Major Muscles & Movements
Which major muscle allows you to raise your arm away from your body (abduction)?
Deltoid
Which muscle tissue is voluntary?
Skeletal muscle
What neurotransmitter is released at the neuromuscular junction?
Acetylcholine (ACh)
What molecule provides energy for muscle contraction?
ATP
Muscles with fibers running straight and parallel are often named with what word?
Rectus
Which muscle group is responsible for extending the knee?
Quadriceps
Which muscle tissue is found in the heart?
Cardiac muscle
Which structure receives the neurotransmitter on the muscle side?
Sarcolemma receptor
300:
What is the functional unit of a muscle fiber where contraction occurs?
Sarcomere
The “maximus” in gluteus maximus refers to what naming characteristic?
Size
Name the muscle group on the back of the thigh that flexes the knee.
Hamstrings
Name the property that allows a muscle to return to its original shape after being stretched.
Elasticity
What ion does the sarcoplasmic reticulum release to trigger contraction?
Calcium (Ca²⁺)
Which filament moves during contraction — actin or myosin?
Actin slides past myosin
Which naming category is used for the deltoid?
Shape
Which muscle is the prime mover for elbow flexion during a curl?
Biceps brachii
What do we call the type of muscle that controls movement inside hollow organs like intestines?
Smooth muscle
What would happen if ACh stayed in the synapse and was not broken down?
Continuous contraction / spasms
What is the main cause of muscle fatigue during intense exercise?
Oxygen debt and ATP depletion
What does “biceps” indicate about the muscle?
It has two heads / origins
A sprinter pushes explosively off the ground. Identify the agonist, antagonist, and synergist involved in plantar flexion.
Agonist: Gastrocnemius
Antagonist: Tibialis anterior
Synergist: Soleus
Explain the difference between contractility and extensibility in muscle tissue.
Contractility = ability to shorten and produce force.
Extensibility = ability to stretch without damage.
Put these NMJ events in the correct order:
A) ACh binds receptors
B) Calcium triggers ACh release
C) Action potential spreads along sarcolemma
D) Nerve impulse reaches axon terminal
D → B → A → C
Explain how calcium, troponin, and tropomyosin work together to allow contraction.
Calcium binds troponin → shifts tropomyosin → exposes actin binding sites → myosin can attach.
Name and explain TWO different ways muscles are named (example not used in previous questions).
Examples:
Location (e.g., tibialis anterior = front of tibia)
Action (e.g., flexor carpi radialis = flexes wrist)
Number of origins (e.g., triceps = three heads)
Direction of fibers (e.g., oblique = angled)
Points of attachment (e.g., sternocleidomastoid)