Coordination in life processes

Human body is a wonderful machine. It is a complicated structure than it appears. Different life processes in living organisms like respiration, digestion, blood circulation, excretion, nervous system etc., are inbuilt in our body at their specific places and carry out their specific functions in a coordinated manner.
Every process is dependent on other to keep the body in good condition. To understand this concept we analyze how digestive system is coordinated with other systems as an example. We shall study the digestive system from feeling hungry to utilization of food, illustrating the inter connected processes going on in our body.

Feeling Hungry

•  A major cause for feeling hungry lies in the physiology of blood circulation. Levels of different substances are generally maintained in the blood mainly by our digestive system. One of the major substances is glucose.
• When its levels in the blood fall, we get hunger pangs in stomach. This again involves production of a series of proteins, some of which are hormones like Ghrelin.
• Secretion of the hormone “Ghrelin” in the stomach when it goes empty. Ghrelin is secreted from certain cells in the wall of the stomach.
• Hunger contractions (hunger pangs) start to occur in the stomach due to hunger generating signals that reach the brain from the stomach due to the secretion of this hormone.
• It is believed that the Diencephalon in fore brain and vagus nerve (10th cranial nerve) plays an important role in carrying these signals to the brain. Hunger pangs continue up to 30- 45 minutes.
• Increase in ghrelin levels results in sensation of hunger and motivation to consume food

Outcome of sensation of hunger

We find that different organ systems are involved in the digestive process. Feeling hungry leads us to consume food. Sometimes you may have often experienced that stale food is out rightly rejected even before intake.

Taste and smell are closely related

• Taste and smell are intimately entwined. This close relationship is most apparent in how we perceive the flavors of food. Anyone with severe cough and cold can not make out the difference in tastes of certain food items.
• Actually, what is really being affected is the flavor of the food, or the combination of taste and smell. That’s because only the taste, not the food odors, are being detected.
• Taste itself is focused on distinguishing chemicals that have a sweet, salty, sour, bitter, or umami taste (umami is Japanese for ‘savory’). However, interactions between the senses of taste and smell enhance our perceptions of the foods we eat.