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

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35
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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 ...
22
votes
2answers
2k 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 ...
17
votes
1answer
2k views

Do insects' muscles become stronger with exercise?

I am curious to know if insect muscles become stronger with exercise, because I have seen many insects get tired out, but I have never seen one get stronger. They always seem to become permanently ...
12
votes
3answers
501 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 ...
11
votes
2answers
446 views

Below which temperature human muscles don't work?

When one exposes theirs body parts to cold environment (especially foot and hands), they may be numb, with temporarily blocked both muscles. What is typical body temperature below which human muscles ...
11
votes
1answer
401 views

What is the mechanism that directs myosin walking?

Myosin, dynein and kinase all "walk" towards specific ends of the microtubule or actin filament they are on. I'm most familiar with the walking mechanism for myosin, where ATP fuels conformal changes ...
10
votes
1answer
1k views

Is there a correlation between muscle fibers and body types?

I have been told the number of muscle fibers a particular muscle has varies from person to person. Unfortunately, the person who told me this did not know much more than this. Initial searching on the ...
10
votes
1answer
1k views

Effects of beer on muscle recovery after exercise

I noticed it several times that when I drink beer (even one bottle) after some heavy workout, the next day my muscles are more stiff than other times, and not the same way... Is it because that ...
9
votes
4answers
10k views

What is the cause of muscle cramps?

According to wikipedia, muscle cramps are caused by myosin fibers not being able to break free from the actin filaments during contraction, resulting in a prolonged contraction. Obviously a lack of ...
8
votes
1answer
138 views

Is it the sphincter that flexes when a human pushes a bowel movement?

Of course the sphincter muscle is at the exit point. To use a toothpaste tube analogy, if I want to squeeze out some toothpaste, it does me little to no good to jostle the nozzle; I need to squeeze ...
8
votes
3answers
7k views

Why is it that cats can jump so high for their size, compared with humans?

My cat is about 1' high at the shoulder, and I am a little over 6', but my cat can easily jump onto something as high as I am. That is 6x it's height. If a cat can do this, then Why can't I jump up ...
7
votes
2answers
629 views

Does muscle get bigger by increase in size of individual cells or increase in number?

Somewhere in the back of my mind, I have the claim that a muscle never increases its amount of cells but, if the muscle gets bigger, it's simply because individual cells get bigger. The book Anatomy ...
7
votes
3answers
378 views

Where does extra blood come from to fill your muscles during exercise?

Let's say I go to the gym and lift some weights an hour. During this time my arms will grow due to the "pump" -- the extra blood rushing in to feed the muscles. For example, I've measured about 2-3 ...
7
votes
2answers
217 views

Would muscle fatigue still occur if aerobic conditions for a working muscle is maintained?

Put another way if the muscle is given everything it needs to contract and do work will it ever get tired or have a reduction in energy efficiency? As far as I understand muscles depend upon a ...
7
votes
1answer
396 views

Skeletal muscle without antagonist

Is there any skeletal muscle that does not have an antagonist? Excluding circular muscles such as around eye and mouth. The reason why I am wondering is because in biology normally nothing is ever ...
6
votes
3answers
174 views

Do both ends of a muscle contract?

I was under the impression that both ends of a muscle contract. For instance, the fibers of the biceps run parallel to the humerus so I thought they pulled toward the middle. But now I'm confused ...
6
votes
1answer
66 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 ...
6
votes
2answers
113 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. ...
6
votes
1answer
198 views

Task-dependent “reversed” handedness: why use left hand for some tasks? How is it controlled by the brain?

I am right-handed. Which means that when I hammer down a nail, I hold the nail in my left hand, with which I can hold it straight and at a controlled position. This is true in situations where the ...
6
votes
1answer
336 views

Stabbing muscles when flexed and when relaxed

Just a random question, would a sharp object pierce your muscle more(stabbed with the same amount of force) when the muscle is flexed or when relaxed?
6
votes
1answer
48 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 ...
6
votes
5answers
2k views

Why do most mammals have long snouts?

