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Musculoskeletal - Coggle Diagram

- - - - ANATOMY
        
        • Whole muscle (organ) • Muscle fibre (muscle cell)
        • Myofibrils (contractile organelles)
        • Sarcomere (functional unit of muscle fibre)- thick (myosin) and thin (actin) filaments (contractile proteins)
        • Other organelles: transverse-tubules (Ttubules) and sarcoplasmic reticulum
  - - - MYOSIN
        
        Myosin is a long fibrous protein with “heads” that stick out
        • Myosin heads contain binding sites for actin
        • Myosin heads also contain ATPase site
        • Multiple myosins group together to form a thick filament
      - ACTIN
        
        • Actin molecules contain myosin binding sites
        • Multiple actin molecules will arrange themselves in a doublehelix to form thin filaments
        • Two regulatory proteins that regulate actin:
        1) Tropomyosin: binds to actin and blocks the myosin binding sites on actin
        2) Troponin: binds to tropomyosin and can move it out of the way
      - SARCOMERE
        
        • Sarcomere: arrangement of overlapping contractile proteins, actin and myosin within a myofibril, forms light and dark striations
        • Z-line: boundary of sarcomere where actin attaches to adjoining sarcomeres
        • M-line: centre of sarcomere
        • A band (dark band): stretches end to end of myosin, contains both actin and myosin filaments
        • I band (light band): space between myosin, contains only actin
        • H zone: non-overlapped regions of myosin only, no actin
        
        • When a muscle contracts, the actin and myosin move, causing the sarcomere to shorten. H zone and I band become shorter, but A band maintains the same width.
        • Sliding filament theory – each sarcomere shortens as myosin heads “sliding” actin toward the centre of sarcomere (M line), the thin filament slides close together between the thick filament, so that the Z-disc are pulled closer together.
  - - - Excitation-Contraction Coupling
        
        Muscle contraction is caused by depolarisation of the muscle cell, which leads to the movement of actin, “sliding” over myosin to cause a contraction.
        1) Action potential: reaches the muscle fibre
        2) Calcium release: Ca2+ binds to troponin
        3) Tropomyosin released: troponin pulls tropomyosin off of myosin binding sites
        4) Cross-bridge: myosin heads grab onto actin, cross-bridge forms
        5) Power stroke: myosin heads pull actin inward, using “power stroke”
        6) Reset: myosin detaches from actin, resets
    - - • Latent period (1-2 msec) – first few milliseconds, excitation-contraction coupling (time delay between stimulation (AP) and contraction due to cross bridge activity)
        • Contraction time (15-50 msec) – cross bridge cycling, tension increases
        • Relaxation time (15-50 msec) – calcium transported back into SR, cross bridge cycling ends, tension decreases
        • Twitch: a single muscle contraction (e.g. twitch on eye)
        
        MUSCLE MECH
        
        • Within a whole muscle, several muscle fibres will contract to create movement.
        • Muscles are surrounded by connective tissue, extending into elastic tendons which attach the muscle to a bone.
        • Contracting the muscle creates tension, which stretches the tendon and applies force to move the bone.
        • The bone itself and anything being held near the bone has weight, called the load, which will oppose the force of movement.
        • E.g. Bicep contracts to pull on the tendon attached to the radius, this pulls the radius toward the upper arm flexing the elbow joint, and lifting a load held in the hand.
    - - • In general, muscle contraction shortens muscle, but there are exceptions.
        • For a muscle to shorten during contraction, the tension developed in muscle must exceed the forces that oppose movement of bone.
        • Concentric contraction: muscle contraction causes shortening.
        • Eccentric contraction: muscle contraction is used as a stabilising contraction, muscle actually lengthens
        
        Isotonic contraction: load remains constant, muscle shortens (e.g. squats, stair climbing, push-ups)
        
        Steady muscle contraction
        
        ➢ Isometric contraction: tension develops at constant muscle length, but bone and load is not moved (e.g. weight lifting, planks
        
