Digestive System: Alimentary Canal Flashcards
A musculomembranous tube that extends from the mouth to the anus
Alimentary Canal
*Long muscular tube
*Functions to convey food and saliva from laryngopharynx to stomach
Esophagus
Components of the Alimentary Canal:
*Mouth
*Pharynx
-esophagus
*Stomach
*Small intestine
*Large intestine (terminated at anus)
Where does the Esophagus originate at?
C6
What plane does the Esophagus Lie
Lies in midsagittal Plane (MSP)
-passes through diaphragm at T10
-joins stomach at esophagogastric junction at T11
Esophagus
Four parts of the stomach:
*Cardia
*Fundus
*Body
*Pyloric Portion
Dilated, saclike portion of the digestive tract extending between the esophagus and small intestine
Stomach
is superior portion that fills the left hemidiaphragm
fundus
Expanded terminal end of the esophagus
Cardiac antrum
what is the section surrounding esophageal opening of the stomach
Cardia
Inferior surface contains numerous longitudinal folds called:
Rugae
located between fundus and pyloric portion
body of the stomach
what is the last portion of the stomach
pyloric portion
lesser curvature of stomach=
right border
consists of the pyloric antrum and narrowed pyloric canal
pyloric portion
greater curvature of stomach=
Left border
Sharper angle at esophagogastric junction
Cardiac notch
what is entrance and exit controlled by
sphincters
opening between esophagus and stomach
cardiac orifice
what controls the opening between the esophagus and stomach
cardiac sphincter
opening between stomach and small intestine
pyloric orifice
what is the opening between stomach and small intestine controlled by
Pyloric Sphincter
how is the stomach in a hypersthenic body structure
Higher and horizontal
how is the stomach in a asthenic body structure
lower and more midline
The most superior portion of the stomach is the
fundus
Contraction waves by which the digestive tube propels contents toward the rectum
Peristalsis
Storage area for food during part of digestion
stomach
mechanically breaks down food by churning and peristalisis
stomach
secrets acids, enzymes, and other chemical to chemically break down food
stomach
average transit time to ileocecal valve is
2 to 3 hours
how many waves per minute occur in the filled stomach
3 to 4
Radiographic demonstration of the alimentary canal requires what?
the use of contrast media
what is the most common contrast for the alimentary canal
Barium sulfate
average emptying time for stomach
2 to 3 hours
what is another form of contrast media that can be used
water soluble iodinated contrast
which solution moves through the GI tract quicker
Iodinated solutions move through the GI tract
quicker than barium sulfate
How fast does the iodinated solution clear the stomach?
clear the stomach in 1 to 2 hours
what does not adhere as well to esophageal mucosa
Iodinated solutions
provide satisfactory
examinations of the stomach, duodenum, and
large intestine
Iodinated solutions
Prep for the exam room
Room should be completely prepared before
patient enters.
Adjust equipment controls to correct settings.
Have footboard and shoulder supports ready.
Check filming devices and number of image
receptors (IRs) available.
Prepare type and amount of contrast.
what is peristalisis affected by
Peristalsis affected by body habitus,
pathology, use of narcotic pain medicine,
body position, and respiration
*easily removed by
aspiration before or during surgery
* Also readily absorbed by the body and
excreted by kidneys in cases of perforation
water-soluble
Before beginning examination, the
radiographer should
*Describe the contrast media and administration
(i.e., taste, enema tip insertion).
* Inform the patient that the room will be darkened
during the procedure.
*Introduce the patient and fluoroscopist to each
other.
what is peristalisis affected by
Peristalsis affected by body habitus,
pathology, use of narcotic pain medicine,
body position, and respiration
where is peristalsis greater
Peristalsis greatest in stomach and duodenum
Where does peristalsis slow down
Slows in distal part of GI tract
What is the challenge of GI radiography
to eliminate motion
time for upright position of esophagus
0.1 seconds or less
what inhibits respiration for several seconds
Deglutition
most exposures for the stomach are made with what breathing
Exposures made at the end of expiration in
routine procedures
Peristalsis is affected by
-body habitus
-use of narcotic pain medicine
-body position
how much time does hypermotility ( excessive movement) of the stomach require
0.1 seconds
normal peristaltic activity of the stomach would require how much time
Normal peristaltic activity – exposure time no
longer than 0.2 second
Never longer than 0.5 second
essential projections of the esophagus
-AP or PA
-AP or PA oblique
-Lateral
double contrast
barium and carbon dioxide crystals
where is the IR places for AP or PA esophagus
IR is placed so that top
is level with the mouth
First part of examination for AP or PA esophagus
fluoroscopy of swallowing
single contrast
barium or water soluble , iodinated
patient position for AP or PA esophagus
Patient position
Supine or prone without
rotation
Head turned to side to
facilitate drinking
incucation of problem with portal vein
varices
where should ir and elevated side of patients be aligned for ap/pa oblique position for the esophagus?
