1 of 50
Which of the following describes voluntary muscle tissue?
| Smooth muscle |
| Cardiac muscle |
| Skeletal muscle |
| Dense irregular |
| Dense regular |
Question2 of 50
What does endomysium cover?
| Smooth muscle only |
| Fascicles of muscle cells |
| An entire muscle |
| An individual muscle cell |
| Myofibrils |
Question3 of 50
What is the name of the plasma membrane of a skeletal muscle cell?
| Sarcoplasm |
| Myofilament |
| Sarcomere |
| Sarcoplasmic reticulum |
| Sarcolemma |
Question4 of 50
Which of the following describes a sarcomere?
| The contractile unit between two Z discs |
| The area between two intercalated discs |
| The wavy lines on the cell, as seen in a microscope |
| The nonfunctional unit of skeletal muscle |
| A compartment in a myofilament |
Question5 of 50
Which of the following lists the structures of the skeletal muscle in order from largest to smallest?
- Fascicle Myofilament Muscle fiber (cell) Myofibril
- Sarcomere
| 3, 2, 5, 4, 1 |
| 1, 3, 4, 5, 2 |
| 2, 5, 4, 3, 1 |
| 3, 1, 2, 4, 5 |
| 1, 4, 3, 2, 5 |
Question6 of 50
What is acetylcholine?
| A source of energy for muscle contraction |
| A component of thick myofilaments |
| An oxygen-binding protein |
| A neurotransmitter that stimulates skeletal muscle |
| An ion pump on the postsynaptic membrane |
Question7 of 50
What is the name of the gap between the axon terminal of a motor neuron and the sarcolemma of a skeletal muscle cell?
| Cross bridge |
| Sarcomere |
| Synaptic cleft |
| Neuromuscular junction |
| Motor unit |
Question 8 of 50
Why are calcium ions necessary for skeletal muscle contraction?
| Calcium increases the action potential transmitted along the sarcolemma. |
| Calcium initiates the depolarization of the sarcolemma. |
| Calcium triggers the binding of myosin to actin. |
| Calcium makes the membrane more permeable to sodium ions. |
| Calcium causes ATP binding to actin. |
Question 9 of 50
What generates the mechanical force of contraction?
| The "accordion-like" folding of thin and thick filaments |
| The temporary disappearance of thin filaments |
| The shortening of the thin filaments |
| The sliding of thin filaments past thick ones |
| The shortening of the thick filaments |
Question 10 of 50
What does a motor unit include?
| Muscle fibers only |
| Motor neurons only |
| Several motor neurons and one muscle fiber |
| Several muscle fibers and one motor neuron |
| One muscle fiber and one nerve |
Question 11 of 50
Which of the following describes when a muscle contracts so completely that no relaxation is seen while the contraction is sustained?
| Tetanus |
| Incomplete tetanus |
| Twitch |
| A normal contraction |
| Summation |
Question 12 of 50
How can the condition of skeletal muscle fatigue best be explained?
| The inability to generate sufficient quantities of ATP due to feedback regulation of synthesis |
| Insufficient intracellular quantities of ATP due to excessive consumption of oxygen |
| The all-or-none law |
| The total lack of ATP |
| Inadequate numbers of mitochondria |
Question 13 of 50
Anaerobic glycolysis occurs when which substance is lacking?
| Glucose |
| Oxygen |
| ATP |
| Lactic acid |
| Carbon dioxide |
Question 14 of 50
What do isometric contractions produce?
| Contractions and shortening, but not movement |
| Movement |
| Contractions |
| Contractions and movement, but not shortening |
| Muscle shortening |
Question 15 of 50
What is the name of the movement that decreases the angle between two bones?
| Abduction |
| Flexion |
| Circumduction |
| Extension |
| Rotation |
Question 16 of 50
While doing "jumping jacks" during an exercise class, the arms and legs move laterally away from the midline of the body. What is this motion called?
| Adduction |
| Extension |
| Abduction |
| Circumduction |
| Flexion |
Question 17 of 50
What is the name of a muscle group that works with and assists the action of a prime mover?
| Antagonist and synergist |
| Fixator only |
| Antagonist only |
| Synergist only |
| Antagonist and fixator |
Question
18 of 50
Which of the following muscles are examples of antagonists?
| Biceps brachii and triceps brachii |
| Vastus medialis and vastus lateralis |
| Gastrocnemius and soleus |
| Masseter and temporalis |
| Biceps femoris and biceps brachii |
Question 19 of 50
Which of the following muscle(s) closes the jaw?
| Sternocleidomastoid |
| Zygomaticus |
| Buccinator |
| Frontalis |
| Both masseter and temporalis |
Question 20 of 50
Which one of the following is the action of the orbicularis oris?
| Pulls the lower lip down and back. |
| Allows blinking, squinting, and various other protective mechanisms for the eye. |
| Draws the eyebrows together. |
| Closes the jaw. |
| Closes, purses, and protrudes the lips. |
Question 21 of 50
Which one of the following muscles is involved in abduction of the arm at the shoulder joint?
| Triceps brachii |
| Biceps brachii |
| Pectoralis major |
| Deltoid |
| Latissimus dorsi |
Question 22 of 50
Which of the following is a muscle located on the ventral (anterior) side of the body?
| Pectoralis major |
| Occipitalis |
| Gluteus medius |
| Latissimus dorsi |
| Gastrocnemius |
Question 23 of 50
What is the main function of the quadriceps femoris group?
| Thigh abduction |
| Foot inversion |
| Arm flexion |
| Hand supination |
| Knee extension |
Question 24 of 50
Which autoimmune muscle disease results from a shortage of acetylcholine receptors at the neuromuscular junction and leaves the patient with generalized muscle weakness and fatigue?
| Multiple sclerosis |
| Muscular dystrophy |
| Scoliosis |
| Myasthenia gravis |
| Spina bifida |
Question 25 of 50
What does the term central nervous system refers to?
| Spinal cord and spinal nerves |
| Brain, spinal cord, and cranial nerves |
| Brain and spinal cord |
| Autonomic and peripheral nervous systems |
| Brain and cranial nerves |