Abdomen Anatomy Flashcards
What part of the oesophagus is in the abdomen?
Last 1/2 inch
What is the shape of the oesophagus?
Muscular tube
How long is the eosophagus?
25 cm
What’s the origin, course and end of the oesophagus?
From pharynx
Through thorax
Terminates at stomach
What does the oesophagus do?
Conducts food from pharynx to stomach
What is the relationship between the oesophagus, trachea, and vertebral column?
Behind trachea
In front of vertebral column
In what direction does the oesophagus move through the thorax?
Goes forwards and lefT
Where does the oesophagus pierce the diaphragm?
At T10 through opening in right crus
On which side of the stomach does the oesophagus enter?
Right side
What are the two muscular layers of the oesophagus?
Outer longitudinal
Inner circular
Is the entire oesophagus smooth muscle?
No, upper part striated
What tissue is the oesophagus lined by?
Stratified squamous epithelium
Abrupt change to gastric mucosa at gastro-oesophageal junction = Z line
- Clear linear demarcation
What is the narrowing of the oesophagus in the cervical region?
Upper oesophageal sphincter
What is the arterial supply to the oesophagus in the cervical region?
Inferior thyroid artery
What is the venous drainage of the oesophagus in the cervical region?
Brachiocephalic system
What is the lymph drainage of the oesophagus in the cervical region?
Deep cervical nodes
What are the narrowings in the oesophagus in the thoracic region?
Aortic arch
Left main bronchus
What is the arterial supply to the oesophagus in the thoracic region?
Oesophageal branches from aorta
What is the venous drainage of the oesophagus in the thoracic region?
Azygous system
What is the lymph drainage of the oesophagus in the thoracic region?
Mediastinal nodes
What is the narrowing in the oesophagus in the abdomen?
Diaphragmatic orifice
What is arterial supply of the oesophagus in the abdomen?
Left gastric artery from aorta
What is the venous drainage of the oesophagus in the abdomen?
Left gastric portal vein overlaps systemic
What is the lymph drainage of the oesophagus in the abdomen?
Pre-aortic nodes
What can happen to the oesophagus with portal hypertension?
Dilated oesophageal veins = oesophageal varices
If breach mucosa > vomit lots of blood
What is a hiatus hernia?
Protrusion of part of stomach through oesophageal hiatus in diaphragm, up into mediastinum
What type of hiatus hernia is most common?
Sliding (95%)
What is a sliding hiatus hernia?
Top of stomach pushes up
Pulls oesophagus with it
What is a paraoesophageal hernia?
Stomach pushes up beside oesophagus
Connective tissue attachments between margins of oesophageal hiatus and oesophagus stretch up and over stomach
In which quadrant of the abdomen is the stomach?
Left upper quadrant
What does the stomach do?
Storage
Start of digestion of food
What is the shape of the stomach?
J-shaped
What are the two openings of the stomach?
Cardiac opening - oesophagus comes in
- On supramedial aspect
Pyloric opening - end of stomach
What are the two curvatures of the stomach?
Lesser
Greater
What are the two surfaces of the stomach?
Anterior - relates to anterior abdominal wall
Posterior - relates to structures on and of posterior abdominal wall
What is the shape of the pylorus?
Funnel
Describe the pyloric canal
Most tubular part of stomach
Pyloric sphincter very muscular
- Controls gastric outflow into duodenum
What tethers the stomach to the liver?
Lesser omentum = double fold of peritoneum between lesser curvature of stomach and liver
Where does the greater omentum go?
Heads down over rest of viscera, from greater curvature of stomach
Eventually attaches to posterior abdominal wall
Describe the fundus of the stomach
Dome shaped part projecting above cardiac orifice
Usually contains gas bubble
Tucks under left dome of diaphragm
Visible on plain film
Describe the body of the stomach
From cardiac orifice to angular notch on lesser curvature
What is the antrum of the stomach?
Start, and narrowing of pylorus
Describe the gastric folds
Called rugae
Longitudinal muscle folds lining surface
Increase in prominence closer to pylorus
What is the blood supply to the stomach?
Right and left gastric arteries run along lesser curvature
- Run between 2 layers of lesser omentum
- Send branches into surface of stomach
Right and left gastroepiploic arteries run along greater curvature
- Anastomose with each other
- Run between 2 layers of greater omentum
What is the duodenum?
1st part of small intestine
How long is the duodenum?
10 inches
- 2 inches
- 3 inches
- 4 inches
- 1 inch
What is the shape of the duodenum?
C shaped
Where is the duodenum?
Sits back on posterior abdominal wall
Relates to pancreas
- C shaped loop around head of pancreas
Is the duodenum intraperitoneal?
Only 1st inch
Rest retroperitoneal
What does the duodenum do?
