Reflex action, Biology

REFLEX ACTION -

  • Marshel Hall discovered reflex action. Best & Taylor defined it. Reflex action is functional unit of CNS.
  • It is sudden, immediate involuntary action against external stimuli. In man it is poly-synaptic.
  • If we prick needle on skin, somatic sensory nerves bring impulses to grey matter. Here these are analysed & order is given to muscle by motor nerve.
  • The path from which impulse is passed is reflex arch.
  • Minimum time is consumed in it. It is not under control of brain.

Some common reflex actions are -

1. Coughing

2. Yawning

3. Sneezing

4. Knee-jerk reflex

5. Bleenking of eyes

6. Scratch reflex

EXAMPLE -

1.       Cycling.

2.       Watering of mouth.

3.       Blinking of eyes in sharp light.

4.       Withdrawal of leg in pithed frog.

5.       Flow of bile from gall bladder.

6.       Peristalasis.

7.       Heart beat.

2243_reflex action.png

SIGNIFICANCE -

1. It enables animal to respond immediately to the harmful stimuli so that no harm is caused to it.

2. It gives more time to brain to work.

Posted Date: 10/3/2012 2:16:32 AM | Location : United States







Related Discussions:- Reflex action, Assignment Help, Ask Question on Reflex action, Get Answer, Expert's Help, Reflex action Discussions

Write discussion on Reflex action
Your posts are moderated
Related Questions
Expression clone  is a clone (plasmid in the bacteria, or might be a lambda phage in bacteria) which is designed to produce the protein from the DNA insert. Mammalian genes do not

What are the three categories in which food protein sources can be divided into Protein food sources can be separated into the following three categories: Proteins of pl

heating a food sample with Benedict''s solution is a test for...

What is the law of limiting factors? How would the rate of photosynthesis be affected if the soil water becomes limiting? Describe.

Exstrophy of the Bladder This is the most common major congenital defect of lower urinary and genital tract. This is found more frequently in males than in females. Exstr

The plasmids below show the insertion of the EZH2 gene into the pBluescript plasmid in either sense (forward) or antisense (reverse) orientation. These are the plasmids you will ho

Q. What are the hormones secreted by the adenohypophysis? What are their respective functions? The ACTH (adrenocorticotropic hormone), adenohypophisys secretes GH (growth hormo

Unilateral Incompatibility This relates to incompatibility that operates in one direction. The most common way to ascertain unilateral incompatibility is to perform crosses be

What is Pancreatic lipase Pancreatic lipase  acts on  the dietary triacylglycerols after it has been incorporated into the mixed micelle  in  the  intestinal lumen. The lipa

INTRODUCTIO N - Fertilization is a complex process which involves fusion of male & female gametes. The male gamete in animals is called as sperm & the female gamete as o