Muscle Basics
What body system generates most of your body heat when you shiver?
Muscular system
What tiny repeating unit inside a myofibril is responsible for contraction?
Sarcomere
Which muscle type is long, striated, and multinucleated?
Skeletal muscle
Why are larger motor units used for powerful movements like jumping?
They activate many muscle fibers at once
What structure attaches muscle to bone?
Tendon
What are the three types of muscle tissue?
Skeletal, cardiac, smooth(viceral)
What contraction type occurs when you stand upright against gravity without moving?
Isometric
What type of muscle lines organs such as the intestines and blood vessels?
Smooth muscle
In striated muscle, what proteins regulate actin and myosin during contraction?
Troponin and Tropomyosin
What structure in cardiac muscle helps cells contract together?
Intercalated discs
Which system works with muscles to stabilize joints and allow movement?
Skeletal system
What happens to the length of the sarcomere during muscle contraction?
It shortens
A rock climber grips a handhold and stays in the same position for several seconds without moving.
Isometric contraction
A muscle that fails to respond to a motor neuron signal is lacking which property?
Excitability
What type of muscle tissue makes up the myocardium?
Cardiac muscle
Which property enables muscle tissue to be stretched without damage?
Extensibility
What byproduct builds up when muscles run low on oxygen?
Lactic acid
A swimmer pulls their arm through the water during a freestyle stroke.
Isotonic
A muscle that can respond to a stimulus and generate force but cannot return to its resting length would have damage to which specific property?
Elasticity
What structures inside the ventricles contract to prevent valve prolapse?
Papillary muscles
What leads to a stronger muscle contraction?
Recruiting more motor units
Which feature allows cardiac muscle cells to contract as a unified tissue?
Electrical connections through intercalated discs
What is the wave-like motion that moves food through the digestive tract?
Peristalsis
Why is the origin typically described as the less movable attachment during a muscle action?
It provides a stable anchor for the muscle to pull from
Why would damage to cardiac muscle cells have more serious consequences than damage to skeletal muscle cells?
Cardiac muscle has limited regenerative ability