Transcript Digestive System Processes - Mr. Lesiuk

Fig. 12.1
Fig. 12.6
Products of Carbohydrate
and Protein Digestion are
actively transported from
small intestine into the
villus. These simple
sugars and amino acids
are taken into the capillary
bed in the villus and
transported to the Liver.
Products of Fat digestion are absorbed into the
central lymphatic vessel called a LACTEAL
The Duodenum is only
about 45 cm (18 inches
long) but it plays a couple
of very important roles:
1. Receives incoming
Stomach Chyme,
Pancreatic Juices and
Bile from Liver and Gall
bladder.
2. Secretes digestive juces/enzymes from
duodenal glands
1. Receives undigested waste and helps absorb fluid
(water) from those wastes back into the bloodstream, to
help keep us from dehydrating.
2. Helps compact and form
feces.
3. Harbours helpful bacteria which
can further break down wastes to
free up minerals and some bacteria
will help produce and free up some
vitamins, such as Vitamin K
1. Storage of a meal – most expanded structure along the
alimentary canal
2. Mechanical Digestion of food – Stomach is very muscular and
it squeezes to churn and mix food to physically break it down
3. Chemical Digestion of food – Adds PEPSIN enzyme to start
chemically breaking proteins into small peptide chains
4. Protection against Germs – HCl helps activate enzymes but it
also helps kill many of the bacteria that we ingest.
Fig. 12.5
Some gastric glands are classified as being EXOCRINE. ????
They are responsible for producing gastric juice which consists of
mucous, HCl, Pepsinogen and water. In the presence of HCl the
Pepsinogen converts to active Pepsin. This Pepsin is a PROTEASE
enzyme, breaking proteins into smaller peptide chains
When the stomach receives a meal, it gets turned on!
The stomach’s exocrine glands are turned on by a Hormone
called GASTRIN. Gastrin is produced and released from the
stomach’s ENDOCRINE glands????
The pancreas is a
glandular organ that
acts both as an
Exocrine Gland and
also as an Endocrine
Gland. We mostly
focus on its exocrine
role. It produces a
variety of hydrolytic
digestive enzymes
that help chemically
finish off the
digestion of
Carbohydrates, Fats
and Proteins.
When acidic chyme from the stomach enters the duodenum, the
pancreas is stimulated to secrete pancreatic juice
INGREDIENTS:
1. Sodium Bicarbonate – NaHCO3?
2. LIPASES?
3. PANCREATIC AMYLASE?
4. TRYPSIN – same function as PEPSIN
5. NUCLEASES (work on Nucleic Acids)?
When blood sugar is getting too
high. The pancreas produces and
secretes INSULIN into the
bloodstream
When blood glucose levels start getting too low, the Pancreas
will produce and secrete the hormone GLUCAGON.
Glucagon will travel through the bloodstream to tell muscle
and liver cells to break down their stored Glycogen back into
glucose and send it back into the blood, to raise blood sugar
levels
1.
2.
3.
4.
5.
6.
Produces Bile?
Converts Carbohydrates to control blood sugar levels.
Detoxifies the blood?
Makes lots of vital Plasma Proteins?
Stores Iron and Fat Soluble Vitamins – ADEK.
Helps break down nitrogenous metabolic wastes.
Example : Ammonia  Urea
7. Produces Cholesterol and regulates blood cholesterol
levels.
Fig. 12.11
Fig. 12.7
Fig. 12.12
Tap. 237