The Muscular System and Methods of Movement

• Functions• Movement

• Protection

• Body Form

• Heat production

Muscle Cells

Cardiac• Heart Muscle• Involuntary

Smooth• Intestinal Muscle• Involuntary

Skeletal• Bone Muscle• Voluntary

Skeletal Muscle Tissue*Muscle tissue is bundled into fibers*Muscle fibers separate into individual

fibers or cells• Cells are broken down into

myofibrils• Myofibrils are divided into

sarcomeres• Sarcomeres are made of myosin

and actin• Actin Fibers move toward each

other as the “oars” of the myosin fiber contract, shortening the length of the sarcomere and entire muscle

• The entire sarcomere contractions• All sarcomeres contract in unison

How muscles move bone

• Muscles generally work in pairs– Flexors and Extensors

• When one contracts the other relaxes

• Muscle are anchored to bone by tendons

• As the muscle shortens it moves the bone it is attached to

Muscle Injuries

• Muscle Strain

Inflamed muscle group or tear in muscle tissue

*Muscle Cramp

When muscles do not relax

Muscle Facts• Muscles cells are multinucleated

• You are born with the same number of muscles cells you will have your entire life

• At maximum effort - only using 30% of your muscle strength

• If all your muscle could be pooled together they could move a mass equal to 50,000 pounds

• Strength depends on size of cell not number of cells

• Muscle mass = 45% of your bodies weight

• Muscle weighs more then fat

Methods of Movement (Bacteria)

• Some bacteria have flagella

• Flagella are not made of muscle

• They are composed of filaments that move back and forth based on polar attraction

Methods of Movement (Protozoan)

• Protozoan can move by flagella

• Cilia

• Pseudopodia

Fungus

• Movement is through growth

• Spores are carried by the wind

Plant Movement

• There is no muscle tissue

• Passing water from cell to cells allows slow movement

• Fast movement is done by rapid change of cell size

• Plants also move by growth

Arthropods/Crustaceans/Mollusk

• Muscle is similar in function

• Structure is different• Very little fat• Muscle is anchored to

exoskeleton• Muscle Contraction

causes movement of limbs

                          

            

A tube foot, an extension of the water vascular system of a starfish. This is not muscular. (star fish, echinoderm)

Bird Muscle

• Dark meat has more myoglibin, a special tissue that provides oxygen to the cells

• White meat has less• Dark meat is usually

associated with areas of more strenuous activity like the legs and wings