Question

fill in the blank question

infoldings of the sarcolemma, called transverse blank, are associated with two terminal cisternae.

Explanation:

Identify the anatomical structure

The question asks for the term that completes the description of the infoldings of the sarcolemma. The text states: "Infoldings of the sarcolemma, called transverse [blank], are associated with two terminal cisternae."

Analyze the physiological relationship

In skeletal muscle fibers, the sarcolemma (plasma membrane) has deep invaginations that penetrate into the cell. These are known as transverse tubules, or simply tubules (often abbreviated as T-tubules).

Determine the correct term

The phrase "transverse [blank]" is followed by "are associated with...", which indicates a plural noun. Therefore, the plural term "tubules" (or "T-tubules") fits grammatically and anatomically to complete the term "transverse tubules". Together with two terminal cisternae of the sarcoplasmic reticulum, a transverse tubule forms a structure called a triad.

Answer:

Infoldings of the sarcolemma, called transverse <blank>tubules</blank>, are associated with two terminal cisternae.