BIOL 2140 Exam 3
____ is needed to stop the cross-bridge.
ATP
Astrocytes are the most abundant ___ (PNS or CNS?) Neuroglia.
CNS
Thin filament are attached in a long polypeptide chain called ___ actin. This folds back on itself to make a twisted ___ strand. It is stiffened by 2 strands of ____. In a relaxed muscle, the tropomyosin ___ active sites of _____.
F; double; tropomyosin; blocks; actin;
The z disc bisects the ___ band which is the light stripes that are made of actin (___ filament).
I; thin
What are the 2 types of glial cells found in the PNS?
Satellite cells, Schwann cells
ATP is need to stop the ___-____.
cross-bridge
A muscle cell is the same as a muscle ___.
fiber
What is the business end of myosin (the tail or the head)? What do they link together during contracting?
head; thick and thin filaments
An IPSP is a local ____ of the postsynaptic membrane. IPSP's drive the neuron ___ from the AP threshold. NT binding opens chemically gated ion channels permeable to either __ or ___.
hyperpolarization; away; K+; Cl-
In the I band, elastic filaments are extensible when muscle is ___ and recoil when the muscle what?
stretching; returns to original length
F actin folds back on itself to make a twisted double strand. It is stiffened by 2 strands of ____. In a ___ (contracted or relaxed?) muscle, the _____ blocks active sites of actin.
tropomyosin; relaxed; tropomyosin
The K+ channels open at __mV because there is a more positive charge on the ____ (inside or outside?) than the ____ (inside our outside?).
+30; inside; outside
Profile of an action potential (Part 1): A small stimulus depolarizes the membrane from ___mV to ___mV. This begins positive feedback that results in a large depolarization to ___mV. Now the inside of the cell is more ____ (positive or negative?) than the outside. Now repolarization returns the cell to ___mV but the K+ efflux continues resulting in the hyperpolarization phase. The cell is now even ___ (positive or negative?) than at rest.
-70; -55; +30; positive -70; negative
A synapse connects # nerves by chemical signals (___): Electrical signal - ___ ___ (Nerve impulse) => ____ signal - NT (_____ receptors) => Electrical Signal - ____ response => ___ ____ - action potentials
2; NT's; action potential; chemical; activates; graded; axon hillock
The sodium/potassium pump pumps out # sodium ions for every # potassium ions it pumps in. Cell membranes are considerably more permeable to ___ than to ___ because they have many ____ K+ leak channels than Na+ leak channels. As such, ____ positive ions (# K+) leak out of the cell than leak back in (Na+).
3; 2; K+; Na+; more; more
Profile of an action potential (Part 2): The Na+/K+ pump returns the ions to their original side of the membrane. These events take about #-# milliseconds (never changes). The amplitude of the depolarization is about ___mV (never changes). The voltage change travels along the axon/sarcolemma/t-tubules. In a neuron, the traveling voltage change is called a ___ ____.
3; 4; 100; nerve impulse
In which band are thick filaments found? In which band are thin filaments found? Which band is darker and which is lighter? When the muscle contracts, which band moves and which band does not?
A band; I band A band is darker and I band is lighter The I band moves and the A band does not (the A band NEVER moves!)
The H zone is a lighter stripe in the middle of the __ band. Does this occur in contracted or relaxed muscle?
A band; relaxed
In a relaxed muscle, the thick and thin filaments overlap at the ends of the ___ band and not in the ___ ___.
A; H zone
Striations are made from repeating series of dark ___ bands and light ___ bands.
A; I
At the junction between the ___ band and ___ band, the sarcoplasmic reticulum gets thicker. This area is called the ____ ____. Between this feature, there are __ ____.
A; I; Terminal Cisternae; T Tubules
Thick filaments run the width of the __ band. They give reason for the thick red stripe you see on the diagram. They are made of ____.
A; myosin
(Forming cross-bridges Part 2): The neurotransmitter (usually ____) flows from the ___ ___ (or neuromuscular junction) and into the ___ ___ (gap between the nerve and muscle). A wave of ____ is then sent down the _____.
ACh; axon terminal; synaptic cleft; depolarization; sarcolemma;
The power stroke occurs due to a loss of ____ and ____. When this is released, ____ is able to attach.
ADP; phosphate; ATP
To stop muscle contraction, you need ___ and the sources of ____ to stop flowing it out. Basically, this is so that the ___ signal will not send the _____ (such as Aceticholine).
ATP; Calcium; neural/electric; neurotransmitter
_______ (*the abbreviation is also acceptable) cuts Ach into acetic acid and choline.
Acetycholinesterase; AchE
Anticholinesterases are enzymes that stop ___. These are drugs that ___ acetylcholinesterase (AchE). Since ___ is not degraded, it leads to too much of it in the ____ ___. This causes excessive stimulation of ___ ___, resulting in muscle paralysis. Do they induce flaccid or spastic paralysis?
AchE; inhibit; Ach; synaptic cleft; Ach receptors; spastic
___-___ is the protein that forms Z discs. They anchor ___ filaments and connect adjacent ____.
Alpha-actin; thin; myofibrils
From the cell body to the terminal is called ____. It moves from top to bottom in the ___ direction. From the terminal to the cell body is ____. It moves from bottom to top in the ____ direction.
Anterograde; forward; Retrograde; backward
______ are enzymes that stop AchE. These are drugs that inhibit ___ (___). Since Ach is not ____, it leads to too much of it in the ___ ___. This causes excessive stimulation of Ach receptors, resulting in ___ ____. Do they induce flaccid or spastic paralysis?
Anticholinesterases; Acetylcholinesterase; AchE; degraded; synaptic cleft; muscle paralysis; spastic
What are the 4 types of glial cells found in the CNS?
Astrocytes, Microglia, Ependymal cells, Oligodendrocytes
_____ are the most abundant of glial cells, outnumbering neurons by about ___ to one. This ratio occurs because they surround the neuron to ____ and provide nutrients (through forming a network on which the neurons can ___). They anchor neurons to ____ and pick up waste around the neuron) i.e. mop up 'leaked' ____).
Astrocytes; ten; stabilize; grow; capillaries; neurotransmitter
What are the 3 parts of a neuromuscular junction?
Axon Terminal, Synaptic Cleft, Sarcolemma
Synapses and neurotransmitters _____ synapses occur between the axon and cell body (i.e. soma). ___ synapses occur between the axon and dendrite. _____ synapses occur between the axon and axon hillock. Which one involves last minute changes being made in order to depolarize the membrane?
Axosomatic; Axodendritic; Axoaxonal; Axoaxona
Why does the Sarcoplasmic reticulum get thicker around the T tubules? (think about what is found there)
Because of the large amount of calcium stored in it
___ ___ is from the bacteria clostridium botulinum (which fosters in an environment with oxygen, making it ____). This blocks ___ release from the nerve terminal. This leads to a ____ of muscles. What type is it and why? What is another way to remember where this comes from?
