Muscular System
Anna Sherwood
Definition of the Muscular System
The Muscular system is an organ system that consists of the skeletal muscle, the cardiac muscle, and the smooth muscle. The functions of the Muscle system permits movement of the body, maintains posture, and circulates blood throughout the body.
Accessory organs and tissues
Connective tissue
Joints
Ligaments
Tendons
The 3 types of Muscles
Smooth Muscle
The smooth Muscle is self-initiated and has myogenic contraction to aid in the rhythmic movement of the organs. The smooth muscle has neurogenic contraction that requires neurons.
Skeletal Muscle
The skeletal muscle is used in locomotion. Each skeletal muscle acts as its own unit and is closely associated with connective tissue and is in control by the nervous system.
Cardiac Muscle
The cardiac muscle does not grow tired and maintains the circulation of blood. The cardiac muscle has mixed control and acts as a single functional unit.
Fun Facts
The term Muscle has 2 meanings
Muscle cell of Fiber- the active contractile component: muscle cells and their endomysium.
Muscle organ- the whole organ: muscle cells plus associated connective tissues, nerves, and blood supply.
Different attachments
Tendon- Cordlike attachments
Aponeurosis-Thin flat sheet
Fascia- Thin flat sheets of connective tissues that wrap and bind parts of the body together
Raphe- Junction of 2 muscles at a band of connective tissue to form a line of fusion, such as the linea alba.
Muscle Contraction
A muscle receiving no nervous stimulus is relaxed or in a resting state- soft shape retained by surrounding collagen fibers.
When nervous stimuli applied beyond muscle's threshold level, contraction results and tensile force is generated, constituting the active state.
The attached bone and/or mass that must be moved represents the load- whether a muscle actually contracts depends on the relative balance between the tensile force of contraction and the load to be moved.