GI organs

Question 1

This is the location of where food is ingested, chewed and mixed with saliva, what does it open to?

Answer 1

oral cavity, opens to the pharynx

Question 2

What is the common chamber shared by the digestive and respiritory system?

1. construct
2. function

Answer 2

phrynx

1. musculofibrous tube
2. transports the bolus of food from the oral cavity to the esophagus during swallowing

Question 3

list the start and end ofthe portion of the digestive sytem located in the abdomen.

Answer 3

from the distal esophagus to the distal sigmoid colon

Question 4

muscular tube connecting pharynx and stomach.

1. begins
2. traverses
3. ends

Answer 4

esophagus

1. begins in tthe neck, mostt of its length is in thoracic cavity
2. traverses the diaphragm ~TX (esophageal hiatus)
3. ends at the stomach

Question 5

what are the contents of the esophageal hiatus?

Answer 5

1. esophagus
2. anterior and posterior vagal trunk
   
   1. anterior vagal trunk
      
      1. several smaller trunks, main contributor is the left vagus nerve
   2. posterior vagal trunk
      
      1. consists of a single trunk whose fibers mostly come from right vagus nerve

Question 6

list and describe the arterial supply of the esophagus

Answer 6

1. gastric artery
   
   1. from the celiac trunk
2. left inferior phrenic trunk
   
   1. left inferior phrenic artery

Question 7

what asisst with control over the contents with in the esophagus?

Answer 7

gaurded at both ends by use of sphincters

1. upper esophageal sphincter
   
   1. helps prevent the enterance of air - during resipration
   2. secondary linge of defense against reflux of gastric contents
2. lower esophageal sphincter
   
   1. located at the esophageal hiatus of the diaphragm
   2. first guard against gastrointestinal reflux
   3. vulnerable to damage from repeated exposure

Question 8

dilated portion of the digestive tract, where food accumulates.

Answer 8

stomach

1. undergoes partial enzymatic digestion into semi-liquid chyme
2. produces
   
   1. HCL
   2. digetsive enzymes
3. four partts
   
   1. cardia/cardiac region
   2. Fundus
   3. Body-major part
   4. pyloric part
      
      1. pyloric antrum leading to a narrow pyloric canal

Question 9

list the superficial structures of the stomach- 4

Answer 9

stomach

1. lesser curvature
   
   1. facin superiorly and to the right
2. greater curvature
   
   1. facing inferiorly and to the left
3. cardial notch
   
   1. lies in the superior angle created shen the exophagus enters thestomach
4. angular incisure
   
   1. a bend on the lesser curvature

Question 10

longest part of GI tract

1. primary site of
2. sections- in order

Answer 10

small intestine

1. primary site for the absorption of nutrients
2. sections
   
   1. duodenum
   2. jejunum
   3. ileum

Question 11

First 2cm of duodenum

Answer 11

duodenal cap or ampulla

1. has a distint radiological appearance
2. clinically important b/c it is the most frequent location of peptic ulcers

Question 12

describe the pathway of content (enzymes and bile) into the duodenum

Answer 12

bile -> bile duct (sphincter control)

pacreatic enzymes->pancreatic duct (sphincter control)

bile duct + pancreatic duct-> hepatopacreatic ampulla

hepatopancreatic ampulla->major duodenal papilla (narrowest)-> descendin portion of the duodenum

Question 13

what holds the duodenum in place (suspends)

Answer 13

ligament of Treitz- suspends the duodenum from the

Question 14

list the surface modifications of the muscoal lining in the small intestine.

1. function
2. modifications

Answer 14

1. increase the surface area for absorption
2. modifications
   
   1. circular folds (plicae circultes)
      
      1. of mucosa-submucosa
   2. villi
      
      1. fingerlike projections of mucosa
   3. micorvilli
      
      1. microscopic projections on absorptive cells of the mucosa

Question 15

first portion of the duodenum curves around the ____

Answer 15

pancreas

Question 16

1. portions of the duodenum

Answer 16

1. superior
2. descending
3. inferior/horizontal
4. ascending

Question 17

bleeds have different characteristics. What landmark is allows for the distinction of these bleeds?

Answer 17

duodenojejunal junction

1. junction between upper GI bleeding and lower GI bleeding, which have different clinical characteristics

Question 18

proximal 2/5 of small intestine

distal 3/5 of small intestine

Answer 18

1. jejunum forming the 2/5 and being located mainly in thte LUQ
2. Ileum form the distal 3/5 and is located mainly in the RUQ

Question 19

how are the jejunum and ileum distiguished?

Answer 19

location and blood supply

1. jejunum have few arterial arcades and long vasarecta in mesentery with little fat
   
   1. few AA
   2. long VR
   3. lil fat
2. Ileum has many arterial arcades, short vasa recta with mesetery laden with fat
   
   1. Many AA
   2. short VR
   3. much fat

Question 20

opening at end of Ileum.

discuss the embryonic development importance of a structure here.

Answer 20

ileocecal junction opens into the large intestine from the Ileum.

Ileal (Meckel’s) diverticulum, attaches from ileum to the ligament that was once the umbilical cord. ~2ft from the ileocecal junction.

Question 21

chyme is highly ____. how is this handeled by the small intestine

Answer 21

chyme is highly acidic, buffered by pancreattic secretions containing high [HCO3]

Question 22

main purpose of the large intestine, distinguishing structtures from small intestine.

Answer 22

Water absorption

1. omental appendices
   
   1. appendices epiloicae, small fatty projections
2. teniae coli
   
   1. three bands of longitudinal smooth muscle
3. haustra-sacculations
   1.

Question 23

of the ducts and passages, where is a gallstone most liekly to be lodged?

Answer 23

major duodenal papula

Question 24

list the sttructures of the large interstin

Answer 24

1. cecum and appendix
2. colon
   
   1. ascending
   2. transcverse
   3. descending
   4. sigmoid
3. rectum
4. anal canal

Question 25

list blind pouch of intestine

1. function
2. surrounding structure

Answer 25

cecum

1. blind pouch of intestine continuous above with the ascending colon
2. receives the contents of the ileum at the ilececal junction
3. has the appendix suspended from it (inferior to the ileocecal junction)

Question 26

list three types of intestinal obstructions with respect to the ileocecal junction and cecum

Answer 26

1. intussicepation
   
   1. telescoping of a proximal segment of the intestine into a more distal part
2. volvulus
   
   1. twisting of the intestine on itself
3. gallstone ileus
   
   1. which a gallstone blocks the ileocecal junction

Question 27

intestinal diverticulum that contains lymphoid tissue

Answer 27

appendix

1. has short mesentery
   
   1. mesoappendix
2. variable in position
   
   1. complicates diagnosisb
   2. most commonly-retrocecal position

appendicitis isa surgical emergency. left unchecked may lead to periotonitis from bacterial infection.

Question 28

list parts of the colon

Answer 28

1. ascending
   
   1. curvature to the transverse =right colic(hepatic)flexure
2. transverse
   
   1. curvature to the descending =left colic (splenic) flexure
3. descending
4. sigmoid
   
   1. meets rectum anterior to S3 with in the pelvic cavity

notet that the rectum and anal canal

1. located withtin the pelvis and perineum (anal canal), not the peritoneum

Question 29

continues inferiorly from the descending colon.

1. suspension and nutrient supply
2. highest % of clincal cases involved here

Answer 29

sigmoid colon

1. suspended by a mesentery
   
   1. sigmoid mesocolon
   2. intraperitoneal
2. if the sigmoid mesocolon is long, it predisposes to volvulus
   
   1. 90% of cases
   2. results in obstruction and infarction