        Load is too heavy, force cannot overcome the load
  - - - MOTOR UNIT
        
        • Not all muscle fibres within a whole muscle are active during contraction
        • A small subset of muscle fibres will be activated based on need
        • The smallest subset is a motor unit.
        • A motor unit: one motor neuron and all the muscle fibres it innervates
        
        RECRUITMENT
        
        Baseline muscle tone: some muscle fibres are always active to maintain muscles, even when no movement is taking place
        
        Motor unit recruitment: activation of more motor units to increase tension in the muscle as the load increases, e.g. more force needed
        • More motor units are recruited, more contraction
    - - Motor unit size / muscle size: number of muscle fibres per motor unit
        • Precise movement: External eye muscles and hand muscles (single motor unit may contain a dozen muscle fibres)
        • Powerful movement: Legs (single motor unit may contain 1500-2000 muscle fibres)
        
        Size of individual muscle fibres: fibres produce more myofilaments in response to demands placed on them (e.g. athletic training)
        • Fibres are hypertrophy (increase muscle cell size)
    - - • A single action potential in a muscle fibre produces a muscle twitch.
        • Repeated stimulation can produce sustained and longer duration contraction of muscles, and greater tension.
        • Muscle fibres can respond to repeated stimuli before they are fully relaxed, this is called twitch summation.
        
        TETANUS
        
        • A muscle fibre at maximum stimulation, with no relaxation will reach a sustained maximal contraction called tetanus.
        • Tetanus will last until the muscle becomes fatigue
    - - Treppe: increased contraction in response to multiple stimuli of the same strength
        
        Different than summation because relaxation occurs. Contractions increase because:
        ➢ There is an increasing availability of Ca2+ in the sarcoplasm (Ca2+ still able being pumped back to SR), like priming the muscles
        ➢ Enhancement of elastic components inside muscles
        ➢ Muscle enzyme system becomes more efficient because heat is increased (warming the muscles)
    - - (1) Slow Oxidative (Type I)
        (slow & endurance)
      - (2) Fast Oxidative (Type IIa)
        (fast & intermediate fibre)
      - (3) Fast Glycolytic (Type IIx)
        (fast & fatigue quickly)
      - EFFECT OF EXERCISE
        
        1) Aerobic exercise
        
        2) Resistance – weight lifting & isometric contractions
  - - - GLYCOLYSIS
        
        – anaerobic
        ➢ Glucose is broken down to pyruvic acid (pyruvate) and produces 2 ATP
        ➢ In the absence of O2 , pyruvic acid is converted to lactic acid (lactate)
        ➢ Produces minimal amounts of ATP but occurs quickly
        ➢ Provides 30-60 seconds of high level activity
        
        CREATINE PHOSPHATE
        
        Creatine phosphate is stored in the muscle fibres
        • Provides a rapid source of energy for 10-15 sec of contraction
        • Creatine phosphate – transfers energy and a phosphate to ADP forming ATP
- - - - INTERVETEBRAL DISC
    - - intervertebral disc
        
        sup & inf art process
        
        intervertebral foramen
        --> accomodate spinal n exit from spinal cord
        --> the vertebral notches of adjacent vertebrae, specifically the superior art notch of the vertebra below and the inferior art notch of the vertebra above.
  - - - FEATURE
        
        Bifid spinous process – at the distal end
        --> except C1-no spinous process
        --> except C7-spinous process is longer than C2-C6, & may not bifurcate
        ● Transverse foramina/foramen transversarium – an opening at each transverse process
        ● Triangular vertebral foramen
        
        TYPICAL
        
        ATYPICAL
        
        ATLAS
        
        AXIS
        
        C7
    - - Vertebral body size increases
        
        Circular-shaped Vertebral foramen
        
        Heart-shaped Vertebral body
        
        Transverse costal facet
        --> Articulation with tubercle of its own RIB
        
        Transverse costal facet
        
        Superior costal facet --> To articulate with the head of its own rib and the head of rib below
        