It seems like most mammals, e.g. dogs, have long snouts. My pet dog's snout would seem to me like an evolutionary disadvantage, since her canine teeth are way out at the end of her jaw, which acts as ...
6
votes
2answers
353 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 ...
5
votes
2answers
279 views

Energy use by muscles, actual work done by muscles and more

Lately, I've started exercising in the gym and outside. I've also started to look at the details of food I eat. Food usually has a label saying the amount of energy is inside it. For example, some ...
5
votes
1answer
375 views

Skeletal muscles in clam

Although skeletal muscle fatigues fairly rapidly, clams have a protein called paramyosin that allows them to sustain contractions for up to a month. What might be the role of paramyosin at the ...
5
votes
2answers
2k views

Why does yawning impair hearing?

When I yawn I can't hear anything happening around me. I also feel some kind of muscles inside my head contract and hear a faint hum, but it is not loud enough to explain not hearing other sounds. I ...
5
votes
1answer
139 views

Mechanism of Muscle Growth

According to this video (sorry for the poor reference but it represents my level of understanding in physiology), muscle grow as a consequence of repairing micro-lesions. How are these micro-lesions ...
4
votes
1answer
36 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 ...
4
votes
1answer
110 views

Trying to differentiate between the three muscle tissues with small pictures

For an assignment I have to differentiate the three types of muscle tissues in these three pictures . I'm having difficulty seeing the striations and branches etc. because the pictures are so small. ...
4
votes
1answer
51 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 ...
3
votes
2answers
2k views

What causes muscles to generate heat on contraction?

I'm curious what the exact cause is of dramatic heat generation that comes along with muscle activity. Can anybody explain this in understandable language?
3
votes
1answer
72 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 ...
3
votes
1answer
102 views

How do muscle relaxants work?

Do they act directly on the muscle and actually relax muscle tissue and ease spasms, or do they just prevent your brain from receiving signals that inform you of tight muscles? In the latter case, ...
3
votes
1answer
3k views

Slow-oxidative fibres vs fast-glycotic fibres

Why do slow oxidative muscle fibres contain more mitochondria compared to fast-glycolytic muscle fibres?
3
votes
2answers
279 views

Correlation between muscle size and absolute strength

Is there a linear connection between muscle size and the power it can produce? If not, why? And what is the true correlation if any, can it be described with an appropriate function? What other ...
3
votes
1answer
127 views

Attachment of muscles during molting in insects

Normally, insects' muscles are attached to their exoskeleton but what happens to this attachment when they are moulting? Sorry if this is an extremely silly question but I have wondered about it for ...
3
votes
1answer
79 views

Text/resource with information on all skeletal muscles and their motor units

Something analogous to an encyclopedia on baseball players with a list of all thier stats would be ideal. I'm not looking for just generic muscle names, locations and illustrations. Good answers ...
3
votes
0answers
35 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
2answers
102 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 ...
3
votes
0answers
129 views

What controls the feeling of discomfort/comfort before and after sleep?

I'm interested in which biological systems or hormones are involved in the following phenomenon: Before sleep it may be difficult to find a comfortable position, and muscular aches and pains are more ...
2
votes
1answer
213 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.
2
votes
3answers
89 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
2answers
161 views

Are there free electrons in muscles, hair, or skin?

Electric shock occurs upon contact of a (human) body part with any source of electricity that causes a sufficient current through the skin, muscles, or hair. In metals many electrons are said to be ...
2
votes
1answer
52 views

Kinesiology Tape Benefits

Recently, kinesiology tape has become popular, especially in CrossFit. I have also noted its' use in the NFL, and I want to say Tennis as well. What beneficial effects does this tape offer our bodies ...
2
votes
1answer
104 views

How much mechanical stress can a skeletal muscle bear?

In the movie- Saw, for the last trap Bobby was told to insert metallic hooks into his pectoralis major muscle. In his fake story Bobby has raised himself successfully, but when he was "really" ...
2
votes
1answer
96 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 ...
2
votes
1answer
69 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
2answers
219 views

Calcium levels and nerve hyperexcitation

Why does lower blood calcium levels (or lower calcium levels in ECF) cause nervous hyperexcitaton? Why does it cause over stimulation of nerves and muscles and spasmic contractions of muscles? This is ...
2
votes
1answer
188 views

Need of Creatinine Phosphate

In muscle cells most of the ATP's phosphate is with creatinine phosphate. So why is the displacement of the phosphate group done ? Is it because creatinine phosphate would give it's phosphate more ...
2
votes
1answer
42 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 ...