Exam 7: February 27 - March 3 Flashcards
1
Q
what information does your vestibular system give?
A
it’s the part of your sensory NS that tells you about your head position and motion
2
Q
what receptors does your vestibular system use?
A
mechanoreceptors
stereocilia specifically
3
Q
what are the components of your vestibular system?
A
1) semicircular canals
2) otolith organs
4
Q
how many semicircular canals do you have?
A
3
5
Q
what do your semicircular canals help with? which vectors?
A
help you tell how your head is moving in a 3D space because each plane gives you a vector of movement and you do vector addition
rotation, acceleration, and deceleration
6
Q
what is the reference that your simicircular canals use?
A
when you solve this 3 plane problem, you get the line that you’re moving but you don’t know if it’s positive or negative direction….you need a reference!
Gravity is always working on us and will tell us which way is “down”
7
Q
what does otolith mean?
A
“lith” means stone
“oto” means ear
if you have rocks in your ears and you tilt you head, the rocks would follow gravity and roll so rocks in your head would be helpful because they would tell us which way gravity is pulling on us
8
Q
how many otolith organs do you have? why do you have that specific number? what are they called?
A
2! because your head can tilt side to side or back and forth so you need one for each
utricle and saccule
9
Q
what are the otolith organs made of?
A
your utricle and saccule are calcium stones
10
Q
when do your otolith organs have difficulty determining orientation? how do you fix this?
A
gravity has a low impact on us when we’re in water
when someone is under water and gets disoriented they have a hard time figuring out which way is up because we’re buoyant in water so gravity doesn’t pull down and the rocks don’t roll right
so how do you solve the problem of which way is up? Bubbles! Follow the bubbles because they will always go towards the surface
11
Q
what do your otolith organs give you information about?
A
your otolith organs give you the information of acceleration relative to gravity
the rocks can only roll so far so you only get the initial component
the rocks are about changes in motion, not constant motion – kind of like cans in your car trunk
with the use of your semicircular canals you know if you’re staying in that position
12
Q
what information does your chemosensory system give?
A
it’s a part of your sensory nervous system that tells us about dissolved chemicals
our eyes are filled with fluid
we breath in air and bring things into our mouth but we have to dissolve them to be able to register
13
Q
what receptors does the chemosensory system use?
A
chemoreceptors
14
Q
what are the components of the chemosensory system?
A
taste and smell
internal and external!!
this is just the way we gather information from the outside – how the chemicals are changing around us or how they’re changing inside us – so these are just the external measurements
internal: pH, O2, CO2 levels – make sure we’re staying in SS and are in homeostasis
15
Q
what is another name for taste?
A
gustation?
16
Q
where do we find the chemoreceptors associated with taste?
A
Your mouth overall because you have your tongue and the back of your throat too
you also have receptors in your GI track and your lungs as well so that’s why when you breath sometimes you feel like you taste it
17
Q
what causes an aftertaste with food?
A
there are different chemoreceptors in the back of your throat
18
Q
what helps to increase the number of taste receptors?
A
where we have these receptors, there’s lots of surface area
our tongue isn’t nice and smooth, it’s bumpy so that you can have lots of receptors (10,000 taste receptors in association)
19
Q
why do we put stuff in our mouth?
A
it’s most likely going to end up going in to your digestive track
you need to decide if you want to swallow something or spit it back up
20
Q
what are primary taste receptors?
A
things that are critical to maintaining homeostasis are important so for knowing if it’s something you want to digest
21
Q
what are the 6 primary taste receptors?
A
1) salty
2) sour
3) sweet
4) bitter
5) umami
6) fat
22
Q
what is your salty primary taste receptor do?
A
need Na for membrane potential, action potential, your nervous system – historically sodium was lacking in our environment – Na acts on the receptors and causes an influx of Na which activates membrane potential
it gives us information about a compound that is of critical importance so we know it’s something we want to swallow and we need more of
we’ve become successful at accumulating salt from our environment but back in time we weren’t and used salt as a monetary unit
23
Q
why do you need sodium?
A
need Na for membrane potential, action potential, your nervous system
24
Q
what is your sour primary taste receptor?
