Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Muscles & Joints Ch. 8 Movements of the body • Flexion: >in angle of a jt. By bending it. • Extension: < in angle of jt. By straightening it. • Hyperextension: extension beyond the anatomical position • Abduction: moving away from midline • Adduction: moving toward midline movements • Dorsi flexion: bending ankle so foot moves toward the shin. • Plantar flexion: bending ankle so foot points downward • Inversion: moving foot so sole move inward( medially) • Eversion: moving sole of foot outward( laterally) movements • Circumduction: circular movement along the length of body part. • Rotation: twisting around the axis of limb internal rotation: moves medially external rotation: moves laterally • Elevation: raising body part • Depression: lowering body part movements • Supination: turning hand palm up • Pronation: turning hand palm down • Protraction: moving part forward • Retraction: moving part backward joints 1. Form where bones meet – Joints are functional junctions between bones 2. Related terms articulation: junction of 2 or more bones arthro: joint arthology: study of joints arthritis: inflammation of the joint Arthroscopic: joint scope surgery Joints 3. Functional vs. structural Functional classification is based on: Available movement Structural classification is based on: Materials that make up the joint Joints 4. Functional classification Synarthroidal= immovable examples: sutures, coccyx-sacrum Amphiarthroidal= slightly moveable examples: pubic symphysis, ribs, vetebral disks, intervertebral jts. Diarthroidal= freely moveable examples: all synovial jts. joints 5. Structural classification – Fibrous – Cartilagenous – synovial Joints of the body 6.Fibrous Joints – Syndesmoses (amphiarthroidal) • Bones held together by connective tissue(interoseous membrane) • Tibia-fibula/Radius-Ulna – Suture (synarthroidal) • Between flat bones – Gomphosis ( synarthroidal) • Teeth to jaw joints 7. Cartilagenous – Temporary: Synchondrosis (synarthroidal) • (bone-cartilage-bone) • Slightly movable: compression • Example – Epiphyseal plates – 1st rib/manubrium – Permanent: Symphasis ( amphiarthroidal) • Example – Pubis symphasis – Intervertebral jts Joints 8.Synovial – Freely moveable – All are diarthroidal – Synovial membrane- secretes synovial fluid • Lubricates joint – Joint capsule( fibrous tissueligament) – Articular ( Hyaline) cartilage ( meniscus/menisci) – Bursae: fluid filled sacs • Reduce friction Joints 8. Types of synovial joints ball & socket condyloid gliding hinge pivot saddle joints 10. Ball & Socket • allows for greatest Range of Motion( ROM) • • shoulder & hip triaxial movement flexion-extension-add/abduction- rotation joints • Condyloid ( ellipsoidal) – Egg in spoon – Flexion/extensionadd/abduction – Wrist- MCP, MTP, IP, PIP, DIP • Gliding joint (plane) – Articular ends nearly flat or slightly curved. – Inter (carpal/tarsal), vertebrae, SI joint Joints – Hinge • spool & cap • Flexion/extension – elbow, Knee, ankle (talus-tib/fib) – Pivot – Cylinder within a ring – Rotation » Radio-humeral, atlas-axis Radius Ulna Joints • Saddle – Saddle on a horse • Flexion/ext, abd/adduction • Carpometacarpal of thumb muscles • 3 types – Skeletal (striated, voluntary) – Cardiac (striated, involuntary) – Smooth ( involuntary) • Characteristics – – – – Irritability: ability to respond to stimuli Contractility: ability to change length Extensibility: ability to be stretched Elasticity: ability to return to original shape Muscle facts • Most common type of tissue in the body (over 600) • Makes up 35-45% of body weight • Muscles produce action only by pulling, they cannot push • Tendons connect bones to muscle • One muscle may attach to another through