Muscle fiber types

Which one of the following is a key characteristic of Fast Twitch B muscle fibers? 

• They are Red in color, meaning they contain a lot of mitochondria
• They contract rapidly with great force but fatigue fast (as they use creatine phosphate pathway)
• They are recruited for long duration activities
• They contain high numbers of Mitochondria

Which one of the following is a key characteristic of slow twitch muscle fibers? 

• They contain large amounts of Mitochondria
• They are fast to fatigue
• They are recruited last
• They contain low numbers of Mitochondria

Muscle fatigue sets in due to the nonavailability of 

• calcium
• ATP
• actin binding sites
• sodium

Fill-in-the-blank! Muscle, Fascicle, _____, Myofibril

• Muscle fiber
• Myofilament
• Sarcomere
• Actin 

Tags

NGSS.HS-LS1-2

A motor unit is made up of _______________.

• all the muscle fibers within a given muscle
• a motor neuron and the muscle fibers it innervates
• all the neurons going into an individual section of the body
• a fascicle and a nerve

Long distance runners have large proportion of ___________ fibers.

• slow oxidative
• fast oxidative
• fast glycolytic

Which fibers are relatively fatigue-resistant and use aerobic respiration?

• oxidative
• glycolytic

Tags

NGSS.HS-LS1-7

NGSS.HS-LS2-3

_________ fibers are white in color due to the lack of myoglobin.

• slow oxidative
• fast glycolytic
• fast oxidative

During a muscle twitch _______________ is the period when tension is decreasing to baseline.

• latent
• contraction
• relaxation

World-class sprinters can have up to ____ more of fast twitch muscle fibres in their body

• 20%
• 40%
• 60%
• 80%