Human Nutrition (The Stomach) Flashcards
What is the stomach?
A muscular bag that holds and digests food
What is a muscular bag that holds and digests food?
The stomach
What is the lining of the stomach called?
The mucosa
What is the mucosa?
The lining of the stomach
Describe the mucosa?
It is heavily folded to form millions of gastric glands
What is heavily folded to form millions of gastric glands?
The mucosa
What do the gastric glands of the mucosa produce?
Gastric juice
What produces gastric juice?
The gastric glands of the mucosa
What is gastric juice made of?
3
Mucus
Pepsinogen
Hydrochloric acid
What coats the stomach and prevents self-digestion?
Mucus
What does mucus coat prevent the self-digestion of?
The stomach
What is pepsinogen?
It is an inactive enzyme which does not digest the cells of the mucosa which produce it
What is an inactive enzyme which does not digest the cells of the mucosa which it is produced from?
Pepsinogen
What is pepsinogen converted into by acid in the stomach?
The active enzyme pepsin
What converts pepsinogen into pepsin in the stomach?
Acid
What does pepsin act on?
Proteins
What does pepsin convert proteins into?
Smaller peptides
What is an enzyme said to be as it acts on proteins?
A protease
What is a protease?
An enzyme that digests protein
What is an enzyme that digests protein called?
Protease
What gives the stomach a pH of 1 or 2?
Hydrochloric acid
What is the role of hydrochloric acid in the stomach?
4
Kills many bacteria
Loosens fibrous and cellular foods
Activates pepsinogen
Denatures salivary amylase
What helps to churn and digest food mechanically in the stomach?
The contraction of the stomach walls
What does the contraction of the stomach walls do?
It helps to churn and digest food mechanically
What is chyme?
A thick, soupy mixture of food in the stomach
What is the thick, soupy mixture of food in the stomach called?
Chyme
How does chyme leave the stomach?
It leaves in small amounts when a muscle at the base of the stomach opens briefly
An overproduction of what leads to heartburn?
Acid
What does the overproduction of acid in the stomach lead to?
Heartburn
What is heartburn?
The rising of acid up the oesophagus which is not as well covered in mucus as the stomach
How is heartburn controlled?
By neutralising the acid with an alkali