Case 9 - Development of skeletal muscle and response to injury Flashcards
what kind of control at skeletal muscles under
voluntary
what type of work do skeletal muscles do
high powered work
what is skeletal muscles typical activity
usually relaxed
where does skeletal muscle originate from
from the somites, you get the bone, connective tissue and muscle fo your limbs (paraxial mesoderm)
skeletal muscle cells originate from dorsal somites
ventral somite makes bone, cartilage and tendons
how does skeletal muscle form
forms in waves: doesn’t develop all at once
histology slide of skeletal muscle
what is the very thick membrane called in striated muscle structure
the epimysium
what are the fascicles of groups of muscle fibres separated by
perimysium membranes
diagram showing striated muscle structure
where are the motor neurones located in the spinal cord
in the anterior horns
what is the neurotransmitter involved and where is it contained
acetylcholine and is contained in the synaptic vesicles
what is the acetylcholine receptor
a ligand operared sodium channel
what is the troponin complex made up of
TnT, TnC, TnL
what is an isotonic force
producing a force that moves the muscle
what is isometric movement
trying to move muscle against resistance that prevents this movement. does not shorten the muscle but essentially increases the tension
what does a motor neurone pool consist of and what do they innervate
consists of many motor neurones, each of which innervates a motor unit with the muscle.
what does a motor neurone innervate
one set of muscle fibres
what is muscle fibre type X
in between type 2B and 2A
what is muscle strain
commonly referred to as a pulled muscle. this injury can happen when the muscle is over stretched, over used or used improperly.
what is a muscle tear
larger injury in which a muscle and the blood vessels that supply it are torn. it typically takes a significant amount of force to cause this type of injury
what is rhabdomylysis
is a serious condition that occurs when muscle fibres die and their contents are released into the bloodstream. Since the kidneys filter out these muscle byproducts, rhabdomyolysis can result in kidney failure, which may be fatal. Symptoms of rhabdomyolysis include muscle pain, weakness and dark urine. Causes include crash injuries, car accidents, heatstroke, infections, intense exercise, seizures and the use of cocaine
what is muscle contusion
also referred to as a muscle bruise. Occurs when a blunt object strikes the body and crushes underlying muscle tissue, but does not break the skin. Contusions typically cause pain, swelling and decreased range of motion.
muscle damage regeneration
what do M1 macrophages do
stimulate production of satellite cells for proliferation and make new muscle fibres
a satellite cell is a stem cell
what is the Duchenne muscular dystrophy
X linked recessive disease caused by mutation of dystrophin gene, the largest known gene (2.4Mb) coding for a 427kD cytoskeletal protein (only males get it)
It is the second most common genetic disorder in man and most common muscular dystrophy of childhood (incidence 1:5000 male live births)
Characterised by degeneration of skeletal muscle due to absence of dystrophin on muscle fibre membrane.
Gastrocnemius muscle inflammation
what is dystrophin
connects the sarcomeres to the membrane and through other proteins to the basal lamina. dystrophin protects from stress and doesn’t let muscle get damaged
what is Becker
mild form of muscle dystrophy
pathophysiology of DMD
pathophysiology of DMD
