2Interactions of Muscles Muscles can be classified into 4 functional groups!Synergist- they help prime movers by adding extra force, reducing unneccessary movements.Fixators- Holds parts of the body in proper position for the action of other muscles, primarily postural muscles.
3Interactions of Muscles Muscles can be classified into 4 functional groups!Prime Mover- A muscle that provides the major force for producing a specific movement.Antagonists- muscles that oppose, or reverse, a particular movement.
4Muscles Work!! Muscles never push they just pull!! Muscles are usually in pairs because whatever one muscles or muscle group can do, there is another muscle or group of muscles that “undoes” the action.
5Naming of the Skeletal Muscles! Skeletal muscles are named according to a number of criteria, each of which describes the muscle in some way.Paying attention to these cues can simplify the task of learning muscle names and actions.
6Naming of the Skeletal Muscles! 1. Location of the Muscle (temporalis)2. Shape of the Muscle (Deltoid)3. Relative size of the Muscle(Maximus, minimus)4. Direction of the Muscle Fibers(rectus –straight: oblique, transversemean to run at right angles.)
7Naming of the Skeletal Muscles! 5. Number of Origins(triceps and biceps)6. Location of the attachments(Sternocleidomastoid)7. Action (adductor longus)
9Orbicularis Oculi The WINKER A ringlike band of muscle, called a sphincter muscle, that surrounds the eye. It lies in the subcutaneous tissue of the eyelidCloses eye in blinkingIt also aids in the compressing the tear glands
10Orbicularis Oris The “Pucker Up” Muscle Sphincter muscle that surrounds the lips.Closes and puckers the lips.Often called the “kissing muscle”
11ZygomaticusExtends from the zygomatic arch downward to the corner of the mouthRaises corner of mouth when smiling and laughing
12Platysma The Frowner Thin sheet like superficial neck muscle. Plays a role in facial expression.Tenses skin of neck. (e.g. during shaving)
13EpicraniusThe epicranius covers the upper part of the cranium and consists of two muscular parts.Frontalis and Occipitalis
14FrontalisLies over the frontal boneWrinkles forehead
16Sternocleidomastoid Praying Muscle Long muscle in the side of the neck that extends upward from the thorax to the base of the skull behind the earPulls head to one side
17Masseter“The Chewer”A thick flattened muscle that can be felt just in front of the ear when the teeth are clenchedElevates mandibleCloses mouth
18Buccinator Blower or Whistler!! Thin, horizontal cheek muscles; Draws corner of mouth laterally, compresses cheek , well developed in nursing infants.
19Muscles that Move the Pectoral Girdle Chest/Back Muscles
20TrapeziusA large triangular muscle in the upper back that extends horizontally from the base of the skull and the cervical thoracic vertebrae to the shoulderRotates scapula.
21RhomboideusThe Rhomboids are very thin muscles which have tremendous responsibility.Connects the upper thoracic vertebrae to the scapula.Raises the scapula and adducts.
22Serratus AnteriorA broad curved muscle located on the side of the chestArises from narrow strips on the upper ribs and extends along the medial wall of the axilla to the ventral surface of the scapulaPulls scapula anteriorly and downwardUsed to thrust the shoulder forward when pushing something.
24Pectoralis Major A thick fan shaped muscle located in the upper chest. Extends from the center of the thorax through the armpit to the humerusAdducts and medially rotates humerus; draws scapula anteriorly and inferiorly.Pulls the arm forward and across the chest.
25Pectoralis MinorA thin, flat muscle that lies beneath the larger pectoralis majorStabilizes scapula by drawing it inferiorly and anteriorly against thoracic wall
26Teres Major Medially rotates and adducts arm. Stabilizes shoulder jointConnects the scapula to the humerus
27Teres Minor Small muscle connecting the scapula to the humerus. Rotates arm laterally
28InfraspinatusOccupies the depression below the spine of the scapula on its posterior surface.Attach the scapula to the humerus; helps to hold humeral head in glenoid cavity of scapula.Laterally rotate arm
29Latissimus DorsiIt is a wide, triangular muscle that curves upward from the lower back, around the sides, and to the armpit.Extends, adducts, and rotates arm, pulls shoulder down or back
30Deltoid Muscle Abducts, extends, and flexes the arm It is a thick, triangular muscle that covers the shoulder joint.
42Biceps femorisHas 2 heads, one attaches to the ischium and the other attached to the femur.Passes along the back of the thigh on the lateral side and connects to the proximal ends of the fiubla and tibia.Flexes and rotates leg laterally and extends thigh.1 of the hamstring muscles
43Semitendinosus (the 2nd muscle of the hamstring) Semitendinosus- long bandlike muscle on the back of the thigh.Connecting the ischium to the proximal end of the tibia.Flexes and rotates the leg medially and extends the thigh
44Semimembranosus (the 3rd muscle of the hamstring) Semimembranosus the most medially located muscle in the back of the thigh; it connects the ischium to the tibia.Flexes and rotates the leg medially and extends the thigh
45SartoriusAn elongated, straplike muscle that passes obliquely across the front of the thigh and then descends over the medial side of the knee.Connects the ilium to the tibia and flexes the leg and the thigh.Flexes leg and thighAbducts and rotates thigh laterally
46Quadriceps Femoris This is a large fleshy muscle group Occupies the front and sides of the thigh and is the primary extensor of the kneeIncludes….Rectus femoris, vastus lateralis, vastus medialis, and vastus intermedius (I am not holding you accountable for the last one)These parts connect the ilium and femur to a common patella tendon, which passes over the front of the knee and attaches to the patella.
51Gluteus MaximusThe largest muscle in the body and covers a large part of each buttockConnects the ilium, sacrum, and coccyx to the femur by fascia of the thigh and extends the thigh.Extends thigh at hip, helps to straighten the lower limb, also used to raise the body from a sitting position
52Gluteus Medius Partly covered by the gluteus maxium. Its fibers extend from the ilium to the femurAbducts and rotates thigh medially
53Adductor LongusA long triangular muscle that runs from the pubic bone to the femurAdducts, flexes, and rotates thigh laterally
54Adductor Magnus The largest adductor of the thigh. A triangular muscle that connects the ischium to the femur.Adducts, extends, and rotates thigh laterally.
55GracilisA long straplike muscle that passes from the pubic bone to the tibia.Adducts thighFlexes leg at knee
57Tibialis AnteriorAn elongated, spindle-shaped muscle located on the front of the legArises from the tibia, passes medially over the distal end of the tibia, and attaches to bones of the footDorsiflexion and inversion of foot
58Extensor Digitorum Longus This is situated along the lateral side of the leg just behind the tibialis anterior.Dorsiflexion and eversion of the footExtension of toes
59Gastrocnemius On the back of the leg forms part of the calf. Plantar flexion of foot and flexion of leg at knee
60SoleusA thick, flat muscle located beneath the gastrocnemius and together these two muscles form the calf of the legArises from the tibia and fibula and extends to the heelPlantar flexion of foot
61Fibularis LongusIt is a long, straplike muscle located on the lateral side of the leg.It connects the tibia and the fibula to the foot.Plantar flexion and eversion of footSupports arch