General Anatomy of Skeletal Muscle

transcript

General anatomy of skeletal muscle,

its innervation and blood supply,

General anatomy of spinal nerve,

General terms of angiology and lymphology

Miloš Grim

Institute of Anatomy, First Faculty of Medicine,

Charles University, Prague

winter semester – 2018/2019

How to study skeletal muscles: identification, muscle groups,

innervation, function, origin, insertion,

position (scheme, tables), osteofascial

spaces (compartments),

transverse sections of limb segments,

dissection

Structure of lecture

General Anatomy of Skeletal MuscleDescription of the muscle, naming of muscles, shape

and fibers architecture

Auxiliary muscle structures

General features and structure of striated muscle (origin,

Insertion, muscle fibers, myofibrils, sarcomeres, sliding filament

mechanism of contraction)

Muscle innervation - motor and proprioceptive

(motor end plate, motor unit, muscle spindle, Golgi tendon organ),

Muscle function

Origin and development of striated muscles,

molecular mechanisms

General features of peripheral mnerves

Terms of angiology and lymphology

Attachments of skeletal muscles – origin, insertion,

endomysial and perimysial sheaths, fascia

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

myo-tendinous junction (MTJ)

pennate muscles

arrangement of parallel

running muscle fibers

Vizualization of axons and zones of motor end-plates

Acetylcholinesterase in the subneural apparatus

Muscle shape and fibers architecture

Naming of muscles IAccording to shape:

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, interosseous (= between bones)

supraspinous (= above spine of scapula),

infraspinous (= 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 muscles IIDepth:

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

Fibrous sheath , synovial sheath, synovial bursa

Auxiliary sructures of striated muscles

Fascia, intermuscular septum, osteofibrous spaces

Muscle fibers

muscle fiber,

myofibril,

sarcomere

sarcoplasmic

reticulum,

T-tubules,

Triads,

mitochondria,

sarcolemma,

basal lamina

Gray´s AnatomySatellite cell

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

striated muscle fibers

Sliding filament mechanism of contraction

Contraction,

Relaxation

Innervation of skeletal muscle

Neurovascular hilum

Blood supply

Motor innervation

motoneurons: slow and fast α motoneurons,

ɣ motoneurons, motor end-plate, ACh

motor unit, zone of motor end-plates,

polyneural innervation, segmental innervation

Sensory (proprioceptive) innervation

muscle spindle, Golgi tendon organ,

proprioceptive reflexes

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

Innervation of skeletal muscle: motoneurons, motor units,

motor end-plates, acetylcholine, proprioceptive neurons,

muscle spindles, Golgi tendon organs

Innervation of skeletal muscle

Spinal cord segment,

dorsal root + ventral root =

spinal nerve

Proprioceptive neurones

in spinal ganglion

α and ɣ motoneurones in

anterior horn of spinal cord

Motor end- plate,

acetylcholine, motor unit,

Muscle spindles,

Golgi tendon organ

Diagram of somatotopic distribution of motoneurons

innervating groups of upper limb and trunc muscles,

transversal section of the cervical spine

Muscle spindle

Golgi tendon organ

Electromyography (EMG)

Oliver Sacks, neurologist…“A young women with sensory

neuropathy of unknown origin who completely lost

proprioceptive sensation:

She could not stand without watching her feet,

she could not held anything in her hands, and they

wandered around without her awareness…

„Something awful´s happened, I can´t feel my body.

I feel weird-disembodied“, she said, and „I may lose

my arms. I think they´re one place and I find they´re

another“.

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 gone

with me, it´s like the body is blind…so I have

to watch it - be its eyes. Right?“

Function of muscleisotonic a isometric contraction

Reciprocal innervation, synergists, antagonists,

atrophy from inactivity,

Resting tension, postural muscles, electromyography,

postcontraction relaxation, denervation atrophy of muscle,

muscle atrophy from inactivity

Voluntary motor activity controls CNS motor systems

according to information from the mechanoreceptors and

proprioreceptors and motivations developed by the limbic

system

Involuntary motor activity is based on reflex activity

Posture, isometric contraction

Motion, isotonic contraction

Muscle fiber types of skeletal muscleSlow-contracting (oxidative) and fatigue resistant fibers are

innervated by slow α motoneurones- SO – Type I

Fast-contracting (oxidative-glycolytic )and fatigue resistant

fibers are innervated by fast α motoneurones- FOG – Type IIa

Fast-contracting (glycolytic) and fibers susceptible to fatigue

are innervated by fast α motoneiurones – FG – Type IIx

Denervation atrophy of muscle fibers, atrophy of muscle

from inactivity, Hypertrophy of muscle

Muscle atrophy

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 susceptible

to fatigue

myosin ATPase, dehydrogenase, glycogen phosphorylase

Type I SO Type IIa FOG Type IIx FG

FG IIx FOG IIa SO I

Capillary bed of the muscle

Density and lengths of muscle capillaries

FG IIx FOG IIa SO I

Development and Differentiation

of Skeletal MuscleOrigin of myogenic cells

Myogenesis,

Myogenic determination factors

Myf-5, myogenin, MyoD and Myf-6 (herculin)

