1. Muscular System

2. What is the muscular system?  The muscular system creates bodily movement, maintains posture & produces heat.

3. What are the 3 types of muscle tissue?  3 types of muscle tissue:  Skeletal  Smooth  Cardiac  All either voluntary or involuntary  Voluntary – under control of animal  Involuntary – not controlled by animal

4. Skeletal Muscle  Skeletal muscle, or striated voluntary muscle, contracts to produce bodily movement  Skeletal muscles are the largest component of red meat animal products

5. Skeletal Muscle - Striated

6. Smooth Muscle  Smooth muscle, or unstriated involuntary muscle, is located in reproductive, digestive & urinary organs  contraction of smooth muscle is involuntary  is necessary for proper functioning of internal organs  Ex: smooth muscle contractions in the intestines permit the movement of food products

7. Smooth Muscle

8. Cardiac Muscle  Cardiac muscle is striated muscle found only in the heart  Contraction of the cardiac muscle is involuntary & is essential for proper blood circulation

9. Cardiac Muscle

10. Muscle Movement  Movement is made possible when muscles shorten  A muscle shortens because its cells are shortening  Muscle cell shortens because basic units of contraction within the cell (sarcomeres) are shortening

11. How do muscles contract to create movement?  Sarcomeres contain two types of protein filaments: myosin & actin.  Myosin is a thick filament, & actin is a thin filament.  During contraction - actin filaments slide past the myosin filaments, causing the sarcomere to shorten  A muscle consists of thousands of muscle fibers, or muscle cells, in bundles  An entire muscle fiber is called a myofiber, & sarcomeres are found within the myofibers

12. What are the common muscles found in livestock animals?  Knowledge of these muscles is important to an effective health care & production management plan  masseter is the superficial muscle of the cheek that aids in chewing & biting movements  trapezius is the superficial, triangular muscle of the shoulder that helps move front appendages

13. What are the common muscles found in livestock animals?  latissimus dorsi is a long muscle that connects the humerus bone of the forearm to the back of the animal  abdominal obliques are large muscles that run along the sides of the animal & help support the internal organs of digestion & reproduction.  gluteals are the large muscles in the upper hind quarter region of the animal that aid in rear leg movement

14. What are the common muscles found in livestock animals?  biceps femoris is a large muscle found in the rear leg of an animal  biceps brachii is the muscle responsible for the flexing of the front legs (elbow joint) of an animal  triceps brachii is the muscle responsible for the extension of the front legs (elbow joint) of an animal

15. What are the common muscles found in livestock animals?  pectorals are large muscles that run across the chest of the animal & are responsible for the primary movement of the front legs  serratus ventralis are muscles that connect the forelimbs (or front legs) to the trunk of the animal