Muscular System

Which systems does the muscular system work with to make our bodies move?

• Digestive System

• Circulatory

• Respiratory

• Skeletal

What is the role of tropomyosin in muscle contraction?

• To release troponin from tropomyosin, allowing myosin to bind to the actin filament

• To release calcium from the sarcoplasmic reticulum

• To prevent myosin from continuing to slide up the actin filament

• To aid in myosin ‘cocking’ on the actin filament

What is the role of acetylcholine in calcium release?

• Stimulates cellular contraction by opening voltage-gated ion channels

• Stimulates postsynaptic acetylcholine receptors to release intracellular calcium

• Binds to sarcoplasmic reticulum, causing calcium release

• Binds to the T-tubules, causing calcium release

Which of the following correctly identifies muscle components in order from largest to smallest?

• Muscle fiber, fasciculus, myofibril

• Sarcolemma, sarcoplasm, fasciculus

• Fasciculus, muscle bundle, myofibril

• Fasciculus, muscle fiber, myofibril

The space between two Z lines constitutes the:

• Sarcolemma

• Sarcophagus

• Sarcoplasm

• Sarcomere

What is an aponeurosis?

• A segment of muscle that is not attached to bone

• An area of smooth muscle in the abdomen

• A large, flat tendon that anchors muscle

• A group of neurons that innervate striated muscle cells

We would expect to find smooth muscle in all of the following EXCEPT:

• Pulmonary circulatory tissue

• Esophagus

• Small intestine

• Myocardial tissue

Curare is a naturally-occurring compound that competitively binds to nicotinic acetylcholine receptors on muscle cells. Which of the following symptoms might be seen in a patient who has been exposed to curare?

• Diaphragmatic paralysis

• Cardiac arrest

• Excessive salivation

• Muscle spasticity

Which of the following is accurate regarding Type I and Type II muscle fibers?

• Type I fibers store much of their energy as triglycerides, whereas Type II fibers store energy as ATP or creatine phosphate

• Type I fibers are easily fatigued and are therefore intended for short bursts of activity

• Type I fibers employ anaerobic metabolism, whereas Type II fibers utilize aerobic metabolism

• Type I fibers are white, whereas Type II fibers are red

Which of the following is NOT innervated by the autonomic nervous system?

• Branching muscle cell

• Striated skeletal muscle cell

• Myocardial cell

• Intestinal muscle cell