General Anatomy of Skeletal Muscle

General anatomy of skeletal muscle,its innervation and blood supply,General anatomy of spinal nerve,General terms of angiology and lymphologyMiloš GrimInstitute of Anatomy, First Faculty of Medicine,Charles University in Praguewinter semester 2013/2014

How to study skeletal muscles:origo, insertion, position (scheme,tables), identification, muscle groups,innervation, function,osteofascial spaces (compartments),transverse sections of limb segments,dissection

eneral Anatomy of Skeletal Musclerigin and development of muscles, molecular mechanismseneral features of striated muscle, its auxiliary structuresotor end plate, motor unit,muscle spindle, Golgi tendon organ),otor and proprioceptive innervationttachments of skeletal muscles – origin, insertionuscle fibres, myofibrils, sarcomeresaming of muscleshape and fibre architecture, pennationhe endomysial and perimysial sheathshe interface between muscle and connective tissueyofibrilar proteinsliding filament mechanism of contractionendons, Aponeurosesynovial sheaths and bursaeascia, intermuscular septa, osteofibrous spaces

Attachments of skeletal muscles – origin, insertion,endomysial and perimysial sheaths, fascia

http://fig.cox.miami.edu/~cmallery/150/neuro/muscle.htmstriated muscle fibres

muscle fibre,myofibril,sarcomeresarcoplasmicreticulum,T-tubules,triadsmitochondria,sarcolemma,basal lamina

Posture, isometric contraction

Motion, isotonic contraction

myo-tendinous junction

synovial sheath, synovial bursa

visualization of motor end plates

pennation of musclesarrangement of parallelrunning muscle fibres

Naming of MusclesShape:deltoid (= triangular), quadratus (= square), rhomboid(= diamond-shaped)teres (= round), gracilis (= slender), rectus (= straight),lumbrical (= worm-like)Size : major, minor, longus (= long), brevis (= short),latissimus (= broadest), longissimus (= longest)Number of Heads or Bellies:biceps (= 2 heads), triceps (= 3 heads), quadriceps (= 4 heads)digastric (= 2 bellies), biventer (= 2 bellies),Position:anterior, posterior, interosseus (= between bones)supraspinatus (= above spine of scapula),infraspinatus (= below spine),dorsi (= of the back), abdominis (= of the abdomen)pectoralis (= of the chest), brachii (= of the arm)femoris (= of the thigh), oris (= of the mouth)

Naming of MusclesDepth:superficialis (= superficial), profundus (= deep),externus (or externi), internus (or interni)Attachment:sternocleidomastoid(from sternum and clavicle to mastoid process)coracobrachialis (from the coracoid process to the arm)Action:extensor, flexor, abductor, adductor,levator (= lifter), depressor,supinator, pronator, constrictor, dilator

Fascia, intermuscular septum, osteofibrous spaces

Innervation of skeletal muscleNeurovascular hilumBlood supplyMotor innervationmotoneurons: slow and fast alfa motoneurons,gamma motoneurons, motor end-plate, AChmotor unit, zone of motor end-plates,polyneural innervation, segmental innervationSensory (proprioceptive) innervationmuscle spindle, Golgi tendon organ,proprioceptive reflexes

tendons, aponeuroses, neuro-vascular hilum (motor point)

Innervation of skeletal muscle: motoneurons, motor units,motor end- plates, acetylcholine, proprioceptive neurons,muscle spindles, Golgi tendon organs

visualization of motor end plates and axons,acetylcholinesterase in subneural apparatus

synaptic vesicles containing acetylcholine(neurotransmitter) in axon terminal of motor end-plate;curare blocks the transmission

Muscle spindleGolgi tendon organElektromyography (EMG)

A young women with sensory neuropathy of unknownorigin who completely lost proprioceptive sensation:She could not stand without watching her feet,she could not held anything in her hands, and theywandered around without her awareness…„Something awful´s happened, I can´t feel my body.I feel weird-disembodied“, she said, and „I may losemy arms. I think they´re one place and I find they´reanother“.After having proprioception explained, she said:„This proprioception is like the eyes of the body,the way the body sees itself. And if it goes, as it´s gonewith me, it´s like the body is blind…so I haveto watch it - be its eyes. Right?“

Fibre Types of Skeletal Muscle• Type 1 fibres are slow-contracting and fatigue-resistant• Type 2A fibres are fast-contracting and fatigue-resistant• Type 2X (B) fibres are fast-contracting and susceptibleto fatigueType I SO Type IIa FOG Type IIx FGmyosin ATPase, dehydrogenase, glycogen phosphorylase

FG IIx FOG IIa SO I

FG IIx FOG IIa SO ICapillaries of skeletal muscle

Development and Differentiationof Skeletal MuscleMyogenesis,Myogenic Determination FactorsMyf-5, myogenin, MyoD and Myf-6 (herculin)MyostatinGrowth of Skeletal MuscleHypertrophy, not hyperplasiaAnabolic SteroidsRegeneration of Skeletal MuscleSatellite cells