A
H+ blocks normal K+ movement
H+ impacts the ability of the regular movement of K into these receptors and therefore impacts membrane potential of these receptors
25
when would we want sour foods?
sour is important for pH regulation of blood: we don’t want to be acidic or basic
if we’re lacking in H+ we’ll want sour things but if we’re already acidic we won’t want to take in sour things
it all depends on your current situation
26
what does a sour taste indicate?
another thing this sour taste tells us is when proteins break down they release H+ so a sour taste typically indicates that that food is spoiled
27
what does your sweet primary receptor tell you? what activates these receptors?
binding of glucose activates these receptors
we need the glucose to do glycolysis and feed into Krebs cycle/ETC
we can run these processes off proteins and fats but it’s not as efficient – this has changed in our history but we’ve also become efficient at extracting sugar out of our environment
28
why do we need glucose?
to do glycolysis and feed into Krebs cycle/ETC
29
what does your bitter primary taste receptor tell you?
it's unlike the other 5 categories in that it's a group category
it’s a grouping of at least 30 compounds that bind to a similar Rs so they historically all get us the same response
they’re typically alkaloids (caffeine) and toxins that bind to these bitter receptors
30
why do bitter things taste bitter?
the compounds that bind to bitter receptors are typically alkaloids (caffeine) and toxins
this makes sense because alkaloids play with pH and toxins are bad
when you taste something bitter you don’t ingest it typically – this is why a lot of pharmaceuticals don’t have a good taste because they’re toxins which makes it hard to give medicine to kids
historically bitter things you avoid ingesting so you avoid toxins and don’t have a pH change – how we deal with them now we can consciously say that it’s okay because it might be healthy actually like kale
31
what does umami mean?
a pleasant or savory taste in Japanese
32
what is the umami primary taste receptor?
it's when you can’t put a name to it when you’re eating it but wow it tastes good - it’s most likely your umami receptors responding
33
what activates umami receptors?
binding of glutamate is what activates umami receptors
34
what makes food taste better?
monosulfate glutamate = MSG
binding of glutamate compounds makes food taste good!
35
why do we like bacon?
glutamate is needed for Krebs
having enough glutamate helps keep aerobic cell metabolism working properly
we also know that lots of our AA can act as neurotransmitter so therefore Glu also acts as a NT so without it there’s nervous system communication problems and ATP production problems
umami are also a protein indicator
36
what can umami receptors also be an indicator for?
umami are also a portion indicator
37
what activates fat primary taste receptors?
binding of a fat that activates these receptors
how that's happening is still being worked out
it’s about a critical need and that it’s something historically was quite low in the environment – we can turn fats into energy!
38
what's another name for smell?
olfaction
39
where does olfaction happen?
3 cmˆ2 patch on the roof of your nasal cavity
not wide spread like taste receptors
40
which receptors does smell use?
chemoreceptors
5 million receptors with 1000 types in this small little patch of area so we don't really categorize or group them
41
what is your sense of smell?
it's about detecting changes in the environment but you don't have intimate contact with it or bring it into your body
42
what happens when you can't smell?
when your nose is a wet area so when your nose dries out your lose your sense of smell because you need the moisture to dissolve
43
how long do your smell receptors last?
2 months = high turnover area
44
how do receptors in the smell and taste turn over?
when individual receptors in our mouth turnover but the categories stay the same
with our sense of smell we add and take away categories all the time
45
what is being nose blind?
your nose receptors have a high turnover rate and you add and take away categories of receptors all the time
being nose blind to things is if you're around something all the time, you'll put away the receptors it and literally stop smelling it like in the febrile commercials
if it’s always in your environment, it’s not interesting like how you don’t need to know that you’re wearing clothes – this is why you need to change your perfume and cologne regularly because you stop realizing how much you’re putting on
46
how do you register smells?
your olfactory bulb is the patch in the roof of our nasal cavity
at this spot we're just picking up the information, we do some initial processing with it so it's your initial sorting
47
how do you process smell?
you initially sort smells at the olfactory bulb
this initial sort then goes to a section of your brain in your cerebral cortex called your primary olfactory cortex which is your secondary processing center that starts getting you to act on what you’ve smelled before you even consciously register it such as getting closer or farther away from the source
when you become conscious of those smells its because of processing done in your orbitofrontal cortex in your cerebral cortex
48
what is the primary olfactory cortex?
subconscious coordination with behavior
49
what happens when you become conscious of a smell?
when you become conscious of those smells it’s because of processing done in your orbitofrontal cortex in your cerebral cortex
this one gives you conscious knowledge of that particular smell and now you register it
you might already be reacting to it before this conscious registering happens which gives you more detail of what you’re detecting
50
what is your vomeronasal organ?
