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
What is a single motor neuron and all the muscle fibers it controls called?
Motor unit
What structure attaches muscle to bone?
Tendon
Approximately how many muscles are in the human body?
Over 600
In the sliding filament model, which protein filament pulls the actin filaments to create contraction?
Myosin
What type of muscle lines organs such as the intestines and blood vessels?
Smooth muscle
Which muscle is the primary mover during an action?
Agonist
What structure in cardiac muscle helps cells contract together?
: Intercalated discs
What is the term for a muscle becoming shorter and thicker when stimulated?
Contraction
During strong contraction, which sarcomere region shrinks or disappears?
H zone
What type of contraction involves changing length to move a load?
Isotonic contraction
What does the antagonist muscle do during movement?
It relaxes or lengthens
What structures attach the valves to papillary muscles?
Chordae tendineae
Why must muscles work in opposing pairs?
Muscles can only pull, not push
What byproduct builds up when muscles run low on oxygen?
Lactic acid
What type of contraction occurs when force is generated without movement?
Isometric contraction
Which muscle type is responsible for rapid reflex actions like pulling your hand away from a hot stove?
Skeletal muscle
What structures inside the ventricles contract to prevent valve prolapse?
Papillary muscles
What leads to a stronger muscle contraction?
Recruiting more motor units
What muscle property describes the ability to respond quickly to a stimulus?
Irritability (excitability)
What is the wave-like motion that moves food through the digestive tract?
Peristalsis
Which part of the nervous system controls involuntary actions of smooth muscle?
Autonomic nervous system
Why is the left ventricle thicker than the right ventricle?
It must pump blood with higher pressure to the entire body