Muscle Exam Prep

Aerobic respiration occurs in the…

mitochondria

Dark turkey meat is dark because it contains more…

myoglobin

More powerful muscle contractions can be produced by…

more action potentials

Small motor units are…

more precise

Fast twitch muscle cells have more \[ \] than do slow twitch cells

glycogen

Does anaerobic respiration produce energy faster than aerobic respiration?

Yes, anaerobic respiration Produces energy faster than aerobic respiration

A single motor neuron and all the muscle fibers it innervates is called a…

motor unit

The troponin-tropomyosin complex prevents…

prevents myosin heads from binding to actin

Calcium ions bind too…

bind to the troponin-tropomyosin complex

Is ATP a neurotransmitter?

no

What gets shorter during muscle contraction?

sarcomeres

Is acetylcholine a neurotransmitter?

yes

The molecule which actively pumps Ca++ back into the sarcoplasmic reticulum is…

calsequestrin

A depolarization strong enough to cause an action potential is called a…

threshold stimulus

Is myosin ATPase an enzyme?

yes (hint: ends in -ase)

Slow twitch muscle cells have more \[ \] than fast twitch cells

Mitochondria and Capillaries

What is the best description of a sarcomere?

a segment of myofibril

Thick filaments contain which protein?

myosin

What prevents myosin from binding to actin?

troponin-tropomyosin complex

The sarcoplasmic reticulum contains…

Ca++

The function of ATP within a muscle cell is to…

\-Fuel the active transport of Ca++ into the sarcoplasmic reticulum

\-Release myosin heads from actin after they have flexed

Increasing the number of action potentials sent down an axon will…

recruit increasing numbers of myofibrils within the motor unit

The all-or-none principle means that…

If a muscle fiber contracts, it always contracts completely

The function of Ca++ within a muscle cell is to…

bind to the troponin-tropomyosin complex, exposing actin binding sites

Acetylcholine

\-is the neurotransmitter found at the neuromuscular junction

\-is broken down by acetylcholinesterase

\-binds to receptor sites on the motor end plate

At the neuromuscular junction…

I don’t know the answer it’s one of these

A. The axon terminals contain receptor sites for neurotransmitter

B. The sarcolemma contains vesicles full of neurotransmitter

C. The axon terminal is separated from the sarcolemma by the synaptic cleft

D. None of these

E. A and C, but not B

Which of the following is NOT a function of the muscular system?

Hematopoiesis

What type of muscle is striated and involuntary?

Cardiac

An action potential occurs when…

enough sodium enters a cell to open voltage regulated gates from the inside