Muscular System Flashcards
What are the 6 functions of the muscular system
produce movement of skeleton
maintain body position
support soft tissues
guard body openings
maintain body temperature
store nutrients
what does producing movement of the skeleton do
pull on tendons across joints
and the muscle: contractile tissues
how does it maintain body position
through posture and stabilizes joints
what does supporting soft tissues entail
abdominal wall muscles
pelvic floor muscles
support weight of organs
sheilds internal structures from injury
how does it guard body openings
with sphincters . if one is skeletal muscle, then it is voluntary control
what is a sphincter
a ring of muscle around tube
how does it maintain body temp
muscle contraction requires energy
chem energy (mechanical energy and heat energy)
how much of chem energy is heat energy
60 %
what does heat energy do
heats blood which is then circulated throughout body
how much of our heat is needed to maintain normal body temp
roughly 85 %
What nutrients are stored in muscles
glucose to glycogen
and protein
what is special about glucose in muscles
it keeps the glucose for itself whereas the liver shares with other parts of the body
what is protein in muscles
protein is there, but is not available instantly. it is only used if starving
skeletal muscle structure, 5 main parts
muscle tissue
connective tissue
nerves
blood supply
satellite cells
what is in muscle tissue
muscle cells and muscle fibers
what are the 3 parts of connective tissue in muscle
epimysium
perimysium
endomysium
info on epimysium
surrounds entire muscle
dense, irregular CT
info of perimysium
where epimysium transitions and penetrates the muscle to separate into fascicles (groups of cells)
endomysium info
where perimysium penetrates fascicules to separate into individual cells (areolar ct)
what do nerves tell muscles to do
to contract
what are the blood supplied to muscles by
arteries, veins, capillaries
what are satellite cells
stem cells that can divide and differentiate and merge with skeletal muscle fiber
What is tendon
rope like
what is aponeurosis
sheet like tendon
what are tendons and aponeurosis continuous with
periosteum
are a really firm attachment point
orgin vs insertion
origin is proximal
insertion is distal
SKeletal muscle fibers length is equal to what
length of entire muscle
are skeletal muscle fibers multinucleated? what else about it
yes, (each cell contains 100s of nuclei)
this is because nuclei get squished against
these cells form by emerging myoblasts or satellite cells
are fibers striated or not
yes, the pattern is perpendicular to fibers
regular arrangement of contractile proteins
what are the 2 steps of skeletal muscle fiber formation
myoblasts fuse to form skeletal muslce,
then
satellite cells are found between muscle fiber and endomysosium
what do satellite cells do
retain ability to divide, can fuse with skeletal muscle fiber, increase growth and or repair
