gather this sensory information are part of the ________. A) central nervous system B) autonomic nervous system C) parasympathetic nervous system D) peripheral nervous system

D) peripheral nervous system

If a cell fires at an extremely high rate, the cell will release neurotransmitter from the ____________ vesicles. A) recycling pool B) reserve pool C) release-ready D) release-ready, recycling pool, and reserve pool

D) release-ready, recycling pool, and reserve pool

Experiencing hunger or seeing color in the environment are possible via the _____________. A) Interneurons B) glial cells C) motor neurons D) sensory neurons

D) sensory neurons

Na+ channels open when the threshold of excitation is reached. Therefore these channels are considered: A) passive. B) chemically-gated. C) passive, voltage-gated, and chemically-gated. D) voltage-gated.

D) voltage-gated.

If Ca2+ was blocked: A) passive channels would close. B) voltage-gated ion channels would remain closed. C) Na+ would be stuck inside of the cell. D) neurotransmitters could not be released from the cell.

D)neurotransmitters could not be released from the cell.

Small synaptic vesicles contain ___________, whereas large synaptic vesicles contain __________. A) peptides; proteins B) proteins; peptides C) peptides; neurotransmitters D) neurotransmitters; peptides

D)neurotransmitters; peptides

-A branched, treelike structure attached to the soma of a neuron -Receives info from the terminal buttons of other neurons

Dendrites

A small bud on the smooth surface of a dendrite, with which a terminal button of another neuron forms a synapse

Dendritic Spines

Synapses in charge of Regulatory functions

Dendrodendritic

A long, complex macromolecule consisting of 2 interconnected helical strands

Deoxyribonucleic Acid (DNA)

Describe examples of nonsynaptic communication -[...] are chemicals released by neurons that travel farther and are dispersed more widely than are neurotransmitters -[...] are secreted by cells of endocrine glands or by cells located in various organs

Describe examples of nonsynaptic communication -Neuromodulators are chemicals released by neurons that travel farther and are dispersed more widely than are neurotransmitters -Hormones are secreted by cells of endocrine glands or by cells located in various organs

Describe the process of neurotransmitter release 1) When AP are [...] 2) A # of small [...] located inside the presynaptic membrane fuse with the membrane and then break open, spilling their contents into the [...] 3) The axon has just been stimulated, and [...] are in the process of releasing the neurotransmitters 4) Some vesicles are fused with the [...], forming the shape of an omega (Ω)

Describe the process of neurotransmitter release 1) When AP are conducted down an axon 2) A # of small synaptic vesicles located inside the presynaptic membrane fuse with the membrane and then break open, spilling their contents into the synaptic cleft 3) The axon has just been stimulated, and synaptic vesicles in the terminal button are in the process of releasing the neurotransmitters 4) Some vesicles are fused with the presynaptic membrane, forming the shape of an omega (Ω)

Describe the propagation of an action potential (AP) -After initiating at the point where the [...], the AP propagates toward the [...] according to the all-or-none law -In an unmyelinated axon, the AP proceeds along the axon but is subject to [...] -In a myelinated axon, the AP in conducted via [...], which speeds the message, reduces decremental conduction, and renews the AP at the [...] -To vary the strength of the message conveyed by the AP, the rate law explains that although each AP event is identical, a stronger message can be conveyed by firing AP at a [...]

Describe the propagation of an action potential (AP) -After initiating at the point where the axon joins the soma, the AP propagates toward the terminal buttons according to the all-or-none law -In an unmyelinated axon, the AP proceeds along the axon but is subject to decremental conduction -In a myelinated axon, the AP in conducted via salutatory conduction, which speeds the message, reduces decremental conduction, and renews the AP at the nodes of Ranvier -To vary the strength of the message conveyed by the AP, the rate law explains that although each AP event is identical, a stronger message can be conveyed by firing AP at a higher rate

Describe the structures and functions of presynaptic cells that are involved in synaptic communication -[...] contain synaptic vesicles filled with neurotransmitters -[...] fill vesicles with the neurotransmitters, and [...] are involved in the release of neurotransmitters and recycling of the vesicles -The presynaptic membrane faces the postsynaptic membrane across the [...].

Describe the structures and functions of presynaptic cells that are involved in synaptic communication -Presynaptic cells contain synaptic vesicles filled with neurotransmitters -Transport proteins fill vesicles with the neurotransmitters, and trafficking proteins are involved in the release of neurotransmitters and recycling of the vesicles -The presynaptic membrane faces the postsynaptic membrane across the synaptic cleft.

