Learning fascinating stuff 06

Learning fascinating stuff.

The reason why your muscles get tired during workouts is because, when the nerve impulses stimulating your muscles exceed rates up to 100 times a second (as it happens during intense workout), the neurotransmitter substance Acetylcholine (which is needed to transmit impulse from nerves to muscles)gets depleted very quickly to such an extent that there remains no more of it to stimulate muscle fibers. Hence, impulse fail to pass into muscle fibers; a condition called fatigue.

In muscle physiology, processes that have multiple steps, involving so many chemicals and enzymes (covering so many pages of my physiology book lol) actually happen in a matter of milliseconds in the human body! So many complex steps, so many moving parts, so much detail executed perfectly, with no mistakes, that too at lightning fast speeds! Human body is truly amazing.

The chemical diisopropyl flurophosphate (which is a powerful ‘nerve’ gas) is very lethal indeed. This chemical inhibits the enzyme acetylcholinesterase (an enzyme that breaks down neurotransmitter acetylcholine and stops the muscle stimulation). When the nerve gas inhibits this enzyme, acetylcholine accumulates around the muscle fibers continually stimulating them, which causes muscle spasms (it can result in death as a result of laryngeal spasm).

Smooth muscles are really different from skeletal muscles! They have completely different structure, different mechanisms of contraction and what’s more? Their contractions can last up to hours and even days! Yup days! Compare that to a few milliseconds of skeletal muscles.

When smooth muscles are stretch to a certain degree, it results in generation of action potentials in it (a particular characteristic of smooth muscles). Hence, when your large intestines are full of waste, they push against the walls of the intestine; stretching and exciting smooth muscles. Hence, they contract as a response to the action potential generated and push the waste towards your anus. That’s how you know when to poop ; )