Gross Anatomy of the Muscular System Lab Week of February 18, 2008 Marieb & Mitchell: Exercise 15 Martini: Chapter 11

Organization of Skeletal Muscle Fibers fascicles fibers fibers of a single fascicle always parallel fascicles of a muscle can be arranged in various ways

Muscles are classified by how the fascicles are organized Parallel (e.g., biceps brachii muscle) most common arrangement Convergent (e.g.,pectoralis muscle) fascicles fan or triangle shaped, converge to attach

Muscles are classified by how the fascicles are organized Pennate (unipennate, bipennate and multipennate) fasicles form angle toward tendon Circular (e.g.,orbicularis oris) sphincter, contracts to reduce diameter of opening

Origins and Insertions The ends of skeletal muscles are always attached to other structures fixed end is called ORIGIN usually attached to bone or cartilage movable end is called INSERTION usually proximal to insertion

How are muscles named? location in the body Origin and Insertion e.g., temporalis muscle Origin and Insertion first part = origin, 2nd part = insertion Fascicle Organization e.g., Rectus means “straight” e.g., transverse means “across” e.g., oblique means “oblique angle”

How are muscles named? Relative Position e.g., superficialis, internus, lateralis, etc… Structural Characteristics (shape and size) e.g., deltoid, rhomboid, major, longus, etc… Action e.g., abductor, extensor, rotator, etc…

Muscular Actions Agonists (prime mover) Antagonist Synergists Fixators responsible for a particular movement Antagonist against movement of agonist Synergists aid agonists, stabilize an action Fixators specialized synergists immobilize the origin of agonist so all tension is exerted at the insertion point

Muscles of the Head and Neck Epicranius frontalis action: raises eyebrows, wrinkles forehead

Muscles of the Head and Neck Epicranius occipitalis action: tenses and pulls scalp posteriorly

Muscles of the Head and Neck Orbicularis Oculi action: closes eye, squinting

Muscles of the Head and Neck Orbicularis oris action: constricts mouth (whistle, kissing)

Muscles of the Head and Neck Zygomaticus action: the elevates corners of mouth and upper lip smiling muscle antagonist to depressor anguli oris

Muscles of the Head and Neck Levator Labii Superioris action: raises upper lip, opens lips

Muscles of the Head and Neck Depressor Labii Inferioris action: depresses lower lip

Muscles of the Head and Neck Depressor Anguli Oris action: draws corners of mouth down frowning muslce antagonist to zygomaticus

Muscles of the Head and Neck Depressor Anguli Oris action: draws corners of mouth down frowning muslce antagonist to zygomaticus

Muscles of the Head and Neck Masseter origin: zygomatic arch insertion: mandibular ramus action: elevates mandible closes jaw

Muscles of the Head and Neck Temporalis action: elevates mandible closes jaw

Muscles of the Head and Neck Sternocleidomastoid origin: clavicle or manubrium insertion: mastoid process action: together: flex neck 1 side: bends head towards shoulder and turns face to opposite side

Muscles of the Head and Neck Scalenes origin: cervical vertebrae insertion: Ribs 1-2 action: elevates ribs, flexes neck

Muscles of the Head and Neck Splenius Capitis action: extend and hyperextend head

Muscles of the Trunk and Back Erector Spinae iliocostalis spinalis longissimus together: extends vertebral column along: lateral flexion

Muscles of the Trunk and Back External Intercostals origin: rib above insertion: rib below action: elevates ribs inspiration

Muscles of the Trunk and Back Internal Intercostals origin: rib below insertion: rib above action: depresses ribs breath out

Muscles of the Trunk and Back Diaphragm origin: xiphoid process, cartilage of ribs 4-10, lumbar vertebrae action: expands thoracic cavity, compresses abdominopelvic cavity

Muscles of the Trunk and Back Transverse Abdominus insertion: linea alba action: compresses abdominopelvic cavity

Muscles of the Trunk and Back Internal Oblique insertion: linea alba action: compresses abdomen, depresses ribs, flexes or bends spine

Muscles of the Trunk and Back External Oblique insertion: linea alba action: compresses abdomen, depresses ribs, flexes or bends spine

Muscles of the Trunk and Back Rectus Abdominus origin: pubic symphesis insertion: xyphoid process action: depresses ribs, compresses abdomen, flexes vertebral column

Muscles of the Trunk and Back Trapezius origin: midline of neck and back insertion: clavicles and scapular spines action: elevation, depression, rotation, adduction of scapula, extension of head