Absorption of digested products
Describe the duodenal cap
2 inches
Location of most duodenal ulcers because of imbalance of stomach acid and mucosal defences
Heads up and back to posterior abdominal wall
Sits on right crus
Just medial to right kidney
Describe the part of the duodenum that turns downwards after reaching the posterior abdominal wall
3 inches
Descends next to head of pancreas
Overlies hilar structures of right kidney
Describe the part of the duodenum that becomes horizontal after heading downwards
4 inches Crosses - Right psoas - Inferior vena cava and aorta - Left psoas at level of L3
Describe the fourth part of the duodenum
1 inch Upwards and forwards Curves anteriorly Forms duodenojejunal flexure Attached by fibrous tissue to left psoas
What overlies the second and third parts of the duodenum?
Anterior attachments of mesentaries
What increases the surface area of the duodenum?
Mucosal folds
Where is the common opening of the common bile and pancreatic ducts?
On posteromedial wall at midpoint of 2nd part of duodenum
What is the minor duodenal papilla for?
Opening for accessory pancreatic duct
How long is the jejunum and ileum?
4-6 m
What is the extent of the jejunum and ileum?
Duodenojejunal flexure to ileocaecal junction
What are the relative proportions of the jejunum and ileum?
1st 0% = jejunum
2nd 60% = ileum
Are the jejunum and ileum intraperitoneal or retroperitoneal?
Intraperitoneal
How do the jejunum and ileum connect to the posterior abdominal wall?
By mesentary
What conducts neurovascular structures to the jejunum and ileum?
Mesentary
What is the demarcation between the jejunum and ileum?
No clear demarcation
What quadrant does the jejunum tend to be in?
Left upper quadrant
What quadrant does the ileum tend to be in?
Right lower quadrant
How is the jejunum different to the ileum?
Jejunum
- Larger in diameter
- Thicker walls
- More mucosal folds
What are the differences between the mesentaries of the jejunum and ileum?
Jejunum - Less fat - Few arcades: 1-2 stacks - Long vasa recta Ileum - More fat - Layers of arcades - Short vasa recta
What is at the ileocaecal junction?
Ileocaecal opening
- Mucosa covering thickened smooth muscle
- Covers sphincter
- Controls passage of contents from small to large intestine
What is the relationship between the small and large intestine?
Coils of small intestine centrally placed
Large intestine runs around perimeter of coils
In which quadrant is the ileocaecal junction?
Right lower quadrant
How long is the colon?
1.5 m
Describe the length of the colon
Extends from caecum in right lower quadrant Up Across Down S shaped loop Straightens in pelvis Terminates at anal canal
What does the large intestine do?
Absorption of water and electrolytes from faeces
Describe the outer longitudinal coat of the large intestine
Divided into 3 discrete longitudinal muscle bands = teniae coli
Teniae coli shorter than internal mucosal tube
- Gather up tube > saculated/haustrated appearance
Have fat tags = fat filled peritoneum = epiploic appendices
What is the caecum?
Blind ending part
Hangs down below ileocaecal junction
Has appendix hanging off it
The location of which part of the appendix is constant?
Base
Describe the teniae coli
3 bands - Anterior - Posterolateral - Posteromedial Unite at posteromedial wall of caecum - where base of appendix attaches Corresponds to McBurney's point
What is McBurney’s point?
1/3 along line between anterior superior iliac spine and umbilicus
Corresponds with base of appendix
How long is the appendix?
Normally 6-9 cm
Where is the tip of the appendix?
Anywhere
- Usually tucked up behind caecum = retrocaecal appendix
- 1 in 5 have it in pelvis = pelvic appendix
Where is the ascending colon?
Above ileocaecal junction
On right side
To hepatic/right colic flexure
Where is the transverse colon?
Right angle turn from ascending to transverse colon
Crosses right to left
To under spleen
Turns at splenic/left colic flexure
Where is the descending colon?
Right angle turn from transverse to descending colon
Down left side
Into left lower quadrant
Where is the sigmoid colon?
S-shaped loop at end of descending colon
Drops down into pelvis
Straightens in midline
Where is the rectum and anal canal?
Straight in midline
In pelvis
Fixed terminal part
Where do the teniae coli unit?
At rectum
Where is the site of portosystemic anastomosis in the large intestine?
Anal canal
In which quadrant is the liver?
Right upper quadrant
How does the liver receive the venous drainage from the gastrointestinal tract?
Via portal vein
What is the diaphragmatic surface of the liver?
Anterior and superior parts relate to diaphragm
Domed
What is the visceral surface of the liver?
Poster and and inferior parts
Has
- Imprints of surrounding viscera
- Liver hilum
What divides the diaphragmatic surface of the liver into two unequal lobes?