Botulinus toxin; anaerobic; Ach; paralysis; Flaccid; Since Ach is not being released, the muscle can not contract; Botox (want muscles to relax so flaccid)
What are the 4 types of glial cells found in the CNS? What are the 2 types of glial cells found in the PNS?
CNS: Astrocytes, Microglia, Ependymal cells, Oligodendrocytes PNS: Satellite, Schwann
___ is needed for muscle contraction to take place.
Calcium
____ causes contraction. ___ stops contraction.
Calcium; ATP
___ is stored in the terminal cisternae and is released by the __ ___.
Calcium; T tubules
(Forming cross-bridges Part 4): ____ binds to TnC and this causes a ____ change (they tip over) in the arrangement of the ____ proteins. The proteins move and as they move, they slide the ____ off the myosin binding sites. At this point, the dimples of the ____ are exposed.
Calcium; conformational; troponin; tropomyosin; actin
Part 2: ____ binds to troponin, exposing the ___ binding site. Cross bridge formation becomes excessive in all muscles. ____, which is necessary for cross bridge detachment, is no longer _____. Without ATP, muscles stay ____ (peaks @ #-# hours). ___ ___ disappears as muscle proteins begin to ____.
Calcium; myosin; ATP; available; contracted; 12-24; Rigor Mortis; breakdown
In the ____ and __ ___, the electrical signal is called a graded potential. In the ____, the electrical signal or "nerve impulse" is called an action potential.
Dendrites; cell body; axon
Put these items in order and match the definition: Terms: Repolarization, Hyperpolarization, Depolarization Definitions: more negative, more positive, even more negative
Depolarization (more positive) -> Repolarization (more negative)-> Hyperpolarization (even more negative)
___ holds adjacent thick filaments together.
Destine
It takes thousands of ____'s to fire on the dendrites and deliver enough ____ current to reach threshold at the ____ ___ of the postsynaptic neuron. These EPSP's can be cancelled out by the ___'s so the sum of the 2 will determine whether enough depolarizing current reaches the first set of ____ gated ion channels.
EPSP; depolarizing; axon hillock; IPSP; voltage
____ cells line cavities of the brain and spinal cord. Since they are ciliated, they circulate CSF (____ ____ ____).
Ependymal; cerebral; spinal; fluid
The M line bisects the ___ ___ and the __ band. What protein is this made of?
H zone; A band; Myomisin
The ___ ____ is a lighter stripe in the middle of A band. Does this occur in contracted or relaxed muscles?
H zone; relaxed
______ makes it harder to fire an action potential. As such, you would need to add up positive and negative charges, traveling to ___ ___, to reach threshold.
Hyperpolarization; axon hillock
Thin filaments are found in the __ band and extend into the __ band; however, they do not touch the ____ ___.
I; A; H zone
The ___ is the inside of the T-tubles. They are also continuous with the ____ space.
Lumen; extraceullar
Myomesin are the fine protein strands that form the ___ ___.
M line
The __ ___ bisects the H zone and the A band. What protein is this made of?
M line; Myomisin
The __ __ and the __ __ work together to hold actin and myosin in place (important proteins).
M line; Z disc
The myosin that makes up the __ ___ acts as the scaffolding for ___ filament. It basically holds these filaments together.
M line; thick
____ have a very proactive role. Since they can sense _____ and debris, they clean up the bad stuff. They transform into ___ and phagocytose ____. Basically, if they see something they need to clean up, they turn into macrophages. As such, they act as ___ cells in the CNS.
Microglia; microbes; macrophages; debris; defensive
Of the two (Multiple Sclerosis and Amyotrophic Lateral Sclerosis), which destroys myelin? Which destroys the neuron directly? Which involves the degeneration of motor nerves? Which involves slow impulse conduction?
Multiple sclerosis; Amyotrophic Lateral Sclerosis; ALS; Multiple Sclerosis
Neurons are classified based on their structure. The three types are multipolar, bipolar, and unipolar. Which types makes up 99% of neurons? Which types has 2 processes (and what are those two?)? Which types has numerous dendrites and 3 or more cell processes? Which is the rarest and found in sense organs? Which has 1 process that emerges from the cell body? Which one is found in the retina of the eye and olfactory mucosa? Which one is mostly sensory neurons in PNS? Which is sensory afferent?
Multipolar; Bipolar (axon and dendrite); Multipolar; Bipolar; Unipolar; Bipolar; Unipolar; Unipolar
Of the 3 types (multipolar, bipolar, unipolar), which has many projections (and looks like your typical axon)? Which has 1 projection and looks like it has a cell body protruding out? Which has 2 projections with the cell body in the middle?
Multipolar; Unipolar; Bipolar
___ are fibers within the sarcomere. They can be thick filaments (___) and thin filaments (___).
Myofilaments; myosin; actin
____ are the fine protein strands that form the M line.
Myomesin
___ holds on to the big, red, thick filaments found in the A band.
Myomisin
What provides the mechanics of muscle contraction? Myosin or Actin?
Myosin
What is the protein involved in thick filament? What are the proteins involved in thin filament (3)?
Myosin Actin, Tropomyosin, Troponin
___ is the protein that makes up the thick filaments. What is their structure? (2 things)
Myosin; 2 heads and a long tail
The Propagation of an Action Potential is a chain reaction opening more of what type of channel? Na+ or K+?
Na+
There are no ___ channels under myelin.
Na+
T tubules conduct ___ ____ deep inside muscle cells. They are responsible for ____ current.
Nerve impulses; electrical
(Forming cross-bridges Part 3): Since the ____ started an electrical current, it flows down the sarcolemma and down the __-____. As it travels down the T-tubles it opens voltage-sensitive ____ channels in the ___ ____ where calcium is stored. The calcium flows out into the cytosol of the cell where it diffuses towards ____.
Neurotransmitter; T-tubles; calcium; terminal cisternae; TnC
___ are chemicals released from the nerve terminal. There are over 50 NT's. Most neurons make # or more NT's. Neurons can release one or __ NT's.
Neurotransmitters; 2; all;
____ circle around the icon and help ___ signals down. They wrap their branches around large nerve fibers. They have an insulating cover (which is ____ active) or in other words, they have a ____ ____. What is the covering used for?
