Muscle 1: Skeletal

Question 1

T/F Skeletal muscle has organized myofibrils

Answer 1

true. they are in functional sarcomere units for directional contraction.

Question 2

what is a fascicle

Answer 2

muscle cell bundle

Question 3

3 connective tissue systems in skeletal muscle

Answer 3

1) epimysium; around entire muscle
2) perimysium; around fascicle of muscle cell

3) endomysium; around individual muscle cells.

Question 4

a myofibril is composed of ___

Answer 4

myofilaments

Question 5

myofibrils consist of repeating units called

Answer 5

sarcomeres

Question 6

during embryonic development, mesenchyme cells differentiate into ____, and the ___ fuse to form ____, an immature muscle fiber. What does this immature fiber do?

Answer 6

during embryonic development, mesenchyme cells differentiate into MYOBLASTS, and the MYOBLAST fuse to form MYOTUBES, an immature muscle fiber.

myotubes later synthesize proteins to make up a MYOFIBRIL and gradually begin to show their STRIATIONS

Question 7

T/F: myoblasts are multinucleated.

Answer 7

false. they are uninucleated but fuse together to form a myotube, which is multinucleated and gives rise to an adult skeletal muscle fiber.

Question 8

I band =
A band =
H zone =

Answer 8

I band = ACTIN ONLY
A band = THICK FILAMENT (including where thick overlaps with thin)
H zone = ONLY THICK