BIOA02H3 Lecture Notes - Lecture 17: Fibrous Joint, Cartilaginous Joint, Biceps
43
BIOA02H3 Full Course Notes
Verified Note
43 documents
Document Summary
Skeletal muscles connect to bones of skeleton: may extend, bend, or rotate body parts. Myofibrils: contractile protein elements of muscle fibres. Sarcomeres: contractile units w/in myofibrils w/ 2 types of filaments arranged in an overlapping pattern. Thin filaments of action slide over thick filaments of myosin simultaneously on each side of sarcomeres: shortens sarcomeres and muscle fibers, produces force that contracts the muscle. Outer layer of circular muscles and an inner layer of longitudinal muscles alternate contracting and relaxing to propel the earthworm. Appendicular skeleton: skull, vertebral column, sternum, and rib cage, shoulder, hip, leg, and arm bones. Spongy bone regions: no spaces except microscopic canals of osteons, open into larger spaces, spaces filled by red or yellow marrow. Calcium and phosphate ions are constantly deposited and withdrawn from bones. Hormonal controls maintain calcium ions @ optimal levels in blood and extracellular fluids. Joints of vertebrate skeleton allow bones to move and rotate.
