GI Tract Organs II Flashcards
The dudodenojejunal junction is defined by what structure?
the ligament of treitz
Where in the abdominal cavity is the jejunum located?
mostly the left upper quadrant and somewhat periumbilical
Where in the abomdinal cavity is the ileum located?
mostly in the lower right quadrant and somewhat hypogastric
The root of the mesentery runs from where to where?
just left of L2 to the right sacroiliac joint in the lower abdominal cavity
How does the wall thickness of the jejunum compare to that of the ileum?
the jejunum is much thicker
How do the vasa recta and arcades of the jejunum compare to those of the ileum?
the vasa recta of the jejunum are longer while the arcades are fewer and larger
What are the folds that protrude into the lumen of the small intestine called?
circular folds/plicae circulares
How do the plicae circulares of the jejunum compare to those of the ileum?
those in the jejunum are taller, larger, and more closely packed together
Which portion of the small intestine, the jejunum or ileum, appears speckled on contrast imaging?
the jejunum
The jejunum and ileum are supplied by what major branch off the aorta?
the SMA
The jejunum and ileum are supplied by what sympathetic nerve?
the less splanchnic nerve
The less splanchnic nerves have what effect on digestion and motility in the small intestine?
they slow digestion and motility
The less splanchnic nerve originates at what vertebral level?
T10
What is Meckel’s diverticulum?
a common congenital anomaly of the gut due to a remnant vitelline duct
Meckel’s diverticulum is due to a remnant what?
vitelline duct
Meckel’s diverticulum may contain what ectopic tissues?
pancreatic and stomach mucosa
What is the rule of 2’s for Meckel’s diverticulum?
seen in 2% of the population, usually 2 inches long, and usually 2 feet proximal from the ileocecal junction
Inflammed Meckel’s diverticulum presents in what fashion?
with pain similar to appendicitis
What is ileus?
a group of small bowel motility disorders that mimic obstruction without actual mechanical obstruction
What is the most common type of ileus?
paralytic ileus
Paralytic ileus is most commonly due to what?
surgery
What are the symptoms of paralytic ileus?
- post-operative
- fluid/gas distention
- hypoactive bowel sounds
- nausea
- malaise
- mild pain
- vomiting
What is intussusception?
when a part of the intestine has invaginated into another section of intestine
Intussusceptions are most common in which age group?
those below the age of five
What is the intussusceptum and the intussuscipiens?
the susceptum is the part that prolapses into the intussuscipiens
A bull’s eye or target appearance on US is indicative of what GI disorder?
intussusception
What are the symptoms of intussusception?
similar to those seen in a bowel obstruction with sudden pain coming and going every 15 to 20 minutes
Small intestine pain refers where?
periumbilical due to innervation by the less splanchnic nerve residing at T10
The ascending colon meets the transverse colon at what point?
the right colic/hepatic flexure
What is the left colic flexure called?
the splenic flexure
What do we call the small, fatty omentum-like projections off the colon?
omental appendices
What are the longitudinal muscle bands of the colon called?
taenia coli
What are haustra?
saccular protrusions between transverse folds of the colon
What are the folds that divide haustra called?
semilunar folds
What acronym describes the unique anatomical characteristics of the large intestine?
- omental epiploic appendices
- taeniae
- haustra
- semilunar folds
- OETHS
Is the cecum intra or retroperitoneal?
intraperitoneal
the ileocecal junction forms what papilla?
the ileal
What is the actual name of the appendix?
Vermiform appendix
The cecum is defined by what structure?
the ileal papilla
What parts of the colon are intraperitoneal?
- cecum
- transverse colon
- sigmoid colon
The transverse mesocolon runs along what?
the inferior edge of the pancreas
The rectum begins at what vertebral level?
S3
Is the rectum intra or retroperitoneal?
retroperitoneal
What line divides the superior anal canal from the inferior anal canal?
the pectinate line
The wall of the anal canal has what two features?
anal columns and anal sinuses
The anal canal is defined by what?
the length of the anal columns and sinuses
What is the anal valve?
the edge that joins the distal ends of anal columns together
The anal columns end distally at what structure?
the anal valve
How does the arterial supply differ above and below the pectinate line?
- IMA above
- internal iliac artery below
How does the venous drainage differ above and below the pectinate line?
- hepatic portal vein above
- IVC below
How does the innervation differ above and below the pectinate line?
- visceral above
- somatic below
At what point in the hindgut does the epithelium change?
the pectinate line
Describe the epithelium above and below the pectinate line?
- simple columnar above
- keratinized squamous below
What is a volvulus?
a loop of bowel and mesentery abnormally twisted on itself
What is the most common type of volvulus?
sigmoid
Which population is most affected by sigmoid volvulus?
middle aged men
What is cryptitis?
inflammation of the anal sinuses
What is an anal fistula?
a channel that connects the anal canal to a perianal abscess
Where does puss accumulate in those with an anal fissure?
in the ischioanal fossa
What is the ischioanal fossa?
an area of pus collection in those with anal fissures
What is an internal v. an external hemorrhoid?
internal are those above the pectinate line
What is an internal hemorrhoid?
a painless prolapse of rectal mucosa
What is an external hemorrhoid?
a painful prolapse of tissue below the pectinate line
What is diverticulitis?
infection of a diverticulosis
What is a diverticulosis?
an external evagination of colon mucosa, typically in the sigmoid colon
What is an ileostomy?
a surgery used to establish an opening between the ileum and skin
What is a colostomy?
a surgery used to establish an opening between the colon and skin
What recommendation is made for colonoscopies as a screening procedure?
everyone should have one at age 50, typically done every five years thereafter
What is the most common cause of lower GI bleeding?
diverticulum
