muscular system

 Muscular system 

Muscular system	Along with the nervous system, the muscular system is an integrated system that affects every part of the body.
Muscular system	It is also vital in controlling involuntary and voluntary movement.
tissue	A group of cells with similar structure that function together as a unit, but at a lower level than organs
Types of Muscle Tissue	There are three types of muscles: skeletal, cardiac,       and smooth muscle
Skeletal muscle	Skeletal muscle often attaches to bone and is involved in the movement of bones.
tendon	Most skeletal muscles are attached to bones by a tendon. Tendons are tough bands of connective tissue that have strong collagen fibers.
Cardiac muscle	Cardiac muscle can be found in the heart and is also striated.  Cardiac muscle tissue cannot be controlled consciously, making it involuntary muscle.
Smooth muscle	Smooth muscle can be found in the walls of hollow organs, such as the stomach and intestines; in the walls of passageways, such as blood vessels; and elsewhere throughout the body, such as the eyes, the tracts of the reproductive system, and the skin.
Involuntary muscle	It is the weakest of all muscle tissues and is considered an involuntary muscle because it is controlled by the unconscious part of the brain
Muscle movement	Muscles move by contracting and shortening their length, which pulls on the tendons, moving one bone closer to another bone that is stationary.
Sarcomere unit	Muscles contain long myofibrils made of sarcomere units, each consisting of long strands of proteins called “actin” (thin filaments) and “myosin” (thick filaments).
. When a muscle is relaxed, myosin and actin filaments are not attached. When they contract, the filaments bind and are pulled together.	When the brain wants to send a message to a particular part of the body, the nervous system sends a signal to a muscle. Actin and myosin proteins in the muscle slide past each other, creating either a contraction or a relaxation of the muscle.
	Each muscle fiber is connected to a nerve fiber. For the entire muscle to move, it takes a concerted effort by many nerves and fibers and the use of adenosine triphosphate (ATP) to power the contraction and relaxation.  Muscle movement use ATP to power the contraction and relaxation
	Actin and myosin proteins in the muscle slide past each other, creating either a contraction or a relaxation of the muscle. These two basic motions are responsible for all muscle movement.
myosin	Muscles contain long myofibrils made of sarcomere units, each consisting of actin (thin filaments) and myosin (thick filaments).
actin	Actin = structure + movement + support inside and outside muscle cells. long strands of proteins called “actin” (thin filaments)
Ligaments and cartilage	Ligaments and cartilage connect bone to bone and help stabilize joints.
Tendon	The role of tendons-Tendons attach muscle to bone.
Skeletal muscle	Skeletal muscles are voluntary.
Cardiac muscle	Cardiac muscle are involuntary
Trapezius muscle	The pectoral muscles are in the chest, the trapezius muscles are in the upper back, and the abdominal muscles are in the abdominal area of the body.
Pectoral muscle	Pectoral muscle are in the chest.
Deltoid muscle	The deltoids are the shoulder muscles.