What is an essential fatty acid?
Essential fatty acids are fatty acids that the body requires for health, but it cannot synthesize. Therefore, we must eat it in our diet. There are 2 essential fatty acids for humans: alpha-linolenic acid (an omega-3 fatty acid) and linoleic acid (an omega-6 fatty acid).
What is the role of calcium in skeletal muscle?
At rest, tropomyosin covers the myosin binding sites on the actin filaments. This prevents the myosin heads from being able to bind to the action. Following an actin potential (electrical signal) calcium is released into the sarcoplasmic reticulum. The calcium binds to troponin which moves the tropomyosin out of the myosin binding sites on the actin. This allows the myosin heads to bind to the actin filament causing a contraction.
What is the rotator cuff?
A rotator cuff is a group of 4 muscles that stabilize the shoulder. These muscles are the supraspinatus muscle, the infraspinatus muscle, teres minor muscle, and the subscapularis muscle. The mnemonic device SITS is used to help remember these muscles. These four muscles are responsible for both external and internal rotation of the humerus as well as shoulder abduction.