Reflexes, Science

Assignment Help:

Reflexes:

It is of  interest  to know,  that all sensory information does not have to go to the  -  brain before we can react to a stimulus. Our responses to certain stimuli are simple unvaried  and quick. For instance, if  a finger  is  too close to a burning match, receptor cells on the skin send the infarmation on a nerve to  the spinal cord, and a 'reflex action' is taken  to move the  finger away fm  the fire. Such 'reflex drcuits' are well distributed and one is shown in Fig.  

432_Reflexes.png

Now  let us see what happens when a pin pricks the finger. 

1  The pin p-rick  is the stimulus which activates a receptor cell at that point. 

2  A nerve impulse  is transmitted away from the skin along a sensory neuron to the spinal cord. 

3  The impulse is now passed  through the inter neuron to the motor neuron and finally passes to the-muscle  which pulls the hand back from the painful event. 

The brain is not normally involved in such simple reflex actions. Only after the event, is the brain informed and we become conscious  of what has happened. The time gap between the stimulus and the response is about 1115th of a second and this is often crucial for survival. For instance,  a person who is driving a car has to apply his brakes to avoid a sudden collision with another car. His reflex action timing is important if he  ( has to avoid the accident. Similarly,  the reflexes of an airplane pilot have to be fast to avoid disaster. Human capacity to handle equipment and machines is limited by  the time taken by one's  reflexes.  


Related Discussions:- Reflexes

Crytosporidiosis, 3 reasons why Minnesota still has crytosporidiosis

3 reasons why Minnesota still has crytosporidiosis

Hazards in the laboratory, HAZARDS IN THE LABORATORY : Laboratories in...

HAZARDS IN THE LABORATORY : Laboratories in the biology department of schools, colleges and universities and other higher level organisation such as hospitals, veterinary esta

Foam extinguishers, Foam extinguishers :  If the burning liquid is in a co...

Foam extinguishers :  If the burning liquid is in a container the jet should be directed at the inside edge of the vessel or at a vertical surface in order to break the jet and al

What are the effects of temperature variations, What are the Effects of Tem...

What are the Effects of Temperature variations Different minerals present in the rock behave differently to the changing temperatures. The rocks expand on getting heated at day

Geology, How to become a geology tutor

How to become a geology tutor

Explain rancidity, Rancidity:- Formation  of aldehyde due  to  oxidatio...

Rancidity:- Formation  of aldehyde due  to  oxidation  of  unsaturated glycerides.

CELLS, Are there living beings without cells?

Are there living beings without cells?

Explain idiopathic thrombocytopenic purpura, Explain Idiopathic Thrombocyto...

Explain Idiopathic Thrombocytopenic Purpura "Thrombocytopenic" means the blood doesn't comprise adequate platelets. "Purpura" means a person has excessive bruising. You may als

Respiratory system, this is a sticky substance that traps dust from the inh...

this is a sticky substance that traps dust from the inhaled air

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd