Part II. Anatomy of foregut derivatives pg 50-59 Flashcards
The esophagus is covered by ______ superior to thoracic diaphragm (esophageal plexus) and covered by (retroperitoneal) inferior to thoracic diaphragm?
NOTE: remember histology
- adventitia
- serosa
Where are the 4 places where esophageal constriction is seen on fluoroscopy following a barium study?
- Upper Esophageal Sphincter where it is crossed by Cricopharyngeus M
- Where it is crossed by Aortic Arch
- Where it is crossed by L Main Bronchus
- Lower Esophageal Sphincter where it passes through thoracic diaphragm
What is the clinical significance of the 4 esophageal constrictions?
- Foreign bodies tend to lodge here
- Swallowed corrosives do greatest damage here
- Carcinoma most frequently occurs here
- Damage resulting from endoscopic instruments most likely to occur here
What is the point of passage for the esophagus through the diaphragm called?
Esophageal hiatus
Where in the diaphragm does the esophagus pass through?
Right curs of thoracic diaphragm
What attaches esophagus to thoracic diaphragm at hiatus?
Phrenicoesophageal ligaments
What is the function of the Phrenicoesophageal ligaments?
- Permit independent movement during respiration and swallowing - Create a seal between thoracic and abdominal cavities
Where is the esophagogastric junction located?
Left of midline at T11 (level with Xiphoid Process)
Note: esophageal hiatus is located just left of midline at T10
The right border of the esophagogastric junction is continuous with what?
lesser curvature of stomach
The left border of the esophagogastric junction is separated from fundus by what?
cardiac notch
What structure of the esophagus prevents gastric reflux?
Cardiac sphincter
What is the arterial supply to the esophagus?
- Esophageal Branch of L Gastric A (which branches from Celiac Trunk)
- L Inferior Phrenic A which branches from Abdominal Aorta
What is the venous drainage of the esophagus superiorly?
drains to Azygos V via Esophageal Vs
What is the venous drainage of the esophagus inferiorly?
drains to Hepatic Portal V via L Gastric V
What are the primary nodes for the esophagus?
L gastric lymph nodes
What are the secondary lymph nodes for the esophagus?
Celiac lymph nodes
Lymph from the esophagus, ultimately drains where?
Thoracic duct
Parasympathetic innervation to the esophagus is via ________.
Vagal trunks
Presynaptic parasympathetic neurons from the vagal trunks, supplying the esophagus, synapse in which plexi?
myenteric and submucosal plexuses
Sympathetic innervation to the esophagus is supplied by _________ from what spinal nerve roots?
Greater Splanchnic N (T5-T9)
Presynaptic sympathetic neurons supplying the esophagus will synapse in what ganglion?
Celiac
How do postsynaptic sympathetic neurons supplying the esophagus get from the celiac ganglion to the esophagus?
follow periarterial plexus
Is the stomach intraperitoneal or retroperitoneal?
Intraperitoneal
What abdominal quadrant is the stomach mostly located in?
Upper left abdominal quadrant
What is the function of the stomach?
- initiate digestion
- Blend food and digestive enzymes into chyme
- food reservoir (can hold up to 2-3 liters of food in an adult)
What are the internal ridges of the stomach called and what function do they have?
Rugae: increase surface area for digestion
Where is the cardia of the stomach located?
2cm left of midline at 6th costal cartilage (T11)
Where is the fundus of the stomach located?
under left dome of diaphragm superiorly to left 5th intercostal space
Where is the cardiac notch of the stomach located?
between esophagus and fundus
What is the pyloric antrum?
The structure in the pyloric part of the stomach that is a wide funnel-shaped extension of the body
What is the pyloric canal?
The narrower reaction in the pyloric part of the stomach that leads from the pyloric antrum to the sphincter
Where is the pyloric sphincter?
Where the stomach and duodenum meet
What is the function of the pyloric sphincter?
It is the thick circular muscle that regulates exit from stomach into duodenum
The concave border on right side of stomach
Lesser curvature
The convex border on left side of stomach
Greater curvature
What is the sharp indentation on the lesser curvature of the stomach at the junction of the body and the pyloric part of the stomach?
Angular Incisure
What is the primary arterial supply along lesser curvature of stomach?
L Gastric A branches directly from Celiac trunk
Very small artery that anastomoses with L Gastric A along lesser curvature?
R Gastric A usually branches from Proper Hepatic A
What arteries supply greater curvature of stomach in greater omentum
R Gastroepiploic A (gastro-omental) which and anastomoses with L Gastroepiploic A (gastro-omental) along greater curvature of stomach
Right gastroepiploic artery is a branch of _______ while left gastroepiploic artery is a branch of _______.
- Right Branches from Gastroduodenal A
- Left Branches from Splenic A
What are the 4-5 very small arteries branching from splenic artery and supplying fundus of stomach?
Short gastric arteries
Venous drainage fo the stomach parallels the arteries supplying it and all eventually drain to where?
The liver
The left and right gastric veins drain into where?
Hepatic portal vein
Short Gastric V and L Gastroepiploic Vs drain to which vein before draining into hepatic portal vein?
Splenic vein
R Gastroepiploic V drains to which vein before draining to the hepatic portal vein?
Superior mesenteric vein
Primary lymphatic drainage on lesser curvature of the stomach is to _______.
Gastric nodes
Primary lymphatic drainage on greater curvature of the stomach is to _______.
Gastroepiploic nodes
Secondary lymphatic drainage for the stomach is to _______.
