Muscles form parts of many of the bodys organs. Together with the skeletal system, they also provide support and motility, allowing animals to move around. Exoskeletons are rigid structures on the outside of the body that support and protect an organism. Endoskeletons are found in vertebrates and are located inside of the body. Skeletal systems contain bone (mineralized collagen), cartilage, ligaments (which connect bones to bones), and tendons (which connect muscles to bones). Muscles can be skeletal, smooth, or cardiac. They can be controlled voluntarily through neuromuscular junctions and motor neurons or involuntarily via the autonomic nervous system and hormones. Skeletal muscles contain bundles of muscle fibers, which are long, multinucleated cells with striated filaments. Cardiac muscle is also striated, but smooth muscle is not.
The skeletal system functions
in support, protection and mobility. An exoskeleton is located
outside of the body, while an endoskeleton is located on the inside
of the body.
Bone is a type of connective
tissue. It is mineralized, which accounts for its strength.
Cartilage is also connective tissue but is more flexible than bone.
Skeletal muscle cells are large
and multinucleated. Skeletal muscle is striated due to the regular
arrangement of actin and myosin within muscle fibers.
The contractile unit of
skeletal muscle is the sarcomere.
According to the sliding
filament theory, during muscle contraction the thick and thin
filaments slide past one another, causing the sarcomere to shorten.
Smooth muscle is under
involuntary control. It lacks striations and unlike skeletal muscle,
the cells have only one nucleus each.
The heart is composed of
cardiac muscle. Cardiac muscle is striated and is inherently
Lecture Slides are screen-captured images of important points in the lecture. Students can download and print out these lecture slide images to do practice problems as well as take notes while watching the lecture.
The book and CD package include two full length practice exams that are presented with all questions answered and explained. The author also presents detailed reviews of all test topics and includes multiple-choice and free-response questions with answers at the end of each topic's chapter.
This book includes a review of the AP Biology exam format and scoring, proven strategies for answering multiple-choice questions, and hints for tackling the essay questions. The practice tests include answers and explanations and there is also proven test-taking strategies for both the multiple choice and essay parts.