JUNIOR MUSCULAR SYSTEM

Janet. J. Nelson RN,CMA

INTRO

• DID YOU KNOW?– There are more than 700 muscles– Muscles make up 40% of our body weight– Bones make up about 18% of body weight– Bones make up the bodies framework BUT

muscles move the bones and create movement– Muscles never “totally” relax. Even when asleep

some muscles are in contraction– Do all muscles cells work all day long? – NO!!! Some muscle cells work (contract) while

others relax

MUSCLE PROPERTIES

• Contractility

• Excitability (Irritability)

• Extensibility

• Elasticity

TYPES OF MUSCLE

FUNCTIONS

• Movement• Peristalsis

• Heat Production • (Thermogenesis)

• Maintain Body Posture & Position

• Stabilize Joints

• Support soft tissue

• Guard entrances and exits

CONNECTIVE TISSUE ORGANIZATION

SARCOMERE

VIEW ADAM ESSENTIALS

• SKELETAL MUSCLE ANIMATION

• TENDON APONEUROSIS

Sarcomere animation

• http://lessons.harveyproject.org/development/muscle/swstfast.html

game

• http://media.pearsoncmg.com/bc/bc_marieb_ehap_8/activities/chapter6/Act6B.html

How myosin heads shorten sarcomere

• http://www.getbodysmart.com/ap/muscletissue/menu/menu.html

CONTRACTION OF SKELETAL MUSCLE

• NERVOUS IMPULSE:– Neuromuscular junctions– Acetycholine– Crossbridges cause

sliding of sarcomere (muscle shortening)

– Muscle shortens– Breakdown of

acetycholine (cholinesterase)

– Crossbridges let go and sarcomere returns (muscle lengthens)

CONTRACTION CONTINUED.

• Skeletal muscle contracts only if stimulated.

• Skeletal muscle contractions can vary

• If nerve supply is destroyed muscle can become flaccid

NAMING MUSCLE HINTS

• ACTION:

• DIRECTION OF FIBERS

• MUSCLE LOCATION

• NUMBER OF DIVISIONS

• SHAPES OF MUSCLE

• POINTS OF ATTACHMENT

• SIZE OF MUSCLE

• MUSCLE DIRECTION

OCULOMOTOR MUSCLES

CHEST MUSCLES

PECTORALIS MINOR

•

ARM MUSCLES

ANTERIOR ARM

POSTERIOR ARM

Diaphragm

Intercostal Muscles

Remember ‘inter-” means between

Abdominal Muscles

Abdominal Muscles

Perineal Muscles

Female Perineum

Male Pelvic Floor

Muscles of the Hip

Thigh muscles

Anterior lower leg

Posterior lower leg