Chapter 10: Muscles Flashcards
muscle fiber
a sketeletal muscle cell
endomysium
delicate connective tissue that covers each muscle fiber
fascicles
bundles of grouped muscle fibers
perimysium
sheath of tougher connective tissue that encases the fascicles
epimysium
layer of connective tissue that surrounds the muscle as a whole and binds all the muscle fibers together
facia
connective tissue that surrounds the muscle outside the epimysium
- deep facia lies between muscles
- superficial facia (hypodermis) resides just under the skin
direct attachment
muscle fibers merge with the periosteum of a bone, forming a strong attachment
indirect attachment
the epimysium extends past the muscle as a tendon. the tendon then merges with the periosteum
aponeurosis
flat, broad tendon that attaches muscle to another muscle (or occasionally a bone)
muscle cells
- long, thread-like
- multiple nuclei pressed against the side of the plasma membrane
sarcolemma
the plasma membrane surrounding each muscle fiber
sarcoplasm
the cytoplasm of a muscle cell
myofibrils
- long protein bundles that fill the sarcoplasm
- store glycogen and oxygen
- thin and thick myofilaments stacked together
sarcoplasmic reticulum (SR)
- the smooth ER of a muscle fiber
- surrounds each myofibril
- where calcium ions are stored
myofilaments
- fine fibers that make up myofibrils
- 2 types:
- thick (myosin)
- thin (actin)
- arrangement if myosin and actin gives skeletal muscle its striated appearance