Skeletal Muscle Flashcards
What does skeletal muscle connect? What energy does it convert?
Bone to bone
Chemical to mechanical
What is skeletal muscle derived from?
Mesoderm
When does contraction occur? How many ATP does this require?
When myosin heads form cross bridges with actin
Uniform contraction of all myofibrils = muscle contraction
1 per sarcomere
What do tendons do? What are they made from?
Attach muscle to bone
Collagen
What is the name of a muscle cell?
Muscle fibre
What is the name of the muscle cell membrane and cytoplasm?
Sarcolemma
Sarcoplsm
what is the smooth ER in a muscle called?
Sarcoplasmic reticulum
What are transverse T tubules?What do they do?
Extensions/invagination of the sarcolemma
Allow action potential to spread to interior of the fibre
Sarcoplasmic reticulum are surrounded by enlarged end regions. What are these calls? Which enzyme pumps calcium out of the sacoplasm and into SR?
Terminal cisternae
SRCaATPase
What is the definition of contraction?
Creation of tension in a muscle
What is tension proportional to?
The number of actin/myosin cross bridges
what is meant by isotonic and isometric contraction?
Isotonic - muscle contracts and shortens with enough power to move load
Isometric - muscle contracts and shortens, but with not enough power to move load (due to elastic components)
What is the sliding filament theory?
Muscles shorten, but actin and myosin remain the same length due to sliding over each other.
Myosin has a binding site for ATP and actin.
