Question

Discuss the function/s and structures of the Digestive body systems. Include in your essay at least 5 different structures that contribute to the functions you choose. Discuss the anatomy of the chosen structures and explain *HOW they contribute to the overall function.

Answer 1

• Digestive system is the system of organs that are responsible for digestion , absorption and elimination of food.
• The digestive system includes teeth ,mouth , esophagus , Stomach, Small, Intestine, Large Intestine.It also relies on support from other organs like liver ,gall bladder and pancreas.

Mouth

• The mouth is the beginning of digestive tract. Salivary gland present in the mouth releases saliva,which contain salivary amylase and salivary lipase which help in carbohydrate and lipid metabolism.
• There are two types of digestion ;- chemical and mechanical .Mechanical digestion occur in mouth by mastication.
• Mouth is also called oral or buccal cavity and its boundaries are defined by the lips, cheeks, hard and soft palates, and glottis.
• It is divided into two section they are  the vestibule, the area between the cheeks and the teeth, and the oral cavity proper.
• Later section is mostly filled by a large tongue ,which is attached to the floor of mouth by frenulum linguae .

Esophagus

• It is a muscular tube that connects mouth and stomach .Food moved through a series of muscular contraction called peristalsis.
• Entry of food is prevented into wind pipe by a muscular flap called epiglottis.
• There are two type of sphincter , they are upper and lower oesophagealsphincter.
• he sphincter then contracts and prevents the contents of the stomach from flowing back into the esophagus.
• Oesophagus is 8 inch long and divided into three parts, cervical , thoracic and abdominal.

Stomach

• Stomach is a hollow organ ,that holds the food, and being mixed with stoamch enzymes.
• Cells in the lining of the stomach secrete a strong acid and powerful enzymes that are responsible for the breakdown process.
• First protein digestion occur in the stomach , which is converted into small polypeptide.
• There are three parts of stomach, they are fundus, pyloric part, body and fundus .Two sphincters are pyloric sphincters and eosphageal sphincter.
• There are numerous fold called rugae which increase the surface area.

Small intestine

• Small intestine are divided into three segment , they are the duodenum, jejunum, and ileum.
• The small intestine is a 22-foot long muscular tube that breaks down food using enzymes released by the pancreas and bile from the liver.
• Digestion of protein , carbohydrate and lipid occur in the small intestine .
• The duodenum is the first segment of the small intestine, which is mainly  responsible for the continuous breaking-down process. It extends from the pyloric sphincter of the stomach, wraps around the head of the pancreas in a C-shape and ends at duodenojejunal flexure
• The jejunum and ileum lower in the intestine are mainly responsible for absorption of nutrients into the bloodstream.Jejunum begins from the duodenojejunal flexure, found in the upper left quadrant of abdomen.The longest part of small intestine is ileum, which is approximately 3.5 cm in length.

Large intestine

• Main water absorbtion occur in large intestine , it is the area which is  responsible for processing waste so that emptying the bowels is easy and convenient.
• It’s a 6-foot long muscular tube that connects the small intestine to the rectum.
• The large intestine is made up of the cecum, the ascending (right) colon, the transverse (across) colon, the descending (left) colon, and the sigmoid colon, which connects to the rectum.
• The good bacteria present in the large intestine help in synthesis of vitamin , processing waste particles and food products.
• An inner organ without any known use that can become inflamed present in large intestine is called appendix .