BIO|Digestive System Flashcards
is a network of organs that help
you digest and absorb
nutrients from your food.
digestive system
digestive system includes:(2)
gastrointestinal (GI) tract
and your biliary system
a series of hollow organs that are all
connected to each other, leading from your mouth to your anus.
gastrointestinal (GI) tract
is a network of three organs that deliver bile and enzymes through to your GI
tract your bile ducts.
biliary system
three organs of biliary system
liver
gallbladder
pancreas
is the process of mechanically and
enzymatically breaking down food into
substances for absorption into the bloodstream.
Digestion
involves physically breaking down food
substances into smaller particles
to more efficiently undergo
chemical digestion.
Mechanical digestion
The role of ______is to further degrade the molecular structure of the ingested compounds by digestive enzymes into a form that is absorbable into the bloodstream.
chemical digestion
Why is digestion important?
Digestion is important because your body needs nutrients from food and drink to work properly and stay healthy. Your digestive system breaks nutrients
into parts small enough for your body to absorb and use for energy, growth, and cell repair.
4 Stages to food processing
Ingestion
Digestion
Absorption
Elimination
taking in/eating of food
Ingestion
breaking down food(mechanically/chemically) into
nutrients
Digestion
taking in of nutrients by cells
Absorption
removal of undigested food and waste products of digestion
Elimination
Digestion begins immediately in
the _______ with both mechanical
and chemical digestion.
mouth
Mechanical digestion in the oral
cavity consists of grinding of food
into smaller pieces by the teeth, a
process called _____________.
mastication
Chemical digestion in the mouth is
minor but consists of ______________________________ and_____________, both contained in the saliva.
salivary amylase (ptyalin or alphaamylase)
lingual lipase
After sufficient digestion in the oral
cavity, the partially digested
foodstuff, or_______, is swallowed
into the esophagus
bolus
connects the mouth to the stomach.
A tube (about 25 cm long)
Located in your throat near your trachea (windpipe), the _______ receives
food from your mouth when you swallow.
esophagus
windpipe
trachea
A series of muscular contractions within the esophagus called peristalsis delivers food to your stomach.
peristalsis
the expanded organ located
between the esophagus and
the small intestine.
stomach
It is a muscular organ, elastic,
pear-shaped organ that is
about 30.5 cm long and 15.2
cm wide. The stomach’s
capacity is about 1 liter.
stomach
The stomach performs three
functions:
stores swallowed food
mixes the food with the digestive juice it reduces
and conveys its contents slowly into the small intestine
Mechanical digestion in the stomach occurs via ________________ of
the smooth muscle from the _____towards the contracted ______,
termed________.
peristaltic contractions
fundus
pylorus
propulsion
There is significant chemical digestion in the stomach. Two types of glands exist in the _____________ that aid in chemical digestion: _________________ and_______________.
gastric mucosa
oxyntic glands
pyloric glands
The majority of chemical digestion occurs in the_______________. A muscular
tube that is small in diameter (2.5 cm) but approximately 7 meters in length.
The muscles of the ____________ mix food with digestive juices from the pancreas, liver, and intestine, and push the mixture forward for further digestion.
small intestine
The walls of the small intestine absorb water and the digested nutrients into your bloodstream. As peristalsis
continues, the waste products of the digestive process move into the _______
It secretes enzymes such as ______, _____, and _______for the digestion into ______________;
large intestine
maltase
sucrose
lactase
monosaccharides
__________that digests peptide molecules into amino acids; and _________for the digestion of nucleic acids into sugar and
nitrogenous bases.
Peptidase
nuclease
By the time food leaves the small intestine, around ____ of all nutrients have been extracted from the food that
entered.
90%
The ______________ is the first segment of the small intestine. It’s largely responsible for the continuous breaking-down process.
To help break food down, the duodenum receives digestive juices from other organs in your digestive system,
including your liver, gallbladder and pancreas. Ducts from these organs feed
into the _____________. The absorption of vitamins, minerals, and other nutrients
begins in the ____________.
duodenum (25 cm)
produces bile (green liquid) to emulsify
fats in the chyme in the small intestine into globules.
liver
is stored in the gallbladder
Bile
secretes digestive enzymes to break
down protein, fats, and carbohydrates. It also converts starch into maltose; fats into fatty acids and glycerol; proteins
into amino acids; and nucleic acids into
nucleotides.
pancreas
The main function of the
________________ absorption of important nutrients such as sugars, fatty acids, and
amino acids.
jejunum ( 1.4 m)
the involuntary contraction of smooth
muscles that moves nutrients through the digestive system, is vigorous and quick in the jejunum. Nutrients
absorbed by the jejunum enter the bloodstream, where they can then be
distributed to the organs of the body.
Peristalsis
The last portion of the small intestine is the ileum which has fewer villi and
basically compacts the leftovers to pass through cecum through large intestine.
It absorbs any final nutrients, with major
absorptive products being ______ and ________
ileum
vitamin B12 and bile acids
_______ from the digestive process include undigested parts of food, fluid, and older cells from the lining
of your GI tract.
Waste products
The____________________ absorbs
water and changes the waste from liquid into stool. Peristalsis helps move the stool into your ________.
large intestine or colon
rectum
All leftover waste is compacted and
stored at the end of the large intestine
called the _________.
rectum
When full, the anal sphincter loosens
and the waste, called ______, passes
out of the body through the anus.
feces
