When a muscle is relaxed and in a lengthened position, what is the relationship between actin filaments?

• They are on top of one another
• They are beside each other
• They are close to each other
• They are far apart from each other

Z represents

• Dendrite
• Axon Terminal
• Neurotransmitters
• Synapse

Once calcium is released, it will

• attaches to myosin head
• attaches to receptors 
• attaches to tropomyosin
• attaches to troponin

Number 3 represents which of the following events

• action potential reaches the axon terminal
• sodium rushes into the muscle fiber
• potassium leaving the muscle fiber
• ACh crossing the synaptic cleft

What are the two ions transported across the membrane in an action potential?

• O^2- and K⁺
• K⁺ and Na⁺
• Ca⁺² and B⁺³
• Na⁺¹ and Cl

Which of the following is NOT a muscle function?

• Movement of skeleton
• Heat generation
• Transport substances around body
• Moves neurons around body

What is the name of the protein myofilament that pulls the actin towards the center of the Sarcomere?

• Fascicle
• Actin
• Myosin
• Titin

Which of the following is the name given to the connective tissue that covers of a muscle fascicle or bundle of muscle?

• Endomysium
• Perimysium
• Epimysium
• Myofilament

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

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