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
Define Various Methods of Food Processing? In this unit, you studied the various methods of food processing. You learnt that food being most vital for the survival of human bei

Define the Spatial processes? Environmental and integrative biology cuts across a wide array of spatial scales, and theoretical approaches that take into account these widely v

What are the Sources of Vitamin K? As mentioned above, in plants, the only important molecular 'form of vitamin K is phylloquinone. Phylloquinone is distributed ubiquitously th

Q. Imaging Techniques to test stress? A screening exam with M-mode and limited Doppler should be performed at the start of the test, but a detailed echo examination is usually

Explain the Executive Functions - Psychological tests Executive functions are those involved in the planning, organisation, regulation and monitoring of goal directed behaviour

Explain Adverse effects of Amprenavir  The most common adverse effects have been nausea, vomiting (especially in combination with zidovudine), perioral paresthesias and rash (J

What is the plant transpiration? What are the two major types of plant transpiration process? Which of them is more important in volume? The Plant Transpiration is the loss of

What is Ascending Aortic Aneurysm ? Ascending Aortic Aneurysm :  In aneurysms confined to ascending aorta well below the innominate artery origin, the technique used is

Q. How is respiration performed by the larva of amphibians? The larva of amphibians has exclusively branchial respiration this is one of the reasons why it depends on water to

An element playing significant role in nitrogen fixation is : 1.  Molybdenum 2. Copper 3. Manganese 4. Zinc An element playing significant role in nitrogen fixation