Digestive System
1a.
Mouth- Digestion begins in the mouth when food is ingested and when the food is
chewed the molar teeth break down the food into smaller pieces, this process is
called mechanical digestion. During this stage saliva from the salivary glands that
contain enzymes are around the mouth and the saliva helps begin to chemically
digest the food. The tongue allows the chewed food to be pushed through the
pharynx (throat) and down the oesophagus.
Oesophagus- The oesophagus (long, thin, and muscular tube) that helps connect the
pharynx to the stomach. The gastrointestinal tract helps food and liquids that have
been swallowed and chewed through the pharynx and into the stomach. The
oesophagus does not digest anything however the walls in the oesophagus help
secrete mucus to allow food to pass easily.
Stomach- The stomach produces enzymes and acids that help digest food. Oxyntic
cells in the gastric pits produce hydrochloric acid, this acid assists on making the ph.
level low and allows many bacteria on the food to be killed/destroyed. The muscles in
the stomach contract continuously, as the stomach churns food, and fats melt and
proteins begin to be digested, at this stage the semi-digested food is called chime.
Following from this the pyloric sphincter muscle (muscular valve) that opens to
release food from the stomach to the small intestine.
Small intestine- The digestion now is taking place in the small intestine, where the
chyme (semi-digested food) enters the duodenum and hormones are transmitted
through the blood and trigger the pancreas to free pancreatic juice and also allowing
the gall bladder to release bile. Bile is made in the liver and stored in the gall bladder,
it contains bile acids which are vital for digestion. Bile has salts that emulsify fats,
increasing their surface area for lipase enzymes to work on, contains hydrogen
carbonate ions that help neutralise the acidic chyme also many waste products are
eliminated from the body to faeces.
Gall bladder- The gallbladder is a small storage organ located close to the liver. It is
small in size; the gallbladder plays a vital role in our digestion of food. The
gallbladder stores bile produced in the liver until it is needed for digesting fatty foods
in the duodenum of the small intestine.
1a.
Mouth- Digestion begins in the mouth when food is ingested and when the food is
chewed the molar teeth break down the food into smaller pieces, this process is
called mechanical digestion. During this stage saliva from the salivary glands that
contain enzymes are around the mouth and the saliva helps begin to chemically
digest the food. The tongue allows the chewed food to be pushed through the
pharynx (throat) and down the oesophagus.
Oesophagus- The oesophagus (long, thin, and muscular tube) that helps connect the
pharynx to the stomach. The gastrointestinal tract helps food and liquids that have
been swallowed and chewed through the pharynx and into the stomach. The
oesophagus does not digest anything however the walls in the oesophagus help
secrete mucus to allow food to pass easily.
Stomach- The stomach produces enzymes and acids that help digest food. Oxyntic
cells in the gastric pits produce hydrochloric acid, this acid assists on making the ph.
level low and allows many bacteria on the food to be killed/destroyed. The muscles in
the stomach contract continuously, as the stomach churns food, and fats melt and
proteins begin to be digested, at this stage the semi-digested food is called chime.
Following from this the pyloric sphincter muscle (muscular valve) that opens to
release food from the stomach to the small intestine.
Small intestine- The digestion now is taking place in the small intestine, where the
chyme (semi-digested food) enters the duodenum and hormones are transmitted
through the blood and trigger the pancreas to free pancreatic juice and also allowing
the gall bladder to release bile. Bile is made in the liver and stored in the gall bladder,
it contains bile acids which are vital for digestion. Bile has salts that emulsify fats,
increasing their surface area for lipase enzymes to work on, contains hydrogen
carbonate ions that help neutralise the acidic chyme also many waste products are
eliminated from the body to faeces.
Gall bladder- The gallbladder is a small storage organ located close to the liver. It is
small in size; the gallbladder plays a vital role in our digestion of food. The
gallbladder stores bile produced in the liver until it is needed for digesting fatty foods
in the duodenum of the small intestine.
