What is the human digestive system?

What is the Human digestive system?

Human digestive system: The biochemical process through which the complex food items taken in by the body are broken down under the influence of various hormones and with the help of enzymes into soluble simple and liquid and usable by the body cells is called digestion.

Anatomy of the Digestive System:

Extracellular digestion: To produce energy during intracellular digestion, glucose, and fatty acids are oxidized. In the alimentary canal lumen, extracellular digestion takes place.

Mechanical digestion: The physical disintegration of large food particles into smaller food particles is known as mechanical digestion.

Chemical digestion: Enzymes are secreted throughout your digestive system during chemical digestion. The chemical bonds that bind food particles together are broken by these enzymes. This enables the food to be divided into manageable pieces for digestion.

Structure and Function of Different Parts of Human Alimentary Tract:

Following is the description of different parts of the alimentary canal or digestive tract:

1. Mouth opening: The transverse hole surrounded by the lips below the nostril is called a mouth opening. The digestive tract starts from here.

Function: Food is received through the stomata.

2. Buccal cavity: The wide cavity after the mouth, protected by the upper jaw and lower jaw is called the mouth. The labia majora has a fleshy tongue, teeth in the upper and lower jaws, and open salivary ducts. The roof of the mouth is called the palate.

Function:

Food is taken orally.
Teeth help in cutting, chewing, and grinding food.
Tongue helps to mix food with saliva, and digest food and its taste buds help to taste food.
Salivary gland juices help in the digestion of some food and in swallowing by salivation.

3. Salivary gland

Location: Mammal salivary glands are exocrine glands that create saliva via a network of ducts. There are three types of salivary glands: serous, mucous, and seromucous.

These are-

(a) Parotid glands below the ears on both sides

(b) submandibular gland on the inner side of the lower jaw; And

Structure: Salivary glands are lined with epithelium and consist of round or oval sacs. In the center of each sac there is a duct. The ducts merge and eventually join the main duct of the gland. The duct then enters the mouth. Glandular cells are of two types – serous cells and mucous cells.

Function: Enzymes are secreted from serous cells of salivary glands and mucus from mucous cells. The digestive function of the salivary glands is to break down starch into isomaltose and the disaccharide maltose by tayalin and convert maltose into glucose by maltase enzyme.

4. Pharynx: The muscular passageway known as the pharynx connects the mouth and nose to the esophagus.

Namely:

The nasopharynx connects the nasopharynx.
Oropharynx, connecting part with the mouth.
Consists of the larynx connecting with the larynx.

Function: Food passes through the pharynx into the esophagus.

5. Esophagus: The muscular, hollow tube known as the esophagus transports food and liquids from the throat to the stomach. Food is transported to your stomach by the muscles in your esophagus. A burning sensation in the middle of your chest, and heartburn is one of the most typical signs of esophagus issues..

Function: Food enters the stomach through the esophagus.

6. Liver:

The liver is situated above the stomach, right kidney, and intestines in the upper right quadrant of the abdominal cavity, beneath the diaphragm. The liver is a dark reddish-brown, cone-shaped organ that weighs about 3 pounds. Approximately one pint (13%) of the body's blood is always stored in the liver. There are two main lobes in the liver. Each is composed of 8 segments, each of which has 1,000 lobules (small lobes). The common hepatic duct is formed by the union of smaller ducts (tubes) that are connected to these lobules. The bile produced by the liver cells is transported by the common hepatic duct to the gallbladder and duodenum (the first section of the small intestine) via the common bile duct.

Structure:

The liver is the largest gland in the body. An adult male weighs about 1.5-2.00 kg. Its weight is 200 grams less in women. The liver consists of four incomplete segments.

Functions:

Production of bile, a digestive fluid that aids in the removal of waste and the breakdown of fats in the small intestine.
Manufacturing specific proteins for blood plasma
Production of special proteins and cholesterol to assist the body in transporting fat
Conversion of extra glucose to glycogen for storage (glycogen can then be converted back to glucose for energy), as well as to maintain balance and produce glucose as needed
Control of blood amino acid levels, which serve as the building blocks for proteins
Iron stored in the liver is used for processing hemoglobin for use.
Ammonia, a dangerous gas, is converted to urea, a byproduct of protein metabolism that is excreted in urine.
Removing drugs and other poisons from the blood
Control of blood clotting
Creating immune factors to fight infections and removing bacteria from the blood
Removal of bilirubin from red blood cells as well. The skin and eyes become yellow when bilirubin levels rise.

7. Stomach: The stomach is a pouch-shaped, thick, walled, and muscular organ. The opening at the junction of the stomach and esophagus is called the cardiac opening and the mbloodstreamuscular ring is called the cardiac sphincter. The opening at the junction of the stomach and duodenum is called the pyloric orifice and the muscular ring is called the pyloric sphincter. The stomach is divided into four parts. Namely:

Cardiac margin—adjacent to the esophagus.
Fundus—portion lying in a straight line parallel to the end of the esophagus.
Vertical part between body and stomach.
Pyloric end-adjacent portion of the duodenum.

The upper curvature of the stomach is called the lesser curvature and the inferior curvature is called the greater curvature.

Functions: The stomach stores food temporarily, sterilizes food, and partially digests some food.

8. Pancreas:

Structure: The pancreas is an abdominal gland that measures about six inches in length. It has a flat pear shape and is surrounded by the liver, spleen, gallbladder, small intestine, stomach, and gallbladder. The head of the pancreas is the wide end on the right side of the body. The neck and body are divided into middle sections. The tail refers to the short end of the pancreas on the left side of the body. The portion of the gland that curves backward and lies beneath the pancreatic head is known as the uncinate process.

Pancreas is a mixed gland. It is broad-headed; with a narrow tail; And the pancreas consists of the middle part of the head and tail. Small ducts emerge from the pancreatic glands and join together to form the ducts of Wirsang.

9. Small Intestine: The longest part of the gastrointestinal tract, or the lengthy, continuous path that food takes through your digestive system, is the small intestine. Food is converted into liquid and the majority of its nutrients are absorbed in the small intestine. The large intestine receives the waste.

The small intestine is divided into three parts. Namely:

U-shaped duodenum next to the stomach.
Middle part jejunum and
End part Ilium. The iliac canal has numerous finger-like projections called villus.

Function: Food is digested and nutrients are absorbed in the small intestine.

10. Large intestine: The part of the digestive system that is most in charge of absorbing water from the indigestible portion of food is the large intestine. Material is passed into the large intestine at the cecum by the ileocecal valve of the ileum (small intestine). The material travels through the colon's ascending, transverse, descending, and sigmoid segments before entering the rectum. The waste is eliminated from the body through the rectum.

Function: Fermentation and digestion of undigested food take place in the large intestine, feces are formed and temporarily stored and some amount of water and salts are absorbed.

11. Anus: The opening through which the rectum opens is called the anus. The anus is bounded by two sphincter muscles.

Function: Excretion occurs through the anus.

Conclusion:

The main job of breaking down energy-containing compounds and transporting them into the bloodstream is done by the digestive system for the rest of the body to use. Equally important are the body's systems for removing substances from the blood. The buildup of waste materials like ammonia, urea, potassium, and hydrogen ions can cause serious pathology. For instance, hyperammonemia can cause severe, irreversible neurological damage. (a buildup of ammonia in the blood).

What is the human digestive system?