Cardiac muscle cell
The cardiac muscle cell builds up the cardiac muscle, the structure of the human heart walls. The function of the cardiac muscle cells is to contract the heart which intern pumps blood around the human anatomy.1
Figure 1 : Cardiac muscle cell: is a photograph of a cardiac muscle cell containing one large nucleus indicated as blue.
The cells size averages to “10–20 µm in diameter and 50–100 µm in length.”2
The cells themselves contain numerous mitochondria, in purple in figure 1 due to the hearts independent aerobic metabolism to obtain energy needed to continue contracting all the time.1
The cardiac muscle cells communicate with other cardiac cells by joining to one another, which is a special intercellular junction called intercalated disks3. The intercalated disks contain gap junctions (like holes) which allow immediate communication between the cells, so that all cells are contracting simultaneously together4.
In the cytoplasm of the cardiac muscle cells contain hundreds of myofibrils, that contain the proteins of actin and myosin, which vary in bands of density see figure 1 of orange, yellow and red bands. 6 There are sarcoplasmic reticulum5 in the cardiac muscle cell that stores and releases calcium into the cell causing myosin heads bind with actin filaments and pull them together, this is how the cardiac muscle cells contract.6
Bibliography of cardiac muscle cell
1) Jeffrey B Kerr PhD 1999: Atlas of Functional Histology: Mosby London pg130 (QM557KER)
2) 1999-2000 by Prentice Hall, Inc: A Pearson Company: Chapter 10 muscle tissue: http://cwx.prenhall.com/bookbind/pubbooks/martinidemo/chapter10/medialib/CH10/html/ch10_8.html (accessed 6 November 2011)
3) 1999 - 2011 HowToMedia: Human muscle cell types: http://www.innerbody.com/image_musc01/musc71.html (accessed 6 November 2011)
4)Oracle ThinkQuest: How cardiac muscle contracts:...