General myology
RNDr. Michaela Račanská, Ph.D.
Lecture 9 – DENTISTRY – Autumn 2016
General function of muscle
*produces movement in sites of skeletal junctions
*changes shapes and dimensions of various body cavities and
openings
*gives important information about the body position in threedimensional
space
*important role during thermoregulation
*helps to blood and lymph circulation
* verbal and non verbal comunication
* about 600 muscles (♂ 35%, ♀ 32%)
* logistic system (supports respiration, digestion…)
There are three different types of muscle:
1) Skeletal: striated muscle fibers that are attached to bone and are responsible for movements of
the skeleton (sometimes simplistically referred to as voluntary muscle – work under control of
our will, spent a lot of energy, produce heat ( musculi sceleti + skin muscles (musculi cutanei)
2) Cardiac: striated muscle fibers that make up the walls of the heart and proximal portions of the
great vessels (myocardium)
3) Smooth (visceral): nonstriated muscle fibers that line various organs, attach to hair follicles, and
line the walls of most blood vessels (sometimes simplistically referred to as involuntary musclework
without our will, without fatigue)
SKELETAL MUSCLES
(Muscles - an active part of the locomotor system)
Skeletal muscle is divided into fascicles
(bundles), which are composed of muscle
fibers (muscle cells). The muscle fiber cells
contain longitudinally oriented myofibrils
that run the full length of the cell. Each
myofibril is composed of many
myofilaments, which are composed of
individual myosin (thick filaments) and
actin (thin filaments) that slide over one
another during muscle contraction.
Striated fibres – endomysium
Primary and secondary muscle bundles – perimysium internum
Surface of muscle perimysium externum – fascia propria musculi
Caput (head)
Venter (belly)
Cauda (tail)
Common structure of muscle
Origo (origin)
Proximal part (more fixed)
Fascia
Tendo, aponeurosis
Insertio (insertion)
– distal part, more movable)
INSERTIO
ORIGO
tendo
fascia
Structure of muscle
fibrous membrane – fascia – separates
the muscles (or groups) from adjacent
structures.
Vessels and nerves enter into muscle by
its hilus (rich ramification)
Tendons are attached to
the bones by Sharpey´s
fibres
Vessels and nerves of the muscles
Hilus – vessels and nerves
Sensory innervation – muscle and tendon
spindles
Motor innervation – motor plate
Auxiliary facilities of muscles
• Fascias – allow to move one muscle against the other
• Synovial bursae – protect muscle tendons against friction
• Tendons, aponeurosis
• Muscular trochleae – fibrous loops keeping tendon to bone, permit change of direction
of muscle pulling
• Sesamoid bones – at the places of pressure
• Tendon sheats – vaginae tendinum
Auxiliary facilities – tendon sheaths = vaginae tendinum
Along the tendons, closed, increasing sliding capacity of tendons
Fibrous layer =
stratum fibrosum
(Osteofibrous canal)
Synovial layer =
stratum synoviale (ext.
and int. layer with
mesotenonium for
penetration of vessels into
tendon)
Division of muscles according to the shape
•long type (predominantly limb muscles)
• flat type of muscles , paralel fibers, flat sheath, flat
tendon – aponeurosis (abdominal wall muscles)
•short type of muscles (circumarticular muscles)
•Circular muscles (sphincters, around openings)
•Composed:
•biceps, begins with two heads (triceps, quadriceps)
•digastric muscle – musculus digastricus (multibellied
muscle)
•unipennate muscles or multipennate muscles –
feathered apereabce
Division of muscles according to the function
synergists x antagonists
flexors x extensors
biceps of brachium x triceps of brachium
abductors x adductors
abductor pollicis brevis x adductor pollicis
dilatators x sphincters eg.
dilatator pupillae x sphincter pupillae
Cranial nerves ( III. – XII.)
Spinal nerves
(31 pairs)
Dorsal branches
Ventral
branches
(form plexus)
Innervation of muscles (motor, sensory)
Cervical plexus
Brachial plexus
Intercostal nerves
Lumbar plexus
Sacral plexus
Muscle forms together with nerve a functional unit (motor fibers of α
motoneurons). They finish at motor plates in the muscle.
Information about the stage of length and tonus of muscle give sensory tracts
(nerve endings as tendon ´s and muscle´s corpuscles).
Tonus (tone of muscles)
is state of excitability of the nervous system controlling
skeletal muscles (the continuous and passive partial contraction of the
muscles).
The maintenance of tone depends upon impulses
reaching brain and spinal cord from sensory endings in
the muscles, tendons and joints.
It helps to maintain upright.
Tone is abolished by anesthesia (increased tone –
spasticity, decreased tone – flaccidity).
Muscles of head
Muscles of neck
Muscles of thorax
Muscles of abdomen
Muscles of diaphragma pelvis
Muscles of back
Muscles of the upper limb
Muscles of the lower limb
Division of muscles according to topography
SPECIAL MYOLOGY
Description of the muscle:
Origo - origin
Insertio - insertion
Functio – function/action
Inervatio - innervation
Used pictures come from:
Moore, K. L. (1992): Clinical oriented anatomy. Third edition.
Williams&Wilkins, A Waverly Company.
Gilroy, A. M. et all. (2009): Atlas of Anatomy. Thieme New York, Stuttgart.
Putz, R. (2008):
Atlas of Human Anatomy Sobotta. Elsevier Books.
Platzer, W., Kahle, W., Leonhardt H. (1992):
Locomotor system. Georg Thieme Verlag, Stuttgart,
New York, 4th edition.
Čihák, R. (1987): Anatomie 1. Avicenum, Zdravotnické nakladatelství.