Falciform ligament
Describe the falciform ligament
Double fold of peritoneum - Has 2 layers Connects liver to anterior abdominal wall Divides diaphragmatic surface into - Small left lobe - Large right lobe
Describe the round ligament, or ligamentum teres, of the liver
At end of falciform ligament
Round fibrous band
Represents obliterated umbilical vein
Connects liver down to umbilicus
Describe the inferior margin of the liver
Sharp
Separates anterior and superior part from posterior and inferior part
Which part of the liver is palpable when the liver is enlarged?
Inferior margin palpable below costal margin
What is the hilum of the liver called?
Porta hepatis
What is the shape of the area around porta hepatis?
H shaped fissure formation
Porta hepatis in centre
What are the structures at the porta hepatis, from anterior to posterior?
Hepatic duct
Proper hepatic artery
Portal vein
What is the hepatic duct?
Duct of liver bringing bile from it
What lobes does the H shaped groove around the porta hepatis form in the liver?
Caudate lobe posteriorly, adjacent to inferior vena cava
Quadrate lobe inferiorly, related to gall bladder
Is the caudate lobe of the liver a discrete lobe?
No, caudate process connects it to right lobe
Which lobes form the left functional half of the liver?
Caudate
Quadrate
Left
Which lobes form the right functional half of the liver?
Right
What are the functional lobes of the liver important for?
Arterial supply
Venous drainage
Bile production
In which groove of the liver is the inferior vena cava located?
In H between right and caudate lobe
Sometimes has own channel
In which groove of the liver is the gall bladder located?
In H between right and quadrate lobe
What does the tip of the gall bladder relate to?
Inferior margin of liver
In which groove is ligamentum teres located?
In H between left and quadrate lobe
What is ligamentum venosum?
Remnant of ductus venosus = shunt between umbilical vein and inferior vena cava
Connects to inferior vena cava
In which groove is ligamentum venosum located?
In H between left and caudate lobe
Into what does the proper hepatic artery divide into at the porta hepatis?
Right and left hepatic artery
Into what does the portal vein divide into at the porta hepatis?
Right and left branch of portal vein
How is venous blood drained from the liver?
Hepatic veins come out of liver, not at porta hepatis
Plug directly into inferior vena cava
Describe the route of bile from the liver to the duodenum
Right and left hepatic duct > porta hepatis > hepatic bile duct > joined by cystic duct from gall bladder > common bile duct > empties into 2nd part of duodenum halfway along posteromedial wall via major duodenal papilla
Where do the structures from the porta hepatis run after leaving the liver?
Between 2 leaves of lesser omentum, near free edge on right side
What is the course of the common bile duct?
1st part at free edge of lesser omentum
2nd part behind 1st part of duodenum
Runs in groove between head of pancreas and 2nd part of duodenum
Enters duodenum
What is the ampulla of Vater?
Where common bile and pancreatic ducts meet
Describe the sphincter surrounding the major duodenal papilla
Complex
Surrounds common opening of common bile and pancreatic ducts
Also surround last part of each individual duct
When digestion not happening > sphincter closed
Bile backs up > enter cystic duct > stored on gall bladder
How is bile released from the gall bladder in response to fatty foods in the small intestine?
Entrance of fatty foods into duodenum Promotes release of CCK CCK stimulates - Contraction of gall bladder - Relaxation of sphincter Concentrated bile released for fat emulsification
What is the shape of the gall bladder?
Pear shaped sack
On which surface is the gall bladder located?
Visceral
What can happen at the site where the gall bladder meets the anterior abdominal wall?
Site of tenderness with gall bladder inflammation
Gall stone erodes through anterior abdominal wall
- Very rare
What is the neck of the gall bladder continuous with?
Cystic duct
Describe the body of the gall bladder
In contact with visceral surface of liver
Narrows to neck
Describe the fundus of the gall bladder?
Rounded tip
Usually projects beyond inferior edge of liver
In contact with anterior abdominal wall
- At lateral border of right rectus abdominis crossing costal margin
What type of gland is the pancreas?
Endocrine
Exocrine
What endocrine substances are released by the pancreas into the blood?
Insulin
Glucagon
Somatostatin
What exocrine substances are released by the pancreas into the pancreatic duct?
Enzymes
Bicarbonate
What is the shape of the pancreas?
Comma
Where is the head of the pancreas located?
Within C shape of duodenum
What is the uncinate process of the pancreas?
Wedge-shaped process of head
Where is the uncinate process of the pancreas?
Tucks behind superior mesenteric vessels
Where is the neck of the pancreas?
Lies over superior mesenteric vessels
Under pylorus of stomach
Where is the body of the pancreas?
Relates to duodenojejunal flexure
- Lies over