1. Topic 6 & 11: Human Health and Physiology
11.2 Muscles and Movement

2. 1 - Anatomy Read & Consider 11.2.1-11.2.3 What do you know?
What questions do you have?
How do skeletons and exoskeletons differ?
1 - Anatomy
Read & Consider

3. Draw, label, & annotate the human elbow joint:
Include:
Bones
Muscles
Ligaments
Synovial joint features
Tendons
Cartilage

4. Synovial Joints Pubic Symphysis: Cartilaginous Joint
Skull Suture Joint: Fibrous Joint

5. Antagonistic Pairs
Both bones and exoskeletons act as anchors for muscle and levers for movement with the use of antagonistic muscle pairs.

6. 2 – Muscle Cells / Muscle Fibers
What do you know?
What questions do you have?
Are all types of muscle the same?
2 – Muscle Cells / Muscle Fibers
Read & Consider

7. Muscle fibers (cells) are multinucleated cells that may shorten to half or one-third of their resting length.
Fibers (cells) are composed of myofibrils contained in a plasma membrane called the sarcolemma. Cytoplasm between myofibrils contains mitochondria. Sarcolemma in-folds to form sarcoplasmic reticulum containing transverse tubules.

8. Draw and label diagrams of the structure of a sarcomere.
Actin & Myosin
Myofibrils are composed of interlocking thick and thin protein filaments.
Thin filaments – actin – long and about 7nm in diameter. The are held together by transverse bands called Z lines.
Thick filaments – myosin – short and about 15nm in diameter.
Muscles are striped or striated due to the repeating pattern of actin and myosin filaments.
Draw and label diagrams of the structure of a sarcomere.

9. 3 - Contraction Read & Consider 11.2.7-11.2.9 What do you know?
What questions do you have?
3 - Contraction
Read & Consider

10. Sarcomere -
Each repeating until of the myofibril (actin and myosin) is called a sarcomere. From z line to z line.

11. Contraction: Action potential arrives at the neuromuscular junction.
Acetylcholine (neurotransmitter) released.
Action potential is initiated in the muscle cell membrane.
T-tubules carry this chemical signal throughout the muscle.
Signal causes a calcium release from the sarcoplasmic reticulum into myofibrils.

12. Power Stroke
Calcium causes troponin (protein) to remove tropomyosin exposing cross bridge binding sites.
An ATP molecule “charges” the cross bridge allowing it to react with the neighboring actin molecule.
The use of the ATP molecule triggers a rowing movement (cross bridge tilts to 45ºn angle) pushing the actin filament along = power stroke and shortening the myofibril.
The cross bridge then returns to resting position, is blocked by tropomyosin, and a new ATP molecule recharges in preparation for the next contraction.

13. Diagram
Muscle Contraction

14. Analysis

15. Works Cited
Contracting Muscles. Digital image. Quick 3D Motion. Gizmag, n.d. Web. 03 Jan
Hip Joint. Digital image. WiseGEEK. Conjecture Corporation, n.d. Web. 03 Jan
Human Skeleton. Digital image. Learn: (by Xinixazi). N.p., n.d. Web. 15 Dec
Pubic Symphysis. Digital image. Pix For Pubic Symphysis. Disqus, n.d. Web. 03 Jan
Water Beetle - Exoskeleton. Digital image. Insect Exoskeleton - Viewing Gallery. N.p., n.d. Web. 15 Dec
Zygote Media Group Inc. Synovial Joint. Digital image. 3D Science Clip Art. N.p., n.d. Web. 03 Jan