Differentiate between the locations and functions of autoreceptors and postsynaptic receptors -Postynaptic receptors are located on the postsynaptic membrane and serve to [...] -Postsynaptic receptors can be [...] -Autoreceptors are [...] receptors located on the [...] that help regulate the [...]

Differentiate between the locations and functions of autoreceptors and postsynaptic receptors -Postynaptic receptors are located on the postsynaptic membrane and serve to relay a message to the postsynaptic cell -Postsynaptic receptors can be ionotropic or metabotropic -Autoreceptors are metabotropic receptors located on the presynaptic membrane that help regulate the amount of neurotransmitter that is released

-Movement of molecules from regions of high concentration to regions of low concentration -Molecules distribute themselves evenly throughout the medium in which they are dissolved

Diffusion-

Effects of Postsynaptic Potentials: Neural Integration 1) Combining of [...], signals 2) Performed by [...] 3) Neural inhibition does not always lead to [...]

Effects of Postsynaptic Potentials: Neural Integration 1) Combining of multiple, sometimes contradictory, signals 2) Performed by axon hillock 3) Neural inhibition does not always lead to behavioral inhibition

-An aqueous solution of a material that ionizes, a soluble acid, base or salt -When some substances are dissolved in water, they split into two parts, each with an opposing electrical charge -Substances with this property are called ?; the charged particles into which they decompose are called ions.

Electrolytes

Cells contain this system, a network of internal membranes comprised of: 1) Endoplasmic reticulum 2) Golgi apparatus 3) Lysosomes

Endomembrane System

Endoplasmic reticulum [...] contains ribosomes that are destined to be transported out of the cell or used in the membrane [...] provides channels for the segregation of molecules involved in various cellular processes; Also produces lysosomes

Endoplasmic reticulum Rough: contains ribosomes that are destined to be transported out of the cell or used in the membrane Smooth: provides channels for the segregation of molecules involved in various cellular processes; Also produces lysosomes

Destruction of a neurotransmitter by an enzyme after its release

Enzyme Deactivation

-Providing structure, proteins serve as, which direct the chemical processes of a cell by controlling chemical reactions -Act as catalysts; cause a chemical reaction to take place without becoming a part of the final product themselves

Enzymes

-The secretion of a substance by a cell through means of vesicles -The process by which neurotransmitters are secreted -The membrane-wrapped product migrates to the inside of the outer membrane of the cell, fuses with the membrane, and bursts, spilling its contents into the fluid surrounding the cell.

Exocytosis

Explain the roles of reuptake and enzymatic deactivation in terminating postsynaptic potentials Postsynaptic potentials can be terminated by [...] from the synapse through reuptake transporters or through breakdown by enzymatic deactivation

Explain the roles of reuptake and enzymatic deactivation in terminating postsynaptic potentials Postsynaptic potentials can be terminated by removing a neurotransmitter from the synapse through reuptake transporters or through breakdown by enzymatic deactivation

-A protein coupled to a metabotropic receptor -Conveys messages to other molecules when a ligand binds with and activates the receptor

G Protein

-Electrical, rather than chemical, synapse -Ions flow between cells

Gap Junction

-The functional unit of the chromosomes, which directs synthesis of one or more proteins -When they are active, portions of the chromosomes cause production of another complex molecule, messenger ribonucleic acid mRNA (transcription), which receives a copy of the info stored at that location -The mRNA leaves the nuclear membrane and attaches to ribosomes. -Then codes for proteins, including enzymes (translation)

Genes

-Special form of smooth ER -Assembles and packages product in a membrane, done through exocytosis -Produces lysosomes

Golgi Apparatus

-Secreted by cells of endocrine glands or by various organs, such as the stomach, the intestines, the kidneys, and the brain -Release these chemicals into the extracellular fluid -Cells that contain receptors for a particular hormone are referred to as target cells for that hormone; only these cells respond to its presence

Hormones

How do molecules of a neurotransmitter produce a depolarization or hyperpolarization in the postsynaptic membrane? 1) [...] across the synaptic cleft and attaching to the binding sites of special protein molecules located in the postsynaptic membrane, called [...] 2) Once binding occurs, the postsynaptic receptors open [...], which permit the passage of specific ions into or out of the cell 3) The presence of the neurotransmitter in the synaptic cleft allows particular ions to pass through the membrane, changing the [...] 4)[...] can't enter into the postsynaptic cell, only ions can enter the cell through ion channels

How do molecules of a neurotransmitter produce a depolarization or hyperpolarization in the postsynaptic membrane? 1) Diffusing across the synaptic cleft and attaching to the binding sites of special protein molecules located in the postsynaptic membrane, called postsynaptic receptors 2) Once binding occurs, the postsynaptic receptors open neurotransmitter-dependent ion channels, which permit the passage of specific ions into or out of the cell 3) The presence of the neurotransmitter in the synaptic cleft allows particular ions to pass through the membrane, changing the local membrane potential 4)Neurotransmitter molecules can't enter into the postsynaptic cell, only ions can enter the cell through ion channels

Inside of an axon becomes more negative

Hyperpolarized

Depolarized

Inside of the axon becomes more positive

Release Zone

Interior of the presynaptic membrane of a synapse to which synaptic vesicles attach and release their neurotransmitter into the synaptic cleft

-Binding site for a neurotransmitter and an ion channel that opens when a molecule of the neurotransmitter attaches to the binding site -Direct method -Sensitive to acetylcholine, contain sodium channels. When these channels are open, sodium ions enter the cell and depolarize the membrane.

Ionotropic Receptors

[...]-A charged molecule -Two types: 1) [...], positive charge (Na+, K+) 2) [...], negative charge (CI)

Ions-A charged molecule -Two types: 1) Cations, positive charge (Na+, K+) 2) Anions, negative charge (CI)

-In the cell body, attach to the item being transported down the axon -Then walks down a microtubule, carrying the cargo to its destination -Energy is supplied by ATP molecules produced by the mitochondria

Kinesin

-A chemical that binds with the binding site of a receptor -Neurotransmitters are naturally occurring ligands, produced and released by neurons

Ligand

[...] interneurons: form circuits with nearby neurons and analyze bits of information. [...] interneurons: connects local neurons found in a region of the brain with those in other regions.

Local interneurons: form circuits with nearby neurons and analyze bits of information. Relay interneurons: connects local neurons found in a region of the brain with those in other regions.

-An organelle surrounded by membrane -Small sacs that contains enzymes that break down waste products or substances no longer needed by the cell -These products are then recycled or excreted from the cell.

Lysosomes

[...] tremors, abnormal eye movements, difficulty in balance and speech

MS: tremors, abnormal eye movements, difficulty in balance and speech

-Difference in charge (positive or negative) across the membrane -Two forces that determine the distribution of ions across the cell membrane: 1)Force of Diffusion 2)Force of Electrostatic pressure

Membrane Potential

-A binding site for a neurotransmitter -Activates an enzyme that begins a series of events that opens an ion channel elsewhere in the membrane of the cell when a molecule of the neurotransmitter attaches to the binding site -Indirect method -Close to a G protein -Takes and lasts longer than ionotropic

Metabotropic Receptors

[...]: electrical recording technique by using sensors Records changes in electrical activity across the axon membrane

Microelectrodes: electrical recording technique by using sensors Records changes in electrical activity across the axon membrane

-The smallest of glial cells -Act as phagocytes, engulfing and breaking down dead and dying neurons -Immune system in the brain, protecting the brain from invading microorganisms and inflammatory response

Microglial

-A long strand of bundles of protein filaments arranged around a hollow core -Part of the cytoskeleton and involved in transporting substances from place to place within the cell

Microtubules

[...] bundles of 13 protein filaments arranged around a hollow core

Microtubules: bundles of 13 protein filaments arranged around a hollow core

-Extracts energy from nutrients and synthesizes adenosine triphosphate (ATP) -The inner membrane is wrinkled, the wrinkles make up a set of shelves (cristae) that fill the inside of the bead -Power plants of neurons

Mitochondria

Located within the CNS that controls movements, accomplished by the contraction of a muscle or secretion of a gland

Motor Neurons

[...] is a condition where body destroys its own myelin sheath, action potential is impaired, disability on cognitive, motor functions

Multiple Sclerosis is a condition where body destroys its own myelin sheath, action potential is impaired, disability on cognitive, motor functions

Surrounds axons and insulates them, preventing messages from spreading between adjacent axons

