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WorksheetsMuscle and Nervous Tissue
Total questions: 50
Worksheet time: 13hrs 30mins
What binds to the exposed cross bridges on actin?
ATP
Myosin
Calcium
Acetylcholine
In skeletal muscle fibers, what is the source of the calcium ions that are released into the sarcoplasm to bind with troponin, resulting in contraction?
Extracellular fluid
Sarcoplasmic reticulum
Mitochondria
Golgi apparatus
What is the function of creatine phosphate?
It catalyzes the decomposition of ATP
It catalyzes the decomposition of ADP
It supplies energy for the synthesis of ATP
It supplies energy for the breakdown of ATP to ADP
How do skeletal muscles help maintain body temperature?
Excess body heat is used to increase muscle function
Muscle contraction releases heat
Excess acetylcholine is metabolized, releasing heat
The movement of thin filaments over thick filaments uses up some body heat
What occurs at a neuromuscular junction?
Actin and myosin filaments slide past one another
Troponin and tropomyosin cover and uncover actin binding sites
Neurotransmitters are released
Calcium and channels open when calcium ions bind to them
Which of these events occur first in muscle fiber contraction?
The muscle fiber membrane is stimulated and a muscle impulse travels deep into the fiber through transverse tubules
Acetylcholine diffuses across a gap at a neuromuscular junction
Acetylcholine is released from the axon of the motor neuron
Calcium ions diffuse from sarcoplasmic reticulum into the sarcoplasm and bind to troponin molecules
Botulism results from ingestion of a toxin produced by a type of bacterium. Along with other symptoms, it causes a type of paralysis in which the muscles cannot contract. Why does this paralysis occur?
The toxin prevents release of acetylcholine
The toxin promotes release of acetylcholine
The toxin binds to acetylcholine receptors at the neuromuscular junction
The toxin prevents the breakdown of acetylcholine
What occurs during excitation contraction coupling?
Release of calcium ions in the cytosol
Binding of myosin heads to actin
Shortening of sarcomeres
Recruitment
What is the location of the vesicle containing neurotransmitter molecule?
Along the side of the myofibrils
Deep to the motor end plate
Within the cisternae
At the distal end of a motor axon
Which statement describes the mechanism of muscle contraction?
Tropomyosin molecules move and expose specific binding sites on thick filaments
Actin filaments slide along myosin filaments
Cross bridges form between actin and the sarcolemma
Filaments of troponin and tropomyosin slide past one another
Acetylcholine released by a myofibril crosses the synaptic cleft to bind to the motor end plate.
True
False
When acetylcholine binds to its receptors at the motor end plate, the muscle fiber membrane becomes more permeable to ___.
Potassium
Sodium
Calcuim
Acetylcholine
Sensory receptors are part of the CNS.
True
False
The oculomotor nerve is a cranial nerve containing nerve fibers that innervate eye muscles and control eye movement. These fibers are examples of ___.
Sensory neurons
Interneurons
Motor neurons
Unipolar neurons
In order for a severed peripheral nerve to regenerate and recover its original function, nerve fibers must sprout and enter tubes formed by ___.
Connective tissue
Former axons
Myelin
Schwann cells
Astrocytes structurally support neurons and also provide important signals and nutrients to neurons.
True
False
A physiologist testing signal transduction rates in two different nerve fibers notices that one fiber conducts signals much faster than the other. Which is the most likely difference between the two?
The faster the nerve fiber has more axons
The faster nerve fiber has more dendrites
The faster nerve fiber is myelinated and the slower one is not
The slower nerve fiber is myelinated and the faster one is not
What is the function of sensory receptors?
To send signals from the brain to muscles
To work with muscles to generate motion
To detect changes in and outside the body
To act as a pathway between the ascending and descending tracts within the spinal cord
A neuron in the aorta detects oxygen content in the blood and relays this information to the brain. This neuron is an ___ fiber in the ___ nervous system.
Efferent; somatic
Efferent; autonomic
Afferent; somatic
Afferent; autonomic
The somatic nervous system controls voluntary actions and the autonomic nervous system oversees involuntary actions.
True
False
A nerve is a single neuron that transmits impulses.
True
False
Neuroglia are specialized to react to environmental change, and neurons support neuroglia.
True
False
Myelin is composed largely of carbohydrates.
True
False
What disorder involves an immune response that affects the myelin coating in axons throughout the spinal cord and brain, triggering inflammation and leaving scars?
