Now that we have gone over covered the skeletal/muscular and Respiratory/Circulatory Systems thus far, let's explore the remaining systems.
a.) Endocrine and Nervous Systems:
Yoga (the only physical culture capable of this) pays great attention to the endocrine system which affects the mind and vice versa.
The endocrine system consists of ductless glands which pass their substances into the blood or lymphs. They consist of the pancreas, thyroid, parathyroid, suprarenal, pituitary and sex glands (sex glands aka gonads.)
Their secretions are known as hormones. The thyroid is perhaps the most important gland in the entire endocrine system and only yoga gives it (and its constituents) the necessary rich supply of blood! Here are some of the functions of the thyroid:
-Regulation of anabolic (growth and repair) and catabolic (waste) processes and functions.-Mental Development-Sexual Maturity.-Protection of the body against poisons.
It is located in the frontal portion of the neck. Disease of this gland is known as goiter, which depending on the kind may lead to such symptoms as sleeplessness, nervousness, high blood pressure etc.
PREVENTION IS BETTER THAN CURE! So with the help of yoga and a proper diet it is obvious that the endocrine system in its entirety must be well catered to.
Mental emotions such as fear, sorrow and grief do have noted effects on the body. Like shock waves they affect the nervous system which (via its sympathetic nerves) control the endocrine systems. Consequently, care must be taken to keep such emotions under control. This perhaps can only be accomplished via yogic exercises mainly and a proper diet intermingled with short and frequent fasts. Poses in yoga help to strengthen the endocrine system through exercise and the emotions are brought under control via concentration and relaxation.
b) Digestive and Excretory System:
The alimentary canal is a long tube made up of the mouth, pharynx, gullet, stomach, small and large intestines.
The Stomach is perhaps the most important part of this chain of organs and if it is not kept clean it can be a major cause of various diseases. Some Yogic exercises (physical, breathing and cleaning) are geared to ensure this. Of course in addition to a proper diet, this ensures maximum efficiency of this body part.