Human Digestive System Essay

The human body is a complex unit of organs and organ systems whose functions are coordinated and related to realize an efficient, fully functional body. These systems include the circulatory system, which transports nutrients and oxygen to the rest of the body parts through blood, the nervous system and the digestive system. Others include the reproductive system and the respiratory system (Rosdhal, 2008). The digestive system involves numerous organs that function as a unit.Human Digestive System Assignment Essay The organs digest and absorb food and nutrients into the body. The absorbed nutrients are then transported to the rest of the body tissues and organs by blood. The process of digestion begins in the mouth and ends in the anus where the indigestible and the undigested food products are expelled from the body by a process called defecation. This essay discusses the processes that ingested food undergoes in various organs of the digestive system until its final stage where it is expelled from the body.


In the mouth, the teeth physically break down large food particles into smaller particles in a process called chewing. It is recommended by doctors and specialists that one should chew food properly (about twenty times) before swallowing (Rosdhal, 2008). This act increases the surface area of the food particles available for the enzymes to digest. The tongue aids in the process of chewing by pushing the food particles to various parts of the mouth. At the same time, the sight and smell of food alone trigger the parotid gland and salivary gland to secrete saliva (Morrison, 2001).Human Digestive System Assignment Essay These glands are situated on the back of the roof of the mouth and under the tongue. Saliva contains enzyme ptyalin that breaks down starch. Other functions of saliva include aiding in the formation of bolus (the circular compaction of food particles) and moistening of food. After complete physical breakdown of the food, the tongue pushes the bolus to the back of the mouth and into the pharynx. The pharynx links the oral cavity to the esophagus, a long, muscular tube that extends to the stomach and is important for swallowing. In the junction of the esophagus and the trachea, there exists a valve-like organ called the epiglottis. It closes during swallowing and prevents food particles from entering the trachea when swallowing. The bolus travels down the esophagus with the aid of gravity and rhythmic contraction and relaxation of its muscular walls in a process called peristalsis. Peristalsis ensures that one can swallow, notwithstanding the physical position one maintains (Morrison, 2001). During the movement of the bolus down the esophagus, the food continuously mixes and churns due to the close contact with the wall of the esophagus. The mucus lining the wall also makes it smooth to allow the bolus to move down easily. The bolus finally enters the stomach through a sphincter (gate) that separates the stomach from the esophagus.

So much stress and so little time? Take care of yourself: let us help you with your task on
Human Digestive System Essay
Get a 20% Discount on this Paper
Get Help Now

Entry of the food in the stomach stimulates the release of certain juices that further aid in chemical digestion of food. In the stomach, secretion of hydrochloric acid occurs. It kills any pathogens and disease-causing organisms in the food.Human Digestive System Assignment Essay The hydrochloric acid could also digest the walls of the stomach due to its high acidity. The stomach wall is lined with mucus to prevent this (Rosdhal, 2008). The stomach also secretes gastric juice, and it contains various enzymes that digest different types of food. Enzyme pepsin is secreted in its inactive form, pepsinogen, so that it does not adhere to the walls of the stomach (Morrison, 2001). Pepsin digests and breaks down proteins to form smaller peptides. Rennin digests milk. Continuous mixture of the food, juices and secretions in the stomach results to formation of a semi-liquid mass of food called chyme. Chyme stays in the stomach for 2-6 hours (Morrison, 2001). It all depends on the amount of food one binged and the type of food. Heavy foods that are not easily digestible, such as meat, stay for longer in the stomach. In the same manner, when one takes a plateful of food, the food will likely remain in the stomach for longer compared to a situation where one takes only a small amount of food. After 2-6 hours, the chyme leaves the stomach and enters the small intestine. Again, there is a sphincter separating the small intestine from the stomach. It prevents regurgitation and mixing of intestinal contents with contents from the stomach.

