Title: Sarcolemma - Definition and Examples - Biology Online Dictionary
Headings: Sarcolemma Definition
Sarcolemma
Table of Contents
Sarcolemma Definition
Characteristics of Sarcolemma
Sarcolemma Structure
The Function of the Sarcolemma
What initiates an action potential on a muscle cell?
The Importance of T-tubules and Triads
Dysfunctional Sarcolemma
Biological Importance of Sarcolemma
References:
Quiz

Content: This forms membranous tubules that pass across the muscle cells. These are called transverse tubules (or ‘T tubules’). The T- tubules contain extracellular fluid, which is high in both calcium and sodium ions. Inside the muscle fibers, the T-tubules lie close to enlarged areas of the sarcoplasmic reticulum known as terminal cisternae. Two terminal cisternae found on either side of a T-tubule is known as a triad. There are thousands of triads in each muscle fiber. The sarcoplasmic reticulum is found surrounding the myofibrils and is made up of membrane-bound tubules. The sarcoplasmic reticulum functions as a calcium store. More information regarding the sarcolemma function is described in more detail below. Figure 5 shows the anatomical relationship of the T-tubules, terminal cisternae, and the sarcoplasmic reticulum, as well as a microscopic image of a triad.