achilles is made up of what muscles
Muscle tissue functions mainly as a source of power and motion in the body. Muscles' main responsibility is for changing or maintaining posture, locomotion, and movement of internal organs. The human body has about 650 muscles, which make up approximately half our bodyweight. How are muscles attached to bone? Most muscles are attached to bones by connecting tendons. Tendons are thick, tough cords of tissue that firmly attach to both the muscle and the bone, connecting the two. A few muscles attach directly to the bone without a connecting tendon. Striated muscles consist of thousands of sarcomeres - muscle units. The muscle has a striped (striated) appearance when viewed under a microscope because each sarcomere is made up of parallel bands of different materials. When various bands in the sarcomeres relax or contract, the whole muscle extends or relaxes. Tendon, tissue that attaches a muscle to other body parts, usually bones. Tendons are the connective tissues that transmit the mechanical force of muscle contraction to the bones; the tendon is firmly connected to muscle fibres at one end and to components of the bone at its other end. The cardiac muscles work non-stop, day and night, 365 days a year. They work automatically, but are similar in structure to the skeletal muscles. They make the heart contract so that blood is squeezed out of the heart, and release so that the heart can fill up with blood again. Tendons connect muscles to bones and can withstand tremendous amounts of tension that the body encounters. Tendons allow movement of bones when the muscle is contracted, which causes the connecting tendon to pull on the bone. The connection between the bone and tendon is tough to break due to the tendon actually growing into the bone. Over-strained tendons are a common injury seen in sports. tendon - Student Encyclopedia (Ages 11 and up) A tendon, or sinew, is a cord of tissue that attaches the end of a muscle to a bone or other part of the body. It is composed of bundles of white fibrous tissue surrounded by a sheath. This tissue enters the bone and blends with the fibers of the bone. A tendon is inelastic but flexible and very strong. Structure[edit] The two muscle layers that make up the triceps surae, namely the gastrocnemius and soleus. The triceps surae is connected to the foot through the Achilles tendon, and has 3 heads deriving from the 2 major masses of muscle. The superficial portion (the gastrocnemius) gives off 2 heads attaching to the base of the femur directly above the knee. All muscles are basically made of the same material, a kind of elastic tissue; packages of stretchable fiber-like material, similar to what goes into making a rubber band. Each muscle is made of thousands, and sometimes tens of thousands of small musculus fibers. Each muscle fiber is about 40 mm in length and is made up of tiny strands of fibrils. Each muscle fiber is commanded by a nerve which makes it contract. How strong a muscle is depends mainly on how many fibers are present. The Achilles tendon connects the calf muscle to the heel bone. The calf muscle is actually two muscles, the gastrocnemius muscle and the soleus muscle. The soleus lies underneath the gastrocnemius. The Achilles tendon is the largest tendon in the body. It allows you to rise up on your toes and push off while walking or running.
Triceps surae namely the gastrocnemius and soleus.