Structure and Function – Working Together, Essay Example

Organ Systems

The endocrine system is composed of hormones and glands. The hormones released by endocrine system glands influence almost all cells, organs, and generally the human body function. For example the endocrine system plays an important role in regulating, metabolism, tissue function, growth and development regulating, reproductive processes and sexual function as well as mood regulation (Lenniger A. 2005) .The digestive system is also vital to the functioning of the body because it plays the role of digestion of food hence ensuring that the various body cells organs and hence body systems are nourished for proper functioning.

The Digestive system

The digestive system is made up of a series of organs that are hollow and joined in a long, twisting tube which run from the mouth to the anus and other organs like the liver and pancreas that produce or store digestive chemicals help the body break down and absorb food (see figure).These organs include the mouth, stomach, the small intestines, the colon (large intestines), rectum and finally the anus. These organs are lined in the inside by a mucosa. The mucosa in the stomach, small intestines and the mouth has tiny glands from which digestive juice is produced. The gastrointestinal tract has a layer of smooth muscles that help propel food along the tract and also assist in its breakdown.

The two digestive organs, (pancrease and the liver) produce digestive juices which are passed through ducts to the intestine. The digestive juices produced from the liver are stored in the gallbladder until when needed in the intestine. Parts of the circulatory and nervous also play a major role in digestion.

The process of digestion starts in the mouth where food is partly broken down through the chewing process and also by the chemical action of enzymes found in the saliva. The salivary enzyme (amylase) is secreted by the salivary glands and helps start starch digestion. From the mouth the partly broken food passes through the esophagus which is along tube which connects the mouth and stomach.  This movement of food from one organ to another is as a result of   muscle movement called peristalsis. The lower esophageal sphincter found at the junction of the stomach and the esophagus relaxes to allow food passage to the stomach

In the stomach swallowed food is stored first then the muscle action of the lower stomach mixes the food with digestive juices produced by the lining of the stomach in a process called chyming and finally the stomach empties its contents into the small intestines .Gastric juice produced by gland on the stomach lining contains hydrochloric acid which helps regulate the acidity of the stomach within the required limits and an enzyme that digest proteins. The mucosa of the stomach is lined with a layer of mucus which prevents HCL from digesting the stomach wall.

After this the chyme from the stomach is passed into three parts of the small intestines first the duodenum, then the jejunum and finally the ileum. In the small intestines pancreatic juices as well as enzyme s from the intestinal wall glands and bile salts from the liver digest food completely into absorbable products. Absorption of nutrients starts in the small intestines. The small intestine mucosa is covered with villi (finger like projections) and microvilli which project from villi whose purpose is to increase surface area for absorption. In addition the small intestines has specialized cells absorption of the digested material across the intestinal wall into the blood for metabolism.

From the small intestines the digested food passes into the large intestines where some electrolytes and water are absorbed .There are microbes in the colon like Escherichia coli and klebsiella which help with digestion.  The colon is made up of several parts. The first part is the cecum which is connected to the appendix. Food from the caecum travels upward in second part which is the ascending colon and then across through the transverse colon, and back down t in the descending colon, and finally through the sigmoid colon.  In the rectum Solid waste is stored it is excreted through the anus via bowel movement.( Stryer L. 2005).

The endocrine system

The endocrine system is composed hormones and glands hormones act as the body’s chemical messengers, transferring instructions and information from between sets of cells. Each hormone has a specific cell that has specific receptors to the hormone.

A gland is formed by a group of cells that produces, secretes and releases the hormones. There are two types of glands; the exocrine glands which release their specific hormones to specific areas for example the sweat and salivary glands whose secretions are released n the mouth and the skin respectively. On the other hand endocrine glands release many hormones into the blood which are then conveyed to different body cells .the major endocrine gland are hypothalamus, thyroid, pituitary, parathyroid adrenals pineal body and reproductive gland s which are the testes and ovaries.  The pancreas is also included in this system.

Once secreted a hormone moves from the endocrine gland via the bloodstream to target cells which should receive its information.  The hormones are bound by Special proteins which act as carriers along the way and also regulate the amount of hormone interacting with the target cells the target cells as well as the hormones have specific receptors to each other which determine the specificity .After the hormone locks into the target cell receptors the hormone- receptor combination transfer information to the inside of the cell.

Hormone secretion is regulated by specific substances in the blood which are related to the hormones or by the hormones themselves through feedback mechanisms. For instance, thyroid hormone secretion by the thyroid glands is regulated by pituitary hormone. When thyroid hormone has been secreted into the blood in quantities that are adequate the levels of thyroid hormone are sensed by the pituitary gland which then adjusts its thyrotrophic release, the pituitary hormone that stimulates production of thyroid hormones by the thyroid gland. Another example regulation of blood calcium by the parathyroid hormone, which raises the calcium levels in the blood. Rise of calcium levels is sensed by the parathyroid glands which then reduce secretion of parathyroid hormone. (Stryer L. 2005),

How the Digestive system and the endocrine systems are interlinked

The human body functions as an interplay of various organ systems, this is a set of various organs operating in tandem and synergistically to form one system (Stryer 2005) The organ systems that are in the human body include, the cardiovascular system, the digestive system, the excretory system, the endocrine system, the lymphatic system, the nervous system and the respiratory system. All the organ systems interlink and function in tandem to form the human body and the human physiology is dependent on the proper functioning of these organ systems.

The Digestive system also called the alimentary canal or the gastrointestinal tract is made up of several organs which include organs of the endocrine system and the excretory system.

The stomach produces hydrochloric acid which helps regulate the acidity of the stomach within the required limits. The production of hydrochloric acid is regulated by two hormones namely somatostatin and cholecystokinin these act antagonistically where somatostatin increases secretion of the acid and cholecystokinin decreases the secretion of the acid (Hames 2000).and this leads to osmotic regulation. Finally the rectum and anus are involved in the excretory processes of the body. The digestive system is interlinked with both the nervous system and endocrine system once the food lands in the mouth which leads to salivation where enzymes, mucus, ions and water are released into the mouth. The interlinking continues into the oesophagus where food is transported in boluses regulated by the sympathetic and parasympathetic system of the nervous system. The stomach secretions are regulated by the endocrine hormones listed above and the parasympathetic and sympathetic nervous system (Lenniger 2005).

The making of a robot that effectively mimics the human homeostatic functions is not possible due to several reasons. First the human homeostatic and organ systems interplay is guided by many organ systems that functions partly due to trigger mechanism as well as feedback mechanism. It is rather hard to programme control panels to respond to the varied signals that the system gives as feedback and thereby regulate itself. This is exemplified by the digestive system where the body gets feedback from the osmo-regulatory function which triggers the absorption of water across the gastrointestinal tract when the body is dehydrated and also secretes the same when there is enough water in the body.

The second reason why the robot cannot mimic the human system is because of the anabolic reactions that occur in the organ systems. Several enzymes and hormones are biosynthesised on ad-hoc basis. This means that the body should have biosynthetic functions to serve this purpose which can not be developed in a robot.

References

Hames B. (2000). Biochemistry. Washington: BIOS Scientific Publishers Limited

Lenniger A. (2005), Principles of Biochemistry. New York: W H Freeman publishers

Stryer L. (2005), Biochemistry. New York: W H Freeman