1. Muscle
Contractions

2. Nelson Martinez-Aguilar
Period 8
DO NOW
Name the muscle layers.
2. What are the thick myofibrils called? Thin?
3. What is the name of the functional units of muscle contraction.
TV/Smart board
Christeen Alsawalha
Jason Cardona
Faith Johnson
Adriana George
Jerionna Joyner
Miah Littles
Rayjah Austin
Molly Wall
Trinity Johnson
Chelsie Coulter
Nelson Martinez-Aguilar
Thomas Kane
Tralynn Williams
Bryanna Haag
Teaona Crawford
Caitlin Keith
Rhyannon Mercer
Kierra Harris
Kaylah Jones
Shannon Baumgartner
Bria Ellison
Tashauna Hills
Carson Josma
David Burritt
Tristan Feder
10 minutes
Daunte Mills Lamaera Wheaton
Maria Moncada Zachary Mooreside Sebastian Moreau Taylor Moss
Khalid Nezami Alejandro Pastrana-Agosto
Jenifer Rodrigues Rineco Solomon
Piper Tremain Greilyn Tuggle

3. Class Rules No Phones out or in use. No heads on desks.
Hall Passes can be given only between 1:00 and 1:15 With ID.

4. Objectives Identify the major events of skeletal fiber contraction.
Describe the energy source for contraction, and the result in the absence of this source.

5. Essential Question
How does muscle tissue contract to move the body?

6. Vocabulary acetylcholine myofibril calcium ions acetylcholinesterase
neuromuscular junction
myosin
actin
sarcomere
binding sites
cross bridge
glycolysis
oxygen debt
fatigue

7. Muscle Fiber Contraction overview

8. Muscle Fiber Contraction

9. Muscle Fiber Contraction
1. A nerve impulse travels down a motor neuron axon

10. Muscle Fiber Contraction
2. The motor neuron terminal releases the neurotransmitter acetylcholine (ACh)

11. Muscle Fiber Contraction
3. ACh binds to ACh receptors

12. Muscle Fiber Contraction
4. The sarcolemma is stimulated, and a muscle impulse travels over the surface of the muscle fiber deep into the fiber through the transverse tubules.

13. Muscle Fiber Contraction
5. The muscle impulse reaches the sarcoplasmic reticulum and calcium channels open.

14. Muscle Fiber Contraction
6. Calcium ions diffuse from the sarcoplasmic reticulum into the sarcoplasm and bind to troponin molecules.

15. Muscle Fiber Contraction
7. Tropomyosin molecules move and expose specific sites on actin.

16. Muscle Fiber Contraction
8. Actin and myosin form linkages

17. Muscle Fiber Contraction
9. Thin (actin) filaments are pulled toward the center of the sarcomere by myosin cross-bridges

18. Muscle Fiber Contraction
10. The muscle fibers shorten as a contraction occurs.

19. Now it is your turn: