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Outline Unit 2
RAD 112
| Question | Answer |
|---|---|
| What is the function of the esophagus? | To convey food and saliva from largopharynx to stomach |
| Where does the esophagus originate? | C5/C6 |
| Where does the esophagus join the stomach? | T11 |
| Where does the esophagus pass through the diagphragm? | T10 |
| What is the expanded terminal end of the esophagus called? | cardiac antrum |
| Describe the stomach. | A dilated, saclike portion of the digestive tract extending between the esophagus and small intestine. |
| Describe the four parts of the stomach. | CARDIA: section surrounding esophageal opening FUNDUS: superior portion fills left hemidiaphragm BODY: located btwn fundus/pylorus, interior surface covered numerous longitudinal folds called RUGAE PYLORUS: narrow end (pyloric antrum/pyloric canal) |
| What is the lesser curvature? | the right border |
| What is the greater curvature? | the left border |
| What is the cardiac notch? | sharp angle at the esophagogastric junction |
| What controls the entrance and exit of material in/out of stomach? | Cardiac (Esophageal) sphincter and pyloric sphincter |
| What are the openings in/out of the stomach called? | cardiac orifice and pyloric orifice |
| What affects the position of the stomach? | body habitus - hypersthenic (high and transverse) asthenic ( low and more midline); body position |
| What is the function of the stomach? | storage area for food during digestion; also processes food bolus into material called chyme |
| What does the stomach do? | secretes acids, enzymes and other chemicals to break down food |
| What is the chemically and mechanically altered food called that leaves the stomach? | CHYME |
| What is peristalsis? | involuntary contraction waves that propel contents toward rectum |
| How often does peristalsis occur in the stomach? | 3 to 4 waves per minute in full stomach |
| How long to empty stomach? | 2 - 3 hours |
| How long is transit from stomach to ileocecal valve? | 2 - 3 hours |
| What is contrast media? | a material that allows radiographic demonstration of alimentary canal |
| What is most common contrast media for gastro studies? What is the alternative? | Barium sulfate; water soluble iodinated contrast media (ie Gastrografin) |
| Why is water soluble iodinated contrast media used as alternative to Barium? | 1) clears stomach 1-2 hrs 2) do not adhere to esophageal mucosa as well 3) provides good exams of stomach, duodenum and large intestine 4) easily removed before/during surgery 5) readily absorbed by body, excreted by kidneys (perforation) |
| What are the essential projections of the esophagus? | AP or PA; AP or PA oblique; Lateral |
| What are the essential projections of the stomach and duodenum? | PA; PA oblique; AP oblique; Lateral (right preferred); AP |
| What is the lower gastrointestinal tract? | a musculomembranous tube that extends from ileocecal valve to anus |
| What are the components of the lower GI? | - large intestine (terminates at anus) |
| Describe the small intestine. | - a musculomembranous tube that extends from pyloric sphincter to ileocecal valve - consists of duodenum, jejunem, ileum |
| Describe the duodenum. | - from pyloric sphincter to jejunem - 8 to 10 inches and C shaped - first portion called duodenal bulb - joins jejunem at duodenojejunal flexure - flexure is supported by suspensory muscle called LIGAMENT OF TRIETZ |
| What is the function of the small intestine? | 1) digests and absorbs food 2) gastrointestinal transit 3) uses peristalsis 4) average transit time to ileocecal valve 2 -3 hours |
| Describe radiation protection during GI studies. | - use shielding, but do not compromise clinical objectives of exam - use close collimation - use optimum technique factors |
| How is contrast administered? | 1) orally 2) reflux filling via large-volume barium enema 3) direct injection via tube placed into small bowel (enteroclysis) |
| What is the most common method of administering contrast? | orally |
| What is patient prep for small intestine orally administered exam? | 1) soft/low residue diet for 2 days 2) FAST 8 hours prior to exam 3) may need cleansing enema for colon |
| Why is it called small bowel series? | - Several identical images are produced at timed intervals - images notated with time since ingestion of barium - patient in PRONE or SUPINE position |
| Why is supine used? | -to view superior and lateral shift of stomach, improving visualization of duodenum and jejunum - prevent compression of overlapping loops of intestine |
| Why is prone used? | To compress abdomen and increase image quality |
| How does technologist determine time intervals between images? | having radiologist inspect each image and give next time frame |
| When is the exam considered completed? | When barium moves through ileocecal valve |
| Describe the large intestine. | a musculomembranous tube that extends from ileocecal valve to anus |
| What is the position of the large intestine? | An arch around small intestine |
| What are the four main parts of the large intestine. | - cecum - colon - rectum - anal canal |
| How long is the large intestine? | about 5 feet |
| What are the series of pouches along the colon called? | haustra |
| What are the muscular bands that form the haustra? | taeniae coli |
| What is the cecum? | pouch-like portion below the junction of the ileum and colon |
| What is the outpouching attached to the posteromedial side of cecum called? | vermiform appendix |
| What are the four portions of the colon? | Ascending Transverse Descending Sigmoid |
| What is the first sharp angle at ascending/transverse colon called? | right colic flexure (hepatic) |
| What is the second sharp angle at transverse/descending colon called? | left colic flexure (splenic) |
| Describe the sigmoid portion. | an S shaped loop that ends at rectum at level of 3rd sacral segment |
| What extends from sigmoid to anal canal? | Rectum |
| What is the final portion that terminates at the anus? | anal canal |
| What is the function of the large intestine? | reabsorption of fluids elimination of waste products |
| Why is carbon dioxide used most commonly in double contrast studies? | absorbed more rapidly |
| When are water soluble contrast agents used? | when retrograde filling is contraindicated usually not satisfactory for double contrast studies because doesn't adhere as well to mucosa |
| Why must the large intestine be completely empty prior to exam? | retained fecal matter can simulate small masses |
| What conditions limit patient preparation for large bowel study? | - severe diarrhea - gross bleeding - obstruction |
| Describe large bowel cleansing methods. | - complete intestinal cleaning kit - GI lavage preparations - cleansing enema |
| What are the components of the GI system? | - mouth - pharynx - esophagus - stomach - small intestine - large intestine - rectum - anal canal |