Question

In which of the following the small intestine is descriptively divided into which three sections?
A. Ileum, caecum, jejunum
B. Duodenum, caecum, jejunum
C. Duodenum, jejunum, ileum
D. Ileum, duodenum, caecum

Answer 1

Hint:-The human digestive system is a collective term to explain the gastrointestinal tract, few accessory organs, and digestive processes happening within the body. The complex of digestive processes gradually breaks down the foods eaten until they're in a form suitable for absorption.

Complete answer: The canal begins at the mouth, passes through the thorax, abdomen, and pelvis and ends at the anus. It’s parts are: Mouth, Pharynx, Oesophagus, Stomach, Small intestine, Large intestine, Rectum and Anal canal

Mouth:
It's the mouth bounded by muscles and bones: anteriorly —by the lips, posteriorly — it's continuous with the oropharynx, laterally —by the muscles of the cheeks, superiorly —by the bony surface and muscular tongue, inferiorly —by the muscular tongue and therefore the soft tissues of the ground of the mouth.
It consists of the subsequent important parts: The tongue and therefore the teeth.

The Pharynx:
Food passes from the mouth into pharynx then to the esophagus.
It is split for descriptive purposes into three parts, the nasopharynx, oropharynx, and laryngopharynx.


The Oesophagus:
- It is in continuation with the pharynx above and below the diaphragm and joins the stomach.
- The upper and lower ends of the esophagus are closed by sphincter muscles.
- The upper cricopharyngeal sphincter prevents air from passing into the esophagus during inspiration and also the aspiration of oesophageal contents.
- The lower esophageal sphincter prevents the reflux of acid gastric contents into the esophagus.


The Stomach
A J-shaped dilated portion of the epithelial duct situated within the epigastric, umbilical, and left hypochondriac regions of the cavum. It's divided into three regions: the fundus, the body, and also the antrum.


The Small Intestine
- The intestine is continuous with the stomach at the sphincter and leads into the big intestine at the ileocaecal valve.
It comprises of:
- The duodenum: Secretions from the gallbladder and pancreas are released into the duodenum through a standard structure, the hepatopancreatic ampulla, and therefore the opening into the duodenum is guarded by the Sphincter of Oddi.
- The jejunum: It’s the center section of the tiny intestine and is about 2 meters long.
- The ileum: this can be about 3 meters long and ends at the ileocaecal valve, controlling the flow of fabric from the ileum to the caecum, the primary a part of the big intestine, and prevents regurgitation.

The Large Intestine
- It is about 1.5 meters long, beginning at the caecum within the right iliac fossa and terminating at the rectum and anal canal deep within the pelvis.
- Its lumen is larger than that of the little intestine. It forms an arch round the coiled-up gut.
- The colon is split into the caecum, colon, colon, colon, colon rectum, and anal canal.

 The Rectum and also the Anal Canal
- It could be a slightly dilated section of the colon about 13 cm long. It leads from the colon and terminates within the anal canal.
- The anal canal may be a short passage about 3.8 cm long within the adult and leads from the rectum to the outside.
- Two sphincter muscles control the anus; the inner sphincter, consisting of smooth muscle fibers, is under the control of the autonomic systema nervosum and also the external sphincter, formed by muscle, is under voluntary control.


Therefore the correct option is c, duodenum, jejunum, ileum

Note:- Accessory Organs of the Human system
- Various secretions are poured into the alimentary canal, some by glands within the lining membrane of the organs, e.g. Digestive juice secreted by glands within the lining of the stomach, and a few by glands situated outside the tract.
- The latter are the accessory organs of digestion and their secretions have ducts to enter the tract. They consist of:
1. 3 pairs of salivary glands
2. Pancreas
3. Liver and biliary tract