#1
Which type of muscle tissue is under voluntary control?
Skeletal muscle
ExplanationVoluntary control distinguishes skeletal muscles.
#2
Which connective tissue surrounds individual muscle fibers?
Endomysium
ExplanationEndomysium envelops individual muscle fibers.
#3
Which muscle is responsible for flexing the forearm at the elbow joint?
Brachialis
ExplanationBrachialis is a muscle involved in forearm flexion.
#4
Which muscle is known as the 'calf muscle' and is responsible for plantarflexion of the foot?
Gastrocnemius
ExplanationGastrocnemius is the 'calf muscle' responsible for foot plantarflexion.
#5
What is the neuromuscular junction?
Area where nerves communicate with muscles
ExplanationThe neuromuscular junction is the site of communication between nerves and muscles.
#6
What is the structural unit of a muscle fiber?
Sarcomere
ExplanationSarcomeres are the basic functional units of muscle fibers.
#7
Which neurotransmitter is released at the neuromuscular junction?
Acetylcholine
ExplanationAcetylcholine mediates signal transmission at neuromuscular junctions.
#8
What is the primary function of the sarcoplasmic reticulum in muscle cells?
Calcium storage
ExplanationSarcoplasmic reticulum stores calcium ions for muscle contraction.
#9
Which of the following is a characteristic of fast-twitch muscle fibers?
Anaerobic metabolism
ExplanationFast-twitch fibers primarily utilize anaerobic metabolism.
#10
What is the function of the H-zone in a sarcomere?
Myosin binding
ExplanationThe H-zone is where myosin binds during muscle contraction.
#11
Which muscle is responsible for abducting the thigh at the hip joint?
Gluteus medius
ExplanationGluteus medius is a muscle involved in thigh abduction.
#12
What is the role of titin in muscle contraction?
Sarcomere stability
ExplanationTitin contributes to the stability of sarcomeres during muscle contraction.
#13
What is the term for the ability of a muscle to return to its original length after being stretched?
Elasticity
ExplanationElasticity enables muscles to regain their original shape after stretching.
#14
Which muscle is responsible for the movement of the arm at the shoulder joint?
Deltoid
ExplanationThe deltoid is a shoulder muscle responsible for arm movement.
#15
What is the term for the point of contact between a motor neuron and a muscle fiber?
Neuromuscular junction
ExplanationNeuromuscular junction is where nerve and muscle communication occurs.
#16
Which hormone stimulates muscle growth and protein synthesis?
Testosterone
ExplanationTestosterone promotes muscle growth and protein synthesis.
#17
In a sarcomere, what happens during the cross-bridge cycle?
Actin and myosin binding
ExplanationThe cross-bridge cycle involves binding of actin and myosin.
#18
Which type of muscle contraction occurs when the muscle length remains constant?
Isometric
ExplanationIsometric contraction maintains constant muscle length.
#19
What is the primary energy source for muscle contraction during short bursts of high-intensity activity?
Creatine phosphate
ExplanationCreatine phosphate serves as the main energy source for short, intense muscle activity.