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Digestive System
by: Angelica Hernandez
Mouth
The mouth is used to eat , talk , and breath
Esophagus
•
The esophagus (oesophagus, commonly known as
the gullet) is an organ in vertebrates which
consists of a muscular tube through which food
passes from the pharynx to the stomach. During
swallowing, food passes from the mouth through
the pharynx into the esophagus and travels via
peristalsis to the stomach. The word esophagus is
derived from the Latin œsophagus, which derives
from the Greek word oisophagos, lit. "entrance for
eating." In humans the esophagus is continuous
with the laryngeal part of the pharynx at the level
of the C6 vertebra. The esophagus passes through
posterior mediastinum in thorax and enters
abdomen through a hole in the diaphragm at the
level of the tenth thoracic vertebrae (T10). It is
usually about 25cm, but extreme variations have
been recorded ranging 10–50 cm long depending on
individual height. It is divided into cervical,
thoracic and abdominal parts. Due to the inferior
pharyngeal constrictor muscle, the entry to the
esophagus opens only when swallowing or
vomiting.
Stomach
• The stomach is located between the
esophagus and the small intestine. It
secretes protein-digesting enzymes
called protease and strong acids to
aid in food digestion, (sent to it via
esophageal peristalsis) through
smooth muscular contortions (called
segmentation) before sending
partially digested food (chyme) to the
small intestines.
Small Intestine
• The small intestine (or small bowel) is the part of the
gastrointestinal tract following the stomach and
followed by the large intestine, and is where much of
the digestion and absorption of food takes place. In
invertebrates such as worms, the terms
"gastrointestinal tract" and "large intestine" are often
used to describe the entire intestine. This article is
primarily about the human gut, though the
information about its processes is directly applicable
to most placental mammals. The primary function of
the small intestine is the absorption of nutrients and
minerals found in food.[2] (A major exception to this is
cows; for information about digestion in cows and
other similar mammals, see ruminants.)
Large intestine
• The large intestine consists
of the cecum, rectum and
anal canal.[1][2][3][4] It
starts in the right iliac region
of the pelvis, just at or below
the right waist, where it is
joined to the bottom end of
the small intestine.
Liver
• This organ plays a major role in metabolism and
has a number of functions in the body, including
glycogen storage, decomposition of red blood cells,
plasma protein synthesis, hormone production, and
detoxification. It lies below the diaphragm in the
abdominal-pelvic region of the abdomen. It
produces bile, an alkaline compound which aids in
digestion via the emulsification of lipids. The liver's
highly specialized tissues regulate a wide variety of
high-volume biochemical reactions, including the
synthesis and breakdown of small and complex
molecules, many of which are necessary for normal
vital functions.[2]
Appendix
• The appendix (or vermiform
appendix; also cecal [or caecal]
appendix; also vermix) is a
blind-ended tube connected to
the cecum, from which it
develops embryologically. The
cecum is a pouchlike structure
of the colon. The appendix is
located near the junction of the
small intestine and the large
pancreas
• The pancreas /ˈpæŋkriəs/ is a glandular organ in
the digestive system and endocrine system of
vertebrates. It is both an endocrine gland
producing several important hormones,
including insulin, glucagon, somatostatin, and
pancreatic polypeptide, and a digestive organ,
secreting pancreatic juice containing digestive
enzymes that assist the absorption of nutrients
and the digestion in the small intestine. These
enzymes help to further break down the
carbohydrates, proteins, and lipids in the chyme.
Gall Bladder
• In vertebrates the gallbladder (cholecyst, gall
bladder, biliary vesicle) is a small organ that aids
mainly in fat digestion and concentrates bile
produced by the liver. In humans, the loss of the
gallbladder is, in most cases, easily tolerated. The
surgical removal of the gallbladder is called a
cholecystectomy.
•
Enzymes
• Enzymes (pron.: /ˈɛnzaɪmz/) are large biological
molecules responsible for the thousands of
chemical interconversions that sustain life.[1][2]
They are highly selective catalysts, greatly
accelerating both the rate and specificity of
metabolic reactions, from the digestion of food to
the synthesis of DNA. Most enzymes are proteins,
although some catalytic RNA molecules have been
identified. Enzymes adopt a specific threedimensional structure, and may employ organic
(e.g. biotin) and inorganic (e.g. magnesium ion)
cofactors to assist in catalysis.
