The contractile tissue of animals derived from the mesodermal layer of embryonic germ cells.

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4
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62 views

What causes humans to be physically weak compared to animals like gorillas?

Animals like gorillas seem to have a physical fitness and muscle mass that don't depend as strongly on how much exercise they get, compared to humans. E.g. gorillas living in the wild sleep and rest a ...
0
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0answers
18 views

Does physical exercise of a specific part affect muscles in the other parts of the body?

There is a theory among bodybuilders, that is, if you train big muscle groups (e.g. legs, chest), it will increase the overall growth of muscles all over the body; the trained muscle will release ...
7
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1answer
103 views

Why do my muscles move slowly when cold?

When my hands are cold, e.g. outside in the winter with no gloves for a while, their muscles begin to move slowly (assume I'm otherwise comfortably warm, e.g. dressed well but gloveless). I don't ...
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0answers
15 views

How are muscle fibre size and oxygen consumption related?

Does anyone know of a paper which correlates the muscle fibre size to oxygen consumption in mammals? I am trying to find a correlation between muscle fibre type, size and (absolute and specific) ...
0
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0answers
24 views

Why doesn't EMG data for triceps show a clear relationship?

In a surface electromyography (EMG) experiment of the triceps muscle where a person lifts weights, I found the value for maximum amplitude of EMG signal to be rather similar for all loads of 0-10kg. ...
3
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0answers
21 views

What are the metabolic consequences of negative mechanical work in muscle contractions?

When a muscle contracts while it shortens (concentric), it consumes ATP I believe primarily due to cross-bridge shortening to remove the myosin head from it's attached state. However, when a muscle ...
2
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0answers
40 views

Why do workouts cause your muscles to feel heavy?

I know that muscle activity causes your muscles to build up lactic acid. Is this the specific reason that your muscles begin to feel heavy? How does this relate to the healing or inflammation process ...
2
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0answers
24 views

Acetylcholine and muscles- excitatory or inhibitory? (muscle atonia and myasthenia gravis)

I have heard that acetylcholine can be excitatory or inhibitory, but I am confused as to which it is when it comes to muscles. On the one hand, I believe that muscle atonia during REM sleep is ...
9
votes
1answer
257 views

How do crocodiles stay fit?

My 8 year old son asked me a question I could not answer (and Google, at least in so far as we tried, was no help either). We were watching a documentary about Salt Water Crocodiles in Northern ...
2
votes
1answer
160 views

What is the difference between muscle fascicle and muscle bundle?

In the photo above (given by Bio teacher), the muscle bundle is shown to be as a bundle of fascicles, but in most web definitions I've seen, the two terms are used interchangeably. What is the ...
1
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1answer
45 views

What differences in effect does fast repetitive exercise have compared to slower muscle-building exercise?

As a drummer who likes to play high-energy music (fast, aggressive metal) it's safe to say I burn a fair amount of calories when doing so. But I've been drumming for over a decade and despite the ...
3
votes
2answers
89 views

Why we have to damage our muscles to build them?

I know that new muscle cells are made when actin fibers are disrupted. My hypothesis is that muscle mass is limited, from birth, and that nutrients (protein) are only directed to grow muscle when ...
3
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2answers
56 views

How do muscles help erect the spine?

Muscles of the spine help to support it against gravity. For example, the multifidi interweave throughout the vertebrae and, as I understand, sort of reinforce the spine. So let's suppose muscles help ...
-1
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1answer
178 views

What will happen if the biceps stop contracting and instead triceps contract? [closed]

For example if i bend my arm the biceps contract and triceps relax but if I bend my arm and the triceps contract instead of biceps what effect would it have?
2
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0answers
28 views

By What Mechanism Does Heat Cause Muscle Relaxation?

Heat is commonly used "loosen" muscles, but what exactly is happening to relax the muscle? It wouldn't make sense that increased blood flow alone would relax muscle.
1
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0answers
17 views

What Effect Does Skin Redness Have On Underlying Tissue?

