Organs of the GI tract Flashcards
What are the main organs of the GI tract?
Mouth and salivary glands
Oesophagus
Stomach
Small intestine which consists of Duodenum , jejunum , ileum
Caecum - just in some cases
Large intestine which consists of the colon
Rectum
What are the accessory organs of the GI tract?
Liver
Gallbladder
Pancreas
What is the role of the mouth in digestion?
The food entering the mouth (with the help of the tongue) where is broken down mechanically by the teeth and chemically by saliva
What is the role of the oesophagus in digestion?
Food travels down the oesophagus and into the stomach , the mixture of food and saliva swallowed down the oesophagus is balled a bolus
What is the role of the stomach in digestion?
Major breakdown of food happens , both mechanical and chemical, producing gastric acid ( affects the structure of proteins in food, exposing the chemical bonds) - it also created a number of enzymes to continue the digestion of food - the stomach muscles will also contract in order to churn up the food and move it along to the small intestine
gastric acid role
affects the structure of proteins in food, exposing the chemical bonds
What is the role of the small intestine in digestion?
The chyme will be broken down into very small nutrient particles which can be absorbed into the cells of the small intestine and from there into the bloodstream - at the end of the small intestine most of the nutrients have been removed and the chyme becomes semi-solid and passes into the large intestine
What is the role of the large intestine in digestion?
Absorbs water from food and the little nutrients left - no digestive enzymes are produced in the large intestine, from there water and any remaining nutrients are absorbed , leaving faeces which are then compacted and eventually passed out through defecation via the anus. The large intestine contains many different bacteria that perform many different functions. One is the production of vitamin K , another is the stimulation of the immune system for effect against pathogens.
What is the role of the rectum in digestion?
Where the stools are formed that need to be excreted
Monogastric Stomach
Single chamber which is a muscular bag which has many large folds(rugae) on the interior surface
- these allow the it to expand when food enters from the oesophagus
- the contractions of the muscles churn the food which helps to mix it with the secretions
What are the layers of muscle in the monogastric stomach?
- Oblique
- Circular
- Longitudinal
What is the role of the oesophagus in digestion?
The tube connecting the mouth to the stomach
- smooth muscle for easy moving food
What is the role of saliva in digestion?
They are produced in the salivary glands and contains important enzymes
- food is coated with it to start enzyme breakdown and protect the oral mucosa
Partition of Protein
Digested by microbes
- amino acids - nitrogen and ammonia
Nitrogen provides growth for the microbes
Some microbes pass through the digestive process and are killed and broken down into amino acids , therefore microbes are a source of protein
What is the role of rumen in digestion?
Where plant material sits until it breaks down . Symbiotic bacteria break down complex plant carbohydrates (cellulose)
- largest segment
- rely on bacterial fermentation
- fats are absorbed there
- by-product is methane expelled through eructation
