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
Basic Physical Concepts of Plant Water Relation The main idea of this section is to explain the concept of chemical potential of water or water potential and the effect of var

Q. What are the characteristics of protozoans that make them resemble animals? Protozoans are unicellular beings with some related characteristics to animal cells. In compar

There are three natriuretic peptides-atrial (ANP) stored mainly in the atrium, brain (BNP) stored mainly in the ventricular myocardium and C-natriuretic peptide (CNP) located prima

Explain the differance between savanna and desert? Savanna : Savanna is characterized by relatively low rainfall and pronounced dry seasons. This type of climate produces a b

Armamentarium 1. Edentulous stock trays 2. Rubber bowl and alginate mixing spatula, plaster mixing spatula 3. Vernier calipers 4. Alginate impression material 5. Gy

Enumerate the major substrates for gluconeogenesis The major substrates for gluconeogenesis are the glucogenic amino acids, lactate  glycerol and (important  in ruminant) propi

Q. Is there any situation in which the DNA is made based on the RNA template? What is the enzyme involved? The process in which the DNA is synthesized having as template a RNA

XYY humans are fertile males. XXX humans are fertile females. What do these observations reveal about the mechanisms of sex determination and dosage compensation?

Lingual nerve and artery It is the branch of mandibular nerve which enters the oral cavity above the posterior edge of the mylohyoid muscle close to the 3 rd molar region proc

What are the biological troubles that molluscs face due to their soft body? Because molluscs have a soft body they are more fragile. They also have more complexity to support t