Skeletal Muscles-Structure Flashcards
What is the shape of a fibre?
long cylindrical cells
What is a muscle fibre?
single muscle cell
How are muscle fibers formed?
by fusion of hundreds of embryonic cells (myoblasts)
How big are muscle fibers?
-run for the entire length of a muscle
*ranges from several cm to dozens of cm
How many nuclei do muscle fibers have?
many
Does a baby or an adult have more muscle cells?
they should have about the same
*most are formed before birth therefore the number doesn’t change
What is hypertrophy?
growth in size of muscles
-stimulated by growth and sexual hormones and sometimes exercise
What are the 3 layers of CT in skeletal muscles?
epimysium
perimysium
endomysium
Where is the epimysium?
-surround the entire muscle
-sometimes blends with deep facia that lies between neighbouring muscles
What is epimysium made of?
“overcoat” of dense, irregular CT
Where is the perimysium?
surrounds fascicles
What is perimysium made of?
fibrous CT
What is a fascicle?
group of muscle fibres (looks like a bundle of sticks)
Where is the endomysium?
surrounds individual fibres
What is the endomysium made up?
fine sheath of loose CT
