The key difference between type 1 and type 2 muscle fibers is that the type 1 muscle fibers contract slowly while the type 2 muscle fibers contract rapidly. Moreover, type 1 muscle fibers depend on aerobic respiration while type 2 muscle fibers depend on anaerobic respiration.
There are three major types of muscles. Among them, skeletal muscle is one type, which is attached to the skeleton. The individual muscle fibers make up the skeletal muscle. There are two main types of muscle fibers namely type 1 and type 2 muscle fibers. They are also known as slow-twitch and fast-twitch muscle fibers respectively.
CONTENTS
1. Overview and Key Difference
2. What are Type 1 Muscle Fibers
3. What are Type 2 Muscle Fibers
4. Similarities Between Type 1 and Type 2 Muscle Fibers
5. Side by Side Comparison – Type 1 vs Type 2 Muscle Fibers in Tabular Form
6. Summary
What are Type 1 Muscle Fibers?
Type 1 muscle fibers are one type of muscle fibers in the skeletal muscle. Moreover, they are also known as slow-twitch fibers due to their slow contraction. They are rich in mitochondria and also contain more myoglobin. Therefore, these fibers are more efficient in using oxygen to produce ATP continuously over a long time.
Figure 01: Skeletal Muscles
Hence, they are the muscles that help us in distance running or marathons, since they can resist fatigue for a long time. Type 1 muscle fibers are red in colour due to the presence of high content of myoglobin, oxygen, and mitochondria.
What are Type 2 Muscle Fibers?
Type 2 muscle fibers are the second major type of muscle fibers in the skeletal muscle. They are also known as fast-twitch fibers. There are two types namely type 2a and type 2b. Furthermore, these fibers use anaerobic respiration to produce fuel. Type 2a fibers are known as intermediate fast-twitch fibers or fast oxidative fibers and they are a combination of type 1 and type 2 muscle fibers. On the other hand, type 2a fibers use both aerobic and anaerobic metabolisms. Type 2b fibers use only anaerobic metabolisms and they are known as fast glycolytic fibers. Both of these types are rapid firing.
What are the Similarities Between Type 1 and Type 2 Muscle Fibers?
- Both Type 1 and Type 2 muscle fibers are muscle fibers of the skeletal muscle.
- Type 1 and Type 2 Muscle fibers contain myoglobin.
- Both Type 1 and Type 2 Muscle fibers can contract.
- These fibers produce ATP.
- Type 1 and Type 2 Muscle Fibers possess many capillaries and mitochondria.
What is the Difference Between Type 1 and Type 2 Muscle Fibers?
Type 1 and type 2 muscle fibers are the main two types of muscle fibers of the skeletal muscle. Type 1 fibers are slow contracting and generate ATP using aerobic metabolism. They contain more mitochondria and high content of myoglobin. They are red in color. These muscle fibers are helpful for distance running. They have a high resistance to fatigue. On the other hand type 2 muscle fibers are the second type of muscle fibers which are fast acting. This is the key difference between type 1 and type 2 muscle fibers. Further, there are two types of Type 2 muscle fibers; type 2a and type 2b. They contain a low level of mitochondria and they use anaerobic respiration. Their resistance to fatigue is low compared to type 1 muscle fibers.
Summary – Type 1 vs Type 2 Muscle Fibers
There are two types of muscle fibers namely type 1 and type 2. Both types contain myoglobin, capillaries, and mitochondria. Type 1 muscle fibers are more resistant to fatigue and produce energy continuously for a long time using aerobic metabolism. They are slow acting hence helpful for distance running etc. Type 2 muscle fibers are of two types; type 2a and type 2b. They are fast acting and use anaerobic metabolism. This is the difference between type 1 and type 2 muscle fibers.
Reference:
1.“Home.” TeachPE.com. Available here
Image Courtesy:
1.’Blausen 0801 SkeletalMuscle’By Blausen.com staff (2014). “Medical gallery of Blausen Medical 2014”. WikiJournal of Medicine 1 (2). DOI:10.15347/wjm/2014.010. ISSN 2002-4436. – Own work, (CC BY 3.0) via Commons Wikimedia