Digestive System Flashcards
What are the 4 parts of the digestive system
- Ingestion (swallowing + peristalsis)
- Digestion
- Absorption
- Defecation (removal of undigested material)
What happens in digestion
The physical (by teeth) and chemical (by enzymes) breakdown of food into nutrients (unit molecules) small enough to diffuse into cells
What happens during absorption
Diffusion and active transport of nutrients into blood
Saliva contains
Mucus (to make food slippery to swallow)
Hydrology enzymes salivary amylase (breaks down starch to maltose and makes food taste better)
Peristalsis
Wave like contractions in the esophagus that push food to the stomach
Cardiac sphincter
Entrance to the stomach which prevents food from leaving the stomach back into the espopagus
When does heart burn occur
When acid escapes through the cardiac sphincter into the esophagus
What does gastric juice contain and where is it found
In the stomach
1. HCl (makes it acidic)
2. Mucus (protects stomach wall from HCl)
3. Pepsinogen
What causes an ulcer
The digestion of proteins in the stomach cell membranes
Pyloric sphincter
The sphincter that acid chyme passes through to go from the stomach to the small intestine
Epiglottis
Closes entrance to trachea (windpipe) so that food doesn’t enter
Why is E. coli found In the colon helpful
Helps breakdown some undigested and produce vitamins and amino acids for our use
Major function of the colon
Absorbs water
Function of the stomach
Store food and digest protiens
Bile
Breaks down fat (inc. surface area)
Liver produces it
Gall bladder stores it
Enters through the duodenum
Emulsifies
When fat disperse in water
Soft palate
Prevents food from entering the nasal cavity
Uvula
Provides gag reflex
deflects large food
Pancreas’s
Secretes pancreatic juice into the duodenum through the pancreatic duct
What is pancreatic juice made up of
- Sodium bicarbonate
- Amylase
- Lipase
- Trypsin
Sodium bicarbonate
Neutralizes acid chyme to a pH of 8
Provides a good pH for the pancreatic enzymes
Pancreatic Amylase
Continues breakdown of starch to maltose (started in the mouth)
Lipase
Breaks down fat to fatty acids and glycerol
helped by the emulsification of fat into smaller droplets by bile
Trypsin
Continues to break down protein into peptides which was started in the stomach