Muscular System PDF

MUSCULAR SYSTEM MLLIPA FUNCTIONS OF THE MUSCULAR SYSTEM  TYPES OF MUSCLES Based on how they work Skeletal/Striped or Voluntary Muscles Smooth or Involuntary Muscles Cardiac muscles  SKELETAL MUSCLES 40-50% of an adult male body wt 30-40% of a female a...

MUSCULAR SYSTEM MLLIPA FUNCTIONS OF THE MUSCULAR SYSTEM  TYPES OF MUSCLES Based on how they work Skeletal/Striped or Voluntary Muscles Smooth or Involuntary Muscles Cardiac muscles  SKELETAL MUSCLES 40-50% of an adult male body wt 30-40% of a female adulty body wt striated: alternating dark & light bands voluntary fibers are long & cylindrical with many nuclei attached to skeleton by _____________  SMOOTH MUSCLE NOT STRIATED INVOLUNTARY FOUND IN THE CIRCULATORY, DIGESTIVE, RESPIRATORY & UROGENITAL SYSTEM FIBERS ARE THIN & SPINDLE SHAPED SINGLE NUCLEI CONTRACTS SLOWLY  CARDIAC MUSCLE STRIATED INVOLUNTARY FOUND ONLY IN THE HEART CELLS ARE BRANCHED & APPEAR FUSED WITH ONE ANOTHER TYPES OF CONTRACTION  SKELETAL MUSCLE ACTIONS  origin – immovable end  insertion – movable end  prime mover (agonist) – primarily responsible for movement  synergists – muscle that aids a prime mover in a movement and helps prevent rotation  antagonist – resist prime mover’s action and cause movement in the opposite direction Fixator – stabilizes the origin of a prime mover 9-30 How are muscles attach to skeleton? EFFECTS OF PHYSICAL ACTIVITY TO MUSCLE muscle fiber becomes larger and stronger. muscular atrophy- Muscle hypertrophy-muscle increases in size regular exercise increases muscle size, strength and endurance. exercise result in stronger, more flexible, muscles with greater resistance to fatigue. aerobic exercise makes the over all body:  metabolism more efficient  improved digestion and elimination  enhanced neuromuscular coordination  makes the skeletal system stronger  the heart enlarges  fat deposits are cleared  lung becomes more efficient response to exercise, a muscle increases in size, or hypertrophies and increases in strength and endurance. Conversely, a muscle that is not used decreases in size, or atrophies. Because muscle fiber numbers do not change appreciably during most of a person’s life, atrophy and hypertrophy result from changes in the size of individual muscle fibers. New nuclei are added to muscle fibers because small satellite cells near skeletal muscle fibers increase in number in response to exercise and then fuse with the skeletal muscle fibers. Other elements, such as blood vessels, connective tissue, and mitochondria, also increase in number. Atrophy due to lack of exercise results from a decrease in all these elements without a decrease in muscle fiber number. However, severe atrophy, as occurs in elderly people who cannot readily move their limbs, does EFFECTS OF AGING IN MUSCLE weak muscles, smaller and dehydrated. fibrous tissue appears; muscles infiltrated with fat. muscle reflex slows. nocturnal cramps- deficiency of sodium, improper blood flow. elderly tend to move about than they should and this would result to the following: 1) cramps, loss of muscle tone, and osteoporosis 2) blood clotting 3) diarrhea, constipation, and general indigestion (decrease peristalsis). 4) accumulation of secretion within the lungs and the rest of the respiratory tract. 5) kidney stones; infections- urinary tract, bedsores there are more than 600 muscles in the body. size: 1) vastus (huge); vastus lateralis 2) maximus (large); gluteus maximus 3) longus (long); palmaris longus 4) minismus (small); gluteus minismus 5) brevis (short); peroneus brevis shape: 1) deltoid (triangular); deltoid muscle 2) rhomboid (like a rhombus with equal and parallel sides); rhomboideus major 3) latissimus (wide); latissimus dorsi 4) teres (round); teres major 5) trapezius (like a trapezoid, a four-sided figure with two sides parallel).  