GI Flashcards
Large intestine consist of the:
Cecum, appendix, colon, rectum, and anal canal
Approx. length of the large intestine from the ileum to the anus
1.5 meters
The large intestine is characterized by the (3):
Taenia coli, haustra, sacculations
Where the fecal material is stored until defecation
Sigmoid colon
Absorb water from the highly liquid material received from the ileum
Cecum and ascending colon
Large blind pouch that extends below the level of the ileocecal valve
Cecum
The splenic flexure is anchored to the diaphragm by the _____
-serves as a boundary between disease processes of the left subphrenic space and the left paracolic gutter
Phrenicocolic ligament
EXTRAPERITONEAL (within the anterior pararenal space, and is covered by peritoneum only on its ventral surface)
colonic segments
Ascending and descending colon
INTRAPERITONEAL COLONIC SEGMENTS
Transverse and sigmoid colon
Average length of the anal canal
3-4 cm
The thickness of the wall of the normal colon does not exceed ____
5mm
The appendix arises from the ______ of the cecum at the junction of the taenia coli, approx _____ below the ileocecal valve
Posteromedial, 1 to 2 cm
Normal average diameter of the appendix
4 to 5 mm
Normal approx length of the appendix
8cm (although it may be up to 30cm long)
The appendix always arises from the cecum on the ____ side of the ileocecal valve
Same
On CT, US and MR, the normal appendix appears as a thin-walled tube less than ____mm in diameter
6
Arbitrarily defined as the proximal 2/5s of the mesentric intestine
Jejunum
The distal 3/5s of the mesenteric intestine
Ileum
Concave border of the small bowel loops
-where the mesenteric leaflet attaches
Mesenteric border
The convex border facing away from the mesentery
Antimesenteric border
Imaging characteristics of the jejunum(4)
- feathery mucosal pattern
- More prominent valvulae conniventes
- Wider lumen
- Thicker wall
Imaging characteristics of the ileum(4):
- Less feathered mucosal pattern
- Thinner,Less frequent folds
- Narrower lumen
- Thinner wall
Finger like projections that extend from the entire mucosal surface of the small bowel
Villi
Normal lymph nodes in the mesentery measure ______
Less than 4mm in diameter
4 GI TRACT layers
Mucosa, submucosa, muscularis propria, serosa or adventitia
Innermost GI tract layer exposed to the lumen
Mucosa
Provides connective tissue support for the mucosa
-contains the primary vascular and lymphatic channels, lymphoid follicles and autonomic nerve plexuses
Submucosa
Major muscular structure of the bowel wall, comprised of the inner circular and outer longitudinal layers
Muscularis propria
Outer covering of the bowel
Serosa or adventitia
Region of the GE junction (part of the stomach)
Cardia
That portion of the stomach above the level of the GE Junction
Fundus
Central 2/3s of the stomach from the Cardia to the incisura angularis
Body of the stomach
Acute angle formed on the lesser curvature that marks the boundary between body and the antrum of the stomach
Incisura angularis
Produce hydrochloric acid in the stomach
Parietal cells
Produce pepsin precursors in the stomach
Chief cells
The parietal cells and chief cells are located in which part of the stomach
Fundus and body
Distal one-third of the stomach than contains gastrin-producing cells but no acid secreting cells
Antrum
Junction of the stomach with the duodenum
Pylorus
Pyramidal first portion of the duodenum
Duodenal bulb or cap
Portion of the duodenum that is lateral to the head of the pancreas
Second or descending portion of the duodenum
Pierces the medial aspect of the descending duodenum at the ampulla of vater
Common bile duct and pancreatic duct
Portion of the duodenum that passes to the left between the superior mesenteric vessels and the inferior vena cava and aorta
Third or horizontal portion of the duodenum
Portion of the duodenum that ascends on the left side of the aorta to the level of L2 and the ligament of treitz
Fourth or the ascending portion of the duodenum
Detailed pattern of the gastric mucosa
Area gastricae
*normal area gastricae varies from a fine reticular pattern to a course nodular pattern
Refers to the gastric mucosal folds that produce distinct radiolucent ridges when the stomach is partially distended
Rugae
Rugal folds are most prominent in the ____ and _____ and are usually absent in the ____
Fundus; proximal gastric body;
Antrum
The ______ of the stomach is attached to the liver by the lesser omentum
Lesser curvature
The greater omentum attaches to the ____ of the stomach
Greater curvature
INTRAPERITONEAL space posterior to the stomach and anterior to the pancreas
Lesser sac
On CT, the normal gastric wall thickness when well distended:
