Connective tissue components 1.Endomysium - Muscle fibers are covered with a delicate connective tissue membrane 2.Perimysium - Groups of skeletal muscle fibers (fascicles) are bound together by a tougher connective tissue 3.Epimysium - the muscle as a whole is covered by a coarse sheath 4.Tendon - fibrous structures that attach muscles to bones 5.Aponeurosis - 6.Tendon sheath -

ParallelConvergentPennateBipennateSphincter Size, shape, and fiber arrangement

Attachment of muscles - point of attachment that does not move when the muscle contracts -point of attachment that does move when the muscle contracts

Muscle actions Functional classification of muscle groups – always function in groups/pairs; some contract as some relax –Prime mover (agonist) – Muscle most responsible for movement; “action” or “function” of that muscle –Antagonist – Muscle responsible for the movement opposite of the prime mover; provides precision and control during contraction of prime mover; relaxes while prime mover contracts –Synergist – Muscles that aid the prime mover; contract at same time as prime mover –Fixator – joint stabilizer; maintains posture or balance during contraction of prime mover

1 st Class Levers 2 nd Class Levers 3 rd Class Levers Bone = lever Joint = Fulcrum (F) Contracting Muscle = Force (P) Load (L)

How Muscles Are Named Features used in naming muscles 1.Location – gluteus, brachii 2.Function 3.Shape - deltoid 4.Direction of fibers – rectus abdominus 5.Number of heads or divisions – points of origin -cep = head 6.Points of attachment -sternocleidomastoid 7.Size of muscle – relative size, maximus, minimus Hints on how to deduce muscle actions 1.Be familiar with name, shape, and location 2.From shape and location, deduce name of origin and insertion bone 3.Determine which bone moves when muscle contracts 4.Deduce action—insertion moves toward origin 5.Deduce which muscle gives a specific action

Muscles Named According To: Overall Shape DeltoidShaped like delta Δ OrbicularisCircular PlatyFlattened; platelike QuadratusSquare RhomboideusDiamond-shaped TrapeziusTrapezoidal TriangularisTriangular

Muscles Named According To: Relative Size BrevisShort LongusLong MagnusLarge MaximusLargest MediusModerately sized MinimusSmall

Muscles Named According To: Direction of Fibers ObliqueDiagonal to body’s midline RectusParallel to midline SphincterCircling an opening TransversusRight angle to midline

Muscles Named According To: Actions Produced AbductorAbducts a part AdductorAdducts a part DepressorDepresses a part ExtensorExtends a part FlexorFlexes a part LevatorElevates a part RotatorRotates a part

Muscles Named According To: Regions Found BrachialisArm FrontalisFrontal (bone) FemorisFemur GluteusPosterior of hip/thigh OculiEye RadialisRadius UlnarisUlna

Muscles of Facial Expression 1. occipitofrontalis – raise eyebrows 2. corrugator supercilii – frowning forehead 3. orbicularis oculi – blinking 4. zygomaticus major – laughing 5. orbicularis oris – puckering 6. buccinator Muscles of Mastication (chewing) 1. masseter 2. temporalis 3. pterygoids Muscles that Move the Head 1. sternocleidomastoid 2. semispinalis capitis 3. splenius capitus 4. longissimus capitus

Posture Good posture – body alignment that favors function, with least work –Standing position: head and chest held high; chin, abdomen and buttocks pulled in; knees bent slightly; feet firmly on ground 6 in. apart. Poor posture – puts abnormal strain on ligaments and bones How Maintained –Muscle Tone (Tonicity) – when muscles exert a pull against gravity

Cycle of Life During infancy and childhood, muscle coordination and control allows developmental sequences to occur Degeneration of muscles with age includes replacement with connective tissue