Align IR and elevated side
of patient approximately 2
inches (5 cm) lateral to
MSP
Criteria for AP or PA esophagus
Esophagus from lower part of
neck to its entrance into the
stomach*
Esophagus filled with barium*
Penetration of barium*
Brightness and contrast
sufficient to visualize the
esophagus through the
superimposed thoracic
vertebrae
No rotation
how long should the patient be NPO for for GI series ?
8-9 hours
patient position for AP/PA oblique esophagus
Recumbent 35- to 40-
degree right anterior oblique
(RAO) or left posterior
oblique (LPO) position
What should you see for AP or PA oblique esophagus
esophagus between the vertebrae and the heart
What is the CR for AP or PA esophagus
Central ray (CR)
perpendicular to
midpoint of IR
*Usually at level of T5-T6
where does cr enter for AP/PA oblique esophagus
CR enters perpendicular to
midpoint of IR
*Enters patient at 2 inches (5
cm) lateral to MSP at level
of T5 or T6
The stomach needs to be empty. what should patients not have other than food that could cause to stimulate gastric secretions with them
-smoking
-gum
indication there is a problem with the portal vein
Varices
if there is concern for perforation what should you not use?
Barium should not be used if concerned for perforation. Gastrografin should be used instead because it is water soluble.
Why do we not use gastrograpin
Is absorbed by the body it doesn’t coat as much, taste worst chance of perforation
When we are laying on our back supine where is the air?
the pyloric has the air
When we are laying on our back supine where is the barium?
barium will be in the fundus
Where is the barium when patient is laying on their stomach prone?
barium is in the pyloric
Where is the air when patients are laying on their stomach prone? PA
Air is in the fundus
Patient position for Lateral esophagus
Recumbent right or left lateral
position
Patient should face
radiographer
Arms forward Midcoronal plane (MCP)
centered
where does the CR enter for lateral esophagus
CR enters perpendicular to midpoint of IR
*enters pt. on MCP at level of T5-T6
Examination often referred to as a
gastrointestinal series (GI series) or upper
gastrointestinal series (UGI series)
Stomach :GI series
what may be included in a UGI or GI series:
May include:
Scout (KUB)
Fluoroscopic and serial radiographic studies of the
esophagus, stomach, and duodenum using
ingested contrast (usually barium)
When requested, the barium may be imaged as it
traverses the small intestines
combination single and double-contrast during the same
procedure
biphasic examination
GI Series Procedure
*Usually begin with patient in upright position,
if possible
* Radiologist may examine heart and lungs
with fluoroscopy and determine whether
stomach is empty
* Radiologist instructs patient to drink cup of
barium
* Esophagus is examined with first two to three
swallows
Spot films made as
needed
* Manual manipulation
used to coat gastric
mucosa
* Spot films may be made
* Patient drinks more
barium to fill stomach
* Spot films taken as needed
What does the GI series examination show?
Examination determines size, shape, and position of stomach; persitalsis; filling and emptying of the duodenal bulb; and abnormalities in function or contour of anatomy
essential projections : stomach and duodenum
-PA
-PA OBLIQUE
-AP OBLIQUE
-LATERAL (mediolateral)
-AP
Patient position for PA stomach and duodenum
recumbent or upright
breathing technique for PA stomach and deodenum
Exposure made at end of suspended expiration take a deep breath in and below all your air out
Where to center ir for PA stomach and duodenum
*Center IR 1 to 2 inches (2.5 to 5 cm) above lower rib
margin (level of L1-L2)
Where to center IR for upright PA stomach and duodenum
- Upright requires IR centered 3 to 6 inches (7.6 to 15
cm) lower
where should you align the midline of grid for PA stomach and duodenum
Align midline of grid to sagittal plane passing
halfway between vertebral column and left lateral
border of abdomen
criteria for pa stomach and duodenum
*Entire stomach
and duodenal
loop
*Stomach
centered at level
of pylorus
*PA- air in
fundus
*AP- barium in
fundus
Entire stomach and
duodenal loop
* No superimposition of
pylorus and duodenal
bulb
*Duodenal bulb and loop
* Stomach centered at
level of pylorus
patient position for PA oblique stomach and deodenum
Recumbent RAO position
where should midline of ir be aligned for PA oblique stomach and duodenum
Midline of IR aligned with sagittal plane passing
midway between vertebral column and lateral
border of elevated side
where should IR be centered for PA oblique Stomach and duodenum
IR centered to lower rib margin (level of L1-L2)
what should you adjust the rotation angle to for PA oblique stomach and duodenum and what does it show?