        Inferior costal facet --> Smaller than superior costal facet
    - - Transverse process --> Thin & long (except L5 massive for attachment of iliolumbar ligaments to connect with pelvic bones)
        
        Vertebral body --> Large & cylindrical
        
        Vertebral foramen --> Large & triangular
        
        LACKS OF =
    - - 5 fused sacral vertebrae
        
        Concave anterior surface
        
        Convex posterior surface
        
        Anterior sacral foramina
        
        Facet for articulation with pelvic bone - posterior dorsal sacral foramina pain --> For S1-S4 spinal nerves passage
- - - - FEATURES
        
        SUP
        
        med 2/3 (flatten end)= convex ant
        
        lat 1/3 (rounded end)= concave ant
        
        smooth surface
        
        INF
        
        Conoid tubercle
        
        rough area= attachment of sternoclavicular lig
        
        trapezoid line= attach' trapezius muscle
        
        rough surface
  - - - ANT - acromion process, coracoid process, glenoid cavity, sup angle, med border, inf angle
      - POST- supraspinous fossa, infraspinous fossa, spine, acromion process
      - LAT- acromion process, coracoid process, glenoid cavity
  - - - MAJOR
        
        cover sup part of chest
        
        O=sternum, upper 6 ribs, med 1/3 of clavicle
        
        I= lat lip of intertubercular groove of humarus
        
        A= adducts & medially rotates the humerus (shoulder J)
        
        N= lat & med pect n
      - MINOR
        
        beneath pect major & surgical landmark in asilla
        
        O= 3rd - 5th ribs
        
        I= coracoid process of scapula
        
        N= med pect n
        
        A= stabilise scapula (inf & ant)
    - - small muscle underneath clavicle
        
        O=
        
        I=
        
        N= n to subclavius
        
        A= depress clavicle (facilitate in depression of shoulder)
        
        ? cephalic v, lat pect n, thoracoacromial a?
    - - O= ext surf of lat 1-8 ribs
        
        I= med border of scapula (ant surf)
        
        N= long thoracic n.
        
        A= protracts scapula (pushing / punching), boxer's muscle, rotate scapula suply
  - - - STRUC= axillary tail - clinical app nipple (position varies & nulliparous -4th intercostal space)
        
        AREOLA - hyperpigmented area
        
        COMP= fat (85-90%), CT + gland (10-15%)
        
        LYMPH DARIN'
        
        75% lymph from skin & breast tissue of lat part of breast --> pect LN --> lat gp + central gp --> apical gp --> subclavian lymph trunk
        
        all through axillary LN
- - - - Most fibres are in circular layer (causes organ constriction & elongation)
        • Some GI fibres are arranged in longitudinal layer (causes organ dilation & shortening)
        • With the exceptions of blood vessels and iris muscles, sometimes smooth muscles are referred to as visceral muscles
        • Blood vessels can have single or multiple layers of smooth muscles
    - - 1) Thick myosin filaments (longer than those in skeletal muscle)
        2) Thin actin filaments (contain tropomyosin but no troponin)
        3) Intermediate filaments (intermediate size)
        
        Do not directly participate in contraction
        
        Form part of cytoskeletal framework (scaffold) that supports cell shape
        
        ARRANGEMENT
        
        • Thick and thin filaments are arranged diagonally from side to side within the smooth muscle (elongated, diamond-shaped lattice), no sarcomere, no striation
        • During contraction, thin filaments slide past the thick filaments, causing:
        --> The filament lattice to shorted and expand from side to side
        --> Whole cell shortens and bulges out between the points
        
