Gastrointestinal system Flashcards
What is the gastrointestinal system?
a tract that runs from the mouth to the anus & includes the organs of the digestive system
How is the GI system divided?
the upper & lower GI system
What is the GI system also known as?
digestive system or alimentary system
What does the GI system do?
breaks down food into nutrients needed for metabolic processes & rids the body of materials that cannot be used
How does the GI system carry out its role?
chewing breaks down the food into small pieces= easy access for enzymes. Enzymes then chemically digest the food into nutrients that are actively transported into the blood & delivered to cells
What components are part of the upper GI system?
mouth, pharynx, oesophagus, cardiac sphincter, stomach
Outline the stages that food goes through in the upper GI system.
1) MOUTH- food is chewed & mixed with saliva- starts chemical breakdown. Teeth mechanically break down the food further before it is swallowed.
2) PHARYNX- food passes through here, a muscular tube, which links the mouth & oesophagus
3) OESOPHAGUS- links pharynx & stomach. Propels food towards the stomach by peristalsis
4) CARDIAC SPHINCTER- joins oesophagus & stomach
5) STOMACH- food is further broken down by chemicals & enzymes. Muscles help move food along the tract & mix it to break it down into smaller pieces
After the food has been processed in the stomach, what does it become?
a thick, cream liquid called chyme (leaves the stomach via the pyloric sphincter
What components are part of the lower GI system?
small intestine, large intestine, rectum, anus
Outline the stages food goes through in the lower GI system.
1) SMALL INTESTINE- long muscular tube, further chemical breakdown, nearly all nutrient absorption
2) LARGE INTESTINE- starts at the ileo-caecal valve, water is extracted from the indigestible food residue & forms into faeces
3) RECTUM- final section of large intestine
4) ANUS- made of 2 circular muscles, opens & closes to release faeces, the end product of digestion
What are the 5 processes of the GI system?
1) ingestion- food enters the GI system
2) propulsion- movement of food through GI system (via swallowing and peristalsis)
3) digestion- breaking down the ingested food (mechanical or chemical)
4) absorption- absorption of vital nutrients into blood & lymphatic systems
5) elimination- excretion of the end product of digestion
What is a nutrient?
a substance in food that the body uses to promote normal growth, maintenance & repair
Outline the macronutrients & why they are needed.
- protein- repair of cells, production of new cells, growth & development in children & pregnant women
- lipids- small amounts needed to provide essential fatty acids & a source of energy
- carbohydrates- needed to provide energy
Outline the micronutrients & why they are needed.
vitamins & minerals- needed in small amounts for the body to work properly & stay healthy
What are the short-term effects of alcohol?
depends on the amount consumed
- increased heart rate
- blood vessels dilate
- impair cells in nervous system- affects speech, vision, reaction time & coordination
- can lead to dehydration
- alcohol poisoning, which can lead to coma & death
