UNIT D1 FLASHCARDS: Digestion, Respiration, Muscle
Peristalsis
The movement
of food through
the entire
digestive tract is
achieved
through the
rhythmic
contractions of
muscle lining the
entire alimentary
canal.
Digestion
The chemical breakdown of organic molecules into smaller
complexes.
Absorption
The movement of digested nutrients to the tissues of the body
Alimentary canal
The digestive tract. An open-ended muscular tube that
measures between 6.5 – 9 meters in length. includes stomach, small and large intestine.
Mastication
-Chewing reduces the size of food particles and increases
the surface area.
-This chewed paste is called a bolus.
Saliva
-A combination of water, mucin and amylase
-Secreted by the salivary glands (pH of 6.4).
-This activates taste buds and lubricates the passage of food.
Amylase
- An enzyme that breaks down starch into dextrin (6 – 8
glucose units) and maltose (2 glucose units).
Cardiac sphincter
-Regulates the movement of food from the esophagus
into the stomach. open and closing door for food to enter stomach from esophagus.
Pyloric sphincter
-Regulates the passage of food from the stomach into
the duodenum. open and closing door for food to enter small intestine from stomach.
Pepsinogen
-The active enzyme for pepsinogen is pepsin.
-Pepsin degrades protiens in to small parts called peptides.
HCl
-An acid secreted by the parietal cells as H+ and Cl- and
acts as an acid only when combined in the stomach cavity
(lumen).
-This activates Pepsinogen and helps break protein
hydrogen bonds.
Rennin (chymosin)
-An enzyme that coagulates
milk so that we can properly digest the milk in a curdeled form
-prodcued only in infants
Mucin
-A bicarbonate rich watery
substance containing
glycoproteins.
-This protects the stomach
lining from digestion!
Hormones
Proteins that enter the blood stream and trigger the
actions of other body structures
Gastrin
-A hormone triggered by the presence of proteins in the
stomach and stomach distension (filling).
-It targets the stomach wall and causes the release of
gastric secretions.
The Pancreas
An organ connected to
the duodenum by the
pancreatic duct. The
secretion of enzymes that
help digest chyme (partly digested food).
The Liver
A large organ that detoxifies
chemicals, breaks down old
red blood cells and produces
bile. An emulsifier that helps to
increase the surface area of
lipids. This does not
chemically digest lipids
The Gallbladder
a small muscular sac that
stores biletha was produced by liver. The gallbladder
empties bile into the
common bile duct. the common blie duct leads to the doudenum.
The Small Intestine
The
absorption of all chemically
digested foods:
Monosaccharides, amino
acids and triglycerides.
An organ located between
the stomach and the large
intestine.
Glucose and Amino
Acids
Actively transport across
the intestinal wall into the
bloodstream.
Glycerol and fatty
acids
Passively diffused into the
lymph vessels for
eventual transport into
the bloodstream.
The Large Intestine (colon)
Water
absorption,
Waste storage
Storage of
bacteria
Production of
some vitamins