Differences Between Red And White Muscle Fibres:
The following are the points of difference between Red And White Muscle Fibres-
Red Muscle Fibre (Tonic) | White Muscle Fibre (Twitch) |
---|---|
It is thin and narrow. | It is thick and broad. |
Due to the presence of myoglobin (a heme-protein), these are dark red in colour. Oxygen combines with myoglobin to form oxymyoglobin which releases oxygen during muscular contraction and again converted into myoglobin. | Light coloured as do not have myoglobin so no oxygen is stored. |
Have abundant Mitochondria as depend upon the energy provided by aerobic cell respiration. | Have less number of Mitochondria as depend upon the energy provided by the glycolytic pathway. |
Perform slow sustained contraction over a long period. | Perform fast strenuous contractions for a short duration. |
They are slow to contract and slow to get fatigued. | These are early to contract and early to fatigue due to lactic acid. |
They have more blood capillaries. | They have fewer blood capillaries. |
They have less sarcoplasmic reticulum. | They have more sarcoplasmic reticulum. |
They are innervated by their slow conducting nerve fibres. | They are innervated by thick, fast conducting nerve fibres. |
Less accumulation of lactic acid. | More accumulation of lactic acid during heavy exercises. |
Examples- Extensor muscles on the back of the human body and flight muscles of kites, pigeons etc. | Examples- Eyeball muscles of human and flight muscles of a sparrow. |
Comments (No)