it's related to olfactory
it's not about general chemicals being registered like in olfaction, it's about chemicals being registered from another organism = receiving signals that are released from another human and come to you to act on your cells
they’re between person signals instead of between your own cells which are called pheromones
you respond to them and recognize and give off certain pheromones that tell information about you and get other individuals to respond to that information you’re giving them – it’s not within smell, it’s similar though
51
what is perception?
it's not identical to detection
ex. obvious case and point is smell because we're reacting to smell before we consciously know that they're even there
ex. pheromones we don't even know they're there but we're responding to them
52
how does perception work?
o Within the interpretation of these signals, the brain sees no reason to keep them as separate entities and often merges them together
you have 6 categories of taste receptors but when your nose gets stuffed up things don’t taste the same because what we perceive as the sense of taste is actually a combination of smelling it, tasting it, hearing it, and seeing it
it’s not just about how it hits and individual’s tongue, it’s also about presentation because if it looks great it’ll influence how you feel about it when you taste it – if you get a bag of chips but can’t hear a crunch, you perceive that it’s stale
53
what kind of process is the interpretation of signals?
the interpretation of signals is a cerebral process
so when you drink your taste and perception change…
54
what are consequences of perception?
we often combine signals so you have to be careful about saying something is just from one area because you're likely responding to multiple things that are happening at that time
we are often very unconsciously acting on the signals that we gather where as we think we’re only consciously acting on them – guys can pick up on signals girls are sending based on what time in her cycle she’s in
55
what does your somatic nervous system do?
the somatic NS controls skeletal muscles only, not cardiac or smooth muscle
56
which muscles are striated? which are not?
skeletal and cardiac are striated
smooth muscles are not striated
57
does your mouth or nose have more receptors?
your mouth has less receptors and less types of receptors than your nose
58
which muscles are voluntary vs involuntary?
skeletal muscle is under voluntary control, we are making them move in a conscious matter, it’s not under the autonomic nervous system
our cardiac and smooth muscle (size of blood vessels, GI tract) are involuntary
59
what do our different types of muscles do?
skeletal muscles move bonds
cardiac muscles are changes in heart volume
smooth muscles are changes in our organ volume
60
what is the organization of a muscle?
cells, tissues, organs, and organ systems are the levels of organization
61
what is your muscle?
your muscle is an organ!
62
what are the units in a muscle?
myfibers → myofibril → myofilaments
myofiber is the container
the myofiber is the straws inside of it
the myofilaments are the stripes on the straw
63
what are myofibers
they're your individual units that are your muscle fibers
64
what does my mean?
muscle
you don't say muscle cell because fiber helps you with how the cell looks = they're long and thing
65
how long are myofibers?
they run from one end of your muscle to the other end
66
how does a myofiber form? how do you know that's how it forms?
in development, there’s a whole series of cells that crosses that distance but then they all fuse together to create one bigger cell
we know this is what happened because all the nuclei of all the individual cells are all still there
one continuous plasma membrane but they used to be separate plasma membranes so now the cells all have the same PM and you can't rip them apart
67
what are myofibrils?
bundles of myofilaments make up myofibers
myofibrils are part of your myofiber
68
what are myofilaments?
they make up myofibrils
69
what are the types of myofilaments?
myosin and actin
70
what is the difference between actin and myosin?
they are the two types of myofilaments (they're proteins)
actin is smaller and thinner than myosin
71
what are actin and myosin referred to as?
myosin is called the thick myofilament
actin is the thin myofilament
72
what is the sarcoplasmic reticulum?
it's what causes the myofibrils to be grouped up because it wraps around them
without the SR the myofibrils wouldn’t exits because there wouldn’t be any bundling
the SR creates structure
73
what is the primary job of the SR?
it's a holding place within our myofibrils for Ca which you need to do contractions for your muscles (that way you aren’t dependent on the external Ca concentration)
74
what are transverse tubules?
they are just extensions of the plasma membrane that come down into the cell to create tubules
they cut all the way across the myofibers aka all the way down to the myofilaments
75
what's inside the transverse tubules?
interstitial fluid
TT are ECF channels because there's interstitial fluid within the tubules
it's not intracellular fluid because it hasn't crossed the PM
76
what are the 6 components of myofilaments?
