1. Muscle Day 3
Twitches

2. Do now Read pages 187-189, section 8.4
Write the vocabulary that is in bold on a paper to turn in
after you have defined each word

3. Vocabulary threshold stimulus twitch latent period summation
titanic contraction
recruitment
muscle tone

4. Objectives Distinguish between a twitch and a sustained contraction.
Explain how muscular contractions move body parts and help maintain posture.

5. Essential Question
How do stimuli contract muscle fibers to move the body?
How do muscles contract to permit precise control of pressure and movement?

6. Why do muscles burn after extended activity
Why do muscles burn after extended activity? What process does this signify?

7. Threshold stimulus
The threshold stimulus is the stimulus required to create an action potential. So any stimulus under this level will not cause muscle contraction, while a stimulus above this level will cause the muscle to contract. The higher the stimulus the more muscle fibers are recruited, and thus the higher the response.

8. Slow and fast muscle twitches
Most of your muscles are made up of a mixture of both slow and fast twitch muscle fibers. But, your soleus muscle in your lower leg and muscles in your back involved in maintaining posture contain mainly slow twitch muscle fibers. And muscles that move your eyes are made up of fast twitch muscle fibers.

9. Motor units
Muscles are organized into many motor units controlled by a single motor neuron. A nerve impulse to that unit will contract all the muscle fibers of that unit at the same time. At higher intensities of stimulation recruitment of motor units occurs until the muscle contracts with maximal tensions.

10. Sustained Contractions
When muscles are at rest, its fibers undergo some sustained contraction. We call this muscle tone and it is important because it helps in maintaining posture. When muscle tone is lost the body will collapse.

11. Origin and Insertion
Bones forming moveable joints function as levers. One end of a skeletal muscle usually fastens to a relatively immoveable or fixed part at a moveable joint, and the other end connects to a moveable part on the other side of that joint.

12. When a muscle contracts, its insertion is pulled toward its origin
The immoveable end of the muscle
The moveable end of a joint

14. Use the following words the label the muscle worksheets
Rectus Femoris Gastrocnemius Trapezius Rectus Abdominus Gluteus Maximus Triceps Brachii Deltoid Semimembranosus Pectoralis Major Biceps femoris Tibialis Anterior Vastus Medialis External Oblique Latissimus Dorsi Vastus Lateralis Semitendinosus Biceps Brachii Soleus

15. Frontalis
Temporalis
Orbicularis oculi
Zygomaticus
Masseter
Orbicularis Oris
Buccinator
Trapezius
Sternocleidomastoid

16. Exit
map of different types of exercise or lack of exercise and their effects on the body, focusing on difference
between strength and stamina training.