Oligodendrocytes; propagate; electrically; myelin sheath; Help to speed up electrical signals that helps propagate signals along the neuron
Types of Anticholinesterases 1. ____ and _____ are the principle anticholinesterases. 2. In large quantities, they cause overstimulation of the ____ nervous system. 3. ____ - parathion, malathion (______) 4. ___ ___ (Organophosphates) - Sarin, Tabun, Soman and VX (kills within minutes)
Physostigmine; neostigmine; parasympathetic; Insecticides; Nerve gases
There are 2 ways to hyper polarize the membrane: 1) ___ channels are opened to let positive ___ ____ (in or out?), making the inside more negative. 2) ___ channels are opened to let negative ___ ___ (in or out?), making the inside more negative.
Potassium; K+; out; Chloride; Cl-; in
Part 1: ___ (stiff) ___ (death) is when the joints of the body become stiff after death for 6-72 hours. This is caused by widespread skeletal muscle ___. After cell death, ____ synthesis stops. ___ is no longer pumped into the terminal cisternae (since this process requires ATP). The calcium flow into the cytosol is _____. Why is this flow like this?
Rigor; Mortis; contraction; ATP; calcium; unstoppable/uncontrolled; because the body systems are not functioning to stop it
What is the functional contractile unit of the muscle?
Sarcomere
What runs from Z disc to Z disc?
Sarcomere
___ cells wrap around neuronal cell bodies (i.e. the ___) in the PNS. They have similar functions to the ____ found in the CNS.
Satellite; soma; astrocytes
___ cells wrap around all nerve fibers in the PNS. They function similarly to the ____ found in the CNS. These types of cells are also referred to as _______.
Schwann; oligodendrocytes; neurolemmocytes
Which of the two types of voltage gates uses the ball and chain method? Which one doesn't?
Sodium; Potassium
___ are basically the stripes of the myofibrils running parallel and lining up.
Striations
The ___-___ delivers electrical current into the muscle cell. As the electrical current travels down the T-tubles, the calcium stored in the ___ ___ is released.
T-tubles; terminal cisternae
The __-__ is formed when the sarcolemma forms a tube that extends deep into the cell. These tubes are continuous and cavity is continuous with the ____ space. They are the tubes between the ___ ___ (that wrap around each myofibril).
T-tubule; extracellular; Terminal Cisternae
Where is calcium stored in the sarcoplasmic reticulum? What structure releases calcium (and where is this structure found)?
Terminal Cisternae; T tubles (found in the middle of Terminal Cisternae; bisects it)
What gives the skeletal muscle its striated appearance? This is very important for ____ muscle to function.
The A bands and I bands of every myofibril line up; skeletal
Why is the H zone so lightly colored?
There is less protein there (you just have thick filament)
(Forming cross-bridges Part 4): Calcium binds to ___ and this causes a ____ change (they tip over) in the arrangement of the ____ proteins. The proteins move and as they move, they slide the ____ off the _____ binding sites. At this point, the dimples of the ____ are exposed.
TnC; conformational; troponin; tropomyosin; myosin; actin
What is considered to be the long piece of thread that blocks active sites of actin?
Tropomyosin
___ is a 3 polypeptide complex that is found in thin filament. TnI bonds to ____. TnT binds to _____ and positions it on actin. TnC binds ____ ions.
Troponin; actin; tropomyosin; calcium
Pharmacology ______ (curare) is a botanical agent from South America. It binds to _____ receptors and prevents it from binding. This is called a ____ _____ (which block receptors). It is classified as a neuromuscular ____ agent and causes muscular _____. Derivatives of curare form modern muscle _____. They are frequently used during surgical ____.
Tubocurarine; Ach; competitive antagonist; blocking; paralysis; relaxants; anesthesia
The __ ___ bisects the I band. It is in the middle of the light stripes. They attach to the ___ of the I band.
Z discs; actin
The ___ ___ must be pulled to echoer in order for muscle contraction to occur. Although the distance between the Z discs becomes ____, (as well as the ___ band), the width of the ___ band never changes.
Z discs; shorter; I; A
Alpha-actin is the protein that forms __ ___. They anchor ____ filaments and connect adjacent ____.
Z discs; thin; myofibrils
Acetycholinesterase (AchE) cuts Ach into ___ ____ and ____.
acetic acid; choline
Skeletal muscle is striated because of ___ + ____ fibers of myofibril.
actin; myosin
The M line and Z disc work together to hold ___ and ___ in place (which are important proteins involved in muscle contraction).
actin; myosin
If the EPSP > IPSP, an ___ ____ can occur. If EPSP < IPSP, an action potential can or can't occur?
action potential; can't
The nerve impulses sent to the CNS are _____ (arrival). They bring information to the ____. You can think of them like your ____ input (since its going in). They are composed of somatic afferent fibers (___, ___, and ____) and _____ afferent fibers (those in the ventral body cavity).
afferent; brain; sensory; skin, muscles, joints; visceral
____ ___ Sclerosis (ALS) which is also referred to as Lou Gehrig's disease and ___ ___ disease. There is a degeneration of ____ nerves. They are often ____, accounting for 90-95% of overall cases; however, some are familial which account for 5-10% of cases. Familial cases have mutation in the gene for SOD1 (___ ___ ___). This leaves them with no protection from ___ ___.
amyotrophic lateral; motor neuron; motor; familial; super oxide dismutase; free radicals
____ ___ Sclerosis (ALS) which is also referred to as Lou Gehrig's disease and ___ ___ disease. There is a degeneration of ____ nerves. They are often ____, accounting for 90-95% of overall cases; however, some are familial which account for 5-10% of cases. Familial cases have mutation in the gene for ____ (super oxide dismutase). This leaves them with no protection from ____ ____.
amyotrophic lateral; motor neuron; motor; sporadic; SOD1; free radicals
An autoimmune disease is when the body begins to destroy itself. It releases _____ which attaches to the "threat" signaling to the ____ (i.e. the trash truck of the body) to destroy it. The symptoms are poor ____, poor muscle control, ____, weakness, and ____.
antibodies; macrophages; vision; clumsiness; paralysis
A positive ion has to enter to stimulate the ___ ____. This ion usually carries #mV of positive charge. ___ is usually the stimulus.
axon hillock; +15; Na/Sodium
If electrical current (Na 2+) travels towards the __ ___ and changes the membrane potential from #mV to #mV then a large ____ will occur.
axon hillock; -70; -55; depolarization
Dendrites transmit incoming information to the ___ ___ by graded depolarizations. It is actually located in the ___ ____ or soma. It is where the __ ___ starts.
axon hillock; cell body; action potential
NMJ MECHANISM 1. Nerve impulse travels down ____ 2. Impulse reaches ____ _____ 3. Voltage gated ____ channels open 4. Ca2+ flows into ___ ____ 5. Ca2+ fuses with ____ ___ 6. Synaptic vesicles fuse with terminal membrane (____ _____) 7. Exocytosis of ___ into Synaptic cleft 8. Ach diffuses across ____ ____ 9. Ach attaches to nAch Receptors on _____ ____ 10. nAch receptors trigger depolarization of ____ 11. Depolarization spreads to _____ 12. Causes Ca2+ binds ____...etc.