1) z-line/disc
2) sarcomere
3) I band
4) A band
5) M line
6) H zone
77
what is the z-line?
it connects up actin = thin filaments
78
what is a sarcomere?
it goes from z line to the next z line
79
what is the I band?
aka the light band
it's where we only have thin filaments = actin
80
why is our I band called the light band?
the I band is where there's just actin
it’s called light because our skeletal muscles are striated and where we have only thin filaments, it appears lighter and that’s where you get the white striations
81
what is the A band?
aka the dark band
it's the *length* of the thick filament = myosin
82
what is the M line?
it's the midpoint between two z lines
aka the midpoint of the sarcomere and the midpoint of the A band
83
what is the H zone?
it's where there's only thick filament = myosin
matching form of our I band because we only see thick filaments
the H zone must be within the sarcomere and it must be within the A band
84
what's the functional unit of the muscle?
the sarcomere
if you want your muscle to contract, your sarcomere must be able to shorten its length
myosin and actin don't change size so how do you get the two z lines closer together? they slide relative to each other to make sarcomere smaller and get the z lines closer to each other
85
can the A band change in size?
no
it's the length of myosin so it won't change during contraction
86
what changes length during a contraction?
I band and H band
the I band is just actin and H band is just myosin so as the sarcomere gets smaller these areas also get smaller
87
what happens to the striations during a contraction?
as the sarcomeres get smaller, the striation pattern will change and the light part will get smaller and smaller and eventually it’ll all be just dark with tiny strips of light
88
what is actin?
it's a protein
the individual units are called actin and the whole structure is called actin
89
what does actin look like? what's located on it?
it's round ball type structures but there’s a green spot on them that is the binding site where it can interact with myosin and bind to myosin – it’s the receptor spot for its ligand, myosin
90
what's the overall structure of actin?
actin subunits form up into a double helix chain to form the overall structure of actin
91
what are the associates of actin?
troponin and tropomyosin
92
what is troponin?
it's the smaller of the two associates of actin (it's smaller than tropomyosin)
it looks like a clump of three balls
93
what binding site does troponin have?
it's bound to actin and tropomyosin
it has a binding site for Ca
it's the only thing on actin that has a binding site aka Ca exclusivity
94
what is tropomyosin?
it's the larger of the two associates of actin
it is a long strand protein that is more fibrous in look
95
how many binding sites does myosin have? what does it bind?
2
one binds actin and the other binds ATP
it's the only one of our components that can bind to/interact with ATP
96
what does myosin look like?
long shaft component with a head like a golf club
but they're lined up in a way that looks like a double sided golf bag
97
what's a cross bridge?
myosin come off sticking in different directions
we know that our myosin can bind to our actin and when it does it looks like a bridge
the cross bridge is flexible and can move however the goldf club head is not! The movement of the cross bridge is what causes the movement of your muscles and allows your forearm to be pulled up to your shoulders
98
what happens at rest during a contraction?
tropomysoin blocks myosin binding site on actin
99
what is innervation?
our NS tells our myofibrils to get their myosin and actin interacting
it's our connection of our nervous system that's coming to impact the effector and get it to work
100
what are motor neurons?
the neurons that tell our skeletal muscles what to do but just like receptor potentials, it’s just an added name to what we already know is going on underneath
receptor potentials are just graded potentials and motor neurons are just **somatic efferents** because they’re going out to an effector
101
what has ATP exclusivity?
myosin
102
what has Ca exclusivity?
troponin
103
what kind of neurons are motor neurons?
somatic efferents because going out to effectors
they help make muscle movements happen
104
what's the relationship between motor neuron and myofiber?
motor neurons can be connected up to multiple myofibers
each myofiber is only being told by one motor neuron what to do
a motor neurons can be connected up to multiple myofibers
105
what's the relationship between motor neuron an muscle?
a particular muscles gets innervated by multiple motor neurons but each of those motor neurons is impacting multiple myofibers
106
what's a motor unit?
one neuron and all of its myofibers that it runs
different muscles have different numbers of motor units so we can have a varying number of motor units getting activated so you create different amount of movement
107
how is the signal getting to the effector?
the signal is coming electrically
it's coming as AP series along myelinated axon that gets turned into an chemical NT message but then you want to put it back into an electrical message
108
what's the first step of a neuromuscular junction?
