Muscular System

Chapters 10 & 11

Did you know?

more than 50% of body weight is muscle

~ 650 muscles in the human body

(we will memorize 53)

Some Muscle Terminology

Muscle fibers = muscle cells

Myo & sarco: word roots referring to muscle(muscle) (flesh)

Three types of muscle tissue:

Skeletal, cardiac, & smooth

Three Types of Muscle

Skeletal Cardiac Smooth

Functions of Skeletal Muscles

• Allow skeletal movement

• Maintain posture

• Support soft tissues

• Guard entrances and exits

• Maintain body temperature

Skeletal Muscle Anatomy

Skeletal muscle are:

• surrounded by connective tissue

• contain nerves

• contain own arteries and veins• arranged in antagonistic pairs (e.g. triceps &

biceps)

• (antagonistic means opposing)

How Skeletal Muscles

Produce Movements

• Muscles exert a force on tendons which pull on bones

• Tendons connect muscle to bone

brachialisflexes forearm

Origin

Insertion

•Origin: the attachment of the muscle to the bone which remains stationary •Insertion: the attachment of the muscle to the bone which moves •Belly: between the origin and insertion

Terminology

Flexion

Types of Movement

p. 271-274

Extension

Hyperextension

Abduction, Adduction, & Circumduction

Rotation

Elevation & Depression

Protraction & Retraction