Myostatin

Muscle morphogenesis

Growth of skeletal muscle

Hypertrophy, not hyperplasia

Anabolic steroids

Myostatin

blocks

proliferation

Mutation of myostatine gene resulting in overproduction of myogenic cells

Epaxial and hypaxial musculature and its innervation

from dorsal and ventral branches of spinal nerves

Epaxial and hypaxial musculature and its innervation

from dorsal and ventral branches of spinal nerves

C Leg HH 22

Colonization

of the limb bud

(myogenic cells,

Schwann cells,

angioblasts,

ingrowing

axons)

QCPN Ab

Experimental embryology

Embryonic chimera of japanese quail Q) and white leghorn chick (C)

Somite grafting, myogenic cells in limb primordium

Jacob M, Christ B,

Jacob HJ, Grim M:

(1970 – 1973)

Migration of

myogenic cells in

limb primordium

Grim M: Z. Anat-EntwGesch 132:260-71,1970

SF/HGFHH 21

Scatter factor

(plasminogen-related

growth factor) /HGF

(hepatocyte growth

factor), expression in

limb primordia

Ventral and dorsal muscle blastema in limb primordium,

their clavage in individual muscles

Desmin

Morphogenesis of limb muscles

Regeneration of Skeletal Muscle

Satellite cells

Muscle regeneration- activation of satellite cells

General anatomy of peripheral nervous systémSystema nervorum periphericum (PNS)

Spinal nerve, Cranial nerve, Autonomic nerves -

Sympathetic part, Parasympathetic part

Neuron, Neuroglia, Endoneurium, Perineurium, Epineurium

Synapses, Ganglion,

Afferent nerve fibers (sensory), Efferent nerve fibers

(motor), Mixed nerve , Spinal nerve plexus, Perivascular

plexus, Autonomic plexus

Segmental innervation, Radicular areas, Dermatomes,

Head´s zones (zones of reffered visceral pain), Sensory

receptors,

Peripheral nerve regeneration

Development of nervous system - neurulation

B.M. Carlson (1999)

Neural tube

Neural crest

Spinal cord

Derivatives of neural crest cells

Neurones of spinal ganglia, of autonomic ganglia, enteric neurons,

Schwann cells, pigment cells, cells of adrenal medulla

Spinal nervetrunk of spinal nerve - mixed nerve, rootlets,

anterior root - motor root,

posterior root - sensory root, spinal ganglion

spinal nerve plexuses,

autonomic plexuses,

perivascular plexuses

Kandel et al:

Principles of neural

science,

2000 McGraw-Hill

Segmental innervation - radicular areas (dermatomes)

Development of segmental innervation of limbs

Segmental

pattern

of muscle

innervation

Localization of motoneurons for individual muscle groups

on transverse section of cervical spinal cord

Regeneration of peripheral nerve

Regeneration of interrupted nerve fiber

Nerve graft bridging the partial defect,

suture of perineurium

peripheral nerve, endoneurium, perineurium,

epineurium

of general angiology

Vascular development, structure

of arteries, veins, lymphatic

vessel, collateral circulation

blood vessels,

arteries, veins, capillaries,

arteriovenous anastomosis,

collateral vessels,

venous plexuses,

hepatic portal vein

Venous valves

Terms of general anatomy of lymphatic systemLymph, lymph node, lymph tissue in the organs, main

lymphatic trunks, lymphatic vessels and ducts

Literature:

Platzer: Color Atlas and Textbook of Human Anatomy –

Vol.1 Locomotor System, Thieme 2008

Kahle, Frotscher: Color Atlas and Textbook of Human Anatomy –

Vol. 3 Nervous System and Sensory Organs, Thieme 2010

Stingl, Grim, Druga: Regional Anatomy, 2012

Netter: Atlas of Human Anatomy, Icon 2003

Sobotta: Atlas of Human Anatomy Vol.1+2, Williams and Wilkins

Sadler: Langman´s Medical Embryology, 11th Edit. 2009

Carlson: Human embryology and developmental biology

Mescher: Junqueira´s Basic Histology 12th Edit., 2010

Different original publications in scientific journals

Author´s own figs. and illustrations

Sources of used illustrations:

Gray´s Anatomy,

Sobotta: Atlas der Anatomie des Menschen

Stingl, Grim, Druga: Regional Anatomy, 2012

Benninghoff, Drenckhahn: Anatomie I., II.

Sadler: Langman´s Medical Embryology, 11th Edit. 2009

Carlson: Human embryology and developmental biology

Čihák: Anatomie 1

Different original publications in scientific journals

Author´s own figs. and illustrations from archive

Build your muscles, build your brain

General Anatomy of Skeletal Muscle

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