Gastrointestinal System Flashcards
What are the function of the GI tract?
digestion and elimination
Explain the function of ‘digestion’ in the GI tract
the ‘breaking down’ (mechanical and chemical) of food and fluid into simple chemicals that can be absorbed and transported throughout the body
Explain the function of ‘elimination’ in the GI tract
waste products are disposed of through the excretion of faeces
The digestive system is made up of the GI tract. Describe it…
This is a series of hollow organs joined in a long, twisted tube from the mouth to the anus.
Name the 6 organs involved in the GI tract
- mouth
- oesophagus
- stomach
- small intestines
- large intestines
- anus
What is meant by an accessory organ?
in relation to the digestive system, is an organ which aids digestion but is not directly part of the digestive tract
What are the accessory organs of the GI tract?
- teeth
- tongue
- salivary glands
- gall bladder
- pancreas
- liver
Explain the role of the mouth in the GI tract?
- chewing
- food reduced to a bolus
- salvia starts to dissolve food
- teeth chop and grind food into small pieces
- lingual lipase activated in stomach to break down fats
- tongue pushes food to back of throat
- nasal cavity and windpipe close to prevent aspiration
- as you swallow the digestive process becomes involuntary
Explain the role of the oesophagus in the GI tract?
- food passes through the pharynx into oesophagus
- involuntary peristalsis involves muscular waves of movement to push the food down the stomach
Explain the role of the stomach in the GI tract?
- a temporary holding station
- hydrochloric acid and enzymes break down the protein
- mucus lining the stomach allows us to eat larger amounts of food
- liquids pass through in minutes
- acts as a food mixer, grinds food into smaller pieces
Explain the role of the small intestines in the GI tract?
- bile enters the duodenum
- pancreatic juices (strong enzymes) enter duodenum to read down fats, carbs and proteins
- duodenum, jejunum, ileum role
- 2-4 hours for food to pass through
When referring to the small intestines in the GI tract, what is the organ and what is the accessory organs?
organ - small intestines
accessory - liver, gallbladder and pancreas
What does the liver do in the GI tract?
produce bile to emulsify fats, makes it easier to break down
What does the gallbladder do in the GI tract?
stores bile that is not needed
What does the pancreas do in the GI tract?
creates pancreatic juices that has enzymes in, squirts into breakdown
Identity the 3 sections of the small intestine
duodenum, jejunum, ileum
Describe bile
a yellow/green fluid containing bile acids to break down fats - ‘stomach acids’
What is the role of the duodenum and jejunum sections in the small intestine?
where the chyme is broken down
chyme = acidic fluid which passes from the stomach to the small intestine
What is the role of the ileum section in the small intestine?
absorbs water and nutrients into the blood stream
What is the role of the large intestines in the GI tract?
- food passes through another sphincter
- cecum - receives chyme from ileum
- colon - absorbs water to form faeces
- mucus helps the faeces slide through
- leaves undigested and indigestible food
- rectum - faeces stored before excreted
What is a sphincter?
Food passes through a sphincter to let food in but prevent it moving back. A sphincter is a strong ring shaped muscle.
What are the 3 sections of the large intestine?
cecum, colon, rectum
What does the cecum section of the large intestines do?
short pouch which receives chyme from ileum
acidic fluid
What does the colon section of the large intestines do?
absorbs water to form faeces
What does the rectum do within the large intestines?
where the faeces is stored before is is excreted
What is the role of the liver in the GI tract?
nutrients from food is absorbed into the blood stream and travels to the liver where food is processed then either stored or sent to other parts of the body to be used