WorksheetsMuscle Cells and Their Functions
Total questions: 40
Worksheet time: 20mins
Which of the following is the main contractile unit inside myocytes?
Lysosome
Sarcomere
Ribosome
Golgi apparatus
Myocytes require many mitochondria because:
They need constant detoxification
They must continuously produce ATP
They must store glycogen
They cannot perform protein synthesis
Which type of cell junction allows rapid communication between muscle cells?
Tight junctions
Gap junctions
Desmosomes
Hemidesmosomes
Which nervous system primarily controls involuntary muscles?
Somatic nervous system
Autonomic nervous system
Central nervous system
Parasympathetic nervous system only
What structure connects skeletal muscle to bone?
Ligament
Tendon
Cartilage
Fascia
Which muscle type is under voluntary control?
Smooth
Cardiac
Skeletal
None
What structural feature makes cardiac and skeletal muscle appear striated?
Nuclei arrangement
Alternating actin and myosin bands
Mitochondria alignment
Connective tissue
Which type of blood vessels are most closely associated with muscles for oxygen delivery?
Arteries
Capillaries
Veins
Lymphatic vessels
The ability of muscle cells to respond to nerve signals is called:
Excitability
Contractility
Elasticity
Extensibility
Which protein directly binds calcium during muscle contraction?
Actin
Myosin
Troponin
Tropomyosin
Smooth muscle fibers are best described as:
Striated and multinucleated
Non-striated and single-nucleated
Striated and branched
Cylindrical and multinucleated
Where is smooth muscle most likely found?
Heart ventricles
Triceps brachii
Small intestine walls
Biceps tendon
What is the primary control system for smooth muscle contraction?
Somatic nervous system
Autonomic nervous system
Skeletal nervous control
Reflex pathways only
Smooth muscle contraction is generally:
Fast and voluntary
Slow and sustained
Random and weak
Absent in blood vessels
Which of the following processes involves smooth muscle?
Heartbeat
Peristalsis
Reflex withdrawal
Running
Smooth muscle cells communicate with each other primarily through:
Desmosomes
Gap junctions
Sarcomeres
Neuromuscular junctions
Which feature allows smooth muscle to stretch and maintain tension?
Striations
High elasticity
Large mitochondria
Skeletal innervation
Contraction of smooth muscle in blood vessels results in:
Vasodilation
Vasoconstriction
Increased heart rate
Peristalsis
Which of the following is an involuntary muscle?
Smooth
Skeletal
Biceps
Quadriceps
A patient with asthma may be given medication to relax smooth muscle in the:
Esophagus
Bronchi
Heart
Stomach
Cardiac muscle cells are connected by:
Tight junctions
Intercalated discs
Elastic fibers
Myelin sheaths
Cardiac muscle is unique because:
It has multiple nuclei
It contracts without nerve stimulation
It is voluntary
It is non-striated
What initiates the heartbeat?
AV node
SA node
Purkinje fibers
Bundle of His
Which feature ensures the heart contracts as a coordinated unit?
Desmosomes
Gap junctions
Large mitochondria
Skeletal innervation
Cardiac muscle fibers are:
Branched and striated
Smooth and elastic
Cylindrical and multinucleated
Non-striated with no nucleus
Cardiac muscle is controlled by:
Voluntary somatic nerves
Autonomic nervous system
Skeletal muscle reflexes
Conscious thought
Which organelle is especially abundant in cardiac muscle?
Ribosome
Lysosome
Mitochondria
Vacuole
The property of cardiac muscle that allows it to contract repeatedly without fatigue is due to:
Intercalated discs
High mitochondrial density
Smooth fibers
Elasticity
Which cardiac structure delays electrical impulses to allow ventricular filling?
AV node
SA node
Bundle branches
Purkinje fibers
What type of muscle makes up the heart?
Smooth
Skeletal
Cardiac
Mixed
Skeletal muscle fibers are:
Branched
Cylindrical and multinucleated
Non-striated
Short and spindle-shaped
Skeletal muscles are organized into bundles called:
Sarcomeres
Fascicles
Filaments
Myofibrils
Which system controls skeletal muscle contraction?
Autonomic nervous system
Somatic nervous system
Endocrine system
Reflex pathways only
What is the role of acetylcholine in skeletal muscle contraction?
Provides ATP
Transmits nerve impulses at neuromuscular junction
Breaks down calcium
Stores oxygen
Which type of skeletal muscle fibers are specialized for endurance?
Fast-twitch glycolytic
Slow-twitch oxidative
Intermediate fibers
Fast-twitch fatigue-resistant
Skeletal muscle contraction begins when calcium is released from:
Mitochondria
Sarcoplasmic reticulum
Nucleus
Golgi body
Which protein filament in skeletal muscle has heads that attach to actin?
Myosin
Tropomyosin
Troponin
Titin
Muscle hypertrophy refers to:
Increase in number of muscle fibers
Increase in size of muscle fibers
Decrease in muscle tissue
Replacement with fat tissue
Skeletal muscle fatigue occurs mainly because:
Decreased oxygen and ATP
Increased protein synthesis
Excess glycogen storage
Increased calcium levels
Which connective tissue surrounds an individual muscle fiber?
Epimysium
Perimysium
Endomysium
Fascia