        Myosin molecules (cross-bridges) arranged along the entire thick filament (no bare portion in the centre).
        • Therefore, the surrounding thin filaments can be pulled along the thick filaments for longer distances than in skeletal muscle.
        • Myosin proteins are organised, so that half of the surrounding thin filaments are pulled toward one end of the stationary thick filament and the other half are pulled toward the opposite end
    - - • No troponin in thin filament
        • Smooth muscle myosin can interact with actin only when the myosin light chain, MLC (like necklace in myosin head) is phosphorylated (has an inorganic phosphate, Pi from ATP attached to it).
        • During excitation, the increase cytosolic Ca2+ binds with calmodulin.
        • Ca2+ -calmodulin complex binds and activates myosin light chain kinase (MLC kinase). MLC kinase phosphorylates the myosin light chain.
        • Pi on MLC permits the myosin cross bridge to bind with actin – cross bridge cycling
      - Smooth muscle contraction is slow & economical
        
        Latch phenomenon - Low energy consumption to maintain tension (economical)
        • Starts slower and lasts much longer than skeletal muscle contraction:
        --> Prolonged presence of Ca2+ in the cell provides for a state of continued partial contraction
        --> Ca2+ moves slowly out of the muscle fibre, delaying
        • Important in the:
        --> Gastrointestinal tract where a steady pressure is maintained on the contents of the tract
        --> In the wall of blood vessels which maintains a steady pressure on blood
        
        Regulation of smooth muscle contraction
        
        Action potentials from the ANS • Pupil constriction due to increased light energy
        
        Stretching • Food in digestive tract stretches intestinal walls initiating peristalsis
        
        Hormones • Epinephrine causes relaxation of smooth muscle in the airways and in some blood vessel walls
        
        Changes in pH, oxygen and carbon dioxide levels
        
        Temperature (cold temperature causes contraction)
        
        Length-tension relationship
        (smooth muscle)
        
        Length-tension relationship is less linked in smooth muscle
        --> Can readjust its resting length when chronically stretched or shortened - length adaptation
        • Resting length (non-stretched) is shorter than optimal length, thus smooth muscle can stretched before reaching its optimal length .
        • Thin filaments still overlap the longer thick filaments even in the stretched-out position, thus cross-bridge interaction and tension still work.
        • E.g. stretched urinary bladder still able to generate tension for bladder emptying
    - - TYPE
        
        1) Multiunit smooth muscle: neurogenic (regulated by neurons from ANS)
        • Iris can response to varies degree of light (close the eye partially)
        • Fine control the blood vessels
        
        • Consists of discrete units that function independently of one another
        • Units must be separately stimulated by nerves to contract (neurogenic)
        • Phasic contraction
        • Non-syncytial: without interconnecting bridges (no gap junction)
        • No spontaneous contraction – no pacemaker activity
        • Do not respond to stretch
        
        FOUND IN: Walls of large blood vessels
        • Small airways to lungs
        • Ciliary muscle of eye that adjusts lens for near or far vision
        • Iris of eye that adjusts pupil size
        • Base of hair follicles (goose bumps)
        
        2) Single-unit smooth muscle: myogenic (regulated by neural input, hormones, pacemakers, stretching, cold temperature)
        
        Alternatively called visceral smooth muscle
        • Regulated by neural input, hormones, pacemakers, stretching, cold temperature
        • Self-excitable (myogenic)
        • Cells electrically linked by gap junctions
        • Can also be described as a functional syncytium (particular regions contract together), e.g. uterine wall contraction during labour – repetitive excited & contract as a unit
        • Contraction is slow and energyefficient
        --> Well suited for forming walls of distensible, hollow organs (GIT, reproductive, urinary tract, small blood vessels)
  - - - Length-tension relationship (cardiac muscle)
        
        Amount of Ca2+ released by SR doesn’t change, but developed tension increase
        • This is, which the force of contraction increase basis for Frank-Starling Law at increased end diastolic length
      - and the Frank-Starling law
        
