molecular mechaniism of contraction

• Stimultion of muscle cells.
• cross bridge
• filament sliding
• ATPase activity of Myosin head
• Troponin-Tropomyosin action
• Attachment and detachment of the myosin head
• calcium and Mg+2 is required for contraction
• Myosin head ATPase activity is Ca+ dependent
• Release of Ca+ from sarcoplasmic reticulum
  

sarcomere shortening

The vertebrate and invertabrate animals muslce has similar structure and function. There are various type of muscle cells. 1. Striated muscle: it can be divided into skeletal and cardiac mucsle. Although the structure are similar in the skeletal and cardiac muscle, contractile activity is different. Skeletal muscle is usually under voluntary control. Cardiac and smooth muscle are involuntary muscle. Innervation of both smooth and skeletal muscle are different.http://muscle-biology.blogspot.com/

organization 3

Connective tissue, nerve, blood vessels. Connective tissue, external lamina, endomysium, perimysium, fasciculus, epimysium. Fascia, nerve and blood vessels, abundant.

properties of muscle

contractility: ability of a mucle to shorten with force. Excitability: capacity of muscle to respond to a stimulus. Extensibility : muscle can be streched to its normal resting lenght and beyond to a limited degree. Elasticity ability of mucle to recoil to original resting lenght after stretched.