The Digestive System Flashcards
What is the role of the digestive system?
The role of the digestive system is to ingest food, digest it, absorb nutrients, turn the food and eliminate undigested material.
What are the processes involved in the digestive system?
Ingest Digest Absorb Eliminate
What is the gastrointestinal tract (GI) tract? What organs are involved in the gastrointestinal tract (GI) tract?
The gastrointestinal tract performs all digestive functions within the body.
- Mouth
- Pharynx
- Oesophagus
- Stomach
- Small Intestine
- Large Intestine
- Rectum
- Anus
What accessory organs are involved in the digestive system?
The accessory organs assist in digestion e.g. through secretion of enzyme rich fluids.
- Tongue
- Salivary Glands
- Pancreas
- Liver
- Gall Bladder
What is the oral cavity?
The oral cavity forms the start of the digestive system.
What features are involved in the oral cavity and how do they work?
- The mouth is formed by the cheeks, hard and soft palate and the tongue.
- Teeth are structures specialises for masticating (chewing food).
- Salivary glands add saliva during chewing to moisten food and aid digestion.
What are salivary glands?
Salivary glands are located towards the rear of the oral cavity and produce a watery substance called saliva.
What is saliva?
Saliva is a fluid like substance produced from the salivary glands which contains an enzyme to assist in mechanical break down of food.
What is salivary amylase?
Salivary amylase is an enzyme within saliva: functioning to break down starch (carbohydrates) to maltose.
What are the functions of the oral cavity?
- Analysis of material before swallowing (taste buds play a role in accepting and rejecting food)
- Mechanical processing by the teeth, tongue and palatial surfaces
- Food mechanically broken down by teeth into smaller pieces
What is the function of the oesophagus?
- Bolus is formed within the mouth and moves to the stomach
- The oesophagus transports food by peristalsis from the mouth to the stomach
- Produces large amounts of mucus to lubricate food
- No production of enzymes
- As swallowing begins, the epiglottis is lowered so that food is directed down the oesophagus
- Lower oesophageal sphincter closes after the food enters the stomach (unidirectional valve)
What is peristalsis?
The process where a bolus is transported through automatic movement (contraction and relaxation) from the mouth to the stomach.
What is the stomach?
The stomach is a muscular, j-shaped enlargement of the intestinal tract. It connects the oesophagus to the duodenum (small intestine).
What are the functions of the stomach?
- Short term storage
- Enzymes start to digest proteins
- Churning of the stomach turning food to “chyme”
- liquefying the food to pass slowly into intestine
What is chyme?
Chyme is a soft semi-fluid mixture made from the mechanical churning and chemical break down.