AP changes membrane potential of axon terminal where we have V.G. Ca channels
if we hit threshold potential, Ca channels open and Ca goes into axon which causes the exocytosis of NT which is Ach
109
what is THE neurotransmitter of our somatic nervous system?
acetylcholine is THE neurotransmitter of our somatic nervous system
110
what are motor neurons categorized as?
somatic efferents because they're going out to an effector
111
what is the second step of a neuromuscular junction?
after V.G. Ca channels are activated, Ca comes in an exocytoses Ach
Ach will move through interstitial fluid of the synapse and will bind to a receptor that is acting as a channel which will then cause ligand gated/chemically gated Na channels to open and Na will influx into the cell
this will depolarize your myofibril and you've now created a graded potential aka you've changed the membrane potential of the cell
112
what happens after a graded potential is created in the myofiber?
after Ach bind to ligand gated Na channel and Na depolarized myofiber, if graded potential is big enough, a different set of Na channels open so there's an influx of Na and you've now started your AP
then more channels open and AP are triggered section by section in our myofibers and our electrical message is moving along
113
what are all the steps of a neuromuscular junction?
1) AP change membrane potential of axon terminal where we have voltage gated Ca channels
2) so if we hit threshold potential, Ca voltage gated channels open and Ca goes in axon
3) the Ca causes exocytosis of NT which is acetylcholine → we have now switched from electrical to chemical message
4) Ach is a NT that will move through interstitial fluid of synapse and it will bind to a receptor that is acting as a channel which then causes ligand gated/chemically gated Na channels open
5) Na will influx which will depolarize your myofibril and you’ve created a graded potential
6) you want this to spread across your myofiber but a graded potential can’t go distance so you need an action potential to travel distance but AP only happen in excitable cells which have to have voltage gated Na and K channels – oh look at that, we have that in our myofibers!
7) So if graded potential turns into a threshold potential, Na channels open so there’s an influx of Na and the start of our AP
8) more channels open and AP are triggered section by section in our myofibers – we now have our electrical message moving along
114
what if you want to stop activity in the neuromuscular junction?
our brain stops sending AP so there's no longer a threshold potential or influx of Ca so exocytosis of Ach will stop
BUT the Na channels are kept open by the Ach that was already there so you need Achase to break down at to allow channels to close
when channels close, there's no more depolarization, no more AP and the message gets stopped
115
how do TT help muscles contract?
AP travel along the PM
we know the plasma membrane of a myofiber doesn’t just stay on the surface, it gives us a new structure called our transverse tubules
our AP will move along plasma membrane just like AP on our axon, and it goes down into transverse tubules also
we need transverse tubules to take AP deep into myofibers to the myofilaments
if the AP was just on the surface the myofibers wouldn’t be as big as they could be
116
what do the AP of our motor neuron do?
they get voltage gated Ca channels to open
117
what do the AP that travel along the PM of a myofiber do to the SR?
SR sits next to the PM and TT
SR has voltage gated Ca channels that our AP on our PM triggers the opening of
118
Ca levels in the SR and cytosol
the cytosol has little Ca
the reason for the SR is to have Ca inside our cell
SR will get triggered by AP traveling across PM and V.G. Ca channels will open and flood out into the cytosol
Ca is coming from sequestered pool of Ca aka it's **intracellular Ca**
119
what happens to Ca after it's released into the cytosol?
Ca binds to the troponin in the cytosol
troponin is a protein so when Ca binds there's a shape change
troponin is bound to actin and tropomyosin so they also shape change → once there's a shape change tropomyosin will move and uncover the myosin binding site on actin
120
what happens after tropomyosin uncovers the binding site on actin?
Ca bind troponin which shape changes and also causes tropomyosin to shape change and uncover myosin binding spot on actin
myosin head binds to actin which causes a shape change
myosin has ADP and Pi attached to it which get released due to the shape change that happened when the myosin bound to actin
energy is released and myosin head pulls and muscle contracts
121
what is cross bridge cycling?
it's about myosin moving (cross bridge) and it's going to be a cyclic process
myosin and actin are proteins so when we do binding and unbinding we get shape changes
so all crossbridge cycling is, is a series of shape changes caused by binding and unbinding of things in association with these two proteins
122
what is blocking the binding site on actin?
tropomyosin
123
what happens when myosin binds to actin?
actin binding releases ADP and Pi
because myosin has shape changed but ADP and Pi don’t
when you break a Pi bond energy is released which is used to make shape change to take the moveable head and get it to flex (bigger angle to smaller angle = flex of crossbridge = myosin grabbed the muscle and yanked like in tug a war)
124
what do you have to do to get myosin to release actin?
ATP binds to myosin
ATP then hydrolyzes to ADP and Pi which is the reflex/cock of cross bridge
125
what are the steps of the cross bridge cycle?