The small intestine is divided into three parts: the duodenum, the jejunum and the ileum. Human Digestive System Assignment Essay Secretions of the liver, pancreas and glands from the intestinal wall itself aid in the digestion of food. The duodenum, the first part of the small intestine, provides a site for digestion and absorption of fats. Bile juice, secreted by the liver and stored in the gall bladder, breaks down large fat molecules into smaller molecules in a process called emulsification. Emulsification ensures that surface area of the fats available for enzymatic action is increased (Morrison, 2001). The bile juice also aids in the absorption of the fats, a process that begins in the small intestine. Pancreas secretes pancreatic juice and bicarbonates. The bicarbonates neutralize the acidic chyme (due to the acidity in the stomach). Intestinal juice produced by glands on the walls of the small intestine also contributes to digestion of food. However, the main process that occurs in the small intestine is absorption. The ileum has various adaptations to ensure that absorption occurs effectively. It is long and coiled to slow down the movement of the digested food. This allows the food to remain in contact with the walls of the small intestine for longer. As a result, many nutrients are absorbed. It is being lengthy also ensures that it provides large surface area for absorption of food. In addition, the walls of the ileum possess villi and microvili, the structures responsible for the process of absorption of nutrients (Rosdhal, 2008). The indigestible and undigested food products pass on to the large intestine also separated from the small intestine by a sphincter.Human Digestive System Assignment Essay The sphincter prevents reentry and mixing of the contents from both organs.

The large intestine is divided into ascending and descending colon, cecum, appendix and rectum. Absorption of water, vitamins and certain minerals occurs in the colon. The cecum is small and functionless in humans. In herbivores, however, it is the site where digestion of cellulose occurs. The rest of the indigestible and undigested food products are passed on to the rectum where they are temporarily stored. When it is socially convenient, these products are expelled from the body through the anus (Rosdhall, 2008). The waste products are called feces or stool. This complex process of ingestion and digestion takes about eight hours to complete. However, the type of food ingested and its amount also determine the time the food lasts in the body. It has been suggested that people should refrain from drinking a lot of water during and after a meal. The water is said to dilute the enzymes and, therefore, neutralizes their effect (Morrison, 2001). Human Digestive System Assignment

RECOMMENDED: [SOLVED] The Anatomy of Human Digestive System

Comprehensive Assessment Tina Jones Shadow Health Transcript, Subjective, Objective & Documentation

Calculate the price
Make an order in advance and get the best price
Pages (550 words)
*Price with a welcome 15% discount applied.
Pro tip: If you want to save more money and pay the lowest price, you need to set a more extended deadline.
We know how difficult it is to be a student these days. That's why our prices are one of the most affordable on the market, and there are no hidden fees.

Instead, we offer bonuses, discounts, and free services to make your experience outstanding.
Sign up, place your order, and leave the rest to our professional paper writers in less than 2 minutes.
step 1
Upload assignment instructions
Fill out the order form and provide paper details. You can even attach screenshots or add additional instructions later. If something is not clear or missing, the writer will contact you for clarification.
Get personalized services with Do My Homeworkk
One writer for all your papers
You can select one writer for all your papers. This option enhances the consistency in the quality of your assignments. Select your preferred writer from the list of writers who have handledf your previous assignments
Same paper from different writers
Are you ordering the same assignment for a friend? You can get the same paper from different writers. The goal is to produce 100% unique and original papers
Copy of sources used
Our homework writers will provide you with copies of sources used on your request. Just add the option when plaing your order
What our partners say about us
Check out the latest reviews and opinions submitted by real customers worldwide and make an informed decision.
Customer 452493, May 16th, 2022
Awesome work, responded well and clarified everything.. Would definitely recommend, great service
Customer 452445, September 8th, 2021
The paper was done to my satisfaction. Thnk you.
Customer 452443, November 18th, 2021
Business Studies
I can't even explain how much your help meant to me. Thnk you always
Customer 452443, November 15th, 2021
Although the paper did not make it at the requested time, the writer did reach out to me and asked for a short extension which I was okay with.
Customer 452493, March 16th, 2022
Excellent services!
Customer 452443, November 11th, 2021
Thank you!
Customer 452493, March 16th, 2022
Thank you
Customer 452445, August 20th, 2021
Chemical Engineering
Amazing. The writer delivered the draft earlier than expected, lol. I am pleased with the work; I hope my supervisor will like it too.
Customer 452443, September 1st, 2021
Leadership Studies
This is great! Thanks a bunch
Customer 452485, March 1st, 2022
Thank you - much appreciated!
Customer 452493, April 2nd, 2022
Looks good. Thank you!
Customer 452523, September 27th, 2022
15% OFF your first order
Use a coupon FIRST15 and enjoy expert help with any task at the most affordable price.
Claim my 15% OFF Order in Chat

Order your essay today and save 15% with the discount code ESSAYHELP