BIOH111. o Cell Module o Tissue Module o Skeletal system o Integumentary system o Muscle system o Nervous system o Endocrine system

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1 BIOH111 o Cell Module o Tissue Module o Skeletal system o Integumentary system o Muscle system o Nervous system o Endocrine system

2 TEXTBOOK AND REQUIRED/RECOMMENDED READINGS o Principles of anatomy and physiology. Tortora et al; 14 th edition: Chapter 11

3 BIOH111 MUSCLE SYSTEM MODULE o Session 11 (Lectures 17 and 18) Muscle physiology: Building of muscle organ cells, tissue, organ and muscle contraction process and regulation o Session 12 (Lectures 19 and 20) - Skeletal muscle metabolism o Session 13 (Lectures 21 and 22) Major muscle groups

4 BIOH111 Lectures 21 and 22 Major muscle groups Department of Bioscience endeavour.edu.au

5 PREPARATION FOR THIS SESSION o Complete any missing concepts and linking words from Session 12 o Write down some muscle names you know (we will learn Latin names for these in the next session)

6 OBJECTIVES Lecture 21 and 22: Structure of muscular system Name major skeletal muscles Function of muscular system: how skeletal muscles produce movement Describe muscle attachment sites origin and insertion and relate to the level systems and leverage Describe the effects of fascicle arrangement and co-ordination within the muscle groups

7 MUSCULAR SYSTEM The voluntarily controlled muscles of the body make up the muscular system. Structure: principal skeletal muscles Function: production of movement; stabilization of body position; regulation of organ volume, movement of substances within the body and production of heat

8 COORDINATION WITHIN MUSCLE GROUPS o Most movement is the result of several muscle working at the same time o Most muscles are arranged in opposing pairs at joints prime mover or agonist contracts to cause the desired action while antagonist stretches and yields to prime mover; e.g. flexors-extensors synergists contract to stabilize nearby joints while prime movers contract fixators stabilize the origin of the prime mover; e.g. scapula held steady so deltoid can raise arm

9 NAMING OF SKELETAL MUSCLES o The names of most of the nearly 700 skeletal muscles are based on several types of characteristics: direction in which the muscle fibers run location size numbers of origins shape sites of origin and insertion of the muscle action o Examples: triceps brachii - 3 sites of origin quadratus femoris - square shape serratus anterior - saw-toothed edge

10 MUSCLE ATTACHMENT SITES: ORIGIN AND INSERTION o Skeletal muscles shorten & pull on the bones they are attached to o Origin: the bone that does not move when muscle shortens (normally proximal) o Insertion: the movable bone (some 2 joint muscles) o Belly: fleshy portion of the muscle between attachment sites

11 HEAD AND NECK MUSCLES o Muscles of facial expression and muscles of mastication: Origin: skull; insertion point: skin Encircle eyes, nose & mouth Express emotions Facial Nerve (VII) o Muscles that move mandible: Origin: skull; insertion point: mandible Cranial nerve V (trigeminal nerve) Protracts, elevates or retracts mandible o Muscles that move head: Origin: sternum & clavicle; insert point: mastoid process of skull Cranial nerve XI (spinal accessory) contraction of both flexes the cervical vertebrae & extends head contraction of one, laterally flexes the neck and rotates face in opposite direction

12 MUSCLES OF FACIAL EXPRESSION

13 MUSCLES THAT MOVE THE MANDIBLE

14 MUSCLES THAT MOVE THE HEAD

15 MUSCLES OF ABDOMINAL WALL o 4 pairs of sheet like muscles 1. rectus abdominus = vertically oriented 2. external & internal obliques and transverses abdominus wrap around body to form anterior body wall form rectus sheath and linea alba o Inguinal ligament from anterior superior iliac spine to upper surface of body of pubis o Inguinal canal = passageway from pelvis through body wall musculature opening seen as superficial inguinal ring

16 MUSCLES OF ABDOMINAL WALL

17 STABILIZING THE PECTORAL GIRDLE o Muscles important for breathing: Pectoralis minor Intercostals (internal and external)

18 STABILIZING THE PECTORAL GIRDLE o Posterior thoracic muscles: Latissimus dorsi Rhomboid major

19 MUSCLES THAT MOVE THE ARM Pectoralis major Latissimus dorsi Deltoid Rotator cuff muscles (supraspinatus, infraspinatus, teres minor and subscapularis)

20 FLEXORS OF THE FOREARM (ELBOW) o Cross anterior surface of elbow joint & form flexor muscle compartment o Biceps brachii o Brachialis o Brachioradialis (posterior view)

21 EXTENSORS OF THE FOREARM (ELBOW) o Cross posterior surface of elbow joint & forms extensor muscle compartment o Triceps brachii

22 MUSCLES/TENDONS USED FOR IDENTIFYING PULSE o Flexor carpi muscles/tendon radialis ulnaris o Flexor digitorum muscles/tendon profundus

23 For interest only/clinical application FLEXOR RETINACULUM o Tough connective tissue band that helps hold tendons in place o Extensor & Flexor retinaculum cross wrist region attaching from bone to bone (carpal tunnel syndrome = painful compression of median nerve due to narrowing passageway under flexor retinaculum