Direction of fibers: Location: 1) Rectus (straight) 1) Pectoralis (chest); RECTUS ABDOMINIS PECTALIS MAJOR 2) Transverse (across) 2) Gluteus (buttock or TRANSVERSE rump); ABDOMINIS GLUTEUS MAXIMUS 3) Oblique (diagonally) 3) Brachii (arm); APONEUROSIS OF BICEPS BRACHII EXTERNAL 4) Supra- (above); OBLIQUE SUPRA SPINATUS 4) Orbicularis (circular) 5) Infra- (below); ORBICULARIS OCULI INFRA SPINATUS 6) Sub- (under or beneath); SUBSCAPULARIS 7) Lateralis (lateral); Number of origins: Origin and insertion: 1) biceps (two heads); 1)Sternocleidomastoideus biceps brachii (origin on the sternum and 2) triceps (three heads); clavicle insertion on the mastoid process) triceps brachii 2) Brachioradialis 3) quadriceps (four heads) (origin on the brachium or arm, insertion on the radius). ACTION 1) Abductor 4) Extensor (to abduct a structure) (to extend a 2) Adductor structure) (to adduct a structure) 5) Levator 3) Flexor (to lift or elevate a  SKELETAL MUSCLE FIBER sarcolemma sacroplasm sarcoplasmic reticulum transverse tubule triad cisterna of sarcoplasmic reticulum transverse tubule myofibril actin filaments myosin filaments sarcomere STRUCTURE OF A SKELETAL MUSCLE  MYOFILAMENTS Thick Filaments Thin Filaments composed of myosin composed of actin cross-bridges associated with troponin and tropomyosin THICK FILAMENT  THIN FILAMENTS ARE MADE OF  ACTIN - 2 PROTEIN CHAINS ENTWINED HELICALLY; EACH MOLECULE HAS A MYOSIN BINDING SITE THAT INTERACTS WITH THE MYOSIN CROSS- BRIDGE  TROPOMYOSIN - 2 STRANDS LOOSELY ATTACHED TO ACTIN THAT COVER THE MYOSIN BINDING SITES IN A RELAXED MUSCLE  TROPONIN - AT INTERVALS ON THE TROPOMYOSIN; CALCIUM IONS WILL BIND WITH IT  MUSCLE ORIGIN FUNCTION Raises eyebrows, Epicranius: Frontalis Epicranial aponeurosis to wrinkles skin of & Occipitalis eyebrows forehead  Portions of the frontal Orbicularis Blinks and and maxilla to the Skin oculi closes eyes around eyes  Closes and Orbicularis oris Skin around mouth protrudes lips Flattens cheek Mandible/maxilla to skin around against teeth, Buccinator mouth pulls corners of mouth laterally Raises corner of Zygomaticus Zygomatic bone to corner of lips mouth  Draws Fascia of chest to lower Platysma mouth border of mandible downward  Temporal bone to Masseter Closes jaw mandible Temporal bone to Temporalis Closes jaw mandible Sternocleidom Sternum/clavicle to temporal Flexes neck, rotates head, raises astoid bone the sternum Splenius Cervical/Thoracic vertebrae to Rotate head, move to one side, capitis Mastoid process holds head upright Semispinalis Cervical/Thoracic vertebrae to Extends head, rotate head, move to capitis Occipital bone one side  TRUNK MUSCLES Sternum/clavicle/ first to Adducts and flexes humerus; Pectoralis sixth ribs to pulls arm across chest, medial major proximal/anterior humerus rotation of arm pulls scapula down and forward; Pectoralis Sternal edge of upper ribs to raises ribs when shoulder held minor the corocoid of scapula still  TRUNK MUSCLES Rectus Pubis to abdominis sternum/xiphoid/fifth to Flexes vertebral column seven ribs External Last eight ribs to iliac oblique crest Flexes vertebral column  Occipital bone/ Thoracic Vertebrae (Spinous Process) to Raises arm, raise, lower, Trapezius Scapular Spine, Acromion and rotate and pull Clavicle scapula medially Thoracic vertebrae (Spinous Rhomboideus Process) to Medial border of Raises and adducts Scapula scapula Extends, adducts, medial Lower spine(sacral, lumbar and rotation of humerus, CLES Latissimus dor thoracic vertebrae), Iliac Crest pulls shoulder down si to proximal, anterior humerus and back Biceps brachii Scapula (Coracoid) to radial tuberosity Flexes elbow and supinates hand Triceps brachii