        The more the ventricle is filled with blood during diastole, the greater the volume of ejected blood during the resulting systolic contraction.
        • The length-tension relationship occurs at maximal thick and thin filament overlap in cardiac sarcomere.
        • Force of contraction will increase as heart is filled with more blood.
        • Increase load stretches myocardium and increase affinity of troponin C (TnC) for calcium at increasing sarcomere length, leading to increase in contractile force, an increase in sensitivity.
  - - - • Cardiac hypertrophy – the number of cardiac muscle cells is not increased; instead, they become longer and larger in diameter
        • Physiological hypertrophy (athlete’s heart) – increase heart mass, normal or enhanced cardiac function
        • Pathological hypertrophy (cardiovascular disease) – increased heart mass, reduced cardiac function, cell death and fibrosis
    - - • Urinary bladder hypertrophy, esp. in men, caused by benign or cancerous enlargement of the prostate gland, which obstructs the bladder outlet
        • Clinical result: difficulty urinating, distention of the bladder, impaired emptying
        • Due to diminished the ability of the bladder smooth muscle to contract and develop stress
    - - • Myometrium becomes hypertrophy as parturition approaches due to increase in hormone (oestrogen)
        • Large numbers of gap junctions form just before birth and convert the myometrium to a single-unit tissue to coordinate contraction during parturition
- - - - radius, ulna, carpal (8), metacarpals (5), phalanges, humerus
        
        HUMERUS
        
        type: long bone.
        
        loc: arm (from shoulder joint--> elbow joint)
        
        Features
        --> sup end= head, lesser tubercle, anatomical neck, surgical neck, greater tubercle, intertubercular groove
        --> body= deltoid tuberosity
        --> inf end
        
        RADIUS (lat), ULNA(med)
        
        RADIUS= head, neck, tuberosity, ant oblique line, styloid process
        
        ULNA= trochlear notch, coronoid process, tuberosity
      - MUSCLE
        
        ARM
        
        ADDUCTION- Triceps, brachii Muscles of posterior wall of axilla, Pectoralis major
        
        EXTENSION- Deltoid, Latissmus dorsi
        
        FLEXION- Deltoid, Coracobrachialis, Pectoralis major
        
        (2) O: coracoid process
        
        I: medi surf of humerus (med 1/3)
        
        A: flex arm at shoulder joint
        
        (1) O: lat 1/3 clavicle, acromion & spine of scapula.
        
        I: deltoid tuberosity
        
        A: powerful abductor--> facilitate flexion and extension of arm
        
        N: axillary nerve
        
        ABDUCTION- Deltoid*, Supraspinatus
        
        ROTATOR CUFF mm --> 'SITS'
        
        S - supraspinatus I - infraspinatus T - teres major S - subscapularis
        
        4 short mm
        
        surround ant post, sup parts of shoulder
        
        stability for shoulder (J) --> tendon fused w/ capsule of shoulder
        
        all rotate humerus exc Supraspinatus
        
        FOREARM
        
        FLEXION- Biseps brachii, Brachialis
        
        (1) - O: coracoid process (for its short head), supraglenoid tubercle (long head),
        
        I : radial tuberosity , bicipital aponeurosis
        
        N: musculocutaneous n.
        
        A: Flex forearm at elbow joint.
        
        (2) O: ant surf of humerus (distal 1/2)
        
        I: coronoid process & tuberosity of ulna
        
        A: flex forearm at elbow joint
        
        EXTRNSION- Triceps brachii
        
        O: long head = infraglenoid tubercle of scapula,
        --> Lat head = post surf of humerus (above radial groove)
        --> Med head = post surf of humerus (below radial groove)
        
        I: olecranon process of ulna
        
        A: extension of forearm (main extensor of forearm), adduction of arm
      - CARPAL TUNNEL - contain tendon from mm=
        
        (Deep mm of ant compartment of forearm*) flexor pollicis longus, flexor digitorum profundus.
        
