Skeletal Muscle Tissue

Question 1

Gross Structures

Answer 1

Fascia (connective Tissue)
Epimysium
Fascicles
Perimysium
Endomysium
Tendon
Aponeurosis

Question 2

Microstructures

Answer 2

Myofiber
Myofibril
Myofilaments

Question 3

Fascia

Answer 3

Connective tissue, around all muscles (not muscle), it groups muscles together and looks like a thick spider web, it’s a space filler. Provides origins of muscles

Question 4

Epimysium

Answer 4

Connective tissue around an entire single muscle (above)

Question 5

Fascicles

Answer 5

Bundles of muscle ells, stringy look like meat, you can see it separated by perimysium

Question 6

Perimysium

Answer 6

Connective tissue, cells, around fascicles (around the stringy part)

Question 7

Endomysium

Answer 7

(not a gross feature) cannot see with bare eye. Connective tissue around single muscle cell

Question 8

Tendon

Answer 8

Attaches muscle to bone (epimysium to periosteum) biggest is the Achilles tendon going from calf muscles to calcaneous bone

Question 9

Aponeurosis

Answer 9

A tendon, broad sheet (not a chord) ex: head, abdominal muscle area, broad sheet like tendon

Question 10

Myofiber

Answer 10

A muscle cell, multinucleate, numerous mitochondria (makes lots of energy, ATP) for contraction all day long, NO mitosis, in skeletal muscle. If injured cannot undergo mitosis and heal, scar tissue develops, has many collagens. Sarcolemma (plasma membrane), sarcoplasmic reticulum (terminal cisternae) ca+ is stored here, Transverse (T) tubules plays a role in muscle contraction, excitment

Question 11

Myofibril

Answer 11

Inside the muscle cell, cylinder striated part attached to sarcolemma, responsible for contraction. I bands (isotropic) light bands, A bands ( anisotripic) dark bands, Z lines where 1 cell ends and another cell begins like a zipper. Sarcomere is the distance from 1 Z line to another Z line squeezed together during muscle contraction, muscle contraction occurs here

Question 12

Myofilaments

Answer 12

Inside Myofibril (smallest) Protein molecule. Its what builds/adds when you are weight training to bulk up.

Thick proteins =

Myosin thick filaments, ex is two golf clubs intertwined together.

Cross bridges (actin binding site), golf club heads,

ATP binding site that bind with actin to aid in contraction “energize”

Thin proteins =

actin protein 2 strands of pearls/beads wrapped around each other anchored to both Z lines squeezes everything together

Tropomyosin protein, 2 ribbon wrapped around actin (strings of beads) prevents contractions, blocks anything from touching beads

Troponin protein holds tropomyosin in place (glue) has a binding site for CA+, if CA+ binds to it, it unglues