When someone applies a rubefacient ( something that increases blood flow to the skin, turning it red), what effect does this have on the underlying tissue? Is blood supply increased radially from ...
0
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0answers
18 views

Model for calculating muscular activity from external measures

A physiologist wants to measure the intensity of the activity of a muscle or muscle group over a certain period of time. But the physiologist cannot measure what happens inside the the muscle itself ...
2
votes
2answers
31 views

Are gizzard muscles voluntary or involuntary?

I started raising chickens this year. They have amazing appetites, and I often wonder what eating is like for them. They have no teeth, so they don't chew their food as they eat it. They do seem to ...
4
votes
1answer
128 views

What neuro-motor diseases cause the lower esophageal sphincter (LES) to malfunction?

Please note: This question is neither homework nor seeking medical advice. I'm simply asking for a factual, objective, biological explanation of the various neuro-motor diseases/illnesses that can act ...
4
votes
2answers
76 views

Why are our muscles limited to 7 Hertz?

I have heard from a (usually very knowledgeable) friend before, that a human can only tap his fingers 7 times per second. I generalized this to "our muscles are limited to 7 hertz" When my wife ...
3
votes
1answer
56 views

Does tremor frequency generally increase as Parkinson's disease progresses?

I've been trying to research this question, but most if not all the on-line journals require costly subscription, and the studies that are posted look at tremor frequency with regards to other ...
3
votes
1answer
70 views

Catabolism and muscle energy intake

From my own reading, there are three ways used by the body to produce energy: Alactic anaerobic (direct degradation of ATP and creatine phosphate for regeneration of ATP) Lactic anaerobic (breakdown ...
0
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0answers
27 views

Book recommendation on the human muscle system

I would like to learn more about the exact mechanism behind our movements, especially about what happens during intense training when anaerobic state arises.
1
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0answers
45 views

How nerves interact with other cells? [closed]

I read in a book by Mick O'Hare, that injuries inflicted by electric current are caused by tension of your muscles. Is that explainable only with physics or nerves really use electrical signal as ...
2
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2answers
97 views

Why a continuous supply of energy is needed to support a weight?

What motivates this question is the apparent discrepancy between the concept of Work in physics and in physiology. Work in physics is defined as the dot product of the force applied to move a certain ...
1
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1answer
26 views

Is there a way to examine amount of red/white muscle fibers without biopsy?

I want to conduct some research on red and white muscle fibers, why do some people tire during certain movements while others do not. Obviously I can't get a biopsy on the subjects so I wanted to hear ...
6
votes
1answer
94 views

How can octopus walk if muscles can only contract?

From this video it is evident, that octopus can make tentacles push: https://youtu.be/zaE-LwDowcU How is it possible, if it is said, that muscles can only contract? What types of muscles can ...
4
votes
1answer
76 views

Why do athletes see a dip in performance in their thirties?

I have noticed a lot of athletes hit their prime when they are in their 20s and that by the time they reach their 30s they are past it and start to decline. Great athletes tend to prolong their ...
42
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4answers
3k views

Why do smaller mammals move intermittently?

I was watching a nice little video on youtube but couldn't help but notice how snappy smaller animals such as rats and chipmunks move. By snappy I mean how the animal moves in almost discrete states ...
23
votes
2answers
3k views

Why does an electrical shock freeze up muscles?

Why is it when someone comes into contact with an electrical supply that their body freezes up and is unable to move away from the electrical source? Can someone explain this through a physiological ...
1
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1answer
118 views

What causes muscle spasms?

What causes muscle spasms with muscles that are not in the heart ? Could it be some sort of stimulus overload that causes a massive contraction?
2
votes
1answer
297 views

What happens when we stretch?

From the wikipedia page on stretching: Stretching is a form of physical exercise in which a specific muscle or tendon (or muscle group) is deliberately flexed or stretched in order to improve the ...
3
votes
2answers
224 views

Before I move my arm the brain sends signals - what causes the brain to send signals? [closed]

Please tell me what causes the brain to send signals, how does the brain send signals? can you tell me what happens between the point when you make an intention to pick up a glass of water, and ...
-1
votes
1answer
384 views

Our muscles give us the ability to move our arms but…? [closed]

I have a strange question, but let me tell you something first. If you think of this carefully, then you realize something, please try this right now: Contract your muscles only so that your arms ...
3
votes
3answers
754 views

Why Doesn’t Hypercalcemia Cause Muscle Spasms?

