MUSCLES Macro Some slides produced by DR. VINIT.K.ASHOK ADJUNCT FACULTY

MUSCLES MUSCLES ATTACHED TO THE SKELETON ARE CALLED SKELETAL MUSCLES AND THEY FORM THE BULK OF THE MUSCULATURE IN THE HUMAN BODY FUNCTIONS- -BRING ABOUT MOVEMENT IN THE BODY -RESPONSIBLE FOR FACIAL EXPRESSIONS( FACIAL MUSCLES) -GIVES SHAPE TO THE BODY

CLASSIFICATION- BASED ON THE LOCATION -name associated w/ region or bone found near ex. Temporalis- located over Temporal Bone BASED ON SHAPE OF MUSCLE -name associated with shape ex. Deltoid- triangular, Trapezius- trapezoid BASED ON SIZE -self explanitory ex. Maximus/ minimus, longus, brevis DIRECTION OF MUSCLE FIBERS -direction of fibers usually in reference to midline ex. Rectus femorus ex. Transversus abdominis (reference handouts) ex. External oblique

CLASSIFICATION part 2 BASED ON NUMBER OF ORIGINS -number of heads/origins ex. Biceps, triceps, quadriceps (Ceps= cephaly=head) BASED ON LOCATION OF ORIGIN AND/OR INSERTION -named due to attachment point. -origin is named first ex. Sternocleidomastoid BASED ON ACTION OF MUSCLE -named for their action ex. Adductor longus – medial thigh ex. Supinator- guess where that is? (Reference handout)

BONE MUSCLE RELATIONSHIP LEVER SYSTEMS LEVER SYSTEM-CONSISTS OF A RIGID BAR ( LEVER) WHICH MOVES ON A FIXED POINT ( FULCRUM) WHEN A FORCE IS APPLIED( EFFORT) TO MOVE A RESISTANCE( LOAD) THE BONES AND MUSCLES IN THE BODY ACT AS LEVER SYSTEMS BONES JOINTS MUSCLES CONTRACTING BONE ITSELF + overlying tissues + other material you are trying to move

LEVER SYSTEM

TYPES OF LEVERS FIRST CLASS LEVERS- -FULCRUM LIES BETWEEN THE EFFORT AND THE LOAD( SEE-SAW) EFFORT IS APPLIED AT ONE END AND LOAD LIES ON THE OTHER END SECOND CLASS LEVERS -LOAD LIES BETWEEN EFFORT AND FULCRUM( WHEELBARROW) GREATER STRENGTH, LESS SPEED AND RANGE OF ACTION THIRD CLASS LEVERS EFFORT LIES BETWEEN LOAD AND FUNCTIONFAST LARGE MOVEMENTS WITH LITTLE EFFORT MOST SKELETAL MUSCLES ARE OF THIS TYPE

1st CLASS LEVER

Let’s go to the weight room! What muscle? Where is fulcrum? Where is effort? Where is load?

Second class levers

2nd class lever Plantar flexion to raise body on toes-. What are the 2nd class lever Plantar flexion to raise body on toes- What are the muscles being used for the effort? Load Effort

THIRD CLASS LEVERS

3rd Class Levers Load or resistance Effort fulcrum

OPERATION OF SKELETAL MUSCLES FUNCTION TYPES BASED ON ACTIONS -PRIME MOVER/AGONIST- THE MUSCLE THAT IS RESPONSIBLE FOR A SPECIFIC ACTION BICEPS FLEXES THE FOREARM AT THE ELBOW ANTAGONIST – MUSCLES THAT OPPSE A PARTICULAR ACTION( RELXED WHEN AGONIST ARE ACTING TRICEPS ARE RELAXED WHEN BICEPS ACT SYNERGISTS- THESE ACT ALONG WITH AGONISTS ADD A LITTLE EXTRA FORCE TO THE ACTION FIXATORS- THEY HELP THE AGONIST BY HOLDING A BONE IN PLACE

DIFFERENCES BETWEEN SKELETAL,SMOOTH AND CARDIAC MUSCLES SKELETAL MUSCLES VOLUNTARY MUSCLE STRIATED NOT BRANCHED MULTINUCLEATED( NUCLEUS PRESENT PERIPHERALLY) CYLINDRICAL IN SHAPE PRESENT INRELATION TO BONES SMOOTH MUSCLES -INVOLUNTARY MUSCLE -NOT STRIATED -SPINDLE SHAPED -SINGLE CENTRAL NUCLEUS -PRESENT IN RELATION TO ORGANS( GIT) CARDIAC MUSCLES -INVOLUNTARY MUSCLE -STRIATED -BRANCHED -SINGLE CENTRAL NUCLEUS -CYLINDRICAL IN SHAPE -PRESENT ONLY IN THE HEART