Scapula (lateral edge)/ proximal, posterior humerus to ulna (olecranon) Extends elbow Pronator teres Medial epicondyle of humerus to distal/lateral Rotates arm medially; radius Pronation Pronator Medial/distal ulna to Rotates arm medially; Quadratus anterior/lateral/distal radius Pronation Supinator Lateral epicondyle of humerus to distal Rotates forearm radius laterally; Supination  Scapula (inf. angle) to prox/anterior humerus Extends humerus, adducts Teres major head and rotates arm medially Scapula (lower/medial border) to humerus Teres minor head (greater tubercle) Rotates arm laterally  Scapular spine/clavicle to Abducts humerus, Deltoid proximal humerus (deltoid rotates humerus tuberosity) laterally and medially Scapula (superior Spine) to Supraspinatus humerus head (greater tubercle) Abducts upper arm  Scapula (inferior Spine) to Infraspinatus humerus head (greater Rotates arm laterally tubercle) Cervical vertebrae (Transvere Levator scapulae process) to superior/medial Elevates the scapula scapula Brachialis anterior/distal Humerus to ulna flex the Elbow Subscapularis Anterior scapula to Lesser Medial rotation of Tubercle of Humerus Humerus  Flexor carpi Distal humerus (medial epicondyle) to Flexes wrist and abducts radialis second and third metacarpals hand Distal humerus (medial epicondyle)/ulna to Flexes wrist and adducts Flexor carpi ulnaris carpals of wrist hand  Distal humerus (medial epicondyle)/ulna Flexes wrists and Flexor digitorum to middle phalanges of second to fifth fingers fingers Palmaris longus Medial epicondyle of humerus to fascia of Flexes wrist palm Extensor carpi distal Humerus (lateral epicondyle) to dorsal Extends wrists and ulnaris surface of fifth metacarpals abducts hand Extensor carpi distal Humerus (lateral epicondyle) to dorsal Extends wrists and radialis surface of second and third metacarpals abducts hand Extensor Distal humerus (lateral epicondyle) to Extends digitorum dorsum of second to fifth fingers fingers/wrist CROSS SECTION OF THE ARM CROSS SECTION OF THE FOREARM Quadriceps: Vasti: Femur to tibial Rectus femoris tuberosity through patellar Vastus lateralis tendon All extend knee; rectus femoris also Rectus femoris: Anterior Vastus medialis Ilium near acetabulum to flexes hip on thigh Vastus tibial tuberosity through intermedius patellar tendon  Distal femur (condyles) to Gastrocnemius calcaneus (heel) through Plantarflexes ankle and flexes knee Achilles tendon Peroneus(longu Fibula (lateral head) to Plantarflexes and everts foot s & brevis) metatarsals of foot (base)  Extensor /Anterior tibia to dorsal second Dorsal flexion of foot and extension of toes digitorum longus and the Lateral third phlanges Flexor digitorum Posterior tibia to dorsal phlanges Plantar flexion of foot and flexion of toes longus  Head of fibula, posterior tibia to Soleus calcaneous Plantar flexion of foot Sacrum/iliac crest to proximal Gluteus maximus femur (Greater Trochanter) Extends hip; Lateral rotation  Iliac crest to proximal femur Gluteus medius (Greater Trochanter) Abducts thigh Iliac crest to proximal femur Gluteus minimus (Greater Trochanter) Abducts thigh Tensor fasciae Abducts, flexes, and rotates thigh latae Illiac crest to fascia of thigh medially; Supports lateral knee through tensing fascia of lateral leg Lower pubic symphysis to medial Adducts thigh, flexes and rotates leg Gracilis tibia (condyle) medially at knee Tibialis Tibia/Fibula to dorsal posterior Tarsal/Metatarsal of the foot Plantarflexion Proximal tibia, lateral condyle Tibialis ventral Tarsal/Metatarsal of Dorsiflexes and inverts foot anterior the foot  MUSCLES OF POSTERIOR THIGH “HAMSTRINGS” RESPONSIBLE FOR KNEE FLEXION & HIP EXTENSION SEMIMEMBRANOSUS SEMITENDINOSUS BICEPS FEMORIS GASTROCNEMIUS KNEE FLEXION