axon; nerve terminal; Ca2+; nerve terminal; synaptic vesicles; presynaptic membrane; Ach; synaptic cleft; postsynaptic membrane; sarcolemma; t-tubules; troponin
NMJ MECHANISM 1. Nerve impulse travels down ____ 2. Impulse reaches ____ _____ 3. _____ gated ____ channels open 4. Ca2+ flows into ___ ____ 5. Ca2+ fuses with ____ ___ 6. Synaptic vesicles fuse with terminal membrane (____ _____) 7. Exocytosis of AcH into _____ ____ 8. ____ diffuses across synaptic cleft 9. Ach attaches to _____ Receptors on _____ ____ 10. nAch receptors trigger _____ of ____ 11. Depolarization spreads to _____ 12. Causes Ca2+ binds ____...etc.
axon; nerve terminal; voltage; Ca2+; nerve terminal; synaptic vesicles; presynaptic membrane; synaptic cleft; Ach; nAch; postsynaptic membrane; depolarization; sarcolemma; t-tubules; troponin
Synapses and neurotransmitters Axosomatic synapses occur between the ___ and ____. Axodendritic synapses occur between the ___ and ___. Axoaxonal synapses occur between the __ and ___ ____. Which one involves last minute changes being made in order to depolarize the membrane?
axon; soma; axon; dendrite; axon; axon hillock; Axoaxonal
(Forming cross-bridges Part 5): The ___ head sees the dimple, since it now has access, and it will bind to the site which will cause a ___-____. Once this has attached, the myosin head flexes inwards, ____ the thin filament towards the M line. ___ is released during the power stroke.
binding; cross-bridge; pulling; ADP
The CNS is composed of the ____ and ___ ___ (in the center) and the ____ are the nerves that are not located the CNS (such as spinal nerves and cranial nerves).
brain; spinal cord; PNS
Dendrites are ____ ____ of the cell body (like an antenna). They also contain ___ and organelles. They provide an ____ (increase or decrease?) in surface area for input signals (basically brings in ___ (more or less?) signals). Some are 'thorny' which are dendritic ____ (which help to increase surface area).
branching extensions; cytoplasm; increase; more; spines
(Forming cross-bridges Part 6): The cross bridge must now detach to either continue the muscle contraction (by forming what?) or to relax the muscles (by no longer forming what?). To detach the cross bridge, ___ must attach to what?
by forming another cross-bridge; no further cross-bridges are no longer formed; ATP; myosin head
If ___ remains bound to the TnC and ___ remains in the groove of the ____ filament, the myosin is ready to form another ___ ___ and ___ ___ again. This can further contract (____) the muscle or maintain muscle contraction without further shortening.
calcium; tropomyosin; thin; cross bridge; power stroke; shorten
Calcium ____ contraction. ATP ____ contraction.
causes; stops
NT's are classified based on ___ ___. The NT released at the NMJ is _____. Is it excitatory or inhibitory? What is it degraded by? Another type are ___ ____. They include dopamine, norepinephrine, ____ (adrenaline), serotonin, and histamine. Lastly, ___ ___ (also the building blocks of proteins) are a type of NT. They are Gamma Aminobutyric acid (GABA), Glycine, and Aspartate. Which are excitatory and inhibitory? Which is the most prevalent?
chemical structure; Ach; Excitatory; AchE; biogenic amines; epinephrine; amino acids; excitatory: GABA; Inhibitory: Glycine, Aspartate; GABA
Similar to the NMJ, ____ synapses are junctions between two cells composed of a ___ neuron, a synaptic cleft and a ____ neuron instead of a ____. NT's act at receptors to open ion channels leading to changes in membrane ____ (ie. depolarizations). The primary difference is that there are different ___ that initiate this change.
chemical; presynaptic; postsynaptic; muscle; permeability; neurotransmitters
A graded potential (occurs at _____ gated ion channels) occurs when a (1) chemical (often a ____) binds to the chemically gated ion channels on the ____ or ___ ___ of another neuron. (2) The two ion channels open allowing ___ ions to flow into the cell ___ their concentration gradient. (3) The inflow of positive charge causes a ___ of the membrane. (4) The more sodium that flows in, the ____ the depolarization. (5) The movement of the positively charged sodium in the cell is ___ ___. (6) The sodium flows a certain distance before the sodium/potassium picks it up and sends it back out of the cell, thus the current becomes ___ the further it travels from the site of the initial stimulus.
chemically; neurotransmitter; dendrites; cell body; sodium; down; depolarization; greater; electrical current; weaker
The positive feedback ends when the inactivation gate ____ (opens or closes?). Sodium influx (starts or stops?). Depolarization ____ (starts or ends?). Slow voltage gated ___ channels open and ____ ions flow out of the cell, down their concentration gradient. The outflow of K+ removes positive charge from the cell and begins the process of repolarization (___mV to ___mV). Towards the end of _____ the activation gates on the sodium channels ____ (open or close?).
closes; stops; ends k+; potassium; +30; -70 repolarization; close
The positive feedback ends when the inactivation gate ____ (opens or closes?). Sodium influx (starts or stops?). Depolarization ____ (starts or ends?). Slow voltage gated ___ channels open and ____ ions flow out of the cell, down their concentration gradient. The outflow of K+ removes positive charge from the cell and begins the process of _____ (+30mV to -70mV). Towards the end of repolarization the activation gates on the sodium channels ____ (open or close?).
closes; stops; ends k+; potassium; repolarization; close
Axons have terminal branches (~10,000) the ___ component of neurons (i.e. transmit impulses). The terminals are the secretory component bring that they secrete ___. Although it contains organelles, it does not contain the ___ or ___. Because of this, it relies on the cell body (___) for ___ ____.
conduction; neurotransmitters; ER; golgi; soma; protein synthesis;
Myofibrils are the ___ element of muscle cell. Each muscle fiber contains 100's-1000 of ____. They run _____ and fill the entire cell (___% of cell volume).
contractile; myofibrils; parallel; 80%
(Forming cross-bridges Part 7): After ATP attaches to the myosin head to detach the __-___, it will then lose its terminal ___ and gives its ____ to the myosin molecule. This causes the myosin head to return to its original __-__ position.
cross-bridge; phosphate; energy; non-flexed
(Forming cross-bridges Part 5): The myosin head sees the dimple, since it now has access, and it will bind to the site which will cause a ___-___. Once this has attached, the myosin head flexes inwards, pulling the ____ filament towards the ___ ___. ADP is released during the ____ ____.
