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 is excretion done in fishes, How is excretion done in fishes? Fish...

How is excretion done in fishes? Fishes have a pair of kidneys that filtrate the blood. Bony fishes excrete nitrogen as ammonia, NH 3 , (they are ammoniotelic) and cartilagino

Development of heart in amphibians, Development of Heart in Amphibians ...

Development of Heart in Amphibians The heart and the surrounding pericardial cavity build up from lateral mesoderm. After gastrulation, the mesodermal mantles carry on to gro

Determine energy expenditure for climbers, Determine energy expenditure for...

Determine energy expenditure for Climbers? The energy expenditure of 3250 Kcal/ day is reported in climbers to Mt. Everest using doubly labeled water teaching. Out of this, 161

Define broken instrument removal procedures, Define Broken Instrument Remov...

Define Broken Instrument Removal Procedures File or reamer Gates-glidden Peso drills Lentulo spiral paste fillers Thermomechanical gutta-percha computer

What are the two main subdivisions of the phylum Chordata, Normal 0 ...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4 What are the two mai

What is joints in human biology, What is Joints Joints are locations...

What is Joints Joints are locations where two or more bones come together, or articulate. Bones are joined with varying degrees of rigidity. Joints may be fixed, as in the s

Examine six bad listening habits, Discuss six bad listening habits. Which d...

Discuss six bad listening habits. Which do you think is the biggest challenge for you personally?

Define functions of vitamin d, Define Functions of Vitamin D? Vitamin D...

Define Functions of Vitamin D? Vitamin D is required to maintain normal blood levels of calcium and phosphate, which are in turn needed for the normal mineralization of bone, m

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