BIO 240 1st Edition Lecture 21 Outline of Last Lecture I. Intro to Skeletal Muscles of the Body A. Quick factsB. 4 Functional GroupsC. Muscle terminologyD. Skeletal muscles to know – Muscles of the headE. Head musclesOutline of Current Lecture I. Skeletal Muscle IdentificationCurrent LectureI. Introduction:> 600 Skeletal muscles in human bodyAge 30 starts to be replaced by fatA. 4 Functional Groups1. Prime Movers (agonists)- causes a specific movement of body2. Antagonists- opposes, reverses, or steadies a movement3. Synergists- assist prime movers by adding extra force & preventing unwanted movement4. Fixators- immobilizers of bone or muscle's origin (e.g. scapula - shoulder)B. Muscle Terminology1. Origin - point of attachment that stays “fixed” during contraction (anchor)These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.2. Insertion - moveable attachment of a muscle3. Actions - what muscle does (ex. flexion, extension, protractio, retraction, pronation, suppination, etc.)C. Skeletal Muscle to Know:Muscles Action 1. Frontalis/Epicranius raises eyebrows2. Occipitalis retracts scalp*galea aponeurotica – aponeurosis of scalp connecting frontalis to occipitalis3. Temporalis elevates/retracts jaw4. Orbicularis oculi closes eye5. Zygomaticus pulls lips superiorly/posteriorly (smile)6. Orbicularis oris puckers lips7. Masseter clenches jaw8. Mentalis pouts (lower lip)9. Buccinator compresses cheek (whistle, suck)10. Corrugator frownCorrugatorMentalisSplenius capitisMuscles Action 1. Platysema tenses skin of neck 2. Sternocleidomastoid flexes/laterally rotates head3. Splenius capitis prime mover of head(cervical vert to skull) up & side to side*antagonists to sternocleidomastoid Anterior Muscles Action chest:1. Pectoralis major push/throw/climb rib muscles: respiration2. Serratus protracts scapula(boxer’s muscle – throw punch, brings scapula forward) 3. Internal intercostals inhalation *forced exhalation 4. External intercostals inhalation 5. diaphragm inhalation abs: torso flexion6. Rectus abdominis sit ups/curls 7. Transverse abdominispresses abd contents 8. External obliques trunk rotation/lat flex9. Internal obliques trunk rotation/lat flexErector spinaeIn general:Ab muscles are FLEXORSBack muscles are EXTENSORS = antagonists!Posterior Muscles Actionback: torso extension1. Trapezius shrugging/slumping2. Latissimus dorsi prime arm extension3. Erector spinae prime back ext./lateral flexionshoulder:4. Supraspinatus slightly abducts humerus5. Infraspinatus stabilizes shoulder6. Teres major arm swing7. Rhomboid major retracts scapula (stand at attention)PECTORAL GIRDLE (shoulder): elevate / depression & retract / protract shoulders**Multiple muscles of head, neck, back, chest, and brachium either originate or insert in the clavicle/scapulaBRACHIUM: upper armMuscle Action1. Deltoid prime mover of arm abduction*adduction - NO specific muscle that adducts arm 1) gravity 2) pectoralis major 3) latissimus dorsi2. Biceps brachii flexor (primary mover)antagonistic3. Triceps brachii extensorANTEBRACHIUM: lower arm or “forearm”Muscle Action 1. brachioradialis (hum-rad) synergists to biceps2. anconeus (distal hum-superior ulna) synergist to triceps (over elbow joint)3. pronator teres (hum-rad, over elbow) pronation pronator quadratus (dist rad to dist ulna)4. suppinator (hum-rad) supinationAPPENDICULAR SKELETAL MUSCLESPELVIC GIRDLE: Coxal boneMuscle ACTION 1. Iliosoas flexion (picking knee up)2. Gluteus maximus extensor (standing up straight)FEMORAL REGION = “Thigh”*3 Compartments for thigh, separated by fascia (dense conn. tissue) – Posterior / Medial / Anterior compartmentsMuscle Action1. Tensor Fascia Lata abducts hip (leg out)*Iliotibial band = IT Band (DCT) *NOT in 1 of compartments (on lateral side of leg Medial Compartment = “groin” muscles2. Adductor magnus #2-#5 = adduction of hip3. Adductor longus 4. Adductor brevis **Antagonistic to Tensor Fascia Lata5. Pectineus ** GROIN PULLS6. Gracilis weak adductor of hip & weak knee flexor (crosses 2 joints – hip & knee)Posterior Compartment = “hamstrings”Muscle Action7. Hamstingsa. semimembranosus (coxal/tibia) all 3 are extensors of hip & flexors of kneeb. semitendinosusc. biceps femorisAnterior Compartment = “quadriceps” Muscle Action8. Quadriceps femoris crosses 2 joints (hip / knee)a. vastus lateralisb. vastus intermedius All are flexors of hip & extensors of kneec. vastus medialisd. rectus femorisSartorius9. Sartorius longest muscle in body - flexes/abducts laterally/rotatesthigh & flexes knee (cross legged position)CRURAL REGION = “lower leg”Muscle Action1. gastrocnemius (posterior “calf”) plantar flexion of foot*Achilles tendon –attaches gastrocnemius to calcaneus (heel bone)2. tibialis anterior dorsiflexion of footAntagonistic groups:hamstrings & quadsTFL & groin