Muscular System PDF

Level 1 Semester 1 ▪ Module (Basic Module)  By DR: Amira El-Sayed What is muscular system  It is formed of contractile cells which concerned with the production of movement both body as a whole and of the internal organ  Skeletal...

Level 1 Semester 1 ▪ Module (Basic Module)  By DR: Amira El-Sayed What is muscular system  It is formed of contractile cells which concerned with the production of movement both body as a whole and of the internal organ  Skeletal Smooth Cardiac muscle muscle muscle striations striated Non striated striated Structure Cells are longer Long spindle shaped Polygonal cells With multinucleated cells peripheral nuclie Central nuclei Central nuclei Not branching Connected by C.T Branching Connected by C.T Connected by intercalated discs  Skeletal Smooth Cardiac muscle muscle muscle control Voluntary control Involuntary control Involuntary control examples include all muscles include muscles of They form the of body wall. blood vessels, and myocardium of muscles of the gut human heart. Skeletal muscle Tendons & ligaments  Tendons : are tough, elastic- type bands of connective tissue which connect muscles with bones. Tendons & ligaments  Ligaments : connective tissue which connect bones to each other. Parts of Muscle  Origin: the attachment of the muscle to the bone that remains stationary  Insertion: the attachment of the muscle to the bone that moves  Belly: the fleshy part of the muscle between the tendons of origin and/or insertion Forms of skeletal muscles 1) Muscles with parallel to the line of pull:  Theses are strap or ribbon like  It has a wide range of movement  Examples : rectus abdominis 2)Muscles with fibers oblique to the line of pull : A. Triangular(fan like):  The fibers converge from the origin to the insertion with variable obliquity to the line of pull B. Pennate muscles ❑Unipennate muscles: The tendon forms along one margin of the muscle and the entire fibers slope into one side of the tendon ❑Bipennate muscle: The tendone forms centrally and the muscle fibers slope into the two sides of the central tendon ❑Multipennate muscle: May be : Flate type Series of bipennate musclelying a longside one another Circumpennate type Slopping fibers of a muscle converge from all sides into a central tendon 3) Spiral muscles : In which there is a twist between two groups of muscle fibers gaining two attachment sites. Example : trapezius and pectoralis Prime mover and antagonist Prime mover : contracting to start a movement. Antagonists – relaxing to allow movement to take place. It oppose the action of the prime mover Fixator muscle  Fixators – contracting to give the working muscles a firm base. Action of paradox Muscles opposing the movement aided by the gravity Example: contraction of biceps brachii to control the passive extension of the elbow Cardiac muscle  Cardiac muscle has property of spontaneous rhythmic contraction which is controlled by impulses arising from S.A.N the pacemaker of the heart and propagated by A.V.N and bundle which consists of specially sensitive cardiac muscle fibers There are about 60 muscles in the face. Smiling is easier than frowning. It takes 20 muscles to smile and over 40 to frown. Smile and make someone happy.