cross-bridge; thin; M-line; power stroke
Muscle contraction occurs when force is generated by myosin ___-___. The contraction ends when they become ____.
cross-bridges; inactive
Pharmacology Tubocurarine (___) is a botanical agent from South America. It binds to _____ receptors and prevents it from binding. This is called a ____ _____ (which block receptors). It is classified as a neuromuscular blocking agent and causes muscular _____. Derivatives of curare form modern muscle _____. They are frequently used during ___ ____.
curare; Ach; competitive antagonist; paralysis; relaxants; surgical anesthesia
Axons decay quickly when _____. In this case, ___ cells help to repair it. The plasma membrane of the axon is the ____. There is a constant # way traffic of molecules inside the axon.
damage; Schwann; axolemma; 2
In a bare plasma membrane (without voltage-gated channels), as on a dendrite, voltage ___ because current __ across the membrane.
decays; leaks
How is signal terminated? 1) ____ nerve impulses, but this is slow. 2)______ (*the abbreviation is also acceptable*) located in the synaptic cleft degrades Ach Since __ (1 or 2) is the most rapid mechanism, it causes the lifetime of Ach in the ____ ____ to be ____ microseconds (.0002 seconds).
decrease; Acetycholinesterase OR AchE; 2; synaptic cleft; 200
The amount of ATP ____ when an animal is hit; however, the muscles are still ___. This impact still causes ____ to be relased. This continues because there is no ___ to come in and detach that cross bridge. Since there is not enough ATP, the muscles remain _____.
decreases; contracted; calcium; ATP; contracted
It takes thousands of EPSP's to fire on the ____ and deliver enough depolarizing current to reach ____ at the axon hillock of the postsynaptic neuron. These EPSP's can be cancelled out by the ___'s so the sum of the 2 will determine whether enough depolarizing current reaches the # set of ____ gated ion channels.
dendrites; threshold; IPSP; voltage
An EPSP is a local _____ of the postsynaptic membrane. EPSP's bring the neuron ___ to AP threshold. NT binding opens chemically gated ion channels, allowing ___ and ___ to pass simultaneously.
depolarization; closer; Na+; K+
Where the NT released at the presynaptic membrane causes _____ at the postsynaptic membrane. These ___ depolarizations are called ___ ___ ___ (___'s). The stimulus causes the reaction to get closer or further away from threshold? (i.e hole or hill?)
depolarization; graded; Excitatory Postsynaptic Potentials; EPSP; closer; hill
A ____ is a change in the resting membrane potential such that the inside now becomes more ___ than it was when at rest.
depolarization; positive
Profile of an action potential (Part 1): A small stimulus ____ the membrane from -70mV to -55mV. This begins ___ ____ that results in a large depolarization to +30mV. Now the inside of the cell is more ____ (positive or negative?) than the outside. Now ___ returns the cell to -70mV but the K+ efflux continues resulting in the ____ phase. The cell is now even ___ (positive or negative?) than at rest.
depolarizes; positive feedback; positive repolarization; hyperpolarization; negative
(Forming cross-bridges Part 6): The cross bridge must now ___ to either continue the muscle ____ (by forming another cross bridge) or to ___ the muscles (no further cross bridges are made). To detach the cross bridge, ____ must attach to what?
detach; contraction; relax; ATP; myosin head
The speed of conduction is determined by the axon ____ and the degree of _____ of the axon. Larger diameter axons provides ____ (more or less?) resistance to flow of ions, therefore the membrane reaches threshold ____ so impulses travel ____. In _____ nerves, Action potentials are generated next to each other, one after another. This is called ____ ____. In myelinated nerves, action potentials occur only at the ___ ___ ____. Since the current flows under myelin from node to node, nerve conduction of impulses are ____. This is called saltatory ____ or ____ propagation.
diameter; myelination; less; faster; faster; unmyelinated; continuous conduction; node of ranvier; faster; conduction; propagation; saltatory
The speed of conduction is determined by the axon ____ and the degree of _____ of the axon. ___ diameter axons provides less resistance to flow of ions, therefore the membrane reaches threshold ____ so impulses travel ____. In _____ nerves, Action potentials are generated next to each other, one after another. This is called ____ ____. In myelinated nerves, action potentials occur only at the ___ ___ ____. Since the current flows under myelin from node to node, nerve conduction of impulses are ____. This is called ____ conduction or saltatory ____.
diameter; myelination; Larger; faster; faster; unmyelinated; continuous conduction; node of ranvier; faster; saltatory; propagation
All cells have an electrical gradient across their membrane due to the ___ in the total number of charges across the membrane. The inside of the membrane is relatively ___ compared to the outside. This produces a voltage difference across the membrane called the ___ ___ ___. In neurons, this voltage difference can be altered by opening ___ ion channels and allowing ions to move ___ their concentration gradients. This creates an ___ ____.
difference; negative; resting membrane potential; gated; down; electrical current
Neurons come in many ____ shapes and sizes which are usually large and complex. They have a receptive region (____) which takes in information, a ____ ____ (soma) which contains DNA, organelles, and things that are synthesized, a conducting region (____) which can spread electrical current and an output region (____ ____) where the axon talks to another friend.
different; dendrites; cell body; axon; nerve terminal
The depolarizing electrical current ____ (does/does not) get smaller as it travels because the sodium that enters the first set of voltage gated ion channels in the axon hillock will then ___ inside the cell membrane, depolarizing other areas of the axon and opening ____ (more or less?) Na+ channels. This chain reaction is referred to as the ___ of an ____ ____ and is the reason the nerve impulse ____ (does/does not) diminish with distance.
does not; diffuse; more Propagation; Action Potential; does not
When the nerves carry impulses from the CNS they are called _____ (exiting). You can think of them like your ____ output (since they are going out). They're made of ___ (voluntary) nerves (things you are in control of) and ____ (involuntary nerves) such s your visceral organs. Of your autonomic nerves, you have your _____ (used for arousal - what essential response takes place here?) and your _____ (used to relax - what 2 processes occur here?)
efferent; motor; somatic; autonomic; sympathetic; fight or flight; parasympathetic; rest and digest
The ___ filaments (which are made of the protein titin) serve to ____. They help the muscle stretch.
elastic; recoil
(Forming cross-bridges Part 1): To form cross-bridges, you must first start with ___ ___ (nerve impulses) from the CNS. ____ nerves exit the spinal cord, branch and travel to every ___ muscle cell in the body. When a nerve impulse reaches the end of the nerve, a ____ is released. This interaction is called a _____ ____.
electrical current; Voluntary; skeletal; neurotransmitter; neuromuscular junction
Usually items ending in -ase are ____. 99% of the ones in the body are ____.
enzymes; proteins
Synapses can be ____ or ____.