Myelin Sheath

-How the CNS communicates with the rest of the body -Bundles of neurons, wrapped in a tough, protective membrane

Nerves

Inhibitory and excitatory postsynaptic potentials summate and control the rate of firing of a neuron

Neural Integration

-Chemicals released by neurons that travel farther and are dispersed more widely than are neurotransmitters -Most are peptides, chains of amino acids -Secreted in larger amounts and diffuse for longer distances, modulating the activity of many neurons in a particular part of the brain

Neuromodulators

-Info processing and transmitting element of the nervous system -Four structures: 1) Cell body or Soma 2) Dendrites 3) Axon 4) Terminal buttons

Neuron

-A chemical released by a terminal button -Has an excitatory or inhibitory effect on neurons

Neurotransmitter

An ion channel that opens when a molecule of a neurotransmitter binds with a postsynaptic receptor

Neurotransmitter-Dependent Ion Channels

-The bare portion of a myelinated axon, between adjacent oligodendroglia or Schwann cells -The myelinated axon, then, resembles a string of elongated beads

Node of Ranvier

A structure within the nucleus of a cell that is responsible for the production of ribosomes, which synthesize protein

Nucleolus

A structure in the central region of a cell, containing the nucleolus and chromosomes

Nucleus

-A type of glial cell responsible for the production of the myelin sheath, that coats the axon in the CNS -Node of Ranvier are the spaces between of the myelin sheath

Oligodendrocyte

Identify synapses other than those involved in neural integration

Other types of synapses include axoaxonic or dendrodendritic synapses and gap junctions

-Exert their effects on target cells by stimulating metabotropic receptors located in the membrane -The 2nd messenger that is generated travels to the nucleus of the cell, where it initiates changes in the cell's physiological processes

Peptide Hormones

Includes all of the nerves that relay info between the CNS and the rest of the body

Peripheral Nervous System (PNS)

-The cell membrane opposite the terminal button in a synapse -Located on the neuron that receives the message

Postsynaptic Membrane

-Alterations in the membrane potential of a postsynaptic neuron, produced by liberation of neurotransmitter at the synapse -Brief depolarizations or hyperpolarizations, that increase or decrease the rate of firing of the axon of the postsynaptic neuron.

Postsynaptic Potentials

A receptor molecule in the postsynaptic membrane of a synapse that contains a binding site for a neurotransmitter

Postsynaptic Receptors

Increases the amount of neurotransmitter released by postsynaptic terminal button, more likely to fire

Presynaptic Facilitation

Reduces the amount of neurotransmitter released by postsynaptic terminal button

Presynaptic Inhibition

-Membrane of a terminal button that lies adjacent to the postsynaptic membrane and the neurotransmitter is released -Located at the end of the terminal button

Presynaptic Membrane

Rate of firing reveals strength of information

Rate Law

-The reentry of a neurotransmitter just liberated by a terminal button back through its membrane, terminating the postsynaptic potential -Rapid removal of neurotransmitter from the synaptic cleft by the terminal button

Reuptake

Reuptake -The membrane contains [...] that draw on the cell's energy reserves to force molecules of the neurotransmitter from the synaptic cleft directly into the [...] -When an AP arrives, the terminal button releases a small amount of neurotransmitter into the synaptic cleft and then takes it back, giving the [...] only a brief exposure to the neurotransmitter

Reuptake -The membrane contains special transporter molecules that draw on the cell's energy reserves to force molecules of the neurotransmitter from the synaptic cleft directly into the cytoplasm -When an AP arrives, the terminal button releases a small amount of neurotransmitter into the synaptic cleft and then takes it back, giving the postsynaptic receptors only a brief exposure to the neurotransmitter

-A cytoplasmic structure, made of protein, that serves as the site of production of proteins translated from mRNA -Involved in protein synthesis.

