7. Cardiac myocytes and intercalated discs

Cardiac muscle is/is not striated and uses sarcomeres

is

cardiac myocytes differ from skeletal-muscle fibers in their _. (4 things)

shape, connections, are smaller, and energy demands.

Are cardiac muscles branched? How many nucleus do cardiac muscles have?

Yes, 1

Why do heart muscle cells contain mitochondria?

the heart must contract continuously and generate ATP reliably

What connects neighboring cardiac cells?

intercalated discs

What are the role of gap junctions and desmosomes in heart cells?

gap junctions permit electrical current to spread from cell to cell and desmosomes mechanically hold the cell together during contraction

How are cardiac muscle cells electrically and mechanically linked?

An action potential can spread through the networks and the cells can contract together without being one giant cell

Cell shape of cardiac vs skeletal muscle

branched myocytes, long non-branched myocytes

Nuclei of cardiac vs skeletal muscle

one, many

Cell connections of cardiac vs skeletal muscle

Intercalated discs with gap junctions and desmosomes, none of those

Energy support of cardiac vs skeletal muscle

mitochondria, varible

T-tubules and SR of cardiac vs skeletal muscle

large T-tubules and small SR, small T-tubules and large SR