Bile/bile duct
• Bile, required for the digestion
of food, is secreted by the liver
into passages that carry bile
toward the hepatic duct, which
joins with the cystic duct
(carrying bile to and from the
gallbladder) to form the
common bile duct, which opens
into the intestine.
Mucus
• In vertebrates, mucus (adjectival form:
"mucous") is a slippery secretion produced
by, and covering, mucous membranes.
Mucous fluid is typically produced from
mucous cells found in mucous glands.
Mucous cells secrete products that are
rich in glycoproteins and water. Mucous
fluid may also originate from mixed glands,
which contain both serous and mucous
cells. It is a viscous colloid containing
antiseptic enzymes (such as lysozyme),
immunoglobulins, inorganic
Chemical Digestion
• Digestion is the mechanical
and chemical breakdown of
food into smaller components
that are more easily
absorbed into a blood
stream, for instance.
Digestion is a form of
catabolism: a breakdown of
large food molecules to
smaller ones.
Absorption
• The small intestine (or small
bowel) is the part of the
gastrointestinal tract following the
stomach and followed by the large
intestine, and is where much of
the digestion and absorption of
food takes place. In invertebrates
such as worms, the terms
"gastrointestinal tract" and "large
intestine" are often used to
describe the entire intestine.
Mechanical Digestion
• Digestion is the mechanical and
chemical breakdown of food
into smaller components that
are more easily absorbed into a
blood stream, for instance.
Digestion is a form of
catabolism: a breakdown of
large food molecules to smaller
ones.
Salivary Amylase
• α-Amylase is an enzyme EC
3.2.1.1 that hydrolyses alpha
bonds of large, alpha-linked
polysaccharides, such as
starch and glycogen, yielding
glucose and maltose.[2] It is
the major form of amylase
found in humans and other
mammals.[3] It is also
present in seeds containing
starch as a food reserve, and
Villi
• Intestinal villi (singular: villus) are small, finger-like
projections that protrude from the epithelial lining
of the intestinal wall. Each villus is approximately
0.5-1.6 (millimetres) in length and has many
microvilli (singular: microvillus), each of which are
much smaller than a single villus. The intestines
villi is approximately around 200m2. The Intestinal
villi should not be confused with the larger folds of
mucous membrane in the bowel known as the
plicae circulares. A villus is much smaller than a
single fold of plicae circulares.
Gastric Juices
• Gastric acid is a digestive fluid, formed in
the stomach. It has a pH of 1.5 to 3.5 and
is composed of hydrochloric acid (HCl)
(around 0.5%, or 5000 parts per million) as
high as 0.1 N[1], and large quantities of
potassium chloride (KCl) and sodium
chloride (NaCl). The acid plays a key role
in digestion of proteins, by activating
digestive enzymes, and making ingested
proteins unravel so that digestive enzymes
break down the long chains of amino
acids.
Duodenum
• The duodenum /ˌduːəˈdinəm/ is the
first section of the small intestine in
most higher vertebrates, including
mammals, reptiles, and birds. In fish,
the divisions of the small intestine
are not as clear, and the terms
anterior intestine or proximal
intestine may be used instead of
duodenum.[2] In mammals the
duodenum may be the principal site
for iron absorption.[3]
Chyme
• Chyme (from Greek "χυμός" khymos, "juice"[1][2]) is the
semifluid mass of partly
digested food expelled by the
stomach into the duodenum.[3]
bibliography
• Bibliography (from Greek βιβλιογραφία, bibliographia,
literally "book writing"), as a discipline, is traditionally the
academic study of books as physical, cultural objects; in
this sense, it is also known as bibliology[1] (from Greek λογία, -logia). Carter and Barker (2010) describe
bibliography as a twofold scholarly discipline—the
organized listing of books (enumerative bibliography) and
the systematic, description of books as physical objects
(descriptive bibliography). These two distinct concepts and
practices have separate rationales and serve differing
purposes. Innovators and originators in the field include W.
W. Greg, Fredson Bowers, Philip Gaskell, and G. Thomas
Tanselle.