Celiac nodes
Lymphatic drainage of the stomach ultimately goes where?
To the thoracic duct
Parasympathetic innervation to the stomach is via _______.
Anterior/Posterior Vagal Trunks
Presynaptic parasympathetic neurons enter the abdomen via ______ and synapse on postsynaptic neurons in the __________ in the stomach.
- esophageal hiatus
- myenteric/submucosa ganglia
What is the result of parasympathetic innervation to the stomach?
- Increase acid secretion
- increase rate of emptying
Sympathetic innervation to the stomach is via ________ from what spinal nerve levels?
Greater splanchnic nerve (T6-T9)
Presynaptic sympathetic neurons that supply the stomach will synapse on postsynaptic neurons in the _______
Celiac ganglion
How do the axons of postsynaptic neurons get from the celiac ganglion to the stomach to innervate it?
They pass in tunica adventitia of arterial vessels to the stomach
Where does the duodenum begin and end?
It is C-shaped, begins at pylorus and ends at duodenojejunal junction (L2 level)
NOTE: it is the first, shortest, widest and most fixed region of small intestine (25cm)
Is the duodenum retroperitoneal or intraperitoneal?
Considered mostly retroperitoneal (the first 2cm are intraperitoneal)
What are the 4 parts of the duodenum?
- superior (1st) part
- Descending (2nd) part
- Inferior (3rd) part
- Ascending (4th) part
The superior part of the duodenum is covered anteriorly by ______ and posteriorly by ______.
- parietal peritoneum
- adventitia
The superior part of the duodenum is attached to the liver by what structure?
Hepatoduodenal L (part of Lesser Omentum)
The superior part of the duodenum, where is ascends from the pylorus, is overlapped by what two structure?
Liver and gallbladder
The descending part of the duodenum curves around what structure?
Right side of head of pancreas
What structures are found in the descending part of the duodenum?
- Major duodenal papilla
- minor duodenal papilla (although not always present)
What is the major duodenal papilla?
Internal opening of Common Bile Duct and Main Pancreatic Duct
What is the hepatopancreatic ampulla?
External union of common bile duct and main pancreatic duct
What is the Minor Duodenal Papilla?
Internal opening if Accessory Pancreatic Duct is present
The inferior part of the duodenum is where it begins to cross to the left. At what vertebral level does this happen?
L3
What vascular bundle passes anterior to the inferior part of the duodenum?
Superior Mesenteric AV
What structures are immediately superior to the inferior part of the duodenum?
Pancreatic head and Uncinate Process
The ascending part of the duodenum rise from and to what vertebral level?
from L3 vertebra to superior border of L2
What landmark denotes the end of the duodenum?
duodenojejunal junction at the point of acute angle
The ascending part fo the duodenum is supported by what?
suspensory muscle of duodenum (ligament of Trietz)
What happens to the acute angle of the duodenum when the suspensory muscle of duodenum (ligament of Trietz) contracts?
widens the angle of flexure facilitating movement through that part of the duodenum (not such a sharp angle)
What Artery Supplies duodenum proximal to Major Duodenal Papilla?
Superior Pancreaticoduodenal A from Gastroduodenal A
What Artery supplies the duodenum distal to Major Duodenal Papilla?
Inferior Pancreaticoduodenal A from Superior Mesenteric A (SMA)
What two arteries supplying the duodenum create an anastomosis between Celiac Trunk and SMA?
Superior and inferior pancreaticoduodenal arteries
What supplies blood from the distal esophagus to the major duodenal papilla (the embryonic foregut)?
Celiac trunk
What supplies blood from the major duodenal papilla to near the left colic flexure (embryonic midgut)?
Superior mesenteric artery
The venous drainage of the duodenum flows the arteries and drains to the __________.
Hepatic portal vein
Anteriorly, lymph from the duodenum drains to ______ and then ______.
- Pancreaticoduodenal lymph nodes
- pyloric nodes
Posteriorly, lymph from the duodenum drains to _______.
Superior Mesenteric nodes
What are the Secondary nodes for the duodenum?
Celiac lymph nodes
Lymph from the duodenum ultimately drains where?
Lymphatic duct
Parasympathetic innervation to the duodenum is via ________.
Posterior Vagal Trunk
Sympathetic innervation to the duodenum is via ______ and ______, originating from what spinal nerve levels?
Greater and Lesser Splanchnic N (originating in T8-T10)
What is the largest gland in the body?
Liver
In what abdominal quadrant is the liver mostly located?
Upper right quadrant
What are the main functions of the liver?
- Carbohydrate metabolism and storage (glycogen)
- Plasma protein and lipoprotein synthesis and secretion
- Bile formation and secretion
- Drug and alcohol detoxification
What are the surfaces of the liver?
- Diaphragmatic surface - anterosuperior and convex aspect
- visceral surface - posteroinferior and flat/concave aspect
What is the space that is the Anterosuperior extension of Greater Sac between liver and diaphragm?
Subphrenic recess
The subphrenic recess is separated into right and left by what structure?
Falciform ligament
What is the space that is the Inferior extension of Greater Sac between liver & R Kidney/Suprarenal gland?
Hepatorenal recess
The diaphragmatic surface of the liver is covered by _______ except posteriorly at the ________
- visceral peritoneum
- bare area of the liver
At the bare area of the liver, the liver is in direct contact with what?
Thoracic diaphragm
The anterior and posterior peritoneal reflections from liver to thoracic diaphragm that outline bare area of liver are called what?
Coronary ligament
NOTE: forms a “crown” on top of the liver