BIO 240 1st Edition Lecture 21 Outline of Last Lecture I Intro to Skeletal Muscles of the Body A Quick facts B 4 Functional Groups C Muscle terminology D Skeletal muscles to know Muscles of the head E Head muscles Outline of Current Lecture I Skeletal Muscle Identification Current Lecture I Introduction 600 Skeletal muscles in human body Age 30 starts to be replaced by fat A 4 Functional Groups 1 Prime Movers agonists causes a specific movement of body 2 Antagonists opposes reverses or steadies a movement 3 Synergists assist prime movers by adding extra force preventing unwanted movement 4 Fixators immobilizers of bone or muscle s origin e g scapula shoulder B Muscle Terminology 1 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 muscle 3 Actions what muscle does ex flexion extension protractio retraction pronation suppination etc C Skeletal Muscle to Know Muscles Action 1 Frontalis Epicranius raises eyebrows 2 Occipitalis retracts scalp galea aponeurotica aponeurosis of scalp connecting frontalis to occipitalis 3 Temporalis elevates retracts jaw 4 Orbicularis oculi closes eye 5 Zygomaticus pulls lips superiorly posteriorly smile 6 Orbicularis oris puckers lips 7 Masseter clenches jaw 8 Mentalis pouts lower lip 9 Buccinator compresses cheek whistle suck 10 Corrugator frown Corrugator Mentalis Splenius capitis Muscles Action 1 Platysema tenses skin of neck 2 Sternocleidomastoid flexes laterally rotates head 3 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 respiration 2 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 flexion 6 Rectus abdominis sit ups curls 7 Transverse abdominispresses abd contents 8 External obliques trunk rotation lat flex 9 Internal obliques trunk rotation lat flex In general Ab muscles are FLEXORS Back muscles are EXTENSORS antagonists Posterior Muscles Action back torso extension 1 Trapezius shrugging slumping 2 Latissimus dorsi prime arm extension 3 Erector spinae prime back ext lateral flexion Erector spinae shoulder 4 Supraspinatus 5 Infraspinatus slightly abducts humerus stabilizes shoulder 6 Teres major arm swing 7 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 scapula BRACHIUM upper arm Muscle Action 1 Deltoid prime mover of arm abduction adduction NO specific muscle that adducts arm 1 gravity 2 pectoralis major 3 latissimus dorsi 2 Biceps brachii flexor primary mover antagonistic 3 Triceps brachii extensor ANTEBRACHIUM lower arm or forearm Muscle Action 1 brachioradialis hum rad synergists to biceps 2 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 supination APPENDICULAR SKELETAL MUSCLES PELVIC GIRDLE Coxal bone Muscle 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 compartments Muscle Action 1 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 muscles 2 Adductor magnus 2 5 adduction of hip 3 Adductor longus 4 Adductor brevis 5 Pectineus 6 Gracilis Antagonistic to Tensor Fascia Lata GROIN PULLS weak adductor of hip weak knee flexor crosses 2 joints hip knee Posterior Compartment hamstrings Muscle Action 7 Hamstings a semimembranosus coxal tibia all 3 are extensors of hip flexors of knee b semitendinosus c biceps femoris Anterior Compartment quadriceps Muscle Action 8 Quadriceps femoris crosses 2 joints hip knee a vastus lateralis b vastus intermedius c vastus medialis d rectus femoris All are flexors of hip extensors of knee 9 Sartorius longest muscle in body flexes abducts laterally rotates thigh flexes knee cross legged position Sartorius Antagonistic groups hamstrings quads TFL groin muscles CRURAL REGION lower leg Muscle Action 1 gastrocnemius posterior calf plantar flexion of foot Achilles tendon attaches gastrocnemius to calcaneus heel bone 2 tibialis anterior dorsiflexion of foot