an aponeurosis (tendon) • Each muscle is made up of many bundles of fibers • Each fiber is an individual cell • Cells are multinucleated • They are thin, elongated cylinders • Each cell may run the entire length of a muscle Features of a muscle • • • • • • • • • • • • Epimysium; muscle facia; outer covering of muscle Perimysium: sheath that separates muscle cells into fascicles Fasicle: bundle of muscle fibers Endomysium: thin covering around each muscle fiber Sarcolemma: membrane of the muscle cell Sarcoplasm: cytoplasm of muscle cell Muscle fiber: muscle cell composed of many myofibrils Myofibril: threadlike structures within sarcoplasm essential for contraction, made of myofilaments. Myofilaments: protein strands actin (thin) and myosin (thick). Give striped appearance to muscle. Sarcomere: functional unit of muscle contraction between Z-lines of each myofibril. Myosin filament: Thick dark filament, make up A bands of sarcomere, contains cross-bridges that connect them to the thin filaments. Actin Filaments: Thin, light colored filaments, make up I bands connected together at Z lines, move with a muscle contraction. Muscle fiber fasicle Actin & myosin filaments Muscle cell diagram I-band A-Band I-band actin myosin Cross bridge Sarcomere Z line –Z line Z-line Z-line H- band sarcomere • • • • • • • • Sarcomere contractile unit of muscle Actin: thin myofilament, troponin & tropomyosin Myosin: thick myofilament, has crossbridges. Z-line: connects ends of actin together, move toward each other during contraction A band: full length of myosin fiber within a sarcomere, between I bands I band: end of myosin in one sarcomere to the myosin in the next sarcomere. H- band: in the middle of the sarcomere between ends of actin gets smaller with contractions. Crossbridge: functional unit of myosin that attach to troponin/tropomyosin heads on actin filament to cause contraction Muscle contraction 8.3-8.4 Muscle contraction Lets watch a sarcomere shortening • http://highered.mcgrawhill.com/sites/0072437316/student_view0/ chapter42/animations.html# • Now let’s discover how this process occurs Muscle contraction (sliding filament theory) 1. Nerve impulse travels down a motor neuron to muscle unit. 2. The motor neuron terminal releases neurotransmitter acetylcholine (ACh) 3. ACh binds to ACh receptors (nicotinic receptor) on muscle Motor end unit http://glencoe.mcgrawhill.com/sites/0015081981/student_view0/chapter8/function_of_the_neuromuscular_j unction_.html Muscle contraction (sliding filament theory) 4.The sarcolemma is stimulated and the muscle impulse travels over the surface of the muscle fiber into the transverse tubules. 5. The impulse reaches the sarcoplasmic reticulum and Ca+ channels open 6. Ca+ ions diffuse from the sarcoplamic reticulum into the sarcoplasm and bind to troponin molecules. 4. 5 6. Ca+ and it’s role in muscle contraction • http://www.youtube.com/watch?v=vv6WBe qw2Nc Muscle contraction (sliding filament theory) • Thin filaments slide past the thick filaments and the sarcomere shortens. • Myosin molecule has a head and a tail – Tail is a hinge allowing head to attach to actin – Head has a power stroke to pull actin molecule. • Myosin uses ATP to contract ( head has binding site for actin & ATP) • Actin molecule has 2 proteins: troponin & tropomyosin – Tropomyosin covers binding site so myosin cannot bind ( prevents contraction) – Troponin exposed binding sites ( w/Ca+) 7. Ca+ ions released by action potential of nerve causes tropomyosin to move off of binding site. 8. Cross-bridge flexes and binds to actin molecule. 