Ribosomes

Saltatory Conduction -Action potential moves passively under the myelin -Conduction and is regenerated at each node of Ranvier -Two advantages: 1) [...], the neuron expends less energy (ATP) to maintain ion balance 2) [...], conduction of an AP is faster in a myelinated axon because the transmission between the nodes is fast. To increase the speed of conduction is to increase size

Saltatory Conduction -Action potential moves passively under the myelin -Conduction and is regenerated at each node of Ranvier -Two advantages: 1) Economic, the neuron expends less energy (ATP) to maintain ion balance 2) Speed, conduction of an AP is faster in a myelinated axon because the transmission between the nodes is fast. To increase the speed of conduction is to increase size

[...] Areas which where myelin has been diminished

Sclerotic plaque: Areas which where myelin has been diminished

-A chemical produced when a G protein activates an enzyme -Carries a signal that results in the opening of the ion channel or causes other events to occur in the cell -Neurotransmitter is the first messenger

Second Messenger

-Detects changes in the external or internal environment and sends info about these changes to the CNS -Info, in the form of light, sound waves, odors, tastes, or contact with objects, is gathered from the environment by specialized cells of the PNS

Sensory Neurons

[...] -A protein found in the membrane of all cells that extrudes sodium ions from and transports potassium ions into the cell -Use [...] levels of energy -Consists of a large # of protein molecules embedded in the membrane, driven by energy provided by molecules of ATP produced by the mitochondria -Molecules, known as [...], pushing 3 Na+ out for every 2 K+ they push in -Helps keep concentration of Na+ l[...] the neuron

Sodium-Potassium Pump -A protein found in the membrane of all cells that extrudes sodium ions from and transports potassium ions into the cell -Use high levels of energy -Consists of a large # of protein molecules embedded in the membrane, driven by energy provided by molecules of ATP produced by the mitochondria -Molecules, known as sodium potassium transporters, pushing 3 Na+ out for every 2 K+ they push in -Helps keep concentration of Na+ low inside the neuron

The cell body of a neuron, contains the nucleus and much of the machinery that provides for the life processes of the cell

Soma (cell body)

Steps in Synaptic Transmission 1) Produce [...] 2) Attach to [...] with complementary shape 3) [...] is a chemical that attaches to a binding site 4) [...] are natural ligands

Steps in Synaptic Transmission 1) Produce postsynaptic potentials 2) Attach to receptor at a binding site with complementary shape 3) Ligand is a chemical that attaches to a binding site 4) Neurotransmitters are natural ligands

-A chemical of low molecular weight, derived from cholesterol -Affect their target cells by attaching to receptors found within the nucleus -Consist of very small fat-soluble molecules

Steroid Hormones

Summarize the contributions of diffusion, electrostatic pressure, and the sodium-potassium pump to establishing membrane potential -The difference in charge between the inside and the outside of the axonal membrane is generated by the force of [...] -The force of [...], process by which molecules distribute themselves evenly throughout the medium they are dissolved in -[...], like charges repel and opposite charges are attracted to each other -The [...] helps maintain the resting membrane potential by pumping 3 Na+ ions out and 2 K+ ions into the cell with each molecule of ATP

Summarize the contributions of diffusion, electrostatic pressure, and the sodium-potassium pump to establishing membrane potential -The difference in charge between the inside and the outside of the axonal membrane is generated by the force of diffusion, electrostatic pressure, and the activity of sodium potassium pumps -The force of diffusion, process by which molecules distribute themselves evenly throughout the medium they are dissolved in -Electrostatic pressure, like charges repel and opposite charges are attracted to each other -The sodium potassium pump helps maintain the resting membrane potential by pumping 3 Na+ ions out and 2 K+ ions into the cell with each molecule of ATP

Summarize the process of neural integration of EPSPs and IPSPs -Neurons [...] EPSPs and IPSPs and integrates these messages -If the integrated messages result in [...] for the cell, the neuron will fire an AP -If the messages are IPSPs or [...], the neuron will not fire an AP

Summarize the process of neural integration of EPSPs and IPSPs -Neurons receive multiple EPSPs and IPSPs and integrates these messages -If the integrated messages result in depolarization beyond the threshold of excitation for the cell, the neuron will fire an AP -If the messages are IPSPs or do not reach the threshold of excitation, the neuron will not fire an AP

-Neurons have a high rate of metabolism but have no means of storing nutrients, they must constantly be supplied with nutrients and oxygen or they will quickly die -The role played by the cells that support and protect neurons is important to our existence.

Supporting Cells

-A small space between the terminal buttons of the sending cell and a portion of the somatic or dendritic membrane of the receiving cell. -Communication at a synapse proceeds in one direction: from the terminal button to the membrane of the other cell.