If you have more calcium in the cell, wouldn’t more attach to troponin and initiate muscle contraction? Why does hypercalcemia cause muscle weakness instead of spasms?
2
votes
1answer
96 views

What is the connection between exercise and muscle growth

From a physiological perspective, all that is done during exercise is the expending of energy in the form of ATP to fuel muscle contraction and extension. When I looked up why muscle grow due to ...
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1answer
2k views

How is ATP involved in muscle contraction?

The sliding filament mechanism as explained by my text does not elaborate on how ATP is involved in the cross bridge binding and contraction process. How does muscle contraction utilize ATP? In my ...
0
votes
1answer
165 views

What is a complex?

In my text book it says that "Troponin" is a complex of Troponin C, I and T. In this sense, what is the relation between Troponin complex and C, I, T?
6
votes
1answer
87 views

Why is there smooth muscle in our bronchioles?

Having muscle tissue in our bronchioles that can constrict seems like a poor choice for tissue. Why would our airway want to ever close up? Wouldn't it be more beneficial for our bronchioles to just ...
1
vote
1answer
74 views

Do muscles still hold glycogen reserves if there is no carbohydrate input

Afaik skeletal muscles take glucose from the blood to store it localy as glycogen, to be used in the case of intensive exercise. Does this still happen if the calorie input is exclusively made up ...
1
vote
1answer
91 views

Why use creatine phosphate?

We use creatine phosphate as an energy storage to resupply ADP with a phosphate group as our muscle cells only contain about 2-5 mM ATP. But why doesn't the muscle cells just keep 20-30 mM ATP instead ...
3
votes
1answer
91 views

Involuntary twitches and apnoea during early phases of sleep

I assume most people either experienced or have seen people with the following phenomenon: in the early phases of sleep sometimes involuntary twitches occur that usually accompany the pause of ...
12
votes
3answers
1k views

Does taking a shower have the same effect on muscles as warming up?

When playing sports, coaches and trainers are always very clear that it is necessary to warm up and stretch. But sometimes athletes sometimes want to get an extra stretch in and don't want to go ...
5
votes
2answers
178 views

Why is living muscle tissue seemingly able to restore its shape under force, while dead tissue is not?

When I press my finger, even with relatively little force, into beef or chicken (say, at a grocery store), the indentation remains. When I poke a cow with my finger, the indentation does not remain. ...
4
votes
1answer
46 views

Hand-eye coordination in 3D space

A simple daily event has amazed me and triggered this question. I have read and heard about hand-eye coordination. It quite straightforward when you e.g. want to open a door or play Xbox. In this case ...
1
vote
0answers
68 views

How do BCAA's promote faster muscle recovery?

I am aware that ingesting Branched chain amino acids (BCAA's) prior, during, and after workouts has an effect on muscle recovery due to their difficulty of metabolism. However, how much more ...
2
votes
1answer
139 views

Is the Klein's bottle a good analogy to the relation between T-tubule and sarcolemma? [closed]

I am not quite seeing how the T-tubule and sarcolemma is connected. It says that the T-tubule is an "invagination" of the sarcolemma, which is sarcolemma folded from the inside to form a T-tubule Can ...
2
votes
1answer
440 views

When contracting a muscle will the muscle spindle stretch or contract?

When you contract your muscle, will your muscle spindle stretch or contract? And why? I was always under the impression that it was contracting your muscle spindle, but now I am not sure.
0
votes
1answer
139 views

Similarity between a heart attack and a spasm

When someone is having a heart attack, could it be considered , in some situations, a spasm? Below, I have written how I believe the process may work. The heart is basically a muscle working ...
6
votes
2answers
2k views

What physiological processes within a muscle cause the latent period in a muscle fiber?

This is a lab question I cant find the answer in the lab manual or in the text book. What physiological processes in a muscle cause the latent period in a muscle fiber? Please help. Edit: The latent ...