digestive system Flashcards
Digestion begins at the ____
proceeds throughout the _____
to the ____
Mouth
Abdominal cavity
Anus
The digestive system function is to
Breakdown food for absorption and distribution of nutrients to the rest of the body
Specialized regions and glands perform both
Mechanical (physical) and chemical (enzymatic) digestion
the smooth muscle involved in mechanical digestion and movement of food through the digestive system is controlled by the
parasympathetic nervous system
Blood vessels located along the stomach & small and large intestines
absorb
digested nutrients
undigested food is stored in the
rectum for elimination
structure and function of the digestive system
- food is ingested through the
mouth where mechanical digestion begins
mechanical digestion: any physical breakdown of food
structure and function of the digestive system
2.
by chewing and grinding food in the mouth, food is broken down into
smaller pieces, which increases surface area
structure and function of the digestive system
3.
mucus in saliva lubricates the
food and provides the enzymes amylase and lipase to initiate chemical digestion of starch and lipids
structure and function of the digestive system
chemical digestion is
the process were enzymes break down food particles into simple chemicals that can be used by the body
structure and function of the digestive system
4.
next food is packaged into small parcels called a
“bolus” and swallowed (deglutition)
structure and function of the digestive system
5.
as the bolus passes through the
pharynx,
the epiglottis closes the tracheal opening so that food does not enter the respiratory system, and the
food passes into the esophagus
structure and function of the digestive system
6.
peristalsis
which is the contractions of muscle,
moves the bolus through the gastric spincter to the stomach
structure and function of the digestive system
7.
the esophageal (cardiac) spincter prevents
reflux of food back into the esophagus
structure and function of the digestive system
8.
once in the stomach, digestion continues.
the stomach is a sac made up of ____ muscles
stomach muscle contractions mechanically break down food even further and mix with secretions to form a substance called
chyme
structure and function of the digestive system
there are 3 main secretions of the stomach
mucus
hydrochloric acid
pepsinogen
structure and function of the digestive system
9.
what are the functions of the 3 main secretions of the stomach
mucus lines the stomach
hydrochloric acid creates an acidic environment
pepsinogen is converted into pepsin
structure and function of the digestive system
pepsin is
an enzyme that helps chemically digest proteins in the acidic environment
structure and function of the digestive system
10.
next the chyme is pushed into the
small intestine
structure and function of the digestive system
11.
the first part of the small intestine is the duodenum.
in the duodenum chyme is neutralized by
- bicarbonate from pancreatic secretions
- receives alkaline bile juices from the gallbladder, which helps neutralize acidic chyme
- produces a large number of “brush border” enzymes, including proteases, lactase and other disaccharidases and bicarbonate
structure and function of the digestive system
12.
Villi and microvilli in the small intestine (largely the ileum) absorb
- water-soluble (polar, hydrophilic) digested nutrients into blood
- lipids into lacteals as chylomicrons and vitamin B12
structure and function of the digestive system
13.
blood, carrying nutrients, passes from the small intestine to the
liver through the hepatic duct, allowing liver enzymes to deaminate amino acids, convert to urea, metabolize consumed toxins, and store glucose as glycogen
structure and function of the digestive system
14
the digested material then passes into the
cecum and into the large intestine or colon
structure and function of the digestive system
15.
the vermiform appendix projects from the cecum, which is located at the
junction of the small and large intestines
structure and function of the digestive system
16.
a lot of water and nutrients are absorbed in the _________ ________
_________ ________ absorbs remaining water and salt from digested food
small intestine
large intestine
structure and function of the digestive system
17.
the waste from the small intestine is exposed to
- bacterial fermentation in the colon
- vitamin K is absorbed in the large intestine
- the waste accumulates in the rectum and is ejected through the anus
hormones involved in digestion
ghrelin induces
hunger
hormones involved in digestion
leptin causes the sensation of
satiety
*satisfied feeling of being full
hormones involved in digestion
insulin induces
cellular uptake of glucose
hormones involved in digestion
glucagon stiumates the breakdown of
stored glycogen
practice problems
which of the following organs does digestion begin?
a. mouth
b. stomach
c. small intestine
d. pancreas
a. mouth
practice problems
which of the following organs does the breakdown of proteins begin?
a. mouth
b. stomach
c. small intestine
d. pancreas
b. stomach
practice problems
which of the following structures absorbs nutrients in the small intestine?
a. mucus
b. microvilli
c. enzymes
d. hormones
b. microvilli
practice problems
which best describes peristalsis
a. the partly digested food moving from the stomach to the small intestine
b. the mechanical breakdown of food entering the stomach
c. muscle contractions that mvoe food through the digestive tract
d. chemical digestion of food with the help of enzymes
c. muscle contractions that mvoe food through the digestive tract