MyogenesisMyoblastMyotubeMuscle fibreSatellite cellMyogenicDeterminationFactorsMyostatin

Mutation of myostatine gene resulting in overproduction of myogenic cells

Development of skeletal muscles

ParaxialmesodermNonsegmentedin the head,somites in thetrunkMyogenic cellsGrowth andmigrationof myogeniccells fromsomitesinto the bodywalland limbprimordia

MyoDHH 25

Epaxial and hypaxial musculature and its innervationfrom dorsal and ventral branches of spinal nerves

Epaxial and hypaxial musculature and its innervationfrom dorsal and ventral branches of spinal nerves

C DK HH 22

Colonizationof the limb bud(myogenic cells,Schwann cells,angioblasts,ingrowingAxons)

Extra-ocular muscles(Innervation III.,IV. VI.)Muscles of branchial(pharyngeal) archesMuscles of auditory ossicles(BA 1,2.- V., VII.)Masticatory muscles(BA 1 -V.)Facial muscles (BA 2 -VII.)Musculi palati mollis et atfaucium (IX., X.)Muscles from occipital somitesMusculi linguae (XII.),Musculi laryngis (X.)M. trapezius,M. sternocleidomastoideus(XI.)

Regeneration of skeletal muscle

Activation of satellite scells in muscle regeneration

Fate of the free muscle graft in the rat60. day Intact muscle30. day1.day7. day3. day5. day

General anatomy of peripheral nervous system (PNS)Cranial nerves Spinal nerves Autonomic nervous systém-sympathetic and parasympathetis partNeural crest cells and their differentiationVentral and dorsal spinal nerve root, dorsal root ganglion, drawgeneral structure of the spinal nerve and its branches, autonomicfibers of spinal nerveSegmental innervation, radicular areas, dermatomes, Head´szones (zones of reffered visceralpain), sensory receptors, peripheral nerve regenerationneuron, neuroglia (Schwann cells) nerve fibres,endoneurium, perineurium, epineurium, synapse, ganglion

Development of nervous system - neurulationB.M. Carlson (1999)Neural tube withbrain vesiclesNeural crestNeural placodes

Derivatives of neural crest cellsHNK-1Neurons of spinal ganglia, of autonomic ganglia, enteric neurons,Schwann cells, pigment cells, cells of adrenal medulla

Migration of NC cells of the headED4 chickN. LeDouarin (1999)Ectomesenchyme:osteoblasts, fibroblasts,chondroblasts, smoothmuscle cells, odontoblastsCardiac NC (R4-R8):for cardiac coutflow tract

Wnt1-cre / R26RXgalBgal

Spinal nervetrunk of spinal nerve - mixed nerve, rootlets,anterior root - motor root,posterior root - sensory root, spinal ganglion

Marking of motoneurons using retrograde transportation ofhorseradish peroxidase (HRP) injected into the muscleQ PL inj. HRPC/Q ED 10C PL inj. HRP

Localization of motoneurons for individual muscle groupson transverse section of cervical spinal cord

spinal nerve plexuses,autonomic plexuses,perivascular plexuses

Segmental innervation - areae aradiculares (dermatomes)Kandel et al:Principles of neuralscience,2000 McGraw-Hill

Regeneration of interrupted nerve fibre

peripheral nerve, endoneurium, perineurium,epineuriumNerve graft bridging the partial defect,suture of perineurium

Termsof general angiologyVascular development, structureof arteries, veins, lymphaticvessel, collateral circulationblood vessels,arteriesies, , veins, , capillariesies,arteriovenous anastomosis,collateral vessels,venous plexuseses,hepatic portal vein

Venous valves

Fetal circulation before birthCirculation after birth

Terms of general anatomy of lymphatic systemTerms of general anatomy of lymphatic systemLymph, lymph node, lymph tissue in the organs, mainlymphatic trunks, lymphatic vessels and ducts

Literature:Platzer: Color Atlas and Textbook of Human Anatomy –Vol.1 Locomotor System, Thieme 2008Kahle, Frotscher: Color Atlas and Textbook of Human Anatomy– Vol. 3 Nervous System and Sensory Organs, Thieme 2010Stingl, Grim, Druga: Regional Anatomy, 2012Netter: Atlas of Human Anatomy, Icon 2003Sobotta: Atlas of Human Anatomy Vol.1+2, Williams and Wilkins2000Sadler: Langman´s Medical Embryology, 11th Edit. 2009Carlson: Human embryology and developmental biologyMescher: Junqueira´s Basic Histology 12th Edit., 2010Different original publications in scientific journalsAuthor´s own figs. and illustrations

Sources of used illustrations:Gray´s Anatomy,Sobotta: Atlas der Anatomie des MenschenStingl, Grim, Druga: Regional Anatomy, 2012Benninghoff, Drenckhahn: Anatomie I., II.Sadler: Langman´s Medical Embryology, 11th Edit. 2009Carlson: Human embryology and developmental biologyČihák: Anatomie 1Different original publications in scientific journalsAuthor´s own figs. and illustrations