a-short-review-of-histology

Smooth Muscle Overview

Smooth muscle cells are usually mononucleate
Their cytoplasm is full of actin and myosin but these proteins are not organised into the highly structured filaments that are typical of cardiac and skeletal muscle cells
Smooth muscle cells are found in bundles and are typically found in the walls of the muscular tubes in the body eg blood vessels, gut
Both smooth muscle and cardiac muscle are controlled by autonomic nerves

Cardiac Muscle Overview

Cardiac muscle cells are found in the heart and are usually mononucleate
Their cytoplasm is full of contractile proteins actin and myosin
In cardiac muscle cells, and in skeletal muscle cells, the actin and myosin proteins are organised into filaments
These filaments are organised into contractile units known as sarcomeres
Unlike smooth muscle and skeletal muscle, cardiac muscle cells are branched and are also connected to their neighbours by complex cell junctions known as intercalated discs
You will study cardiac muscle cells again in a later class