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Reflex actions are loosely defined as any action that the body performs unconsciously. There are several different kinds of reflex actions, including some that are responses to external stimuli and others that regulate body organs and functions. There is also a theoretical class of reflex actions that can be learned, but the existence of these and the mechanism behind them is debated.

Many reflex actions happen in response to external stimuli, and most of these actually work without any involvement from a person's brain. For example, if a person trips at a campsite and his hand falls into the campfire, he will quickly retract it without even thinking. This happens because the nerve signal from the injury travels through the body-when it reaches the spinal cord, it triggers an automatic response before the brain can ever get involved. The spinal cord reacts by sending back another signal that causes the person to automatically pull his hand away from the fire.

This kind of response is also responsible for the well-known knee-jerk reflex that doctors use to test a person's nervous system. In that case, the purpose of the reflex is to help a person stay balanced when walking. Most of these kinds of reflexes exist to protect people from injury or deal with things that require immediate action. For example, people blink when something is flying towards their eyes, and this sometimes happens so fast that people don't even realize they're doing it.

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Is the response of your pupil a reflex or a voluntary action?

The constriction of pupils in response to bright light is called the pupillary light reflex. If the light is shining directly into one eye, then the pupil in that eye will constrict (a direct response), but so will the pupil in the non-illuminated eye (a consensual response).This reflex involves two cranial nerves: the optic nerve, which senses the light, and the oculomotor nerve, which constricts both pupils. It is considered involuntary since you don't think about it.


Where do reflex actions occur?

Reflex action means a reaction you have given involuntarily. If you touch the immensely painful object, the touching hand or foot is removed away with out your knowledge. Here three neurons are involved. 1) Afferent 2) In the spinal cord 3) Efferent. This is called as reflex arc. Simultaneously information goes to higher centers and you notice the the problem, later on. So reflex action occurs at the level of spinal cord only.


what type of reflex is the knee?

The knee reflex is also called the knee-jerk reflex by tapping the patellar tendon with a reflex hammer. This sends sensory information to the spinal cord at L4 and motor information back to the Quadriceps in the thigh (relaxing the hamstrings). This is reflex requires only two neurons. No interneuron. And so is very rapid. It is important in balance and posture.


Which reflex arcs contain no association neuron?

The patellar reflex is an example of a 2-neuron reflex arc. It has 1 sensory neuron and 1 motor neuron. It does not contain an association neuron and so is considered the most simple reflex in humans.


Describe the reflex arc?

A reflex arc is the neural pathway that mediates a reflex action. In higher animals, most sensory neurons do not pass directly into the brain, but synapse in the spinal cord. This characteristic allows reflex actions to occur relatively quickly by activating spinal motor neurons without the delay of routing signals through the brain, although the brain will receive sensory input while the reflex action occurs.

Related Questions

How does a reflex cause you to act so quickly?

It bypasses the brain.


Is the pupil a reflex or voluntary?

Pupils reacts to light, narrowing in bright light and widening in poor light - so is a reflex action.


How do you float on modern warfare reflex on the wii?

the only way possible for that to happen is if the game glitches. There is no way that it can happen it does so unexpectedly if the game is glitched.


Why brain is not involve during reflex actions?

A reflex action or reflex arc bypasses the brain as to decrease transmission time from detection to response, i.e. the time it takes for the body to initiate a response in relation to the effecting stimulus. This decrease in time allows for minimal damage to tissue or surrounding cells which may be affected by a certain stimulus.


What are the 5 types of reflex action?

Porilteation systmy. manaractioin of and reaction compinds with the andcreatsir that will prove that the human reaction type. the 5 reflex action is a polarication and will spare and exraction and will privede saysrmad that will come. The 5 types of reflex action is. 1) The columents system will react faste as you know what you are doing. 2) reaction of your eyes so you will see what you are doing. 4) see what your doing in an insteant. 5) recover from what you see and doing and a reaction time that is friar andasrtment from your eyes and hand to see the reaction for example you a stop watch you will need fast reaction time to make your caluation right.


What is with this weird phenomenon so called de ja vu is it psychic?

De ja vu is more a reflex action than a psychic one


When you touch something very hot you move you your hand away from the object as soon as you feel the sensation why is this so?

This is an automatic response known as a withdrawal reflex. It is your body's way of protecting itself from harm by quickly moving away from a potential threat (in this case, the hot object) to prevent injury. The sensation of heat is detected by specialized nerve endings in your skin, which send a signal to your spinal cord to trigger the reflex action.


What will happen if you run away from destiny?

The dictionary explains destiny as "An event (or a course of events) that will inevitably happen in the future". So destiny is the result of an action on our part. We can wait the result of that action which is destined to happen. Even if we change that action destiny will always be there, there is no escape, so must accept what destiny awaits us.


Would salivary reflex be a somatic reflex?

In some circumstances I guess so.


Why do I yawn so much when I sing?

Yawning while singing can happen because singing requires deep breathing, which can trigger the body's yawning reflex.


What are the advantages of the fact that most reflex actions are governed by spinal cord?

Reflex actions are governed by three neurons only. If some body tries to hit on your eye, you blink by reflex action. Here again only three neurons are involved, although the middle neuron passes through your brain. Reflex action means only three neurons are involved and that saves lot of time required to think over the serious matter. So in reflex action you respond first and then brain notice the problem.The spinal reflex is fast. The reason it is fast is because the decisions are made at spinal cord level, rather than the nerves having to travel up to the brain and back down to the source.Because you are able to react quicker without having to think about it.1 It reduces the work load of brain. 2 The reflex action is under control of spinal cord, the message is sent to the brain later on.If it would have been under control of brain, it would have reqired longer duration for us to react, which has potential to cause damage to body tissue. Hence presence of spinal cord increases efficiency of reflex action.


Why do you shiver when scared?

Shivering when scared is a result of the body's fight-or-flight response to stress. When you feel frightened, your body releases adrenaline, which can cause muscles to tense up and shiver in order to prepare for potential danger. It's a reflex action designed to help you respond quickly to threats.