GI Viscera Flashcards
Is a muscular tube (approximately 10 in. or 25 cm long) that extends from the pharynx to the stomach, but the short abdominal part extends from the diaphragm to the cardiac orifice of the stomach, entering the abdomen through an opening in the right crus of the diaphragm
Esophagus
How long is the abdominal part of Esophagus?
0.5 inches
circular layer of smooth muscle at the terminal portion of the esophagus
physiologic esophageal sphincter
What prevents the stomach contents from regurgitating into the esophagus?
tonic contraction of physiologic esophageal sphincter
At what level does the esophagus enter the abdomen?
T10
Anterior relations of Abdominal Esophagus
left liver lobe & left vagus
Posterior relations of Abdominal Esophagus
left crus of diaphragm & right vagus
Arterial supply of Abdominal Esophagus
Left gastric artery
Where is the origin of Left gastric artery?
ciliac artery
Lymph Drainage of Abdominal Esophagus
Left gastric nodes
Nerve supply of Abdominal Esophagus
anterior & posterior gastric nerves (vagi) & sympathetic branches of thoracic part of sympathetic trunk
Cricopharynx vertebral level
C6
Oesophageal hiatus vertebral level
T10
What is the portion of esophagus with direct voluntary / sympathetic control?
upper portion (cricoid area)
What are the difference in the course of right and left vagus nerve?
Left vagus nerve CROSSES left surface of aortic arch.
Right VN: reforms to make POSTERIOR gastric nerve
Left VN: reforms to make ANTERIOR gastric nerve
caused by a lower esophageal sphincter dysfunction (relaxation or weakness) and/or hiatal hernia, causing reflux of stomach contents
Gastroesophageal reflux disease (GERD)
a (congenital) herniation of part of the stomach through the esophageal hiatus into the thoracic cavity
Hiatal or esophageal hernia
What forms the stomach bed?
pancreas, spleen, left kidney, left suprarenal gland, transverse colon and its mesocolon, diaphragm
covered entirely by peritoneum and is located in the left hypochondriac and epigastric regions of the abdomen.
Stomach
What are the 4 regions of stomach?
cardia (nearest to esophagus),
fundus,
body, and
pylorus (nearest to duodenum)
What are divisions of pylorus?
pyloric antrum and pyloric canal
a group of thickened circular smooth muscles in the pyloric orifice
pyloric sphincter (true sphincter)
What does pyloric sphincter control?
rate of discharge of stomach contents into the duodenum
What happens to pyloric sphincter during sympathetic and parasympathetic?
Sympathetic: Constricted
Parasympathetic: Relaxed
What are two openings of stomach?
cardiac and pyloric openings
What are the 2 curves of stomach?
greater and lesser curvatures
Junction between pylorus and duodenum and body of stomach
Incisura angularis (angular notch)
What are the two notches in stomach?
cardiac and angular notches
Junction between esophagus and cardia and fundus
cardiac notch
What are structures of the stomach bed separated from stomach by lesser sac?
Diaphragm Left suprarenal gland Left kidney Splenic artery Pancreas Transverse colon Splenic flexure of colon
What structure of the stomach bed is separated from stomach by greater sac?
Spleen
What is the left side of colon before it becomes the descending colon?
Splenic flexure/ Left colic flexure
What is the right side of colon before ascending colon becomes transverse colon?
Hepatic flexure
What are the postero-inferior surface of stomach?
Structures of Stomach bed
What are the left and right antero-superior surface of stomach?
Left: diaphragm, pericardium, 7-9 ribs, left intercostal spaces
Right: left lobes of liver and anterior abdominal wall
Where does stomach receive blood?
right and left gastric,
right and left gastroepiploic, and
short gastric arteries.
What are the appearance of longitudinal folds of mucous membrane during contraction?
rugae
a grooved channel along the lesser curvature formed by the rugae, directs fluids toward the pylorus.
gastric canal
What does stomach produce?
mucus, hydrochloric acid, pepsin, and the hormone gastrin
It protects the stomach from self-digestion
Mucus
It destroys many organisms and provides the required acid environment for pepsin activity
hydrochloric acid
It converts proteins to polypeptides
pepsin
It is produced in the stomach that stimulates gastric acid secretion.
gastrin
What stimulate gastric secretion in the vagus nerve?
Parasympathetic fibers
What cells secrete mucus?
Goblet cells
Principally secrete HCl acid and intrinsic factor
Parietal cells
What is the intrinsic factor in stomach?
a glycoprotein secreted by parietal cells necessary for absorption of Vit B12
Nerve supply of stomach
LARP: left vagus nerve, anterior vagal trunk; right vagus nerve, posterior vagal trunk
A thin colorless, acidic liquid secreted by stomach glands
Gastric juice
Where is the origin of left gastroepiploic and short gastric arteries?
Splenic artery
What is the origin of right gastric and gastroduodenal artery?
Proper Hepatic Artery
Where is the origin of right gastroepiploic artery?
Gastroduodenal artery
What are the three main venous drainage of stomach?
Hepatic portal vein
Splenic vein
Superior mesenteric vein
What drains into hepatic portal vein?
Right and left gastric vein
What drains into splenic vein?
Left gastro-omental vein
Short gastric vein
What drains into superior mesenteric vein?
Right gastro-omental vein
erosion in the lining of the stomach or duodenum
Peptic ulcer
Causes of peptic ulcer
Helicobacter pylori
denuded mucosa of stomach because of increase acid content
Where is peptic ulcer most common to occur?
first part of the duodenum (duodenal ulcer)
Extends from the pyloric opening to the ileocecal junction where complete digestion and absorption of most of the products of digestion and water, electrolytes, and minerals such as calcium and iron occur.