24 INTRINSIC MUSCLES OF THE HAND o Origins & insertions are within the hand o Help move the digits o Thenar muscles move the thumb o Hypothenar muscles move the little finger o Opposition, flexion, extension, abduction & adduction

25 Non-examinable MUSCLES THAT MOVE THE VERTEBRAE o o o Quite complex due to overlap Erector spinae fibers run longitudinally 3 groupings spinalis iliocostalis longissimus extend vertebral column Smaller, deeper muscles transversospinalis group semispinalis, multifidis & rotatores run from transverse process to dorsal spine of vertebrae above & help rotate vertebrae

26 MUSCLES CROSSING THE HIP JOINT o Iliopsoas flexes hip joint arises lumbar vertebrae & ilium inserts on lesser trochanter o Quadriceps femoris has 4 heads Rectus femoris crosses hip 3 heads arise from femur all act to extend the knee o Adductor muscles bring legs together cross hip joint medially see next picture o Pulled groin muscle result of quick sprint activity stretching or tearing of iliopsoas or adductor muscle

27 Non-examinable ADDUCTOR MUSCLES OF THE THIGH o Adductor group of muscle extends from pelvis to linea aspera on posterior surface of femur pectineus adductor longus adductor brevis gracilis adductor magnus (hip extensor)

28 MUSCLES OF THE HIP & THIGH o o o Gluteus muscles maximus, medius & minimus maximus extends hip medius & minimus abduct Deeper muscles laterally rotate femur Hamstring muscles semimembranosus (medial) semitendinosus (medial) biceps femoris (lateral) extend hip & flex knee Pulled hamstring tear of origin of muscles from ischial tuberosity

29 MUSCLES OF THE CALF (POSTERIOR LEG) o 3 muscles insert onto calcaneus gastrocnemius arises femur flexes knee and ankle plantaris & soleus arise from leg flexes ankle o Deeper mm arise from tibia or fibula cross ankle joint to insert into foot tibialis posterior flexor digitorum longus flexor hallucis longus flexing ankle joint & toes

30 Non-examinable MUSCLES OF THE LEG AND FOOT o o o Anterior compartment of leg extensors of ankle & toes tibialis anterior extensor digitorum longus extensor hallucis longus tendons pass under retinaculum Shinsplits syndrome pain or soreness on anterior tibia running on hard surfaces Lateral compartment of leg peroneus mm plantarflex the foot tendons pass posteriorly to axis of ankle joint and into plantar foot

31 Non-examinable MUSCLES OF THE PLANTAR FOOT o Intrinsic muscles arise & insert in foot o 4 layers of muscles get shorter as go into deeper layers o Flex, adduct & abduct toes o Digiti minimi muscles move little toe o Hallucis muscles move big toe o Plantar fasciitis (painful heel syndrome) chronic irritation of plantar aponeurosis at calcaneus improper shoes & weight gain

32 FUNCTION OF MUSCULAR SYSTEM Movement

33 FASCICLE (MUSCLE BUNDLE) ARRANGEMENTS Parallel Fusiform Pennate Circular Triangular Bipennate Multi-pennate o Contracting muscle shortens to about 70% of its length o Fascicular arrangement correlated with the power of the muscle and its range of motion and muscles with longer fibers have a greater extensibility a short fiber can contract as forcefully as a long one

34 RELATING MUSCLE ATTACHMENT SITES TO MOVEMENT Lever systems and leverage (mechanical advantage)

35 THREE TYPES OF LEVERS o First class levers (EFL): seesaw; e.g. the head on the vertebral column o Second-class (FLE): wheelbarrow; e.g standing on tiptoes o Third-class (FEL): forceps; e.g. the elbow joint

36 FIRST CLASS LEVER o Can produce mechanical advantage or not depending on location of effort & resistance if effort is further from fulcrum than resistance, then a strong resistance can be moved o Head resting on vertebral column weight of face is the resistance or load joint between skull & atlas is fulcrum posterior neck muscles provide effort

37 SECOND CLASS LEVER o Similar to a wheelbarrow o Always produce mechanical advantage Resistance or load is always closer to fulcrum than the effort o Sacrifice of speed for force o Raising up on your toes resistance is body weight fulcrum is ball of foot effort is contraction of calf muscles which pull heel up off of floor

38 THIRD CLASS LEVER o Most common levers in the body o Always produce a mechanical disadvantage effort is always closer to fulcrum than resistance o Favors speed and range of motion over force o Flexor muscles at the elbow resistance is weight in hand fulcrum is elbow joint effort is contraction of biceps brachii muscle

39 Recap of Session 13 Muscle groups in red boxes are examinable and needed for completing the content in subsequent subjects (e.g. BIOE221) Movement by muscles is accomplished using levers (first, second and third class)

40 PREPARATION FOR NEXT SESSION o NO MISSING CONCEPTS OR LINKING WORDS from Session 13 o Review: animal cell components plasma membrane tissue types o Think about cells as immature and specialised (mature) why is there a difference?