Why do we need involuntary muscles?

Answer 1

We all know that muscles can help us to do something specially when it comes to work. it is one of the human system that can help brain to controll each part of our body.

There are many kinds of muscles in our body. The voluntary and involuntary muscles.

Voluntary muscles are the muscle that can be controlled by the brain.

Example of Voluntary muscles are:

1. Muscles of our eyes,arms,feet

Involuntary muscles are the muscle that can be located in our heart and mind. These are muscles that cannot be controlled by our brain.

1. Muscles of our heart and brain.

Furthermore, Muscles can also receive some information from the brain even though the brain is at rest.

Answer 2

The autonomic (self-regulating) nervous system controls most involuntary nerve functions. It is made of the sympathetic nerves (originating in the thoracic=chest and lumbar=lower back regions) and the parasympathetic nerves (originating in the cervical=neck region and the sacral=tail/pelvic region). These nerves can go to secretory effectors (actors) like sweat glands or salivary glands. These nerves can also go to smooth muscle in blood vessels to allow for expansion and contraction of vessels to modify blood flow. In general, the sympathetic nervous activity to muscles and glands gets the body ready to do activity, e.g. get excited by danger and run away from a lion, including make the heart beat more quickly and forcibly. The parasympathetic part of the system is for calming down the human body and doing things like digestion or reproductive functions, i.e. things humans can do when they are safe and calm and cozy, e.g. calming down the heart after a period of intense activity. The celiac plexus is a group of nerve cell bodies in the abdomen which go to smooth muscle in the wall of the intestine, and its self-regulating or involuntary nerve firings to smooth muscle help control when and where the intestines constrict to move food along as it is digested. All preceding relates to cardiac type muscle, or smooth type muscle. Skeletal muscle can also be considered involuntary under certain circumstances. For instance, if you touch a hot stove your arm will involuntarily jerk back by reflex even though the autonomic nervous system is not involved. This is because a sensory nerve from your arm directly triggers a motor nerve via a reflex arc in the spine, so the signal gets processed in the spine faster than would happen if the "decision" had to go all the way up to the brain to be decided. So, voluntary muscles in the arm become hijacked temporarily and turned into involuntary muscles that retract your arm from a hot stove before you know what is happening. For complex whole-body jerk-away reflexes, e.g. jumping away from a snake even before you consciously know what you are doing, the decision can be made in the superior colliculis (in the lower-middle part of the brain) without nerve impulses taking a few milliseconds more to go all the way up to the cerebral cortex to be processed. In this case skeletal muscles that are ordinarily voluntary also become "hijacked" and practically the entire body is used to involuntarily jump away from the snake or whatever other danger is being faced. The purpose of all the various involuntary muscle activity is to do things that don't need conscious thought (e.g. your body automatically regulating heart beat, breathing, digestion), or to do things that can't wait and will decrease your chance of survival if extra time is taken for a conscious decision (e.g. the urgent need to jerk away from a hot stove or poisonous snake).

Answer 3

contract and relax only what a easy question!

Answer 4

some one with epilepsy has involuntary muscle spasms