The term ''tissue'' refers to a group of similar cells. Being a combination of equal cells, a tissue has the same function in any part of the body.
The four types of tissues are:
. The epithelial tissue
. The connective tissue
. Muscle tissue
. The nervous tissue
. The epithelial tissue serves as a cover, among these are the skin and the lining of several ducts inside the body. It is divided into two general classifications: Simple Epithelium and Stratified Epithelium.
. The connective tissue supports and joins other tissues such as bone, blood and lymphatic as well as adipose tissue and reticular tissue.
. Muscle tissue consists of striated or voluntary muscles that move the skeleton and smooth muscle, such as the one that surrounds the stomach. It is divided into three types: Skeletal Muscle Tissue, Cardiac Muscle Tissue and Smooth Muscle Tissue.
. Nervous tissue is formed by nerve cells or neurons and serves to carry messages to and from various parts of the body. This tissue is present mostly in the brains and spinal cord. It has two types of tissue: The Nerve Cell and the Neuroglia.
Fat (lipid) molecules are made up mostly of long chains of carbon atoms.
For a fat molecule to be considered saturated, the carbon chain must have only single bonds between them.
Schematically, they look like -C-C-C-C- ...
If the carbon chain contains one or more double bonds, such as -C=C-C-C, then the given lipid molecule is unsaturated.
If a lipid molecule (fatty acid) contains exactly one double bond in its chain, and the rest are single bonds, it is then called monosaturated. It is a more healthy food source than saturated fats.
Saturated fat are generally solid at room temperatures. Examples include lard, butter, mostly from animal sources. However, coconut oil (solid at room temperatures as well) is a saturated fat.
