Lecture 14: The Muscular System I PDF

LECTURE FOURTEEN THE MUSCULAR SYSTEM – I © Dr. Nicole M. Ventura, PhD. © All slides are property of Dr Ventura. Instructor Assistant Professor, Teaching Stream generated course materials are protected by law and...

LECTURE FOURTEEN THE MUSCULAR SYSTEM – I © Dr. Nicole M. Ventura, PhD. © All slides are property of Dr Ventura. Instructor Assistant Professor, Teaching Stream generated course materials are protected by law and may not be copied or distributed in any form or in any School of Kinesiology & Health Sciences medium without explicit permission of Dr Ventura and/or 3rd party (published texts) where applicable. Faculty of Health, York University LEARNING OBJECTIVES Review details of the muscular system. Define range of motion and discuss the various forms range of motion can be assessed on a patient. Define extrinsic and intrinsic muscles of the back Distinguish between the muscular layers of the back. Identify and describe the origin(s), insertion(s), and action(s)/function(s) of the muscles of the back, neck, shoulder and arm. INTRODUCTION TO MUSCLES Muscles utilize chemical energy (ATP) and convert this into mechanical energy (and heat!) Anatomical terms that begin with “myo” or “mys” = muscle Muscle fiber = myofiber = muscle cell (skeletal or smooth) – they are called “fibers” because they are elongated Cardiac muscle cells are not “elongated” and are also interconnected - thus we typically refer to them as cardiac muscle cells and not fibers! OUR FOCUS FOR THIS UNIT OF KINE 1101 à SKELETAL MUSCLE Skeletal muscle … is consciously controlled (somatic nervous system). is rich with blood supply. contains a nerve ending associated with each muscle fiber (motor unit) – tells muscles to contract!  RANGE OF MOTION (ROM) The measurement of the amount of movement around a specific joint or body part. Active Range of Motion = movement occurring around a joint or body part in which the muscles are activated, independent movement Passive Range of Motion = movement occurring around a joint or body part in which the muscles are not activated, instead the body is manually moved by someone else (health care practitioner) Active-Assisted Range of Motion = movement occurring around a joint or body part in which the muscles are activated, but the movement is still assisted by someone else https://i.pinimg.com/736x/a8/c0/c7/a8c0c776410a95f8d1566cd3cac118f4.jpg  EXTRINSIC vs. INTRINSIC MUSCLES OF THE BACK Intrinsic Muscles of the Back Extrinsic Muscles of the Back Superficial muscles Muscles with attachment sites on the Primary function is vertebrae or ribs movement of upper limb Primary function is movement and support of vertebral column Innervation: Posterior rami of spinal nerves Gilroy, Anatomy: An Essential Textbook, Copyright © 2013 by Thieme INTRINSIC MUSCLES OF THE BACK ERECTOR SPINAE 3 vertical columns of muscle I L Iliocostalis, Longissimus, Spinalis Iliocostalis S Longissimus “I Like Standing” muscles Spinalis FUNCTION: Bilateral: extension of the spine Unilateral: lateral flexion of spine (iliocostalis) MUSCLES OF THE NECK CAPITIS SPLENIUS CAPITIS and CERVICIS CERVICIS Spinous Capitis: insertion onto the skull (mastoid Processes process) Cervicis: insertion onto TPs of cervical upper cervical vertebrae MASTOID FUNCTION: Bilateral: extension of the spine Unilateral: ipsilateral lateral flexion and rotation of the head and cervical spine  MUSCLES OF THE NECK STERNOCLEIDOMASTOID Origins: Sternum & Clavicle Insertion: Mastoid Process Sagittal View FUNCTIONS: Bilateral: extension of the head/neck; flexion of the neck (inferior cervical vertebrae - sternal head) Unilateral: contralateral rotation, ipsilateral lateral flexion Gilroy, Anatomy: An Essential Texbook, Copyright © 2013 by Thieme  DEEP MUSCLES OF THE NECK: ANTERIOR ACCESSORY MUSCLES OF RESPIRATION FLEXORS of the HEAD LONGUS CAPITIS & NECK Flexion of the head (attachment points between cervical spine and the skull) LONGUS COLLI ANTERIOR SCALENE Flexion of the cervical Insertion on rib 1 spine (neck) MIDDLE SCALENE (attachment along the Insertion on rib 1 cervical spine anteriorly) POSTERIOR SCALENE Insertion rib 2 Gilroy, Anatomy: An Essential Texbook, Copyright © 2013 by Thieme  EXTRINSIC MUSCLES: FIRST LAYER (Superficial) TRAPEZIUS Origin: posterior skull and cervical and thoracic vertebrae Insertion: clavicle, acromion and spine of the scapula. FUNCTION(s): fiber group dependent (1) Elevation of scapula – upper fibers (2) Retraction of the scapula – middle fibers (3) Upward rotation of the scapula during abduction of the arm, depression of scapula – lower fibers Superior View Lateral Gilroy, Anatomy: An Essential Textbook, Copyright © 2013 by Thieme Martini, Timmons & Tallitsch: Human Anatomy, Eighth Edition. Copyright © 2013 by Pearson Education Inc.  