excitatory; inhibitory
Nervous tissue cells are densely packed due to having little _____ space (small amount of space to move around)
extracellular
Speed of nerve impulses: They are ____ in nerves found in skeletal muscle (i.e. 300 mph) and are ____ in nerves found in the gut, glands (i.e. 40 - 2 mph). The speed of conduction is determined by what two things?
faster; slower; axon diameter; degree of myelination
Large, long axons are covered in Myelin (___ protein) that ____ insulates axons. It ___ transmission of nerve impulses along axon. It is formed by ___ cells.
fatty; electrically; propagates; Schwann
There are two types of electrical signals because there are two types of ___ ___ ____. The dendrites and cell body have ____ and/or mechanically gated ion channels (i.e. ____). The axons, sarcolemma and T-tubules have ___ gated ion channels (i.e. ____ and ____).
gated ion channels; chemically; calcium; voltage; sodium, potassium
There are two types of electrical signals because there are two types of ___ ___ ____. The ____ and ____ ___ have chemically and/or mechanically gated ion channels (i.e. ____). The ____, _____ and ____ have ___ gated ion channels (i.e. ____).
gated ion channels; dendrites; cell body; calcium; axon; sarcolemma; T-tubules; potassium
The subunit of thin filament is ____ ____. (otherwise referred to as G actin).
globular actin
There are 2 types of electrical signals: In the dendrites and cell body, the electrical signal is called a ___ ____. In the axon, the electrical signal or "nerve impulse" is called an ____ ____.
graded potential; action potential
So what's the difference (part 1 - answer graded or action (for potentials)). ____ potentials can differ in size but are never as big as an ____ potential (which is just one large size). Which occurs on the axon (sarcolemma and T-tubues)? Which occur at the receptive region of the neuron (dendrites and cell body)? Which are due to the opening of chemically gated ion channels and which are due to the voltage gated ion channels?
graded; action; action; dendrite; graded; action
So what's the difference (part 2 - answer graded or action (for potentials)). In which is the degree of the voltage change relatively small? In which is the degree of the voltage change relatively large (and temporarily reverses polarity)? In which is the degree of the voltage change does not vary once a minimum stimulus has been reached? In which is the degree of the voltage change dependent on the magnitude of the stimulus? In which does the intensity decrease with distance? In which does the intensity NOT decrease in strength with distance?
graded; action; action; graded; graded; action
Directly on the postsynaptic membrane, there is a ____ potential/response (due to the chemically gated ion channels). Further along the muscle fiber, there are ____ gated channels, causing an action potential.
graded; voltage
Where the NT released at the presynaptic membrane causes ____ of postsynaptic membrane. These ____ hyperpolarizations are called ___ __ __ (____'s). If enough IPSP's are produced, generation of action potentials at the ____ ____ will be ____.
hyperpolarization; graded; Inhibitory Postsynaptic Potentials; IPSP; axon hillock; prevented
During contraction, the Actin/Myosin overlap ____. When stretched, the Actin/Myosin overlap is ____.
increases; minimal/small
Myelin embedded in Schwann cells create a fatty ___ around the axon. If axons didn't have myelin, they would shock each other in _____. Neurons communicate with each other by generating ___ signals which are just the movement of ____ ____ (i.e. Na+, K+).
insulator; crossing; electrical; charged ions
Why is there a voltage difference between the inside of the membrane and the outside? Because there are ___ ion channels sprinkled all over the membrane of the neuron. These leak channels allow ___ to leak out of the cell easier than ___ can leak back into the cell. There is a large amount of potassium ____ the cell and a large amount of sodium ___ the cell.
leaky; K+; Na+; inside; outside
___ ___ provide a temporary removal of pain while fully conscious. It is procaine, lidocaine (xylocaine), and ____. This prevents the conduction of nerve impulses by blocking ___ gated ___ channels. This interferes with depolarization and ____ _____.
local anesthetics; cocaine; voltage; Na+; action potentials
Neurons have _____ (>100 years), living as long as you live. They are ___ so they do not divide or replicate. They have a very high ____ rate. This causes it to need a constant supply of ___ and ____. As such, they require 20% o your calories.
longevity; amitotic; metabolic; glucose; oxygen
Examples of anterograde are _____ (organelles used for energy), and replacement molecules for the axolemma (those involved in ____ synthesis). They are transported by the protein ____ (like Fedex).
mitochondria; neurotransmitter; kinesin
For electrical to chemical signaling, nerve impulses travel along ____ neurons. The end of the axon branches to form a ____ ____ with a single muscle fiber. The NMJ consists of a motor nerve ending (_____), the ____ ___ (the gap), and at the ____ ____ ____ (the receptive muscle fiber).
motor; Neuromuscular Junction; terminal; synaptic cleft; motor end plate
Myosin is associated with motion or ____.
movement
_____ Sclerosis is when the immune system makes _____ (i.e. Y shaped proteins in response to a pathogen) to ____. This causes the ___ cells to get destroyed, disrupting saltatory conduction. As such, the _____ _____ is destroyed, leading to a ____ impulse conduction, ____, and _____-_____ of electrical current. Eventually, impulse conduction ____.
multiple; antibodies; myelin; Schwann; myelin sheath; slow; leakage; short-circuiting; stops
An autoimmune disease is when the body begins to destroy itself. The symptoms are poor vision, poor ____ ____, clumsiness, _____, and paralysis.
muscle control; weakness
Paralysis occurs when there is a lack of control of ____. There are 2 types: flaccid and spastic. Flaccid paralysis is when muscles do not ____. Spastic paralysis is when muscles do not ____.
muscles; contract; relax
Oligodendrocytes have processes that form ___ ___ around ___ (CNS or PNS?) nerve fibers.
myelin sheath; CNS
Sarcomere units end to end are what form a ____.
myofibril
Wherever you have the A band, you have ____. The ___ band is where you don't have myosin.
myosin; I
The inside cell is more ___ than the outside (-70mV). This is called a ___ (opposite) state. This occurs only at the ____. The cytoplasm and the extracellular space is ____.
negative; polarized; membrane; neutral
Neurotransmitters are chemcials released from the ___ ____. There are over 50 NT's. Most neurons make # or more NT's. Neurons can release one or __ NT's.
nerve terminal; 2; all;
The synaptic cleft is the gap between the ____ ___ and _____.
nerve terminal; sarcolema
The outermost layer of the myelin sheet is called the ____. It is a tight coil of wrapped membranes. A gap is left between adjacent ___ cells called a ___ __ ____. They have ___ ___ as checkpoints.
neurilemma; Schwann; Node of Ranvier; ion channels
The cells of the nervous system are ____. There are a 100 billion neurons in the ___. They are specialized to conduct ____ impulses which normally fire 80 times per ____. In epilepsy, they can fire ____ times per second.
