Anatomy - Muscle Structure/Contraction

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

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 Acetylcholine (ACh) in the axon is identified as #4

• Motor Neuron

• Axon Terminal of Motor Neuron

• Sarcolemma

•  Synaptic Vesicle

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

• Muscle cell
• Motor Neuron

• Gland
• Cardiac Muscle

What state is the sarcomere in B.

• Relaxed

• Contracting

• Both

• None of the above

What is a crossbridge?

• Where myosin binds to actin

• Where the calcium crosses into the cytoplasm

• Where calcium binds with troponin

• None of the answers are correct.