9. Head flexes (power stroke) and pulls the actin, thus shortening the sarcomere ( muscle contraction) Sliding filament in action Myofilament Contraction Sarcomere shortening • http://glencoe.mcgrawhill.com/sites/0015081981/student_view0/ chapter8/action_potentials_and_muscle_c ontraction.html Muscle relaxation 1. Acetylcholinesterase(enzyme) decomposes ACh, and the muscle fiber membrane is no longer stimulated (no ATP) 2. CA+ ions are actively transported back into sarcoplasmic reticulum. 3. ATP breaks linkages between actin & myosin filaments 4. Tropomyosin slides back over myosin binding sites 5. Muscle is relaxed and ready for next contraction Energy source is ATP - We use creatine phosphate to re charge the ATP molecule - Has High energy phosphate bonds - 4-6x more abundant in muscle than ATP - Active muscle uses Creatine Phosphate rapidly.uses cellular respiration after creatine is gone. - Krebs cycle in aerobic environments - lactic acid fermentation in anaerobic Figure 08.10 Figure 08.11 Oxygen supply - Myoglobin (like hemoglobin) helps provide muscle with extra oxygen during respiration. - Oxygen Debt - During strenuous muscle use, anaerobic path ways are used to obtain energy (1-2 mins) - the amount of Oxygen the liver needs to covert lactic acid to glucose + the amount of oxygen required to restore ATP/creatine phosphate back to original concentrations) VERY SLOW process - Can train to increase aerobic capacity - Fatigue is usually caused from a build up of lactic acid. - Lowers pH so muscle cells no longer respond to stimuli Muscle control • All-or-nothing response – Threshold: weakest stimuli to elicit a response - muscle fibers have different thresholds. must have threshold for muscle to contract (twitch) - Frequency fibers are stimulated & how many are stimulated determine contractile force - Recruitment of fibers occurs with larger stimuli Muscle parts • 3 main parts – Origin= proximal; usually immovable belly • 2 origins= biceps • 3 origins= triceps • 4 origins= quadriceps – Insertion= distal attachment, usually movable – Belly= “body” of muscle, between O&I Muscle names • Named for their – Action ( flexor, extensor) – Location (carpi, tibialis) – Shape and size ( deltoid, maximus, longus) – Number of attachments ( bi, tri..) – Point of attachment ( sternocleidomastoid) – Direction of their fibers ( transverse, oblique) Muscle work in groups • Prime mover (agonist) Muscle primarily responsible for movement – Ex. Deltoid-abducting arm/biceps-arm flexion biceps • Synergist assist prime mover – Make movements more smooth and efficient – Ex. Rotator cuff deltoid in arm Abduction Brachialis (under biceps) triceps • Antagonist performs opposite of agonist – Ex. Triceps/biceps; quad/hamstrings Muscles of the face • Muscles of facial expression(6) – – – – – – Epicranius: Orbicularis oris Orbicularis oculi Buccinator Zygomaticus Platysma • Muscles of mastication(2) – Masseter – Temporalis 1. epicranius: lifts eye brows “flirting: frontalis+ occiptalis 2. Orbicularis oculi: closes eye 5. “winking” 3. Orbicularis oris: close mouth “kissing” 4. Buccinator: compress cheeks in “whistle” 5. zygomaticus: raises corner of mouth “smile” 4. 6. platysma: draws angle of mouth downward “pout” 7. Sternocleidomastoid: Turns head to side, pulls head to chest, raises sternum 6. 7. 8. masseter: elevates mandible “chew” 9.Temporalis: elevates mandible “chew” Figure 08.17b 11. Extends head, bends to one side, rotates head 10.Rotates head, bends head to one side, brings head to upright position Muscles of pectoral girdle 1. Trapezius: A. upper: rotate/raise scapula B. Middle: adduct scapula C. Lower: depress scapula/shoulder 2. Deltoid A. anterior: flex shoulder B. Lateral: abduct shoulder C. Posterior: extend shoulder 3. Rhomboid: major& minor a. raise & Adduct shoulder 4. Levator scapulae: “IDK” a. elevate & adduct shoulder b. flex head to side Muscle that move