digestive system Flashcards
overall purpose of the digestive system
The organs of the digestive system mechanically and chemically process food
overall purpose of the digestive system
why?
Large molecules of food must be broken down into small molecules that can be absorbed by the epithelium lining the digestive tract for transfer to the circulating blood
peritoneum
The peritoneum is a serous membrane with two parts
peritoneum
partial peritoneum that covers the
abdominal wall
peritoneum
visceral peritoneum which covers
the abdominal viscera
there is a potential space between the two peritoneum layers called
peritoneal cavity
the organs within the abdominal cavity are often described in relation to the peritoneal membranes
intraperitoneal organs
retroperitoneal organs
mesentery
intraperiotneal organs
are completely wrapped in peritoneum
retroperitoneal organs
are located posteriorly to the peritoneum, and only their anterior surfaces are covered with peritoneum. they do not have a mesentery
mesentery
-double layer of peritonuem
-suspended organs from wall
peritoneal folds suspend most of the digestive organs to eahcother and to the abdominal cavity there are
5
secondary retroperitoneal organs
are digestive tract organs that are intraperitoneal organs in the early embryonic state but during the embryonic development become retroperitoneal.
greater omentum: attaches to the greater ________- to the ______
greater curvature of stomach to the transverse colon
lesser omentum: attaches stomach and ______ to liver
duodenum
falciform ligaments: attaches _____- to abdominal wall
liver
mesentery proper: binds the jejunum and ____ of the small intestine to the posterior abdominal wall
ileum
mesocolon: bind the transverse colon, sigmoid colon of the ________- and appendix to the posterior abdominal wall
large intestine
oral cavity
the frenulum is
is a small fold of tissue found in different parts of the body
oral cavity
the uvula is part of the soft palate; it helps ….
it helps prevent food and liquid from going up the nose when swallowing
oral cavity
the tongue is secreted to the floor of the oral cavity with a _______-
lingual frenulum
oral cavity
tongue tie is a problem with the tongue that is present from birth. it occurs when the
the frenulum on the bottom of the tongue is too short and tight.
the teeth are composed of four dental tissues, three of them ______ , ________- and ______ are hard tissues
enamel, dentin and cementum
the fourth tissue of dental tissues is the pulp, it is the centre of the tooth that contains
nerves, blood vessels and connective tissue is a non-calcified, tissue.
humans have four types of teeth
incisors, canines, premolars, and molars, which each have a specific function.
nasopharynx functions
only in respiration
oropharynx functions
in digestion and respiration
laryngopharynx functions
in digestion and respiration
swallowing is a process that is initiated voluntarily but continues _________
involuntarily
there are three phases of swallowing
-buccal
-pharyngeal
-esophageal
the pharyngeal muscles cooperate with muscle of the ____ and _____ to initiate and continue the swallowing process
oral cavity and esophagus
what are the 4 major histological layers of the digestive system
-muscosa
-submucosa
-muscular layer
-serous layer or serosa
peristalsis
rhythmic waves of muscle contraction
waves of muscular contractions that move the bolus along the esophagus
Movement of the bolus along the esophagus is called
peristalsis
the peristaltic wave is determined by
longitudinal and circular muscles
esophagus
hollow muscular, transports foods and liquids to the stomach
esophagus enters the peritoneal cavity through an opening in the diaphragm ______
esophageal hiatus
the esophagus begins at the level of the ________- and ends anterior to T7
circuit cartilage anterior to C6
the functions of the stomach are to (3)
- Store food for a bit
- Breaks down food by crushing it (mechanically digest)
- Breaks down food more using acids and enzymes (chemically digest)
the stomach is an _____ organ located between the oesophagus and the duodenum
intraperiotoneal
stomach has four main anatomical divisions
fundus
cardia
body
pyloric part
__ are gastric folds that appear in the empty stomach, increasing its surface are for area for better function
rugae
the small intestine has three anatomical subividions
duodenum, jejunum and ileum
duodenum
the shortest segment of the small intestine. it is approx 25cm long
-C shaped, surrounding the pancreas
duodenum
2.5cm is ____- while the rest is secondarily retroperitoneal
intraperiotoneal
jejunum (2.5m long) at this junction the small intestine re-enters the _____ becoming intraperiotneal and supported by a sheet of mesentery
peritoneal cavity
ileum
the third segment of the small intestine. it is _____ and is the longest segment
intraperiotoneal
ileum
3.5 m in length. the ileum ends in the ________. the sphincter controls the flow of material from the ileum into the cecum of the large intestine
iliocecal valve
large intestine
the horse-shoe shaped large intestine begins at the junction with the ___ and ends at the anus
ileum
the large intestine forms
almost a complete frame around the small intestine
the large intestine is often called
the large bowel or colon
cecum
the cecum is the first part of the large intestine and is located in the right lower abdomen, near the appendix
the cecum is also located intraperitoneally but
lacks a mesentery
large intestine
the colon has pouches called _____ which allow for expansion
haustra
large intestine
longitudinal muscle bands known as _____ create the haustra by maintaining muscle tone
teniae coli
large intestine
the _____ help the the large intestine (colon) by expanding and contracting to mix and move fecal material. This process aids in absorbing water.
