Muscles

The contractile unit of a muscle:

• sarcomere

• motor unit

• fascicle

• myofibril

Thick filaments within a myofibril are:

• ATPase

• Sarcoplasmic reticulum

• Actin

• Myosin

Thin filaments in a myofibril are

• Sarcomeres

• Sarcoplasm

• Actin

• Myosin

The energy needed to perform a muscle contraction comes directly from

• ATP

• Oxygen

• Glucose

• Calcium

Tags

NGSS.HS-LS1-7

The neurotransmitter stored in the axon terminal identified as #3

• Calcium Ion (Ca²⁺)

• Protein Channel

• Acetylcholine

• Synaptic Cleft

The gap between a neuron and a muscle cell: (#4 in the diagram)

• synaptic cleft (synapse)

• sarcolemma
• vesicle
• Ca²⁺ ion

The plasma membrane of a skeletal muscle cell is called the:

• sarcomere
• myofilament
• sarcolemma
• sarcoplasm

The organelle that stores ACh in the axon is identified as #4

• Motor Neuron
• Axon Terminal of Motor Neuron
• Sarcolemma
•  Vesicle

Skeletal Muscle contraction is initiated when the ________ sends a message to the muscle cell.  

• Muscle cell
• Motor Neuron

• Gland
• Cardiac Muscle

As calcium binds to actin the myosin heads are allowed to bind to the actin forming a cross-bridge and begin to slide over mysoin.

• True

• False