Adjust rotation to 40 to 70 degrees to demonstrate
pyloric canal and duodenum
What is the crieteria for PA oblique stomach and duodenum RAO position
Entire stomach and
duodenal loop
* No superimposition of
pylorus and duodenal
bulb
*Duodenal bulb and loop in profile
* Stomach centered at
level of pylorus
Patient position for for AP oblique stomach and duodenum
Recumbent LPO position
what should you adjust rotation to for AP oblique stomach and duodenum
30 to 60 degrees (average is 45)
where do you center IR for AP oblique stomach and duodenum
Center IR to a point midway between xiphoid process and lower rib margin
where to align midline of IR for AP oblique stomach and duodenum
Align midline of IR with a
sagittal plane passing
midway between the
vertebrae and the left
lateral border of the
abdomen
Criteria for AP Oblique Stomach and Duodenum
Entire stomach
and duodenal loop
* Fundic portion of
stomach
* No
superimposition of
pylorus and
duodenal bulb
*Body and pylorus
with double-contrast
visualization
Part position for Lateral stomach and duodenum
*true lateral position
*Align plane passing
midway between
MCP and anterior
surface of abdomen
to midline of grid
Where do you center IR for Lateral stomach and duodenum for recumbent position
Center IR at level of
L1-L2 for
recumbent position;
Where do you center IR for Lateral stomach and duodenum for upright position
L3 for upright
position
Patient position for Lateral Stomach and Duodenum
Recumbent right
lateral demonstrates
right retrogastric
space, duodenal
loop, and
duodenojejunal
junction
Criteria for Lateral stomach and duodenum
*Entire
stomach
and
duodenal
loop
* Stomach
centered at
level of
pylorus
Patient Position for AP stomach and Duodenum
Supine
What position for the AP stomach and duodenum would you do for demonstration of hiatal hernia
Trendelenburg’s for demonstration of hiatal hernia
What does the trendelenburg position show and what is it for?
Trendelenburg’s for demonstration of hiatal hernia
About how far is the trenedeleburg position
10 degrees
What does the treneleburg position show for the esophogus
to see if there reflex or hiatal hernia or varices of the esophagus
Part position for AP stomach and duodenum :
Where do you align midline of grid and center for a 10 X 12 inch IR
on 10- x 12-inch (24- × 30-cm) IR, align midline of
grid to sagittal plane passing midway between
MSP and left lateral margin of abdomen
Center 10- x 12-inch (24- x 30-cm) IR to level
midway between xiphoid and lower rib margin
Part position for AP stomach and duodenum :
Where do you align midline of grid and center for a 14 X 17 inch IR
*Align midline of grid to MSP on 14- x 17-inch (35-
× 43-cm) IR.
*Center 14- x 17-inch (35- × 43-cm) IR; may be
adjusted to demonstrate more diaphragm or small
bowel.
Criteria for AP stomach and Duodenum
*Entire stomach and
duodenal loop
* Double-contrast
visualization of
gastric body,
pylorus, and
duodenal bulb
* Retrogastric portion
of duodenum and
jejunum
antegrade
with the flow
structure and function
retrograde
goes against
shows structure
Where does the alimentary canal start and end at?
start at the mouth and ends in the anus
How long is the alimentary canal?
approximately 30 feet long
What ways can we check the esophagus?
by using barium and carbon dioxide fuzzies crystals
- single or double contrast
What is considered contrast?
-barium
-iodine
-air
Air is considered what kind of contrast?
negative contrast
Barium and iodine are considered what kind of contrast?
positive contrast
When doing an esophagus you first want to start what?
Upright
Best way to see the esophagus of the spine is what position?
RAO position
The very top of the stomach is what?
the fundus
What aspect is the lesser curvature of the stomach?
medial aspect
-right border
What is the sphincter that you first enter from the esophagus to the stomach?
-is the opening of the stomach
-closer to the heart
-helps so we don’t regurgitate up
Cardiac sphincter
What are the folds of the stomach called?
rugae
What aspect is the greater curvature of the stomach?
lateral aspect
-left border
The heaver and hypersthenic you are what happens to the stomach?
the more transverse or horizontal your stomach is
The more sthenic or asthenic you are, meaning skinnier what happens to the stomach?
the stomach will go closer to the spine, making it more vertical
When we get to the lower part of the stomach what is that called?
Pyloric region
Where is the duodenum bulb located at?
Pyloric sphincter
the opening between the stomach and the small intestine (duodenum)
Pyloric sphincter
The fundus is normally what?
tip back
If I am laying supine what happens to the fundus?
the fundus has the barium
If i am laying prone what happens to the fundus?
the fundus has air in it
If I am laying supine what happens to the pyloric
the pyloric has air
If i am laying prone what happens to the pyloric?
the pyloric has barium in it
The best way to see the retro or posterior aspect of the stomach is?
right lateral position you will see the duodenum and duodenum bulb
what is the expanded terminal end of the esophagus called?
cardiac antrum
chemically and mechanically altered food that leaves the stomach
chyme
