Diet 1 - Digestive System Flashcards
1
Q
Phases of digestion
A
- Ingestion
- Movement
- Mechanical and chemical digestion
- Absorption
- Elimination
2
Q
Types of digestion
A
- mechanical (physical)
Mastication - chemical
Enzymatic reactions to improve digestion of
> carbohydrates
> proteins
> lipids
3
Q
Alimentary tract
A
- mouth
- pharynx
- oesophagus
- stomach
- small intestine
- large intestine
- rectum
- anal canal
- accessory organs
> saliva glands
> pancreas
> liver
> biliary tract
4
Q
Digestive system organisation
A
- gastrointestinal tract (GI) tract
- direct link/path between organs
structures: - Mouth
- Pharynx
- Oesophagus
- Stomach
- Small intestine
- Large Intestine
- Rectum
5
Q
Mouth
A
- teeth mechanically break down food into small pieces
- tongue mixes food with saliva (contains amylase - helps break down starch)
6
Q
Pharynx
A
- epiglottis is a flap at back of throat
- it closes over preventing food from entering it
7
Q
Oesophagus
A
- approx. 10” long
- functions are:
1. Secrete mucus
2. Move food from throat to stomach using muscle movement called peristalsis
(If acid from stomach gets in here = heartburn)
8
Q
Stomach
A
- J shaped muscular bag - stores food eaten and breaks it down into tiny pieces
- mixes food with digestive juices - contains enzymes to break down proteins and lipids
- acid in stomach kills bacteria
- food found here is called chyme
9
Q
Small intestine
A
- 7 meters long
- lining of walls has finger like projections called villi - increases surface area
- villi are covered in microvilli - further increases surface area for absorption
- 3 parts - Duodenum, Jejunum and lleum
10
Q
Small intestine (2)
A
- nutrients from food pass into bloodstream through small intestine walls
Absorbs:
– 80% ingested water
– Vitamins
– Minerals
– Carbohydrates
– Proteins
– Lipids
- secretes digestive enzymes
11
Q
Large intestine
A
- 5 feet long
- accepts what small intestines don’t absorb
Rectum (short term storage - holds faeces before expelled)
12
Q
Large intestine (2)
A
Functions:
- bacterial digestion.
Ferment carbohydrates
- protein breakdown
- absorbs more water
- concentrate wastes
13
Q
What are your accessory organs
A
- liver
- gall bladder
- pancreas
Not part of food path - but play critical role
14
Q
Liver
A
- directly affects digestion by producing bile
Bile: - helps digest fat
- filters out toxins and waste - including drugs and alcohol
15
Q
Gall bladder
A
- stores bile from liver - releases into small intestine
- fatty diets cause gallstones