Muscular tissue practice exam
Which of the following properties of muscle tissue is its ability to generate tension to do work? A. extensibility B. elasticity C. contractility D. excitability
C
Muscles generate heat, stabilize the body positions and: A. line organs that open to the outside B. coordinate homeostatic functions for the body C. protect the body from invading organisms D. produce body movements
D
If ACh is not released at the neuromuscular junction then:
Muscle contraction will not happen
Identify the struture
Myofibril
The term aponeurosis refers to a
broad, flat, sheetlike tendon
Cardiac muscle fibers are attached to one another at
intercalated discs
Muscle contraction is triggered by impulses carried over
motor neurons
A motor neuron and all the muscle fibers it stimulates form a
motor unit
In tetanus
muscles undergo sustained contractions
A muscle fascicle is surrounded by
perimysium
An increase in the number of active motor units in a muscle is called
recruitment
Excitability refers to the ability of a cell to
respond to a stimulus by producing an electrical signal
Elasticity refers to the ability of a muscle fiber to
return to original shape after contracting or stretching
Creatine phosphate supplies energy for
synthesis of ATP
When ATP attaches to the myosin head
the head detaches from actin
In an isometric contraction
the muscle contracts but does not shorten
When calcium ion concentration in the sarcoplasm is low, the
troponin-tropomyosin complex slides back over the myosin binding sites
The following is a list of events in random order that occur in the contraction of skeletal muscle. Identify which of the subsequent letters represents the correct chronological order of these events. 1. Ca2+ binding to troponin 2. release of Ach at the neuromuscular junction 3. coming together of Z discs 4. depolarization of sarcolemma 5. myosin head attaches to myosin binding site on actin 6. depolarization of T-tubules
2, 4, 6, 1, 5, 3
For the initiation of an action potential that starts contraction in skeletal muscle fiber: A. Ach must bind to receptors on the motor end plate B. Ach must bind to the neurolemma of the somatic neuron C. acetylcholinesterase must break down Ach at the synapse D. K+ must flow into the neurolemma
A
The _______ is responsible for the striation of striated muscle.
Alternating of A bands and I bands
The sarcoplasmic reticulum A. is the cell membrane around each muscle fiber. B. stores Ca2+ when the fiber is at rest. C. opens to the outside through the sarcolemma. D. produces ATP for muscle contraction.
B
Which of the following does NOT have T-tubules? A. Skeletal B. Smooth C. Striated D. Cardiac
B
What links thin filaments to the sarcolemma?
Dystrophin
When examined under a microscope, in which type of muscle tissue are myofibrils not apparent?
Smooth muscle
Which type of muscle tissue is involuntary, slow in contracting, and able to regenerate considerably better than other types of muscle?
Smooth muscle
The binding of Ca2+ to ____________ starts the contraction cycle
Troponin
The enzyme acetylcholinesterase causes
acetylcholine to break down
Myofibrils are composed primarily of
actin and myosin
Calcium ions move from the cytoplasm (sarcoplasm) into the sarcoplasmic reticulum because of the action of
active transport pumps in the sarcoplasmic reticulum membrane
The outermost layer of connective tissue surrounding a skeletal muscle is the
epimysium
The elevated use of oxygen after exercise is called
excess post-exercise oxygen consumption
A sustained muscle contraction without partial relaxation stimuli is called
fused (complete) tetanus
Smooth muscle differs from skeletal because smooth muscle
has dense bodies instead of Z discs
The motor end plate is part of a
skeletal muscle at the synapse
Calmodulin is involved in the contraction of:
smooth muscle
When smooth muscles are stretched they contract, but within a short time the tension decreases. This is called
stress-relaxation response