shoulder girdle 5. Serratus Anterior a. Abducts scapula & rotates Serratus anterior 6. Pectoralis Minor a. Draws scapula forward & downward b. elevates ribs Pectoralis minor Muscles that move Arm 7. Pectoralis Major a. flex, adduct & medially rotate arm 8. Latissimus Dorsi (Lats) a. extend arm b. adduct medially rotate arm c. pulls shoulder down & back “Rotator Cuff” 9. Teres Major: extends, adducts & medially rotates arm 10. Teres Minor*: Rotates arm laterally w/ infraspinatus 11. Infra spinatus: rotates arm laterally 12. Supraspinatus: abducts arm 13. Subscapularis*: medially rotates arm Muscles that move forearm 1. Biceps brachii: a. Flexes forearm b. Supinates hand 2.Brachialis a. flex forearm 3. Brachioradialis a. flex forearm Muscles that move forearm 4.Triceps brachii – A. extend forearm supinator 5. Supinator* a. supinates hand 6. Pronator teres* a. pronates hand 7. Pronator quadratus* a. pronates hand Superficial muscles that move hand/wrist 1. Flexor carpi radialis* a. Flex abduct wrist 2. Flexor carpi ulnaris* a. Flex adduct wrist 3. Palmeris longus* a. Flex wrist 4. Flexor Digitorium 1. Flexes distal phalanges (digits) Superficial muscle that move wrist/hand 5. Extensor carpi radialis* longus & brevis a. extend wrist, abduct hand 6. Extensor carpi ulnaris* a. extend adduct wrist 7. Extensor digitorum* a. extends fingers Muscles of Abdominal Wall • Rectus abdominis – – • External oblique – – – • both side together compress abdomen one side, aids back in rotation one side aids in trunk flexion internal oblique – – – • flex trunk, compress abdomen both side together compress abdomen one side, aids back in rotation one side aids in trunk flexion transverse abdominis – – – both side together compress abdomen one side, aids back in rotation one side aids in trunk flexion Muscles of Abdominal Wall 5. intercostal muscles a. depress & elevate ribs for breathing 6. erector spinae extends back Intercostals Muscles that move the Thigh 1. Tensor facia latae a. abducts, b. flexes c. medially rotates thigh 2. Gluteus maximus a. Extends thigh 3. gluteus medius a. abducts b. medially rotates thigh 4. adductor longus a. adducts, b. flexes, c. laterally rotates thigh 5. adductor magnus a. adducts b. anterior portion flexes c. posterior portion extends 6. gracilis a. adducts b. flexes c. medial rotation Muscle that move the thigh 5. adductor magnus a. adducts b. anterior portion flexes c. posterior portion extends 6. gracilis a. adducts b. flexes c. medial rotation 7. iliopsoas a. Flexes( primary hip flexor) b. Medial rotation Muscles that move hip/leg 1. Sartorius (basket weaver) a. flex leg & thigh b. abducts & laterally rotates thigh c. rotates leg medially Quadriceps femoris group 1. Rectus femoris*: a. extends knee b. flex hip 2. Vastus lateralis: a. extend knee 3. Vastus medialis: a. extend knee 4. Vastus intermedius*: a. extend knee IT band Muscles that move the leg Hamstring group* 1. Biceps femoris*: a. flex knee b. extend thigh c. rotates knee laterally 2. Semitendonosis: a. flex knee b. extends thigh c. more superficial w/ long tendon 3. Semimenbranosis: a. flex knee b. extends thigh c. deep to semitendonosis d. broad tendon Muscles that Move the Foot and Toes 1. Anterior a. Tibialis anterior a. Dorsi flex b. Inversion b. Extensor digitorum longus a. Dorsi flexion b. eversion 2. Posterior a. gastrocnemius* 2 joint muscle a. plantar flex foot b. flexion of knee b. soleus a. plantar flex foot c. flexor digitorum longus a. curl toes 2-5 b. plantar flexion c. inversion foot Muscles that Move the Foot and Toes 1. Lateral a. peroneus longus a. plantar flexion b. eversion foot c. support arch b. peroneus brevis a. plantar flexion b. eversion foot c. peronius tertius a. dorsi flexion b. eversion foot