Reflex action, Biology

Assignment Help:

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.


Related Discussions:- Reflex action

Heart, which part of human body purify the blood

which part of human body purify the blood

Functions of skin, FUNCTIONS OF SKIN - Skin performs various diverse fu...

FUNCTIONS OF SKIN - Skin performs various diverse functions, that is why it is called "jack of all trades". 1 .      Protection - The skin protects the internal soft or

Describe arteriovenous continuous murmur, Describe Arteriovenous Continuous...

Describe Arteriovenous Continuous Murmur? Arteriovenous Continuous Murmur :  These can be congenital as in coronary artery fistula entering RA/RV/PA, sinus of valsalva to rig

Importance value index (ivi) - synthetic characters, Importance Value Index...

Importance Value Index (IVI) - Synthetic Characters In any study of community, the quantitative value of each of the frequency density, and cover has its own importance. But t

Chordates and non chordates, give an account of ciliary and flagellar move...

give an account of ciliary and flagellar movement in protozoa

Different modes of nutrition, Explain different modes nutrition like Autotr...

Explain different modes nutrition like Autotroph,hetrotroph,saprotroph,holozoic

Kin selection, While explaining the concept of natural selection, we have s...

While explaining the concept of natural selection, we have stressed the fact that natural selection is synonymous with differential or non-random reproduction. Natural selection ai

How is the nervous tissue distributed in cnidarians, Q. How is the nervous ...

Q. How is the nervous tissue distributed in cnidarians? Their nervous system is diffuse there are no ganglia or brain. Q. What are the kinds of reproduction presented by cn

Bronchiectasis, Bronchiectasis: Bronchiectasis literally means abnorma...

Bronchiectasis: Bronchiectasis literally means abnormal dilation of bronchi. It is a chronic  inflammatory condition which is characterised  by permanent dilation of bronchi a

What is the stage of cellular respiration, What is the stage of cellular re...

What is the stage of cellular respiration during which carbon dioxide is liberated? In aerobic cellular respiration the release of carbon dioxide occurs in the transformation o

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