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

How can you convert 147.05mg%, How do you convert 147.05mg% of plasma gluco...

How do you convert 147.05mg% of plasma glucose to mM/L please show work.

Explain apoptosis, Changes those are associated with programmed cell death,...

Changes those are associated with programmed cell death, containing release of apoptotic bodies, blebbing, and nuclear fragmentation.

Explain acid and bases, Explain acid and bases? Acids and Bases :  So...

Explain acid and bases? Acids and Bases :  Some aqueous solutions, however, such as HCl, form an excess of hydrogen ions [ H + ] and are called acids. Others, such as NaOH,

Function of adenosine in brain, Q. Function of Adenosine in brain? Aden...

Q. Function of Adenosine in brain? Adenosine has four different receptor subtypes (A1, A2A, A2B and A3). Adenosine A2A receptors are concentrated in striatum. Adenosine recepto

Kreb''s cycle, Kreb's cycle is the biochemical cycle in the cellular aerob...

Kreb's cycle is the biochemical cycle in the cellular aerobic metabolism where the acetyl CoA is combined with the oxaloacetate to form citric acid; the resulting citric acid is c

Qualitative estimation of protein-amino acid content in food, Define Qualit...

Define Qualitative Estimation of Protein/Amino Acid Content in Foods? The protein and amino acid content of foods helps to interpret nutritional differences among foods in term

Vapour theory - pre-mendelian theory, V apour Theory (i)         It wa...

V apour Theory (i)         It was proposed by a Greek philosopher Pythagoras in 500 B.C. (ii)         Each organ of an animal body emitted some kind of vapour and that a ne

Sympathetic and para sympathetic nervous system, SYM P A THETI C NERVOU...

SYM P A THETI C NERVOUS SYSTEM These sympathetic chain are connected with ramus comminicause of thoracic & lumber part. Due to this reason this system is called as t

How can you categorize flowering plants, Q. What are the two major groups i...

Q. What are the two major groups into which flowering plants are divided? Angiosperm plants are separated into monocotyledonous (monocots) and dicotyledonous (dicots).

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