Muscle [Skeletal 1] Flashcards
Motor unit
A group of muscle cells which are innervated by a single neuron
4 filaments that make up thin filament
F-actin, nebulin, tropomyosin and troponin
What happens during contraction to the bands?
Z discs pulled in, the I band and H zone become narrower. A bands do not change
How is force produced?
There is motion between filaments when the myosin head swings. If this is prevented, force is produced.
How are calcium ions transported into the cell vs out?
Into the cell: passively from the SR or outside.
Out of the cell: actively by pumps.
What happens when the muscle is stretched over 2.2?
Active force (tension) decreases as less overlap. Passive force increases as elastic CT stretches.
Maximal force range
2.0-2.2 micro metres
What happens when the muscle is under stretched (less then 2?)
Active force is decreased as the filaments overlap too much and interfere.
What happens to the length for isotonic and isometric contractions?
Isotonic shortens, isometric no change.
Total tension = _____ + ______
Active + passive force
