Muscles

    Put the following structures in order from superficial to deep.

1.   muscle fiber

      2.   perimysium

      3.   myofibril

      4.   fascicle

      5.   endomysium

      6.   epimysium

• 6, 2, 4, 5, 1, 3

• 1, 3, 5, 6, 4, 2

• 1, 5, 4, 3, 2, 6

• 6, 2, 5, 4, 1, 3

Tags

NGSS.HS-LS1-2

  At rest, the tropomyosin molecule is held in place by

• ATP molecules.

• troponin molecules.

• myosin molecules.

• actin molecules.

  The action potential is conducted into a skeletal muscle fiber by

• motor end plates.

• neuromuscular junctions.

• transverse tubules.

• triads.

In the sarcomere which elastic protein attaches the thick filament to the Z line?

•  titin

• actin

• G actin

• nebulin

The following is a list of the events that occur during a muscle contraction. What is the correct sequence of these events?

 

1. Myosin cross-bridges bind to the actin.

2. The free myosin head splits ATP.

3. Calcium ion is released from the sarcoplasmic reticulum.

4. The myosin head pivots toward the center of the sarcomere.

5. Calcium ion binds to troponin.

6. The myosin head binds an ATP molecule and detaches from the actin.

• 3, 5, 1, 2, 4, 6

• 3, 5, 1, 4, 6, 2

• 5, 1, 4, 6, 2, 3

• 1, 3, 5, 4, 6, 2

Cross bridge detachment is caused by ________ binding to the myosin head.

• ATP

• Calcium

• Magnesium

• Acetylcholine

Put the following events of the neuromuscular junction in the order in which they occur.

 

1. Action potential is propagated in the sarcolemma.

2. Acetylcholine binds to ligand gated sodium channels.

3. Action potential arrives at the neuromuscular junction.

4. Vesicles full of acetylcholine are stored at the axon terminal.

5. Acetylcholine is released into the synaptic cleft.

• 4,3,1,5,2

• 4,5,3,2,1

• 4,3,5,2,1

• 4,3,5,1,2

The type of muscle fiber that is most resistant to fatigue is the ________ fiber.

• intermediate

• slow

• fast

• anaerobic

Most of the skeletal muscles in the body are ________ muscles.

• parallel

• convergent

• straight

• pennate

The fulcrum of a lever system is the

• load

• bone

• muscle

• joint

Tags

NGSS.MS-PS2-2