Synapse

-The space between the presynaptic and postsynaptic membrane -Contains extracellular fluid, through which the neurotransmitter diffuses -A meshwork of filaments crosses the synaptic cleft and keeps the presynaptic and postsynaptic membranes in alignment

Synaptic Cleft

-Communication between neurons across a synapse, carried by neurotransmitters, released by terminal buttons of the sending, or presynaptic cell -These chemicals diffuse across the fluid-filled gap between the terminal buttons and the membranes of the neurons with which they form synapses, called the postsynaptic cell

Synaptic Transmission

-Small, rounded structure located in terminal buttons -Contains molecules of a neurotransmitter

Synaptic Vesicles

The type of cell that is directly affected by a hormone or other chemical signal

Target Cell

-The bud at the end of a branch of an axon -Forms synapses with another neuron -Sends info to that neuron

Terminal Buttons

-Higher concentration outside the axon -The force of diffusion pushes inward -The inside of the axon is negatively charged, electrostatic pressure pushes this anion outward -Two opposing forces balance each other, no net movement

The Chloride Ion (Cl-)

-Higher concentration inside the axon -The force of diffusion tends to push it out of the cell -The outside of the cell is charged positively, so electrostatic pressure tends to push this cation inside -The two opposing forces balance, and potassium ions tend to remain where they are, with little net movement

The Potassium Ion (K+)

-Higher concentration outside the axon -Diffusion pushes in -Positively charged -Electrostatic pressure pushes in -Membrane relatively impermeable

The Sodium Ion (Na+)

The front of this card is blank. More information

The front of this card is blank. More information

The membranes of vesicles in the re- serve pool are recycled through a process of [...]

The membranes of vesicles in the re- serve pool are recycled through a process of bulk endocytosis

The Most Important Source of EPSP

The neurotransmitter-dependent sodium channel, when they are opened, the result is a depolarization

The original second messenger to be discovered was [...]

The original second messenger to be discovered was cyclic AMP,

The process of neurotransmitter release -Following an AP, a neurotransmitter is released from vesicles in the presynaptic cell that move and dock with the [...] -Docking and [...] is triggered by the influx of calcium ions -The neurotransmitter is released into the [...] through the fusion pore -Following release, the membranes of the vesicles are [...] and return to the pool of available vesicles for future neurotransmitter release

The process of neurotransmitter release -Following an AP, a neurotransmitter is released from vesicles in the presynaptic cell that move and dock with the terminal membrane -Docking and creation of a fusion pore is triggered by the influx of calcium ions -The neurotransmitter is released into the synaptic cleft through the fusion pore -Following release, the membranes of the vesicles are recycled and return to the pool of available vesicles for future neurotransmitter release

The value of the membrane potential that must be reached to produce an action potential

Threshold of Excitation

[...]: when sodium channels close, start of hyperpolarization

absolute refractory period: when sodium channels close, start of hyperpolarization

[...]-sensory, [...]-motor

afferent-sensory, efferent-motor

conduction velocity depends on the: [...]

conduction velocity depends on the: fibre size internode distance) and myelin sheath thickness

hyper polarization voltage: [...]

hyper polarization voltage: -75mV

lethal injection first is relaxant, [...] increases gaba, decreases act of body, then [...] to make heart beat irregularly; [...] is used to cause muscle paralysis and respiratory arrest, [...]e to stop the heart, and [...] for sedation.

lethal injection first is relaxant, thiopental increases gaba, decreases act of body, then k to make heart beat irregularly; Pancuronium bromide (Pavulon) is used to cause muscle paralysis and respiratory arrest, potassium chloride to stop the heart, and midazolam for sedation. TPP that popo

A macromolecule that delivers genetic info concerning the synthesis of a protein from a portion of a chromosome to a ribosome

messenger Ribonucleic Acid (mRNA)

[...], a disease in which the im- mune system destroys ACh receptors, reducing the amount of information conveyed from the ACh system to the mus- cles, thereby producing muscle weakness.

myasthenia gravis, a disease in which the im- mune system destroys ACh receptors, reducing the amount of information conveyed from the ACh system to the mus- cles, thereby producing muscle weakness.

[...] property: sliding of AP in myelin sheath

passive-cable property: sliding of AP in myelin sheath

[...], by dynein, terminal buttons to soma

retrograde, by dynein, terminal buttons to soma

sensory neurons are [...]r while motor neurons are [...]r

sensory neurons are unipolar while motor neurons are multipolar

the threshold of excitation ([...]

the threshold of excitation (-55mV)