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?
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?
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
triceps is
the muscle responsible for
the extension of the front
legs (elbow joint) of an animal

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
pectorals are large muscles that run across the chest of the animal & are responsible for the primary movement of the front legs