A. In the antrum
B. In the body
A. 5 to 7mm
B. 2 to 3mm
Normal duodenal wall thickness
Less than 3mm
3 pharyngeal compartments
- nasopharynx
- oropharynx
- hypopharnyx(laryngopharynx)
Pharyngeal compartment that extends from the skull base to soft palate
Nasopharynx
Pharyngeal compartment that is posterior to the oral cavity and extends from the soft palate to the hyoid bone
Oropharynx
Pharyngeal compartment that extends from the hyoid bone to the cricopharyngeus muscle
Hypopharynx (laryngopharynx)
Anterior boundary of the oropharynx
Base of the tongue
Separate the larynx from the oropharynx and hypopharynx
Epiglottis and aryepiglottic folds
2 symmetrical pouches formed in the recess between the base of the tongue and the epiglottis
Valleculae
*divided medially by the median glossoepiglottic fold and bounded laterally by the lateral glossoepiglottic folds
Deep symmetrical lateral recesses formed by the protrusion of the larynx into the hypopharynx
Piriform sinuses
The esophagus extends from the ______ muscle at the level of C5-C6 to the ______
Cricopharyngeus ; GEJ
Esophagus is a muscular tube formed by an outer ____ muscle layer and inner _____ muscle layer lined by _______ epithelium
Longitudinal; circular; stratified squamous
The esophagus lacks a _______ layer
Serosal
A. Proximal 1/3 of esophagus muscle type
B. Distal 2/3 of esophagus muscle type
A. Striated muscle
B. Smooth muscle
Normal extrinsic impression on the esophagus are made by the (3):
Aortic arch, left mainstem bronchus , left atrium
Esophageal pattern with multiple regular transverse folds ,1mm thick, result from contraction of the longitudinal fibers in the muscularis mucosa
Feline esophagus
Distension of the upper esophagus ______ OR
the lower esophagus ________ is abnormal
More than 10mm ; more than 20mm
______ in the esophagus is always abnormal
Air-fluid levels
The wall of the distended esophagus should not exceed ____ in thickness
3cm
Demarcates the pharynx and the esophagus
Cricopharyngeus muscle(C5-C6 level)
Saccular termination of the esophagus
Esophageal vestibule
The tubulovestibular junction (in esophagogastric region) is formed by a symmetrical muscular ring called the ______
A ring
An asymmetrical mucosal ring or notch that occurs at the junction of esophageal squamous epithelium with gastric columnar epithelium
B ring
Seen best on double contrast study, this marks the junction of the squamous epithelium of the esophagus and the columnar epithelium of the stomach
Z line
2 Radiographic markers of the GE junction
B ring and the Z line
Normal process of swallowing can be divided into (3):
Oral, pharyngeal and esophageal stages
Esophageal motility is evaluated by observing fluoroscopically at least ______ separate swallows of barium with the patient in a _____ position
5; prone-oblique
Radiographically appears as a stripping wave that traverses the entire esophagus from top to bottom
Primary peristalsis
Has the same radiographic appearance as primary waves except that they may start at the point of the retained barium bolus
Secondary peristalsis
Nonperistaltic contractions that cause a corkscrew or beaded appearance of the esophageal barium column
Tertiary waves
A tongue-shaped organ , approx 12 to 15 cm in length, that lies within the anterior pararenal compartment of the retroperitoneum
Pancreas
Pancreas location:
_______ to the left of the liver, stomach and lesser sac;
_______ to the spine,IVC and aorta
Posterior ; anterior
The splenic vein and pancreas are ______ to the superior mesenteric artery
Anterior
Maximum dimensions for pancreatic size are (diameter):
A. Head B. Body C. Tail
A. 3.0 cm; B. 2.5 cm; C. 2.0 cm
(In Brant) pancreatic duct normally measures ____ mm in diameter in the head and tapers smoothly toward the tail
3-4mm
Body’s largest lymphoid organ
Spleen
- sequesters abnormal and aged RBC and WBC
- reservoir for RBCs
Average spleen dimension in adults (in Brant)
12 x 7 x 3-4 cm (L x W x thickness)
Term applied to a normal spleen positioned outside of its normal location in the LUQ
Wandering spleen
*caused by laxity of the splenic ligaments
Refers to multiple implants of ectopic splenic tissue that may occur after traumatic splenic rupture
Splenosis
During arterial phase the spleen exhibits alternating bands of hi and low density
Arciform enhancement pattern
Congenital absence of the spleen
Asplenia(Ivemark syndrome)
Splenules
Accessory spleen
Maximum enhancement of the liver parenchyma occurs at _____ second
60 to 120 seconds following hepatic arterial enhancement
Longitudinal plane thru the middle hepatic vein, IVC and gallbladder fossa divides the livers into ____
Right and left lobes
