Chapter 9: Histology and Microanatomy Flashcards
What are the three structures involved in muscle cell contraction?
sarcolemma
transverse tubules
sarcoplasmic reticulum
sarcolemma
The plasma membrane name change. (sarcoplasma is the cytoplasm)
transverse tubules
inward folds on the inside of the sarcolemma which project into the interior of the cell.
sarcoplasmic reticulum
The specialized smooth endoplasmic reticulum that stores large amounts of Ca+
terminal cisternae
Enlarged end of the sarcoplasmic reticulum in the area of the T tubules. It stores CA+.
what are the two mechanical structures that aid in muscle contraction?
myofibrils
myofilaments
myofibrils
the generic term for a bundle of fibers
myofilaments
the structures that make up the fibers in the myofibrils
myosin
The thick myofilaments
actin
The thin myofilaments
sarcomeres
The parts of the cell that are giving skeletal muscle and cardiac muscle its striations. The actin and myosin myofilaments make up these.
Describe the structure of the actin
two actin fibers form a double helix that extend the length of the myofilament and that attach at either end of the sarcomere. They are made of G-actin monomers.
tropomyosin
A regulatory protein that blocks the site of the binding site on the G actin, which wants to get in contact with myosin.
troponin
A regulatory protein that has binding sites for calcium, actin and tropomyosin.
Describe the structure of myosin myofilament
Many elongated myosin shaped like golf clubs. Each one contains a myosin head, a myosin hinge, and a myosin “rod portion.” The head is where the binding site is.