neurons; CNS; electrical; second; 500
In the PNS and CNS, nervous tissue are made of nerve cells (____) and supporting cells (____). Neurons are information _____ that are ____ (can conduct electrical current). What is the most diverse kind of cell in the body? Despite this diversity, neuroglia outnumber neurons by #:1.
neurons; neuroglia; messengers; excitable; neurons; 9
During the refractory period, the channels upstream are unable to open up. This explains why the electrical current flows in ____ direction(s).
one
Nerve impulses travel in ____ direction(s) (even though the sodium ions diffuse in ___ direction(s)) because of the ____ period. During this period the upstream channels will or will not open? The channels must have been ___, that means the ____ gate must be open and the ____ gate must be closed in order for another action potential to occur.
one; all/multiple; refractory; will not; reset; inactivation; activation
Nerve impulses travel in ____ direction(s) (even though the sodium ions diffuse in ___ direction(s)) because of the ____ period. During this period the upstream channels will or will not open? The channels must have been ___, that means the inactivation gate must be ____ and the activation gate must be ___ in order for another action potential to occur.
one; all/multiple; refractory; will not; reset; open; closed
There is # axon per neuron. It is a ____ of the cell body. It arises from the ___ ___. It can be short or long, proving that the axon is what makes a nerve small or large. It can branch into ___ ____. It is the only part of the neuron that can ____ because it can grow into new branches.
one; projection; axon hillock; axon collaterals; change
Since more K+ goes out than Na+ comes in, the net effect is changed: more positive charges collect on the ___ surface of the cell membrane than the ____ of the surface. The Voltage (charge) difference is #mV. This is called the ___ ___ ___.
outside; inside; -70; resting membrane potential
The RMP is negative because there are more positive charges on the ____ of the membrane than the ____. ___ channels are located everywhere and they are open all the time. ____ gated ion channels are located on the dendrite and cell body. ___ gated ion channels (specifically of Na+ and L+) are located along the axon. The ____-____ pump is located everywhere.
outside; inside; leak; chemically; voltage; sodium potassium
Urination is sympathetic or parasympathetic?
parasympathetic
The cell body (or soma or ___) contains the usual organelles (i.e. nucleus, ribosomes, ___ ER, golgi, and ____). It also contains ____ which maintain cell shape and integrity. A cluster of cell bodies is called ___ in the CNS, but it is called ___ in the PNS.
perikaryon; rough; mitochondria; neurofibrils; nuclei; ganglia
The tail of myosin is 2 twisted "heavy" ____ chain. The ends of the heavy chains are referred to as the heads which have 2 "___" polypeptide chains.
polypeptide; light
The K+ gates are slow to close and ____ keeps flowing out of the cell even though the potential across the membrane has returned to ___mV. As K+ continues to efflux the cell becomes more ____ (negative or positive?). This is called _____. It is often short-lived
potassium; -70; negative; hyperpolarization
When it closes slowly, the inactivation site pulls the ____ (sodium or potassium?) in. Since the voltage gates of (sodium or potassium?) do not have an inactivation site (and not a ball and chain method), too much potassium escapes.
potassium; potassium
The NMJ is composed of 3 primary things: The _____ ____ (the neuron nerve terminal), ____ ____ (gap), and lastly, the postsynaptic membrane (which is also referred to as the ___ ____ ____).
presynaptic membrane; synaptic cleft; motor end plate
A synapse has 2 parts: 1) Nerve terminal - contains synaptic vesicles that fuse with ____ membrane to exocytose Nt's into ___ ___. 2) A _____ region - an area of the postsynaptic membrane with specific _____ _____.
presynaptic; synaptic cleft; receptor; neurotransmitter receptors
The "hair" of the neuron (i.e. the dendrites) ___ information. At the nerve terminals, _____ are released. Which part communicates with the rest of the body (dendrites or the nerve terminal)?
receive; neurotransmitters; nerve terminal
Examples of retrograde are molecules and organelles for degradation and ____. They are transported by the protein ___ (like UPS).
recycling; dynein
The ____ period is the reason why we have a unidirectional flow.
refractory
The refractory period: During the depolarization and most of the depolarization phase, the membrane is _____. This means the neuron ____ (can or cannot) respond to another stimulus. Why?: The reason for this is the voltage gated ion channels are already ___ or the inactivation gate is ___. For the nerve to respond to another stimulus, the activation gate must ____.
refractory; cannot; open; close; reset
When muscles are ___, the H zone is present. When it ___, the H zone gets smaller/disappears.
relaxed; contracts
Although myosin heads can attach and detach many times, all myosins do not attach and detach at the ___ time. At any one time, some myosin heads are bound to ___, maintaining tension on the ___ and some have detached.
same; actin; sarcomere
The motor end plate is a dimple in the _____. They are the junctional ____ of the sarcolemma. This allows for an increase in ____ ____. Many Ach receptors, called ____ ____ receptors (or nAchR) transmit the ___ signal into ____ signal.
sarcolemma; folds; surface area; nicotinic acetylcholine; chemical; electrical
The _____ ____ is the endoplasmic reticulum of muscle cells. It is a network of tubules that surrounds each ____. Does it act like the rough ER or the smooth ER?
sarcoplasmic reticulum; myofibril; smooth ER
The central and peripheral nervous systems function together ___ information (internal and external) to bring about some type of awareness. They process, ___, and ____ information. They produce a response that is _____ (in control) and _____ (not control).
sensory; filter; interpret; voluntary; involuntary
The process of information is ____ input (receiving information), _____ (integrate), and ____ output (doing something with that signal).
sensory; integration; motor
Speed of nerve impulses: They are faster in nerves found in ____ muscle (i.e. 300 mph) and are slower in nerves found in the ____, ____ (i.e. 40 - 2 mph). The speed of conduction is determined by what two things?
skeletal; gut; glands; axon diameter; degree of myelination
Neuroglia are ___ than neurons and are also called ____ cells. They are a total of 6 types (# in the CNS and # in the PNS). A ____ is a cancer that began in a glial cell.
smaller; glial; 4; 2; glioma
Although ____ (sodium or potassium?) flows in multiple directions (up and downstream), only the ions flowing directly downstream will activate the ion channels. The recharge occurs from ___ to ____. Therefore, there is a _____ flow of the electrical current.
sodium; left; right; unidirectional
Proteins made in the ____ are sent all the way down. The electrical current, starting at the ___ ____ , occurs in a phospholipid membrane that is __-directional. The electrical current travels down the axon to the nerve ___.