Longitudinal plane thru the right hepatic vein divides the right lobe into _____
Anterior (VIII and V) and posterior (VII and VI) segments
Longitudinal plane thru the left hepatic vein divides the left lobe into _____
Medial (IVa and IVb) and lateral (II and III) segments
Transverse plane thru the left portal vein divides the left lobe into ______
Superior (IVa and II) and inferior (IVb and III) segments
Oblique transverse plane thru the right portal vein divides the right lobe into _____
Superior (VIII and VII) and inferior (V and VI) segments
Hepatic segment that extends between the fissure of the ligamentum venosum and the IVC
Segment I (caudate lobe)
Transient enhancement differences(liver)
- page 694
- systemic venous blood drains into hepatic sinusoids altering normal intrahepatic blood results in focal areas of increased or decreased enhancement during the various phases of parenchymal enhancement
Transient hepatic attenuation differences (THADs) or Transient hepatic intensity differences (THIDs)
(On CT), the normal liver parenchymal attenuation is ______ than the attenuation of normal spleen parenchyma on UNENHANCED images
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*during arterial phase, spleen
The ducts of the left hepatic lobe are more ______ than those of the right hepatic lobe
ANTERIOR
Cystic duct + common hepatic duct
Common bile duct
The CBD tapers distally as it ends in the _____
Sphincter of Oddi
*protrudes into the duodenum as the ampulla of vater
Descriptive folding of the gallbladder Fundus, is a common normal variant
Phrygian cap
Small folds in the cystic duct
Spiral valves of Heister
A gallbladder greater than 5 cm in diameter is considered _____
Enlarged (hydropic)
A gallbladder less than 2cm in diameter is considered _____
Contracted
The normal gallbladder wall does not exceed __ mm in thickness, measured from the gallbladder lumen to liver parenchyma, when gallbladder is distended
3
The peritoneal cavity is divided into the ____
Greater peritoneal cavity and the lesser peritoneal cavity(lesser sac)
Space which communicates around the liver with the anterior subhepatic and posterior subhepatic space(Morison pouch)
Right subphrenic space
Most dependent portion of the abdominal cavity in the supine position
Morison pouch (right hepatorenal fossa)
Left subphrenic (perisplenic) space communicates freely with the left subhepatic space but is separated from the right subphrenic space by the ________ and from the left paracolic gutter by the _____
Falciform ligament; phrenicocolic ligament
Space affected by diseases of the duodenal bulb, lesser curve of the stomach, gallbladder, and left lobe of the liver
Left subhepatic space (gastrohepatic recess)
Most dependent portion of the peritoneal cavity in the upright patient
Pelvis
Remnant of the obliterated umbilical vein
Ligamentum teres
*found in the caudal free end of the falciform ligament
Part of the liver not covered by peritoneum
Bare area
Composed of the gastrohepatic and hepatoduodenal ligaments, suspends the stomach and the duodenal bulb from the inferior surface of the liver
Lesser omentum
*separates the gastrohepatic recess of the left subphrenic space from the lesser sac
Isolated peritoneal compartment between the stomach and the pancreas
Lesser sac
*communicates with the rest of the peritoneal cavity only through the small foramen of Winslow
A double layer of peritoneum that hangs from the greater curvature of the stomach
Greater omentum
*serves as fertile ground for implantation of peritoneal mets
3 divisions of the retroperitoneal space
Anterior pararenal, perirenal, posterior pararenal
Space that Extends between the posterior parietal peritoneum and the anterior renal fascia
Anterior pararenal space
- bounded laterally by the lateroconal fascia
- contains the pancreas, duodenal loop, ascending and descending colon
Anterior and posterior renal fasciae encompass the kidney, adrenal gland, and perirenal fat within the ______
Perirenal space
A potential space filled only with fat
Posterior renal space
*continues into the flank as the properitoneal fat stripe
3 major anatomic compartments of the pelvis
- Peritoneal cavity
- Extraperitoneal space
- Perineum
Peritoneal cavity extends to the level of the vagina forming the _____, or to the level of the seminal vesicles forming the _______
Pouch of Douglas (cul-de-sac); rectovesical pouch
Anterior boundary of the rectouterine pouch
Broad ligament
Most dependent portion of the peritoneal cavity
Cul-de-sac
Continuous with the retroperitoneal space of the abdomen
Extraperitoneal space of pelvis
Anatomic landmark of the perineum
Ischiorectal fossa
Lies below the pelvic diaphragm
Perineum