        (Superficial mm of ant compartment of forearm*) flexor digitorum superficialis
        
        awkward postures or repetitive hand movements
        
        tendons in carpal tunnel can become irritated & inflamed
        
        Swelling of the tendons
        
        Compress the median nerve
        
        Pain at the wrist region.
    - - main aa of arm
        
        begin at cont of Axillary aa.
        
        end at ant to elbow (cubital fossa) level of neck of radius (radial aa & ulnar aa)
        
        axillary -> brachial --> profunda brachii --> nutrient --> sup ulnar collateral --> inf ulnar collateral --> muscular br. --> radial & ulnar aa
    - - hollow triangle area on ant surf of elbow
        
        content: radial nn, median nn, brachial aa, biceps tendon, pronator teres, BR supinator
        
        brachial aa = blood pressure measurement
        
        venepuncture= to withdraw blood
        SUPF = cephalic vv, lat cutaneous nn of forearm, basilic vv, med cutaneous nn, median cubital vv
  - - - Gluteal region
        --> Location: on the back & side of pelvis
        --> Two parts: posterior region (buttocks) & lateral region (hip/hip region)
        
        Thigh region
        --> Between gluteal and knee regions
        --> Femur articulate with the hip bone in the hip joint
        
        Knee region
        --> Consists of: condyles of femur & tibia, head of fibula and patella
        --> Posterior aspect of the knee presents a hollow named popliteal fossa
        
        Leg region
        --> Includes 2 bones: tibia and fibula
        --> Triceps surae m. created the bulge look (posterior of knee)
        
        Ankle region
        --> Contains distal part of the leg & bulges of tibia and fibula
        --> Ankle joint found between malleoli and talus
        
        foot
        --> Distal part of lower limb
        --> Consist of 26 bones (7 tarsals, 5 metatarsals, 14 phalanges)
    - - JOINT:
        
        Hip joint --> Between pelvic bone + femur)
        
        Knee joint--> Between femur + tibia
        
        Ankle joint --> Between tibia & fibula + talus
        
        BONE: - Pelvis --> Pelvic bone (link to sacrum)
        ➢ Thigh --> Femur (largest bone of the body)
        ➢ Knee --> Patella
        ➢ Leg --> Tibia (medial) & Fibula (lateral)
        ➢ Foot --> Tarsals (7) ▪ Metatarsals (5) ▪ Phalanges (14)
      - FEMUR
        
        PROXIMAL
        
        HEAD • articulates with acetabulum to form hip joint
        • Smooth surface, covered with articular cartilage
        • Fovea – where ligamentum teres attaches
        
        INTERTROCHANTERIC LINE- Known as pectineal line after passes lesser trochanter
        
        LESSER TROCHANTER - Attachment site for iliopsoas muscle (psoas major & iliacus m.)
        
        GREATER TROCHANTER- The site of attachment for gluteal region muscles: gluteus medius, gluteus minimus & piriformis
        
        DISTAL- Lateral and medial condyle
        • Articulate with tibia
      - PATELLA
        
        • Located anterior to the knee joint
        • Embedded in the tendon of quadriceps femoris
        • Protects the structures within the knee joint during movement
      - TIBIA
        
        Larger than fibula
        
        Main weight-bearing bone of the lower leg
        
        Proximal end has lateral & medial condyles to articulate with femur → knee joint
        
        Tibial tuberosity → site of attachment for patellar ligament
        
        Distal end articulates with talus, and the laterally with fibula
        
        Medial malleolus → the medial prominence of ankle
      - FIBULA
        
        Thinner than tibia
        
        Supports tibia and stabilizes ankle & lower leg
        
        Both proximal and distal end are enlarged
        
        Proximal → articulate with lateral surface of tibia (not involved in knee joint)
        
        Distal end articulates with tibia & talus
        
        Lateral malleolus → the lateral prominence of ankle
      - TOES BONES
        
        TARSALS - - 3 groups: distal, intermediate & proximal
        
        Composed of 7 bones
        
        Most prominent: talus & calcaneus (heel bone)
        
        PHALANGES - Each toe consists of 3 phalanges (proximal, middle and distal) → except great toe
        