soma; axon hillock; uni; terminal
There are 3 classifications nerve fibers. There is Group A, B, and C. Group A: It is mostly ____ sensory. They are also ___ fibers serving skin, skeletal muscles, and joints. They have a ___ diameter and ___ myelin sheaths. The speed of conduction is the ____ of all the groups (i.e. 150 m/s or 300 mph). Group B: It is ___ nervous system sensory. They are also ___ fibers. In this group, they are small ___ sensory fibers (pain + small touch fibers). They are ____ diameter, ____ myelinated, and are the ____ fastest of all the groups (i.e. 15 m/s or 40 mph). Group C: It has the same fibers as group ___. They are a ___ diameter, are _____ (no myelin). Because of this, they have no ____ ____. The speed of conduction is the ____ of all the groups (i.e. 1 m/s or 2 mph).
somatic; motor; large; thick; fastest autonomic; motor; somatic; medium; lightly; 2nd B; small; unmyelinated; saltatory conduction; slowest
There are 3 classifications nerve fibers. There is Group A, B, and C. Group A: It is mostly ____ sensory. They are also motor fibers serving ___, ____ muscles, and ___. They have a ___ diameter and ___ myelin sheaths. The speed of conduction is the ____ of all the groups (i.e. 150 m/s or 300 mph). Group B: It is ___ nervous system sensory. They are also ____ fibers. In this group, they are small somatic sensory fibers (___ + small touch fibers). They are ____ diameter, ____ myelinated, and are the ____ fastest of all the groups (i.e. 15 m/s or 40 mph). Group C: It has the same fibers as group ___. They are a ___ diameter, are _____ (no myelin). Because of this, they have no ____ ____. The speed of conduction is the ____ of all the groups (i.e. 1 m/s or 2 mph).
somatic; skin; skeletal; joints; large; thick; fastest autonomic; motor; pain; medium; lightly; 2nd B; small; unmyelinated; salutatory conduction; slowest
The myelin sheath helps to ___ up the propagation of signals.
speed
Part 1: Rigor (___) Mortis (___) is when the joints of the body become stiff after death for 6-72 hours. This is caused by widespread ___ ____ contraction. After cell death, ATP synthesis ____. Calcium is no longer pumped into the ____ ___ (since this process requires ____). The calcium flow into the ___ is unstoppable/uncontrolled. Why is this flow like this?
stiff; death; skeletal muscle; stops; terminal cisternae; ATP; cytosol; because the body systems are not functioning to stop it
Skeletal muscle is ___ because of actin + myosin fibers of myofibril.
striated
The nerve terminal contains ___ ____ (sacs containing a neurotransmitter). The neurotransmitter is a chemical _____. At the NMJ, the NT is _______.
synaptic vesicles; message; Acetylcholine (i.e. Ach)
The nerve terminal contains ____ ____ (sacs containing a _____). The NT is a chemical message. At the NMJ, the NT is ____.
synaptic vesicles; neurotransmitter; Acetylcholine (i.e. Ach)
Local anesthetics provide a ____ removal of pain while fully conscious. It is ____, ____ (xylocaine), and cocaine. This prevents the conduction of nerve impulses by blocking voltage gated ___ channels. This interferes with ___ and action potentials.
temporary; procaine; lidocaine; Na+; depolarization
Thick filament is when the myosin tails bundle together (forms the ___ filament) and the myosin heads poke ____. The Myosin ___ come in contact with the thin filaments. They are the bonding sites for ___ and ___.
thick; outwards; heads; actin; ATP
The A band is where ___ filaments are found. The I band is where ___ filaments are found but not ___ filaments.
thick; thin; thick
At the junction between the A and I band, the sarcoplasmic reticulum gets ____. This area is called the ____ ____. Between the terminal cisternae are ___ ____.
thicker; Terminal Cisternae; T Tubules
In myosin, during contraction, one head binds to the ___ filament and the other binds to ____.
thin; ATP
Tropoin, a 3 polypeptide complex found in ___ filament has 3 parts. ___ bonds to actin. ___ binds to tropomyosin and positions it on actin. ____ binds to Calcium ions.
thin; TnI; TnT; TnC
When the voltage across the membrane reaches -55mV (____) some voltage gated sodium ion channels open and sodium flows in, down its concentration gradient. This further depolarizes the membrane, causing ___ (more or less?) channels to open. This is called ____ ____ (which is where an initial ____ (small or large?) change gets amplified into a ____ (small or large?) change. An initial small dempolarization (___ mV to ___ mV) turns into a large depolarization (___ mV).
threshold; more; positive feedback; small; large -70; -55; +30
Elastic filaments are composed of the giant protein called ___. They run from __ __ to ___ and on to the __ __. They only connect to __ filaments since they help to hold them in place.
titin; Z disc; Myosin; M line; thick
The elastic filaments (which are made of the protein called ____) serve to recoil. They help the muscle ____.
titin; stretch
Part 1: For muscles to relax, the ____ must return to its original position of ___ the myosin binding site. For this to occur, ____ must be pumped back into the ___ ___ (where it is stored) to create a diffusion gradient that draws the bound calcium off the ____.
tropomyosin; blocking; calcium; terminal cisternae; TnC
The shape of troponin determines the position of what protein? The position of tropomyosin determines the ability of muscles to what?
tropomyosin; contract
Part 2: Calcium binds to ___ exposing the myosin binding site. ___ ___ formation becomes excessive in all ____. ATP, which is necessary for cross bridge ____, is no longer available. Without ___, muscles stay contracted (peaks @ #-# hours). Rigor Mortis ____ as muscle proteins begin to breakdown.
troponin; Cross bridge; muscles; detachment; ATP; 12-24; disappears
Part 2: In continuing muscle relaxation, the 3 ____ proteins must return to their original conformation. ___ slides back and now blocks the ____ binding site. Because of this, no __-___ can form (since ____ no longer has access to the binding site). At this point, the muscle ____.
troponin; Tropomyosin; myosin; cross-bridges; myosin; relaxes
The shape of ___ determines the position of tropomyosin. The position of ___ determines the ability of muscles to contract.
troponin; tropomyosin
The ion channels in the axon hillock are ____ (chemical or voltage?) gated. Sodium channels have 1 or 2 gates? The ___ gate opens the channel and the ____ gate blocks the open channel. Both gates must be ___ for sodium to enter. Potassium has 1 or 2 gates? This gate just opens and closes ____.
voltage 2; voltage; activation; inactivation; open 1; slowly
Pathology of the NMJ Myasthenia Travis causes muscle ____, difficulty ___, and drooping _____. This is an _____ disease caused when the immune system develops antibodies to ____ receptors. This targets the receptor for destruction by ____.
weakness; swallowing; eyelids; autoimmune; neurotransmitter; macrophages
Myelinated fibers are ___ matter and Unmyelinated fibers and cell bodies are ___ matter.
white; gray