1) Ca binds to troponin
2) troponin shape change moves tropomyosin from the myosin binding site on actin
3) myosin (ADP and Pi) binds actin
4) release of ADP and Pi
5) flex of cross bridge
6) ATP binds to myosin
7) myosin unbinds actin
8) ATP hydrolyzes to ADP and Pi
9) deflex/cock of cross bridge
10) repeat
126
when can't we get the cross bridge cycle to continue?
we can't run out of Ca because we're putting it back to the SR
what if we run out of ATP? we can't have it bind to myosin so we can't let go = rigor mortis
when you die your cellular processes stop so ATP production stops so your muscles get stuck in the holding position and can't release
127
how far does a cross bridge cycle get us to move?
it gets us a pull/movement but only 10 micrometers of movement per cycle so you need a ton of little pulls happening at the same time
128
how does skeletal muscle relaxation happen?
relaxation comes from getting our crossbridge cycling to stop which means we have to stop sending the message on our motor neuron to cause the process to happen
have to tell the effector to stop contracting
129
what's the catch to skeletal muscle relaxation?
skeletal muscles are somatic efferents which can't inhibit, they can only excite or stop sending signals
130
how do you stop CBC to induce relaxation?
no more motor neuron AP → no more Ach released → no opening of V.G. Ca channels → no myofiber AP aka no Ca released from SR
however, you have to get rid of the Ca that was in the cytosol and get it back to the SR
131
how do you get the Ca in the cytosol back to the SR?
active transport
you need an ATPase driven pump that will pump the Ca into the SR
pumps don't work as fast as channels so putting them back is a slower process than releasing them
every time you move Ca back to the SR, it costs us an ATP to relax the muscle
132
what is twitch?
the contraction pattern happening in our muscle
it's the pattern of tension due to a single AP getting created on that myofiber that triggers a cascade of AP and gets Ca channels to open
133
what is tension?
is the force that gets generated from the pull from cross bridge cycling
134
what is a latent period?
when there's a delay between when an AP is triggered and when tension actually happens
135
what are our semicircular canals vs. otolith organs?
semicircular canals are acceleration due to gravity
otolith are acceleration with our head moving side to side or up and down
Ca stones also have to due with gravity
vestibular is stereocilia in a fluid environment and are mechanoreceptors
136
how does the chemosensory system work?
DISSOLVED receptors that are chemoreceptors that can be impacted by tasting something as well as internal concentrations of CO2 or O2
137
why don't a lot of people like sour and bitter food?
sour causes a Ph issue if you eat too much
bitter causes toxin issue if you eat too much
138
what happens if sour receptors stay activated?
it H continues to block K channels, whatever you put in your mouth will also taste sour or spoiled
139
what taste receptors are critical to metabolism?
umami and fat
140
olfaction receptors between people?
Avalon has different smell receptors than me
there's more olfaction receptors than taste receptors
141
what does the olfactory bulb do?
first sorting
will detect that I smelled something and perceive something but don’t know what you smelled
142
what does the primary olfactory cortex do?
coordinate body in relation to the smell
move away or towards without registering
143
what does the orbitofrontal cortex do?
you consciously understand what you smell
144
what are vomeronasal organ?
unconscious with pheromones
145
which muscles are the only unstriated ones?
smooth
146
which muscles are autonomic?
cardiac and smooth
autonomic is parasympathetic and sympathetic which has different NT released like norepinephrine and Ach
Ach is released in somatic and parasympathetic so if you mess with Ach it'll effect both but will impact parasympathetic more since it's the only one used
147
what are types of smooth muscle?
stomach and bladder
148
what is your muscle?
an organ because it has muscle tissues and cells
149
what are the two functions of the SR?
holds Ca and structural component for myofibrils
an SR is a component that runs parallel to myofiber because it wraps around myofibrils
150
what are the transverse tubules made of?
interstitial fluid = only one made of IF
run perpendicular to myofibrils
151
what is the SR made of?
intracellular fluid
152
what parts of the sarcomere change in size?
H band and I zone
H band is space that's just myosin
I zone is just actin space
153
what does the A band contain?
the H zone
154
what does the I band contain?
z lines
155
what is the overall thing that's happening during relaxation of a muscle?
Ca put back to SR through ATPase pumps and everything goes back to shape and tropomyosin will cover myosin binding spot
156
can the latent period change?
no but the length of the twitch can be changed
