Anatomy- Skeletal Muscles
Muscle Test #1 Study Guide
1. What are the primary functions of muscles? What are skeletal muscles made of?
Five Skeletal Muscle Functions
1.Produce movement of the skeleton
•By pulling on tendons that then move bones
2.Maintain posture and body position
3.Support soft tissues
•With the muscles of the abdominal wall and the pelvic floor
4.Guard entrances and exits
•In the form of sphincters
5.Maintain body temperature
•When contraction occurs, energy is used and converted to heat
Skeletal muscles are organs Made of:
•Connective tissue
•Blood vessels
•Nerves
•Skeletal muscle tissue
2. List and describe the three layers of connective tissue associated with muscles.
1.Epimysium
•Covers the entire muscle
2.Perimysium
•Divides the muscle into bundles called fascicles
•Blood vessels and nerves are contained in the perimysium
3.Endomysium
•Covers each muscle fiber and ties fibers together
•Contains capillaries and nerve tissue
3. Describe a sarcomere. Where is it found? What does it do? How is it “defined” within the muscle? What is it made of?
Sarcomeres
•Smallest functional unit of skeletal muscle fiber
•Formed by repeating myofilament arrangements
•Each myofibril has about 10,000 sarcomeres
•Thick and thin filament arrangements are what produce the striated appearance of the fiber
•Overlapping filaments define lines and bands
4. How does calcium interact with troponin and tropomyosin? What does this do? Where is this calcium stored?
Steps of Contraction
1.Calcium released from Sarcoplasmic Reticulum (around myofibril)
2.Calcium binds to troponin
3.Change of troponin shape causes tropomyosin to move away from active sites
4.Myosin heads bind to active site, creating cross-bridges, rotate and cause actin to slide over myosin
5. How are skeletal muscle cells different from other cells?5.) Skeletal muscle fibers are quite different from the typical cells. One obvious difference is size: Skeletal
1. What are the primary functions of muscles? What are skeletal muscles made of?
Five Skeletal Muscle Functions
1.Produce movement of the skeleton
•By pulling on tendons that then move bones
2.Maintain posture and body position
3.Support soft tissues
•With the muscles of the abdominal wall and the pelvic floor
4.Guard entrances and exits
•In the form of sphincters
5.Maintain body temperature
•When contraction occurs, energy is used and converted to heat
Skeletal muscles are organs Made of:
•Connective tissue
•Blood vessels
•Nerves
•Skeletal muscle tissue
2. List and describe the three layers of connective tissue associated with muscles.
1.Epimysium
•Covers the entire muscle
2.Perimysium
•Divides the muscle into bundles called fascicles
•Blood vessels and nerves are contained in the perimysium
3.Endomysium
•Covers each muscle fiber and ties fibers together
•Contains capillaries and nerve tissue
3. Describe a sarcomere. Where is it found? What does it do? How is it “defined” within the muscle? What is it made of?
Sarcomeres
•Smallest functional unit of skeletal muscle fiber
•Formed by repeating myofilament arrangements
•Each myofibril has about 10,000 sarcomeres
•Thick and thin filament arrangements are what produce the striated appearance of the fiber
•Overlapping filaments define lines and bands
4. How does calcium interact with troponin and tropomyosin? What does this do? Where is this calcium stored?
Steps of Contraction
1.Calcium released from Sarcoplasmic Reticulum (around myofibril)
2.Calcium binds to troponin
3.Change of troponin shape causes tropomyosin to move away from active sites
4.Myosin heads bind to active site, creating cross-bridges, rotate and cause actin to slide over myosin
5. How are skeletal muscle cells different from other cells?5.) Skeletal muscle fibers are quite different from the typical cells. One obvious difference is size: Skeletal