51
votes
Accepted
Why do smaller mammals move intermittently?
Short answer
Intermittent locomotion can increase the detection of prey by predators (e.g. rats), while it may lead to reduced attack rates in prey animals (e.g., rats and chipmunks). It may also ...
- 51.8k
37
votes
Accepted
Why does an electrical shock freeze up muscles?
Interesting question!
An important factor here is the let-go phenomenon, which is defined as the current level in the arm that will cause the hand to involuntarily grip the current source. When the ...
- 51.8k
23
votes
Accepted
How did the largest/longest dinosaurs hold their head and necks up?
There are lots of papers on this. A good summary article is Why sauropods had long necks; and why giraffes have short necks, by Taylor and Wedel. They list a number of anatomical features that ...
- 14.1k
17
votes
Why do smaller mammals move intermittently?
In addition to @AliceD's excellent answer, I would like to add that a simple mechanistic relationship between body size and "snappiness" may explain the observed pattern.
Basics of biophysics
...
- 67.8k
14
votes
Accepted
Do eye's muscle share the same nerve?
Each eye is controlled separately. Three cranial nerves emerge at the brain for each eye to control the so called extraocular muscles. That we usually move both eyes in one direction is due to that ...
- 2,076
13
votes
Why does an electrical shock freeze up muscles?
When the body comes in contact with an electrical power supply, two things can happen. If the current flow is high enough, the body heats up just like a heating resistor, and opposed to the resistor, ...
- 7,097
12
votes
Accepted
Bending your little finger without bending ring finger
This does not have to be the case always, For example if you are a pianist you need all your finger to work independently.
OK, So coming to the main question.
In simple words, They are all ...
- 293
11
votes
Accepted
Can acetylcholine leak away from the synapse and cause spasms?
The enzyme responsible for the breakdown of acetylcholine (Ach), i.e., acetylcholinesterase, rapidly degrades, and inactivates Ach in the synaptic cleft after release. This process is particularly ...
- 51.8k
9
votes
Accepted
How can octopus walk if muscles can only contract?
Kier and Smith wrote a paper on how tongues tentacles and trunks worked. It explains in detail exactly how their legs (and our tongues) elongate, shorten and move about without any bones for support. ...
- 3,064
8
votes
Accepted
Do both ends of a muscle contract?
The muscular fibers (or more exactly the actin and myosin filaments) are contracted towards each other. This makes them "move to the middle" and you build up a force on both sides of the muscle. See ...
- 51.1k
8
votes
Why does it hurt the next day after doing significant exercise?
It should be noted that in some people (somewhere between 1% and 3% of the population, depending on who's counting) there is another mechanism for delayed muscle pain. Myoadenylate Deaminase ...
- 210
8
votes
Accepted
Biological Neural Network Training for Babies
Biological neurons function in a very different way, as compared to the simplistic artificial neural networks of machine learning. For example, see how real neurons work and how they connect with each ...
- 251
7
votes
What causes spontaneous muscle twitches?
Short answer
Spontaneous muscle twitches are thought to be caused by spontaneous activation of motoneurons controlling the muscles.
Background
Spontaneous muscle activity (twitching) is referred to ...
- 51.8k
7
votes
Accepted
Are there genetic causes underlying the difference in circumference of the upper arm and foream?
The first answer explains that proximal limb segments do more "work" * using quotes to be careful w.r.t. technical definitions of work. Genetically, this is correct--it's the ancestral condition for ...
- 587
7
votes
Do eye's muscle share the same nerve?
There are basically four different types of eye movements:
smooth pursuit (think about following a moving target with both your eyes, note how smooth the movement is)
saccades (think about moving ...
- 173
7
votes
Biological Neural Network Training for Babies
Some babies start walking by 12-15 months, so it's not exactly years before they can do it. They can also grasp things with their hands from birth. When first born they still don't have full ocular ...
- 15.2k
6
votes
Accepted
Hand-eye coordination in 3D space
Short answer
Proprioceptic receptors provide a feedback mechanism from the body to the brain, telling the brain what our limbs are doing and where they are with respect to the body without visual ...
- 51.8k
6
votes
Does taking a shower have the same effect on muscles as warming up?
Hot shower will definitely affect your muscles health. Hot water shower results in Vasodilation,which will decrease the vascular resistance and allows blood to flow easily through the blood vessels. ...
- 1,874
6
votes
Accepted
Why is there smooth muscle in our bronchioles?
There are at least two things to consider.
First, ability to limit airflow is a defense mechanism for animal. Imagine getting into area of some sort of toxic evaporation, e.g. CO2 cloud near volcano ,...
6
votes
Accepted
Are glands in human made up of muscles?
No they are not made of muscles. Glands are modified epithelial tissues. Glands are basically of two types Endocrine and Exocrine glands.
Endocrine gland
It is a gland that lacks a duct system. ...
- 8,784
6
votes
Are there genetic causes underlying the difference in circumference of the upper arm and foream?
Yes, there are genetic reasons for this. But your observation is either incorrect or abnormal.
The shoulder (and hip) muscles do the heavier work, thus have larger (and bulkier) muscles. The more ...
- 24.5k
6
votes
Why doesn't muscle strength depend on its length?
It's simply that the fibers are arranged end-to-end. If you simplify this down and imagine a single muscle fiber you have actin and myosin like this:
...
- 8,884
5
votes
Accepted
How is ATP involved in muscle contraction?
ATP prepares myosin for binding with actin by moving it to a
higher-energy state and a "cocked" position.
Once the myosin forms a cross-bridge with actin, the Pi disassociates
and the myosin ...
- 2,278
5
votes
Accepted
What is a complex?
The word complex in your sentence designate a protein complex, also called multiprotein complex.
A protein complex is a group ...
- 67.8k
5
votes
Similarity between a heart attack and a spasm
I was able to do some reading and research and I found some interesting information that was a). news to me. And b). the answer is yes... And no.
A spasm can be the cause of a heart attack by causing ...
- 1,122
5
votes
Accepted
Trying to differentiate between the three muscle tissues with small pictures
Without answering the problem for you, because you have not shown work yet to try to figure out which is which, let me tell you that you have three options.
Skeletal Muscle- striated, peripherally ...
- 1,624
5
votes
Accepted
What is the actual storage form of energy in muscles? ATP or Glycogen?
This is a typical MCQ which in order to answer you have to have been at somebody’s lectures or be able to read his mind. The antithesis of education! Cells don’t store energy like car batteries.
...
- 23.3k
Only top scored, non community-wiki answers of a minimum length are eligible