Muscle Types & Functions
This muscle type is voluntary and helps you move your skeleton
What is skeletal muscle?
The basic repeating unit of a muscle that contracts is called a what? (Pg 94)
What is a sarcomere?
The point where a motor neuron meets a muscle fiber is called what? (Pg 96)
What is a neuromuscular junction?
Moving a body part away from the midline of the body is called what? (Pg 101)
What is abduction?
This type of muscle contraction occurs when a muscle shortens as it produces movement (Pg 98)
What is concentric movement?
This type of muscle is involuntary and found in internal organs
What is smooth muscle?
This protein filament is responsible for thick filament structure in muscle fibers (Pg 97 image)
What is myosin?
The neurotransmitter (a chemical) that triggers muscle contraction is called what? (Pg 96)
What is acetylcholine?
Moving a body part toward the midline of the body is called what? (Pg 101)
Adduction
This type of contraction happens when a muscle lengthens in a controlled way while still producing force (Pg 98)
What is eccentric?
This muscle type is only found in the heart
What is cardiac muscle?
The connective tissue covering a muscle fiber is called the what? (Pg 93)
What is the endomysium?
What molecule provides energy for muscle contractions? (Pg 97)
What is ATP?
When you move your arm in a circle at the shoulder joint, you are performing what motion? (Pg 101)
What is circumduction?
In this type of contraction, the muscle generates force but does not change in length (Pg 98)
What is isometric?
What characteristic allows muscles to shorten and produce movement?
What is contractility?
The “sliding filament theory” involves actin sliding over what? (Pg 97)
What is myosin?
When oxygen is low, muscles produce this substance, causing soreness
What is lactic acid?
Raising your arms out to the sides at shoulder height demonstrates which movement? (Pg 101)
What is abduction?
What type of muscle contraction helps you maintain posture while standing still?
What is isometric contraction, because muscles hold tension without movement?
Name one function of muscles besides movement (Pg 92)
What is maintaining posture, stabilizing joints, producing heat?
What ion is essential for muscle contraction to occur? (Top of pg 94 & pg 97)
What is calcium (Ca²⁺)?
This ion causes muscle cells to depolarize (Pg 97)
What are sodium ions?
How do ball-and-socket joints allow circumduction, but hinge joints do not? (Pg 101)
Ball-and-socket joints allow movement in multiple directions, enabling circular motion; hinge joints move in one direction only.
Explain the difference between isometric and isotonic contractions. Bonus 200 points: Give an example of each (Pg 98)
Isometric: muscle contracts without movement (e.g., holding a plank).
Isotonic: muscle changes length while contracting (e.g., lifting or lowering a dumbbell).