haustra coli
appendix
the appendix is attached to the posteromedial surface of the ___
cecum
appendix
the primary function of the appendix is an an organ of the __________
lymphatic system
rectum
the rectum is the final part of the digestive tract leading to
the anal canal
the anus is controlled by two muscles
the internal anal sphincter (involuntary) and the external anal sphincter (voluntary).
inside the anal canal are veins that can damage due to pressure causing hemorrhoids
Strain during bowel movements
Chronic constipation
Diarrhea
Pregnancy
Long therm sitting
the small intestine is responsible for ____ % of digestion, plus a major site of absorption
90%
duodenum extends from pylorus to ________
duodenoiejunal junction
duodenum
_____ regulates movement of chyme from stomach into duodenum
pyloric sphincter
bulk of chemical digestion and nutrient absorption happens in the
jejunum
ileum
mesenteric fat is
abundant
the largest intestine is the last portion of the digestive system
-thinner than
small intestine, no vili
large intestine functions:
secretion of a ______- and movement of remaining non-digested food
protective mucous
cecum
connected to the ileum via ________
iliocecal valve
the cecum collects and stores materials from the _____ and begins the process of compaction
ileum
a small mesentery called the ________– connects the appendix to the ilieum and cecum
meso-appendix
both the cecum and the appendix are
intraperitoneal
colon
haustra
series of pouches - permit considerable distention and elongation
colon
teniae coli
run along the outer surface of the colon- bands of smooth muscle- muscle tone here creates the haustra
colon
omental appendices
teardrop shaped sacs of fat
the ascending colon begins at the superior bodied of the
cecum
the ascending colon turns to the left at the __________ this bend marks the beginning of the transverse
hepatic flexure
______ curves anteriorly form the right colic flexure
transverse colon
the ascending colon is _______-
secondarily retroperitoneal
the initial segment of the transverse colon is ______-
intraperitoneal
the transverse colon is supported by the _______
transverse mesocolon
as the transverse colon passes inferior to the greater curvature of the stomach it becomes _______
secondarily retroperitoneal
descending colon is ______-
secondarily retroperitoneal
at the iliac fossa the descending colon curves and becomes the _______
sigmoid colon
the sigmoid colon is suspended from the _______
sigmoid mesocolon
rectum and anal canal
continence depends on
compliance, consistency and control
rectum and anal canal
the smooth muscles fibers of this sphincter are not ______-
under voluntary control (IAS)
upper right abdominal quadrant
liver and gall bladder
upper left abdominal quadrant
stomach and spleen
lower right quadrant of abdomen
appendix and upper colon
lower left quadrant of abdomen
sigmoid colon
liver and gallbladder
detoxify a wide range of chemicals brought into the body through ________-
food digestion (liver)
liver and gallbladder
regulates metabolism
metabolize nutrients into other forms for storage or use by other tissues (liver)
liver and gallbladder
produce and secrete
(liver) and store bile until it is needed for fat digestion (gallbladder)
liver is the largest
accessory digestive organ
liver lies in right ____ and epigastric regions
hypochondriac
liver extends into the
left hypochondriac and umbilical regions
4 lobes of the liver
right
left
caudate
quadrate
ligaments of liver
falciform
round
coronary
gallbladder is an intraperiotoneal organ
-located ?
located in a fossa on the posterior surface of the livers right lobe
the gallbladder store and concentrates
bile before its transfer to small intestines
three regions of gallbladder
funds, body and neck
gallbladder
cystic duct exits the gallbladder and unties with the __________ to create the common bile duct
hepatic duct
gall bladder
at the duodenum a muscular sphincter of ampulla surrounds the lumen of the ______ and duodenal ampulla
bile duct
the _____ brings blood from the intestine to the liver
hepatic portal system
circulation in the hepatic portal system
_____ of the blood enters through portal vein
75%
circulation in the hepatic portal system
____ of blood enters through hepatic artery
25%
circulation in the hepatic portal system
central veins drain into the ______
hepatic vein
pancreas posses both ____ and _____ gland components
endocrine and exocrine
pancreas
is 99% endocrine gland
produces digestive enzymes and buffers
pancreas is 1% endocrine
(Islet of Langerhans – Alpha and Beta Cells
Pancreatic exocrine glands contain acini and ducts
acini
grape like clusters of exocrine cells that secrete digestive enzymes
Pancreatic exocrine glands contain acini and ducts
islet of langerhans
secrete insulin, glycogen and other hormones (alpha and beta ducts)
Pancreatic exocrine glands contain acini and ducts
ducts
fuse and drain into duodenum