Small Intestine
Is a C-shaped tube surrounding the head of the pancreas and is the shortest (25 cm [10 in.] long or 12 fingerbreadths in length) but widest part of the small intestine.
Duodenum
Which part of duodenum is not retroperitoneal?
First Part (Superior)
What connects first part of duodenum to the liver?
hepatoduodenal ligament of lesser omentum
Where does duodenum receive blood?
celiac (foregut) and superior mesenteric (midgut) artery
Has a mobile or free section, termed the duodenal cap (because of its appearance on radiographs), into which the pylorus invaginates.
Superior (First) Part (Horizontal Cap)
Contains the junction of the foregut and midgut, where the common bile and main pancreatic ducts open.
Descending (Second) Part(Pars Descendens)
It is where terminal openings of the bile and main pancreatic ducts (of Wirsung) are located
greater papilla
It lies 2 cm above the greater papilla and marks the site of entry of the accessory pancreatic duct (of Santorini)
lesser papilla
Is the longest part and crosses the IVC, aorta, and vertebral column to the left.
Transverse (Third) Part (Pars Horizontalis)
Is crossed anteriorly by the superior mesenteric vessels
Transverse (Third) Part (Pars Horizontalis)
Ascends to the left of the aorta to the level of the second lumbar vertebra and terminates at the duodenojejunal junction, which is fixed in position by the suspensory ligament (of Treitz).
Ascending (Fourth) Part (Pars Ascendens)
Anatomic landmark dividing gastrointestinal tract into upper and lower GI Tract
Ligament of Treitz
What vertebral level are the first, second, and third part of duodenum respectively?
L1, L2, L3
What is the arterial supply pf duodenum?
Upper half: superior pancreaticoduodenal artery
Lower half: inferior pancreaticoduodenal artery
Origin of superior pancreaticoduodenal artery
Gastroduodenal artery
Origin of Gastroduodenal artery
primary hepatic artery
caused by postoperative adhesions, tumors, Crohn’s disease, hernias, peritonitis, gallstones, volvulus, congenital malrotation, stricture, and intussusception (invagination of one part of the intestine into another)
Small bowel obstruction
Makes up the proximal two-fifths of the small intestine
Jejunum
emptier, larger in diameter, and thicker walled than the ileum
Jejunum
Has the plicae circulares (circular folds), which are tall and closely packed
Jejunum
Contains no Peyer patches (aggregations of lymphoid tissue)
Jejunum
Has translucent areas called windows between the blood vessels of its mesentery
Jejunum
Has less prominent arterial arcades (anastomotic loops) in its mesentery
Jejunum
Has longer vasa recta (straight arteries, or arteriae rectae)
Jejunum
Longer than the jejunum and occupies the false pelvis in the right lower quadrant of the abdomen
Ileum
Characterized by the presence of Peyer patches (lower portion), shorter plicae circulares and vasa racta, and more mesenteric fat and arterial arcades
Ileum
an outpouching (fingerlike) pouch of the ileum, derived from an unobliterated vitelline duct and located 2 ft proximal to the ileocecal junction on the antimesenteric side.
Meckel’s diverticulum
Has ascending and descending colons that are retroperitoneal and transverse and sigmoid colons that are surrounded by peritoneum (they have their own mesenteries, the transverse mesocolon and the sigmoid mesocolon, respectively).
Colon
The ascending and transverse colons are supplied by?
superior mesenteric artery and the vagus nerve
the descending and sigmoid colons are supplied by the?
inferior mesenteric artery and the pelvic splanchnic nerves
three narrow bands of the outer longitudinal muscular coat
Teniae coli
produced by the teniae, which are slightly shorter than the gut
Sacculations or haustra
peritoneum-covered sacs of fat, attached in rows along the teniae
Epiploic appendages
Extends from the ileocecal junction to the anus and is approximately 1.5 m (5 ft) long
Large intestine
Consists of the cecum, appendix, colon, rectum, and anal canal
Large intestine
Functions to convert the liquid contents of the ileum into semisolid feces by absorbing water, salts, and electrolytes. It also stores and lubricates feces with mucus.
Large intestine
Blind pouch of the large intestine. It lies in the right iliac fossa and is usually surrounded by peritoneum but has not mesentery.
Cecum
Is a narrow, hollow, muscular tube with large aggregations of lymphoid tissue in its wall. Is suspended from the terminal ileum by a small mesentery, the mesoappendix, which contains
the appendicular vessels.
Appendix
Causes spasm and distention when inflamed, resulting in pain that is referred to the periumbilical region and moves down and to the right.
Appendix
Has a base that lies deep to McBurney point, which occurs at the junction of the lateral one-third of the line between the right anterior superior iliac spine and the umbilicus
Appendix
This is the site of maximum tenderness in acute appendicitis.
McBurney point
Most common site of appendix
Retrocecal
Where does Appendiceal artery arise?
Iliocolic artery from Superior mesenteric artery
Arterial supply of cecum?
Anterior and posterior cecal arteries form iliocolic artery (branch of superior mesenteric artery)
an internal examination of the colon, using a flexible colonoscope with a small camera.
Colonoscopy
described as pelvic organs
Rectum and Anal Canal
Extend from the sigmoid colon to the anus
Rectum and Anal Canal
Where is villi present?
small intestine
Arterial supply of rectum
Middle rectal artery from Internal iliac artery
Inferior rectal artery from Internal pudendal artery
Superior rectal artery from Inferior mesenteric artery