        METATARSALS - Support instep
        
        Numbered I - V
        
        Tarsals & metatarsals are bound by ligaments to form arches of the foot
    - - ANT - illiopsoas (iliacus, psoas major), sartorius (longest), quadriceps femoris (vastus lateralis, medialis, intermedius & rectus femoris)
        
        ACTION: Adduction of hip joint ❖ Flexes knee joint (only gracilis)
        
        NERVE SUPPLY--> Obturator nerve
        
        O: Body of pubis --> Adductor longus
        
        Body of pubis • Inferior pubic ramus --> Adductor brevis
        
        Inferior pubic ramus • Ischial ramus --> gracilis & Adductor magnus
        
        I: Posterior border of femur (linea aspera) --> Adductor longus | Adductor brevis | Adductor magnus
        
        Upper part of medial surface of tibia (behind sartorius) --> gracilis
      - MED- gracilis & adductor longus, brevis, magnus
        
        Biceps femoris
        
        O: i. Long head: upper area of ischial tuberosity
        ii. Short head: lateral lip of linea aspera
        
        I: Head of fibula
        
        A: i. Extends & laterally rotates thigh at hip joint
        ii. Laterally rotates leg at knee joint
        
        Semitendinosus:
        
        O: Upper area of ischial tuberosity
        
        I: Medial surface of proximal tibia
        
        A: i. Flexes leg at knee joint & extends thigh at hip joint
        ii.Medially rotates thigh at hip Semimembranosus joint & leg at knee joint
        
        Semimembranosus:
        
        O: Superolateral impression on the ischial tuberosity
        -I: Quadriceps tendon
        -A: i. flexes leg at knee joint & extends thigh at hip joint
        ii.medially rotates thigh at hip semimembranosus joint & leg at knee jointer
      - POST - (biceps femoris, semitendinosus, semimembranosus)
        
        SARTORIUS
        
        PECTINEUS
        
        ILIOPSOAS
        
        QUADRICEPS FEMORIS
        
        FEMORAL TRIANGLE
    - - SCIATIC NERVE
        
        MOTOR- ❑ Posterior compartment of thigh ❑ Entire leg (via terminal branches) ❑ Entire foot (via terminal branches)
        
        SENSORY - (via terminal branches) ❑ Lateral leg ❑ Heel ❑ Dorsal & plantar foot
        
        INJURY- to sciatic nerve can be resulted from: i. Misplaced gluteal injection ii. Trauma to hip (stab wounds); dislocation or fracture
        
        MOTOR DEFICIT - 1. Paralysis of hamstring muscle • Inability to stretch thigh & bend knee
        
        Foot drop/flail foot • Paralysis of leg & foot muscle • Trouble in walking (walks with high-stepping gait)
        
        SENSORY LOSS - Sensory loss on the back thigh & entire leg (except medial aspect of leg & foot  innervated by saphenous nerve)
        
        ❑A branch of the sacral plexus
        ❑Composed of L4, L5, S1, S2 and S3 of spinal nerves
        ❑2 main branches: ▪ Tibial nerve ▪ Common peroneal nerve
      - CLINICAL
        
        SLEEPING FOOT: temporary compression of the sciatic nerve against femur at the lower border of gluteus region causes paresthesia in the lower limb (“when a man sits on the hard edge of the seat for a long time”)
        
        SCIATICA: shooting pain along the course of distribution of the sciatic nerve (eg buttocks, posterior thigh, lateral leg, foot) due to the compression of L4 and S3 spinal nerve roots
- - - - LAT - Intertubecular gv of humerus, Biceps brachii
        
        MED - ribs, serratus ant
        
        ANT - clavicle, pectiral mm. (subclavius, pect major & minor)
        
        POST - scapula, subscapularis, latissimus dorsi & teres major
      - MUSCLE
        
        SUBSCAPULARIS
        
        O: subscapular fossa
        I: lesser tubercle of humerus
        N: subscapularis n.
        A: (all mm forming post wall of axilla) adduction & medial rotation of arm
        
