Question

Draw a well-labelled diagram of the human digestive system.

Answer 1

1. Mouth:
   • The first part of the digestive tract is the mouth, also known as the oral cavity.
   • It is designed to absorb food, masticate it into minute particles, and combine it with saliva.
2. Teeth:
   • There are 20 teeth in a complete set of deciduous (primary) teeth.
   • A complete permanent (secondary) set contains 32 teeth.
   • Each tooth type has a unique form that corresponds to how it chews food.
3. Salivary glands:
   • Salivary glands are essential in digestion because they produce saliva.
   • Saliva helps to moisten food so that it is easier to swallow.
   • It also contains amylase, an enzyme that helps in the digestion of starch in food.
4. Pharynx:
   • The pharynx, sometimes known as the throat, is the tract that connects the mouth and nose to the oesophagus and larynx.
   • The pharynx allows swallowed solids and liquids to flow into the oesophagus.
   • It has a flattened funnel that is linked to the surrounding structures but is loose enough to allow the pharyngeal wall to glide against them during swallowing movements.
5. Oesophagus:
   • The oesophagus is a muscular hollow tube that transports food and liquid from the mouth to the stomach.
   • When food enters the oesophagus, it is pushed downward by waves of muscle contractions (peristalsis).
   • Because no digestion is taking place, it does not secrete any enzymes.
6. Liver:
   • The liver is a big organ that can be found on the right side of the abdomen.
   • It has a correlation with the small intestine.
   • The liver secretes bile, which aids in the breakdown of big globules of fat into smaller droplets for chemical digestion.
   • It also eliminates toxins and other metabolic wastes.
7. Stomach:
   • The stomach is a muscular organ that assists in the digestion of food.
   • It secretes gastric juices containing mucus, HCl, and pepsin enzymes.
   • The mucus is in charge of protecting the stomach lining.
   • The HCl destroys bacteria and makes the medium acidic, while the pepsin digests protein in the stomach.
8. Pancreas:
   • The pancreas secretes digestive enzymes that break down protein, lipids, and carbs in the duodenum.
   • The pancreas also produces insulin, which is released directly into the bloodstream.
   • Insulin is the hormone responsible for sugar metabolism in the body.
9. Large intestine:
   • The colon and rectum form the large intestine.
   • The absorption of water and the egestion of undigested food are the two main functions of the large intestine.
   • In the large intestine, no enzymes are produced.
10. Small intestine:
    • The small intestine is a highly coiled portion of the digestive system that is located in the lower abdomen.
    • It secretes intestinal juice.
    • Secretions from the liver and pancreas are also sent into the small intestine.
    • The small intestine is responsible for the digestion of starch, proteins, and fats.
    • Villi are finger-like extensions on the inner wall of the intestine that help in absorption.
11. Rectum:
    • The rectum is a part of the large intestine.
    • It is responsible for storing undigested food.
12. Anus:
    • The opening of the rectum is called the anus.
    • Undigested food is thrown out of the body in the form of feces.