This preview shows page 1. Sign up to view the full content.
Unformatted text preview: f each thin
myofilament is attached to the
α-actinin in the Z line within the light
areas called the I bands.
The areas of the A bands contain the
heavier thick filaments as well as thin
filaments and are therefore denser
and darker staining. Thin myofilaments are F-actin, with Ca2+-binding troponin and
tropomyosin. The thick filaments are bundles of myosin. The end of
each myosin contacts F-actin in the thin filaments. These
interactions cause the filaments to slide past each other, shortening
the sarcomeres (next 2 slides.)
DIMERS. Interaction b/w
THIN and THICK
ﬁlaments (actin &
myosin) slide against
each other, thus
causing a CONTRACTION. Sarcomere? Contractile
region of muscle ﬁber.. Fig. 10-9 Fig. 10-11
Surface of muscle ﬁber (sarcolemma)
has DEEP INVAGINATIONS which
protrude down to the center of the ﬁber -surround all the ﬁbrils in there!!
These invaginations called
T-TUBULES. T tubules are invaginations of the sarcolemma
which coordinate Ca2+ release throughout the
View Full Document
This document was uploaded on 02/04/2014.
- Spring '14