The structure of the digestive system in the human body

A digestive system is a group of organs that break down chemical components of food into tiny nutrients, which are absorbed to generate energy for the body.

Functions of the digestive system are:

1. Ingestion – eating
2. Digestion – breakdown of food
3. Absorption – extraction of nutrients from food
4. Defecation – removal of waste products

The digestive system contains:

1. Mouth
2. Pharynx
3. Oesophagus
4. Stomach
5. Liver
6. Gall bladder
7. Pancreas
8. Jejunum, Ileum
9. Colon

The functioning of this system 

1. The buccal cavity:

• Food is chewed by teeth, turned and mixed with saliva; the sensations of smell and taste stimulate the salivary glands.

2. The salivary glands:

• Lubricates the food, which enables swallowing it, and ptyalin starts the breakdown of starch.

3. The pharynx:

• Receives softened food mass and initiates swallowing; epiglottis moves over the trachea and prevents food from entering the windpipe.

4. The oesophagus:

• Food moves in a wave-like motion called peristalsis caused by a contraction in longitudinal and circular bands.
• Anti-peristalsis, here the movement occurs upward. It is the reflex action of vomiting, and the abdomen and diaphragm help it.

5. The stomach:

• The stomach acts as a reservoir for food for two to six hours. The food mixes with various hormones and enzymes to begin the digestion of protein; other chemicals are secreted further down the tract.
• It has a capacity of 1 litre and varies in shape. The stomach is impermeable to most substances. Pylorus opens at regular intervals allowing food to enter the small intestine.

6. The liver: 

• Secretion of bile to gall bladder
• Carb, protein and fat metabolism
• Storage of glycogen
• Ingestion of worn-out RBC, WBC, and bacteria

7. The gall bladder:

• Emulsifies fat which makes it easier to breakdown

8. The pancreas:

• It aids in the process of digestion.
• Release insulin directly into the bloodstream to control blood sugar levels.

9. The small intestine:

• It is 7 meters long in an adult and consists of the duodenum, jejunum, and ileum. It has a large lymph and blood supply and is ready to transport the nutrients to the rest of the body.

10. The large intestine:

• 5 m long and consists of the caecum, appendix, colon and rectum.

ACHIEVE EFFICIENT PERFORMANCE IN SPORTS:

As we know, food consumed after ingestion and digestion gets stored in the liver’s glycogen stores. Proper planning of food before an event can make all the difference. 

Once the glycogen in the blood depletes, the brain sends a signal and uses the glycogen stores in the liver. Proper diet before any meet or event will ensure that all glycogen stores are full. Hence energy is always available, which increases the athletes’ performance.

Not being careful or selective with our food intake can cause nausea, vomiting, allergic reactions, feeling heavy, food poisoning, or diarrhoea. All of which will affect the performance and sometimes may even lead to being admitted to the hospital.

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