Food being chewed into a small pieces (BOLUS) and get mixed with saliva

Saliva is secreted by 3 glands that located around the mouth region

• Parotid gland

• Submandibular gland

• Sublingual gland

Saliva contains water, salts and also ENZYME

• ENZYME; this is when the digestion of carbohydrate

• Alpha 1-4 amylase is secreted and digest amylose (polysaccharide) into a smaller form of sugar (oligosaccharide, disaccaharide).

When the bolus get swallowed, it will go through pharynx.

Pharynx helps the bolus to enter the right tube which is suppossed be esophagus which connect with stomach.

If the bolus enter the other tube (trachea), that person will get choke since trachea connected to the lung for respiration.

Esophagus is a long tube that connected to the stomach.

it brings bolus to the stomach using wave movement (PERISTALSIS).

Esophagus has 2 types of muscles

• Circular muscle

• Longitudinal muscle

  
  

These type of muscles will take turn to contract and relax. By this, the bolus is able to move down to stomach.

• When circular muscle is contract, longitudinal muscle will in relax state.

• Vice versa, when logitudinal muscle contratc, the circular muscle will relax then.

Major protein breakdown; PROTEIN.

Through the esophageal sphincter, bolus enter the stomach.

Esophageal sphincter is a tight muscle that keeps the acid stomach (hydrocloric acid) stay in the stomach.

Gastric juice is secreted and contains acid that kill bacteria, an enzyme that help to break down proteins and fats to simpler form and mucus that protect the stomach lining.

Chyme is a "food processed".

From BOLUS to CHYME.

Chyme then transferred to the small intestine for further digestion and absorption process.

Small intestine is divided into 3 parts; duodenum, jejunum and ileum.

Is a place where the bile salts and pancreatic juice is secreted.

Bile salts is important as a emulsifier to the fat since fat is hydrophobic. When the fat is emulsified, it will allow the fat to absorb into lacteal vessel and blood vessel.

It is a place where most of the nutrients get absorbed.

It digest CHO, PROTEIN AND LIPID into simpliest form/unit. (CHO to glucose, Protein to amino acid and lipid to tryglicerides).

Vili at the lining of the small intestine has a smaller projection called microvilli.

Microvilli make the surface area bigger and allowed large quatities of nutrients to be absorbed in the same time.

This allowed those nutrients to get absorb into lacteal vessel (into lymphatic system/ for lipid) or blood capillaries into circulatory system (for water soluble nutrent).

A place for further absorption of nutrients that did not absorb at duodenum and jejunum.

Ileum connects small intestine to large intestine as a second last destination of food digestion.

Before entering cecum, the chyme first went through a tube called ileocecal valve.

The chyme then go through ascending and tranverse of the colon using peristalsis waves.

As it go through, the water get absorb to make faeces; a solid form waste and and absorption left over nutrients that were not absorbed in small intestine.

Faeces can be watery or too hard depends on the water absorption in the colon. It contains waste body product and also fibres (a nutrient that can't be absorbed)

Then, it continues to descending of the colon and sigmoid.