        TERES MAJOR - O: scapula (inf angle post ly)
        
        I: intertubercular gv
        
        N: lower subscapularis n
        
        LATISSIMUS DORSI
        
        O: lower part of thorax postly, illiac crest, thoracolumbar fascia
        
        I: intertubercular gv
        
        N: thoracodorsal n
    - - NERVES
        
        BRACHIAL PLEXUS - net of nerves innervating struc of UL --> 5 parts (roots, trunks, division, cords, branches)
      - VESSELS
        
        AXILLARY
        
        ARTERY
        
        large vessel
        
        begin at lat border of 1st rib (cont of subclavuan aa)
        
        end: inf border of teres major (continue as brachial aa)
        
        pect minor divides artery to 3 parts
        
        --> 1st: above pect minor (sup thoracic aa)
        --> 2nd: behind pect major (thoracoacromial aa, lat thoracic aa)
        --> 3rd: below pect minor (post & ant circumflex humeral aa)
        
        VEIN
        
        lies med to axillary aa
        
        begin: inf border of teres --> continuation of basilic vv
        
        end: subclavian vv (lat border of 1st rib
        
        tributaries follow axillary branches)
        
        LYMPH NODE
- - - - STRUCTURE
        
        FIBROUS
        
        joint btw 2 bones i/membranous by fibrous tissue.
        
        usually immovable
        
        SUTURE
        
        immovable
        
        found btw bones of skull
        
        in foetus --> sutures are wide and bone have smooth opposing surfaces
        
        --> to allow slight move' during passage through birth canal
        
        after birth --> suture become rigid over time (ossification)
        
        SYNDESMOSIS
        
        bone com are placed apart connected by intraosseous ligament -
        -> distal tibiofibular joint
        
        GOMPHOSIS
        
        peg and socket btw teeth and alveolar process of maxilla and mandible
        
        CARTILAGINOUS
        
        unites bone by hyaline / fibrocartilage - partially movable
        
        SYNCHONDROSIS - - temporary unions of bones by hyaline cartilage --> later ossify
        
        SYMPHISIS - opposing surface of bones
        --> covered by thin film of hyaline cartilage.
        --> but the bond provided by intervening fibrocartilage
        
        SYNOVIAL
        
        unite bones by several comp (fibrous capsule, synovial membrane, synovial fluid within s. cavity)
        
        freely movable
        
        features: periosteum, fibrous capsule, synovial mem, articular hyaline cartilage, synovial cavity
        
        joint cavity - area btw articulating bones surrounded by capsule
        synovial mem - lining of non-articular parts of synovial joint
        --> secrete viscous lubricating fluid 'synovium'
        
        capsule
        
        fibrous sleeve, attached to circumference of involved bones to enclose a jointt cavity
        
        some part of caps are thickened --> form ligaments of joints
        
        collagen fibres run in all direction but mainly in spiral manner
        
        articular surface
        
        coated w/ hyaline cartilage, contain no nerves and no vessels
        
        nourishment comes from epiphyseal vessells, synovial fluid and from vascular net of synovial mem
        
        DISC (meniscus - incomplete disc)
        
        some joint contains cartilagenous disc interposed btw articular surfaces.
        
        connected to fibrous capsule
        
        wholely across joint dividing into 2 parts
        
        peripheral zone invaded by vessels
        
        FX: shock absorption, improvement of fit btw joint surfaces, facilitation of move' (rolling / spread of lubricant), distribution of weight over larger surface,
        protection of articular surfaces
        
        CLASSIFICATION
        
        UNIAXIAL- only 1 degre of freedom [eg: hinge, pivot bicondyloid TMJ]
        
        BIAXIAL
        
        MULTIAXIAL- 2 DOF [eg: saddle, condyloid]
      - MOBILITY DEGREE
        
        SYNARTROSES (immovable)
        
        AMPHIATHRODIAL (partial)
        
        DIARTHROSES (movable)