Ch 11.1-11.4 Flashcards
muscle and nerve cells have developed which characteristic more than other cells? A. Movement B. Permeability C. Excitability D. Reproduction
C. Excitability
Because skeletal muscles is under the conscious control it is staid to be \_\_\_\_\_\_\_\_\_. A. Involuntary B. Smooth C. Voluntary D. Visceral
C. voluntary
Muscle cells contain __________, a starch-like carbohydrate that provides energy during intense exercise.
glycogen
What is myoglobin?
A. An enzyme found in the synaptic cleft
B. A molecule that stores oxygen in muscles
C. A carbohydrate that provides a muscle cell with energy
D. A hormone that triggers contraction
B. A molecule that stores oxygen in muscles
Which membranous structures conduct impulses through the sarcoplasm to stimulate the release of calcium?
A. Troponin
B. Sarcomeres
C. Myosin
D. T-tubules
D. T-tubules
A. troponin is a regulatory protein.
B. A sarcomere is the portion of the myofibril from one Z disc to the next; it constitutes one contractile unit.
C.Myosin is a contractile protein.
The characteristic that allows muscles to pull on bones and organs to create movement is called_____.
A. metabolism
B. Excitability
C. Contractility
D. Conductivity
C. Contractility
True or false.
The sarcoplasmic reticulum releases calcium through gated channels when the T-tubules are stimulated.
true
skeletal muscles exhibits alternating light and dark bands called_________.
striations
In a myofibril, a thick filament is composed of pairs of ___________ molecules intertwined together.
myosin
muscle cells contain _____________, a red pigment that stores oxygen need for muscular activity.
myoglobin
Thin filaments are primarily composed of which protein? A. F actin B. Elastin C. Dystrophin D. Myosin
A. F actin
what is the function of T-tubules?
A. to stimulate the terminal cisternae to release sodium
B. to stimulate the terminal cisternae to release calcium
C. to stimulate the terminal cisternae to release acetylcholine
B. to stimulate the terminal cisternae to release calcium
gated channels in the sarcoplasmic membrane open to release which ions into the cytosol? A. Sodium B. Phosphate C. Potassium D. Calcium
D. Calcium
In a thin filament, each tropomyosin molecule has a small calcium-binding protein called _________ bound to it.
troponin
Which protein makes up the thick filaments of a myofibril? A. Actin B. Tropomyosin C. Troponin D. Myosin
D. Myosin
within skeletal muscle cells, what extends from on Z disc to the next and constitutes one contractile unit? A. Thick filament B. Sacromere C. Terminal Cisterna D. T-Tubule
B. Sacromere
Multi-Select Which of the following are found in thin filaments? A. Troponin B. Tropomyosin C. F actin D. Titin E. Myosin
A. Troponin
B. Tropomyosin
C. F actin
What is a motor unit?
A. all of the muscle fibers innervated by a single motor nerve fiber.
B. A muscle unit within the epimysium
C. All of the nerve fibers that innervate a muscle group
D. A single bundle of fascicles
A. all of the muscle fibers innervated by a single motor nerve fiber.
What is myoglobin?
A. a carbohydrate that provides a muscle cell with energy
B. A hormone that triggers contraction
C. A molecule that stores oxygen in muscles
D. An enzyme found in the synaptic cleft
C. A molecule that stores oxygen in muscles
What is a neuromuscular junction?
A. a site where a nerve fiber communicated with a muscle fiber
B. A site in the spinal cord where nerve impulses from the somatic receptors are received
C. where a synaptic bulb is attached to a T-tubule
D. A passageway into a muscle for arteries and veins
A. a site where a nerve fiber communicated with a muscle fiber
which membranous structures conduct impulses through the sarcoplasm to stimulate the release of calcium? A. sarcomeres B. Myosin C. Troponin D. T-tubules
D. T-tubules
what is acetylcholine?
A. the name of the plasma membrane of a muscle fiber
B. The enzyme that removes the neurotransmitter in the neuromuscular junction.
C. an autoimmune disorder where the immune system attacks ACh receptors
D. The neurotrasmitter release at a neuromuscular junction
D. The neurotrasmitter release at a neuromuscular junction
when a muscle is at rest, what molecule blocks the active sites on the actin molecules?
A. Myosin
B. Tropomyosin
C. Troponin
B. Tropomyosin
What do neurons and muscles cells have in common?
A. their membranes undergo voltage changes when stimulated
B. Neurons and muscles cells are autorhythmic
C. Neurons and muscles cells are both multinucleated.
D. Both cells shorten when stimulated
A. their membranes undergo voltage changes when stimulated
the portion of a myofibril from one Z discus to the next is called ___________.
sarcomere
What is a difference in electrical charge from one point to another called? A. Charge difference B. Anion gap C. Battery D. Electrical potential
D. Electrical potential
all of the muscle fibers innervated b a single nerve fiber constitute a _______ unit
motor
What is the change in membrane potential with the entry of sodium ions called? A. repolarization B. Hyperpolarization C. Depolarization D. Unpolarizaton
C. Depolarization
A synapse is the point where a nerve fiber meets a target cell. When the target cell is a muscle fiber this type of synapse is called _______ junction.
neuromuscular
What is the process by which action potentials of a nerve fiber lead to action potentials in the muscle fiber called?
A. contraction
B. excitation
C. polarization
B. excitation
the neurotransmitter used in a neuromuscular junction is \_\_\_\_\_\_. A. Adrenaline B. Acetylcholine C. Norepinephrine D. GABA
B. Acetylcholine
at the synaptic knob of the motor neuron, calcium stimulates exocytosis of the synaptic vesicles to release the neurotransmitter \_\_\_\_\_\_\_\_ into the synapse. A. GABA B. Glucagon C. Sodium D. Acetylcholine
D. Acetylcholine
which cells have plasma membranes that undergo voltage changes in response to stimuli? A. Neurons and muscle cells B. Osteocytes and muscles cells C. Glial cells and osteocytes D. Glial cells and muscles cells
A. Neurons and muscle cells
what is the function of a t-tubule
A. carry the action potential through the sarcoplasm
B. are one component of the rigor complex
C. store ACh
D. Store and phosphorylate ATP needed for contraction
A. carry the action potential through the sarcoplasm
the voltage measured across the muscle cell at rest is about -90mV and is called resting membrane _____________.
Potential
Action potentials cause the opening of voltage-gated sodium ion channels in the ______ tubules. this leads to the opening of calcium ion channels in the terminal cisternae of the sarcoplasmic reticulum.
T or transverse
during depolarization of a muscle cell or nerve cell, ion channels in the plasma membrane open allowing which ions to enter the cell? A. Calcium B. Chloride C. Sodium D. Potassium
C. Sodium
Which occurs during muscle contraction?
A. The myofilaments lengthen
B. Myofilaments shorten
C. Overlapping of myofilaments decreases
D. Overlapping of myofilaments increase
D. Overlapping of myofilaments increase
Regarding skeletal muscle contraction, what is excitation?
A. the process by which rigor complexes are formed in the sarcomere
B. the process by which action potentials in the sarcolemma lead to calcium release
C. the stimulus that leads to the stretching of the elastic fibers in sarcomere
D. The process by which action potentials in a nerve fiber lead to action potentials in muscle fiber
D. The process by which action potentials in a nerve fiber lead to action potentials in muscle fiber
what does the sliding filament theory describe?
A. action potential propagation
B. Muscle contraction
C. Synaptic transmission
B. Muscle contraction
