Muscular System ▪ Contractility: ability of the muscle to shorten. ▪ Extensibility: ability of muscle to lengthen. ▪ Elasticity: ability of muscle to return to normal size. ▪ Atrophy: is the wasting of muscle tissue ▪ Hypertrophy: is the increase in size of muscle tissue. ▪ Controlled by nerve stimuli. ▪ Fed by capillaries. Characteristics common to muscle tissue

Muscular System ▪ Smooth ▪ Cardiac ▪ Skeletal Different types muscle tissue Muscle types tutorial

Muscular System Skeletal Muscles (striated or voluntary muscles) are those which attach to bones and have the main function of contracting to facilitate movement of our skeletons. Different types muscle tissue

Muscular System Smooth muscle (Unstriated) Involuntary muscle due to our inability to control its movements. Found in the walls of hollow organs such as the stomach, esophagus, bronchi and in the walls of blood vessels. Different types muscle tissue

Muscular System Different types muscle tissue Cardiac muscle only in the walls of the heart. Similar to: skeletal muscle -striated smooth muscle- involuntarily controlled

Muscular System Structure of skeletal muscle

Muscular System Structure of skeletal muscle Epimysium: This is the connective tissue wrap just under the deep fascia that surrounds the entire muscle Perimysium: This connective tissue surrounds each individual fascicle (bundle of muscle fibers). Endomysium: This is the connective tissue wrapped around each individual muscle cell (fiber). Myofibrils: threadlike fibrils that make up the contractile part of a striated muscle fiber. skeletal muscle structure Structure of skeletal muscle

Muscular System ▪ Muscle fibers are made up of a group of myofibrils. ▪ Myofibrils contain myofilaments. ▪ The myofibrils have distinct, repeating microanatomical units, termed sarcomeres, which represent the basic contractile units of the muscle fiber/cell (myocyte). ▪ Myofilaments (actin & myosin) are responsible for muscle movement. Structure of skeletal muscle

Muscular System ▪ Myofilaments: (Thick and Thin) ▪ Myosin: thick filaments ▪ Actin: thin filaments ▪ A unit of thick and thin filaments is known as a Sarcomere. ▪ These structures hold the key to muscle contraction. The staggered thin and thick filaments has the effect as one might pull a rope towards oneself hand over hand. Structure of skeletal muscle

Muscular System Structure of skeletal muscle

Muscular System Structure of skeletal muscle Structure of a muscle video clip

Muscular System Origin and insertion of muscles ▪ Origin: the point where the tendon attaches to the bone which does not move during muscle action. ▪ Insertion: the point where the tendon attaches to the bone which moves during an action. ▪ e.g. Action of biceps muscle: Scapula is origin (Proximal point) and radius is the insertion. (distal point) x.htm Link for origin & insertion of muscles

Muscular System State the origin and insertion of the following muscles: (show a picture of each with your answer) Anterior muscles deltoid pectoralis major & minor iliopsoas sartorius quadriceps group (rectus femoris, vastus intermedialis, vastus medialis, vastus lateralis.) Tibialis anterior Abdominus rectus External obliques Biceps brachii

Muscular System

Rectus Femoris Actions: flex hip, extend knee (two joint muscle) Vastus Lateralis Vastus Intermedius Action: extend knee (single joint muscle) Vastus Medialis Rectus Femoris Origin – inferior pelvis Vastus Lateralis Vastus Intermedius Vastus Medialis Origin – proximal femur

Muscular System

Pubic symphysis

Muscular System

State the origin and insertion of the following muscles: (show a picture of each with your answer) Posterior Muscles Trapezius triceps brachii latissimus dorsi gluteus maximus hamstrings group (biceps femoris, semitendinosus, semimembranosus) gastrocnemius soleus erector spinae

Muscular System Base of skull (occipital protuberance)

Muscular System

Olecranon process

Muscular System

Medial Hamstrings Lateral Hamstrings

Muscular System Two Joint Muscle

Muscular System One Joint Muscle

Muscular System