Muscular dystrophy
Multiple Sclerosis
Alzheimer's disease
Cerebrovascular accident
Each neuron in the CNS may receive input from which structures?
From a single axon
From a single dendrite
From ten dendrites
From thousands of axons
Which of the following neuroglia are not part of the CNS?
Ependymal cells
Astrocytes
Satellite cells
Microglia
Synaptic knobs are at the ends of ___.
Axons
Dendrites
Cell bodies
Neuroglia
Which of these options list the structures in order, from deepest to most superficial?
Perimysium, epimysium, endomysium, fascia
Fascia, endomysium, perimysium, epimysium
Fascia, epimysium, perimysium, endomysium
Endomysium, perimysium, epimysium, fascia
What causes the striated appearance of skeletal muscle fibers?
Arrangement of transverse tubules
Position of the sarcoplasmic reticulum network
Organization of components of the sarcomeres
Location of cisternae
What is a function of muscles?
Pumping blood
Generating electrical impulses
Storage of minerals
Cushioning tissues from blunt force
Which statement describes a sarcomere?
A segment of the sarcoplasmic reticulum
A group of fascicles
A group of muscle fibers
A segment of a muscle fiber
What is the name of the outermost layer of connective tissue surrounding a skeletal muscle?
Epimysium
Perimysium
Endomysium
Sarcolemma
Endomysium separates individual muscle fiber from each other.
True
False
What is the main component of thin filaments?
Myofibrils
Acetylcholine
Actin
Myosin
What is the functional unit of muscle contraction?
Muscle
Muscle fiber
Myosin cross bridge
Sarcomere
Doing a plank is often part of a yoga or pilates workout. It is done by holding the body straight in a prone position, engaging the abdominal muscles and supporting oneself on arms and toes. It is much like the up position of a push up, but is held 30 to 60 seconds. What type of contraction would be occuring in the abdominal muscles?
Isotonic contraction
Eccentric contraction
Isometric contraction
Concentric contraction
The term ___ refers to an increase in the number of motor units activated as a result of more intense stimulation.
Latency
Recruitment
Threshold stimulation
Sustained contraction
What is a threshold stimulus?
Minimum stimulus strength required to release acetylcholine
Minimum stimulus strength required to produce ATP
Minimum stimulus strength required to contract a skeletal muscle
Minimum stimulus strength required to contract a muscle fiber
What type of muscle fiber will be more resistant to fatigue?
Fast twitch fiber
Slow twitch fiber
Recruitment refers to increasing the number of motor units involved in a muscle contraction.
True
False
What type of muscle consists of muscle cell that are separate rather than organized into sheets?
Multiunit smooth muscle
Visceral smooth muscle
Skeletal muscle
Cardiac muscle
A muscular contraction in which the muscle shortens, moving an object, is called a(n) ___ contraction.
Concentric
Eccentric
Isometric
Tetanic
Which statement describes cardiac muscle?
The cells are multinucleated
It does not require stimulation by motor neurons
The cell contains very few mitochondria
It lacks the striations formed by regularly arranged sarcomeres
How does smooth muscle compare to skeletal muscle?
Smooth muscle contracts more slowly and relaxes more slowly
Smooth muscle relaxes more slowly and relaxes more rapidly
Smooth muscle contracts more rapidly and relaxes more slowly
Smooth muscle contracts more rapidly and relaxes more rapidly
What type of muscle cells lack transverse tubules, have a single nucleus, and are under involuntary control?
Skeletal muscle
Smooth muscle
Cardiac muscle
In producing a movement, the muscle that causes an action is acting as the ___.
Synergis
Antagonist
Agonist
Mediator
What has happened in someone with myasthenia gravis that causes them to have muscle weakness?
Abnormal formation of the protein transverse tubules
Decreased supply of troponin
Decreased number of acetylcholine receptors
Lack of sodium channels in the motor and plate
While examining a sample of muscle tissue under a microscope, you notice that the cells have a single nucleus. The fibers are striated and heavily branched. Which muscle type does this sample contain?
Skeletal muscle
Smooth muscle
Cardiac muscle
What neurotransmitter(s) can stimulate smooth muscle cells?
Both norepinephrine and acetylcholine
Only norepinephrine
Only acetylcholine
Only calcium
What term describes the more moveable end of a muscle?
Origin
Fulcrum
Insertion
Source