Muscles of the Trunk and Back Rhomboid Major origin: T2-T5 spinous processes insertion: vertebral border of scapula action: adduction of scapula

Muscles of the Trunk and Back Rhomboid Minor origin: C7 and T1 spinous process insertion: vertebral border of scapula action: adduction of scapula

Muscles of the Trunk and Back Levator Scapulae origin: C1-4 transverse process insertion: vertebral border of scapula action: elevates scapula

Muscles of the Trunk and Back Pectoralis Minor origin: anterior surface of ribs 3-5 insertion: coracoid process of scapula action: depresses and contracts scapular end of clavicle (in complement with subclavius muscle)

Muscles of the Trunk and Back Serratus Anterior origin: ribs insertion: scapula action: abducts scapula, swings shoulder anteriorly

Gross Anatomy of the Muscular System Lab Week of February 25, 2008 Marieb & Mitchell: Exercise 15 Martini: Chapter 11 MUSCLES OF THE UPPER EXTREMITIES

Pectoralis Major Origin Insertion Action Cartilages of ribs 2-6, body of sternum, inferior medial clavicle Insertion Humerus (greater tubercle and lip of intertubercular groove) Action Flex, adduct, medially rotate shoulder joint

Latissimus Dorsi Origin Insertion Action T6-12, lumbar, sacrum, ileum Humerus (floor of intertubercular groove) Action Adduction, extension, medial rotation at the shoulder joint

Coracobrachialis Origin Insertion Action Coracoid process of scapula Humerus (shaft) Action Adduct, flex at shoulder joint

Supraspinatus Origin Insertion Action Rotator cuff group Supraspinous fossa of scapula Insertion Humerus (greater tubercle) Action Abduction at shoulder joint, stabilizes joint Rotator cuff group

Infraspinatus Origin Insertion Action Rotator cuff group Infraspinous fossa of scapula Insertion Humerus (greater tubercle) Action Lateral rotation at shoulder joint Rotator cuff group

Teres Minor Origin Insertion Action Rotator cuff group Lateral border of scapula Insertion Humerus (greater tubercle) Action Lateral rotation at shoulder joint, stabilizes Rotator cuff group

Subscapularis Origin Insertion Action Rotator Cuff Group Subscapular fossa of scapula Insertion Humerus (lesser tubercle) Action Medial rotation at shoulder joint Rotator Cuff Group

Teres Major Origin Insertion Action Inferior angle of scapula Humerus (lip of intertubercular groove) Action Extension, adduction, medial rotation at shoulder joint

Deltoid Origin Insertion Action Clavicle, scapula (spine and acromion) Deltoid tuberosity of humerus Action Altogether  Abduction at shoulder joint Anterior  flexion, medial rotation at shoulder Posterior  extension, lateral rotation at shoulder

Biceps Brachii Origins Insertion Action Long head Short head Supraglenoid tubercle of scapula Short head Coracoid process of scapula Insertion Tuberosity of radius Action Flex at elbow AND shoulder joint, supination

Brachialis Origin Insertion Action Humerus Ulna Flexes forearm (elbow joint)

Triceps Brachii Origin Insertion Action Long: Infraglenoid tubercle of scapula Lateral: humerus Medial: humerus Insertion Olecranon of Ulna (for all 3) Action Long: extension elbow joint, extension and adduction at shoulder joint Lateral and Medial: extension at elbow joint

Brachioradialis Origin Insertion Action Distal humerus radius Flexion at elbow joint

Pronator Teres Action Pronation (forearm)

Flexor Carpi Ulnaris Action Flex, adduct wrist

Flexor Carpi Radialis Action Flex, abduct wrist

Flexor Digitorum Superficialis Action Flexion at proximal interphalangeal Flexion at metacarpophalangeal Flexion at wrist

Extensor Carpi Radialis Longus Action Extend, abduct wrist

Extensor Carpi Radialis Brevis Action Extend, abduct wrist

Extensor Carpi Ulnaris Action Extend, adduct wrist

Extensor Digitorum Action Extension at finger joints and wrist joints

Adam Packet 1: muscles of the head, neck, chest and back Using the Adam software, identify the muscles in the packet (pgs 8-16). Answer questions 1-15 on a SEPARATE piece of notebook paper and turn it in by NEXT LAB PERIOD. NOTE: You will find the answers in Exercise 15 of Marieb and Chapter 11 of Martini.