EXTRINSIC MUSCLES: FIRST LAYER (Superficial) LATISSIMUS DORSI Origin: lower thoracic and lumbar vertebrae, the sacrum & iliac crest Insertion: floor of the intertubercular groove of humerus. FUNCTION(s): Extension, adduction and medial (internal) rotation of the arm at the glenohumeral joint Intertubercular Groove of the Humerus Lateral Medial L Gilroy, Anatomy: An Essential Textbook, Copyright © 2013 by Thieme  EXTRINSIC MUSCLES: SECOND LAYER (Superficial) LEVATOR SCAPULAE Origin: cervical spine Posterior Shoulder Insertion: superomedial border of the scapula. Levator Scapula FUNCTION(s): M Elevation of the scapula in or M ajo RHOMBOID MAJOR & MINOR r Origin: cervical and thoracic spine Insertion: medial border of the scapula. FUNCTION(s): Retraction (adduction) of scapula Moore: Clinically Oriented Anatomy, 7th Edition. Copyright © 2014 by Lippincott Williams & Wilkins All contribute to downward rotation of the scapula! Gilroy, Anatomy: An Essential Textbook, Copyright © 2013 by Thieme EXTRINSIC MUSCLES: THIRD LAYER (Superficial) ACCESSORY MUSCLES OF RESPIRATION * SP = spinous process SERRATUS POSTERIOR SUPERIOR Origin: SPs of lower cervical to upper thoracic spine Insertion: first 4 ribs Function: Elevation of the ribs SERRATUS POSTERIOR INFERIOR Origin: SPs of lower thoracic vertebrae Insertion: ribs 9-12 Function: Depression of lower ribs  MUSCLES OF THE SHOULDER: ANTERIOR PECTORALIS MAJOR Origin: Clavicular and sternal heads Insertion: Lateral lip of the intertubercular groove. FUNCTION(S): Glenohumeral flexion, medial (internal) rotation and adduction of the arm Intertubercular Groove of the Humerus P Lateral Medial Medial (internal) rotation Lateral Medial Gilroy, Anatomy: An Essential Textbook, Copyright © 2013 by Thieme  MUSCLES OF THE SHOULDER: ANTERIOR Clavicle Coracoid Process SUBCLAVIUS Origin: first rib (costal cartilage) Insertion: clavicle (inferior surface). FUNCTION(s): Depression of the clavicle PECTORALIS MINOR Origin: ribs 3-5 Insertion: coracoid process of the scapula. FUNCTION(s): Depression of the scapula Gilroy, Anatomy: An Essential Textbook, Copyright © 2013 by Thieme  MUSCLES OF THE SHOULDER: LATERAL SERRATUS ANTERIOR Origin: lateral borders of the ribs Insertion: anteromedial border of the scapula FUNCTION(s): Protraction of the Scapula Insertion Anterior View Summary Video Of Anterior and Lateral Shoulder Muscles: Sagittal View https://www.youtube.com/watch?v=NCZJNZCyqAw Gilroy, Anatomy: An Essential Textbook, Copyright © 2013 by Thieme  MUSCLES OF THE SHOULDER: LATERAL Posterior Anterior Fibers DELTOID Fibers Origin: clavicle, acromion and spine of the scapula Insertion: deltoid tuberosity on the humerus. Middle Fibers FUNCTION(s): fiber group dependent (1) Glenohumeral flexion (anterior fibers) (2) Glenohumeral abduction (middle fibers) Delta (3) Glenohumeral extension and lateral (external) rotation (posterior fibers) Superior View Lateral Sagittal View Martini, Timmons & Tallitsch: Human Anatomy, Eighth Edition. Copyright © 2013 by Pearson Education Inc. Gilroy, Anatomy: An Essential Textbook, Copyright © 2013 by Thieme  MUSCLES OF THE ROTATOR CUFF Anterior View SUBSCAPULARIS Origin: subscapular fossa Insertion: lesser tubercle of the humerus. FUNCTION(S): Medial (internal) rotation of the glenohumeral joint Common function: S Create a cuff around I S the glenohumeral joint to stabilize the t joint Medial (internal) rotation Sagittal View Gilroy, Anatomy: An Essential Textbook, Copyright © 2013 by Thieme  MUSCLES OF THE ROTATOR CUFF SUPRASPINATUS Origin: supraspinous fossa Insertion: greater tubercle of the humerus FUNCTION(s): Initiation of arm abduction at the glenohumeral joint (~30 degrees). Sagittal View Acromion Posterior View S I S t Acromion Superior View Subacromial posterior anterior Subdeltoid Bursa Bursa Gilroy, Anatomy: An Essential Textbook, Copyright © 2013 by Thieme  Posterior View MUSCLES OF THE ROTATOR CUFF S INFRASPINATUS I Origin: infraspinous fossa Insertion: greater tubercle of the humerus t FUNCTION(s): Lateral (external) rotation of the arm at the Lateral glenohumeral joint (external) rotation TERES MINOR S Origin: lateral scapular border (superior) I S Insertion: greater tubercle of the humerus I t t FUNCTION(s): Lateral (external) rotation of the arm at the glenohumeral joint Sagittal View Gilroy, Anatomy: An Essential Textbook, Copyright © 2013 by Thieme  SUMMARY: THE ROTATOR CUFF Subscapularis on Lesser Tubercle Known as the “S I t S” muscles S.I.T. Insertion on Greater Tubercle Supraspinatus Infraspinatus teres minor (small “t” because minor, not major) S Subscapularis (only muscle located on the anterior scapula) I S t Common function: Create a cuff around the glenohumeral joint to stabilize the joint Summary Video of the Rotator Cuff Muscles https://www.youtube.com/watch?v=qj87kCy5HOk Sagittal View Gilroy, Anatomy: An Essential Textbook, Copyright © 2013 by Thieme  MUSCLES OF THE SHOULDER: POSTERIOR TERES MAJOR Origin: lateral scapular border (inferior) Insertion: medial lip of the intertubercular groove on the humerus. FUNCTION(s): IN O R M Extension, adduction and medial (internal) rotation of the arm at the glenohumeral joint Intertubercular Groove of the Humerus Teres Major Teres PLT Minor Lateral P L T Medial ** A MISS between two MAJORS ** P = Pectoralis major L = Latissimus Dorsi T = Teres major Gilroy, Anatomy: An Essential Textbook, Copyright © 2013 by Thieme MUSCULAR COMPARTMENTS OF THE ARM ANTERIOR POSTERIOR COMPARTMENT OF COMPARTMENT OF THE THE ARM ARM Flexor Compartment Extensor Compartment “flexion of the forearm at “extension of the the elbow” forearm at the elbow” Biceps Brachii Triceps Brachii (long and short heads) (medial, lateral and long heads) Coracobrachialis, Brachialis  THE ARM: ANTERIOR COMPARTMENT Term Break-down → BI = two, CEPS = heads BICEPS BRACHII Long Head Origins: Long Head - supraglenoid tubercle of scapula Short Head – coracoid process Short Head Insertion: Radial tuberosity FUNCTION: PRIMARY = Supination of forearm Flexion of the elbow joint, accessory flexor of GH joint, Bicipital Anterior View Aponeurosis Gilroy, Anatomy: An Essential Texbook, Copyright © 2013 by Thieme  Supination vs. Pronation Supination Pronation Axis of Rotation Radial Tuberosity In the pronated position, the tendon of the biceps brachii muscle is turned posteriorly - thus impeding on the function of the biceps brachii Radius muscle at the Radius elbow Ulna Lateral Lateral Medial Medial Moore: Clinically Oriented Anatomy, 7th Edition. Gilroy, Anatomy: An Essential Texbook, Copyright © 2013 by Thieme Copyright © 2014 by Lippincott Williams & Wilkins  THE ARM: ANTERIOR COMPARTMENT CORACOBRACHIALIS Origin: coracoid process Insertion: anterior humerus (shaft). FUNCTION(s): Flexion of the arm (at the glenohumeral joint) Anterior View BRACHIALIS Origin: anterior shaft of the humerus Insertion: ulnar tuberosity FUNCTION(s): Flexion of the forearm (at the elbow joint) Radius Ulna Gilroy, Anatomy: An Essential Texbook, Copyright © 2013 by Thieme  EXCEPTION TO ARM COMPARTMENTS BRACHIORADIALIS Stretches across the elbow joint – from the lateral supracondylar ridge of the humerus to the styloid process of the radius FUNCTION(s): Flexion of forearm at the elbow Tested In Neutral Position: Sagittal View Posterior View Gilroy, Anatomy: An Essential Texbook, Copyright © 2013 by Thieme  THE ARM: POSTERIOR COMPARTMENT TRICEPS BRACHII Origins: Long head = infraglenoid tubercle of the Long scapula head Lateral & Medial Heads = (cut) posterior shaft of humerus MEDIAL HEAD Insertion: Olecranon of the Ulna LONG HEAD FUNCTION(s): LATERAL HEAD Extension of the MEDIAL HEAD LATERAL HEAD elbow joint Olecranon Superficial View Deep View Gilroy, Anatomy: An Essential Texbook, Copyright © 2013 by Thieme