Abdomen: Viscera Flashcards
Innervation of peritoneum
Parietal: spinal somatic fibres: localised pain
Visceral: visceral afferents: referred pain
Greater sac and lesser sac (omental bursa)
Greater sac contains most of the abdomen
Lesser sac: posterior to stomach and liver
Omental epiploic foramen
Joins lesser sac to greater sac
Structures anterior to omental (epiploic) foramen
Hepatoduodenal ligament:
Portal vein
Hepatic artery proper
Bile duct
Structures posterior to epiploic foramen
inferior vena cava
Structures inferior to epiploic foraman
1st part of duodenum
Structures superior to epiploic foraman
caudate lobe of liver
Greater omentum
Greater curvature of stomach
Drapes down anterior to transverse colon, ileum and jejunum
Loops back up and joins transverse colon peritoneum
Lesser omentum
Lesser curvature of stomach to inferior liver
Mesenteries
Mesentery
Transverse mesocolon
Sigmoid mesocolon
Mesentery
The only double layered fold of peritoneum (4 layers)
connects jejunum and ileum to posterior wall
- at the jejunoduodenal junction just to the left of L2
Structures entering through the diaphragm
Vena cava + right phrenic T8
Oesophagus + vagus T10
Aorta + thoracic duct T12
Blood supply to abdominal oesophagus
Left gastric artery
Inferior phrenic artery
Different parts of stomach
Note: cardial notch: superior angle where oesophagus enters stomach
Angular incisure: bend on lesser curvature
Arterial supply of stomach
Left gastric
Short gastric
Gastro-epiploic arcade
Parts of duodenum
Superior
Descending
Inferior
Ascending
Duodenum intra or extraperitoneal
First part: extra peritoneal
Rest: intra peritoneal
Blood supply to duodenum
- Superior pancreaticoduodenal artery - arises from Gastro duodenal artery
- Inferior pancreaticoduodenal artery - arises from SMA
Their anastomosis represents the transition point from the foregut to the midgut at the dueodenal papilla
Difference in blood supply to ileum and jejunum
Supplied by SMA
Jejunum: longer vasa recta, smaller arcade
Ilieum: smaller vasa recta, more developed arcade
Source of bleeding from a posterior duodenal ulcer
Posterior wall
Gastroduodenal artery
The pancreas is the most intimate relation of the duodenal and patients will often complain of pain radiating to the back (dorsolumbar region) as a result of an ulcer or cancer irritating the pancreas
Different positions of appendix
Retrocaecal 74%
Pelvic 21%
Postileal
Subcaecal
Paracaecal
Preileal
Identification of appendix during surgery
Caecal taenia coli converge at base of appendix and form a longitudinal muscle cover over the appendix.
Blood supply to appendix
Appendicular artery (branch of ileo-colic artery)
Colon, intra or retroperitoneal
Appendix and caecum: intra
Ascending: retro
Transverse: intra
Descending: retro
Sigmoid: intra
Rectum: (distally) retro
Arterial supply of colon
Ascending: ilio-colic and right colic (joined by marginal artery)
Transverse: middle colic
Descending: Inferior mesenteric artery (left colic)
Arterial supply of rectum
Superior rectal artery (IMA)
Middle rectal artery (internal iliac)
Inferior rectal artery (internal pudendal, from internal iliac)
Recesses around liver
Hepatorenal recess
Subphrenic recess
What space does the hepatorenal recess communicate with
Right paracolic gutter and lesser sac
Is liver intra or retroperitoneal
Intra (mostly)
Porta hepatis content
Hepatic artery
Portal vein
Common hepatic bile duct
Blood supply to liver
Right lobe: right hepatic artery
Left lobe: left hepatic artery
Quadrate lobe: Left hepatic artery (anatomically part of right)
Caudate: both hepatic arteries
Ligaments of inferior aspect of liver
Falciform ligament
Left triangular ligament
Right triangular ligament
Anterior and posterior coronary ligaments
Falciform ligament
Connects umbilicus to liver
Contains ligamentum teres (remnant of umbilical vein)
Splits into coronary and left triangular ligaments
Ligamentum venosum
Remnant of ductus venosus
Parts of gallbladder
Fundus
Body
Neck
Blood supply to gall bladder
Cystic artery (branch of right hepatc artery)
Pancreas parts
Pancreas ducts
Accessory -superior
Hepatopancreatic- inferior
Pancreatic blood supply
Head: pancreatoduodenal artery
Rest: splenic artery
Biliary tree anatomy
Position of spleen (ribcage)
Ribs 9 -12
Branches of abdominal aorta
Coeliac axis branches
Left gastric
Hepatic
Splenic: branches- Pancreatic, Short Gastric, Left Gastroepiploic
Superior and inferior mesenteric artery branches
Branches of common hepatic artery
Right Gastric
Gastroduodenal
Superior Pancreaticoduodenal
Cystic (occasionally).
Branches of splenic artery
Pancreatic
Short Gastric
Left Gastroepiploic
Portotal venous system
Ends in portal vein (union of splenic and SMA)
IMA draines into splenic
Renal anatomy
Outer cortex
Inner medulla: including pyramids
Papilla: apex of pyramids
Lymph drainage of kidneys
Structures in renal hilum
Anterior to posterior
- renal vein
- renal artery
- ureter
Fascia surrounding kidneys
Gerota’s fascia
Sites of constriction of ureters
Ureteropelvic junction
Crossing common iliac at pelvic brim
Entering the wall of the bladder
Blood supply to ureters
Upper 1/3: Renal artery
Middle 1/3: testicular/ovarian/common iliac
Lower 1/3: Superior vesical (internal iliac)
Lymph drainage of ureter
Upper- lateral aortic
Middle- common iliac
Lower- External and internal iliac
Adenal gland arterial supply
Superior suprarenal artery (inferior phrenic)
Middle suprarenal artery
Inferior suprarenal artery
Venous drainage of adrenal gland
Suprarenal vein
Lumbar plexus nerves
Ilio-hypogastric innervates
Internal oblique and transvesus abdominis
Ilio-inguinal innervates
Internal oblique
Transversus abdominis
Genitofemoral innervates
Genital branch: cremester reflex
Obturator innervates
Obturator externus
Pectineus
medial compartment
Femoral innervates
iliacus
pectineus
anterior compartment
Retroperitoneal viscera
SAD PUCKER
Suprarenal (adrenal glands)
Aorta & IVC
Duodenum (2-4th parts)
Pancreas
Ureters
Colon (descending and ascending)
Kidneys
Esophagus
Rectum
Calot’s triangle borders
Inferior edge of liver
Common Hepatic duct
Cystic duct
Calot’s triangle content
Cystic artery
Lymph drainage of rectum
Above dentate line: mesorectal node
Below dentate line: Inguinal node
Structures within gastro splenic ligament
short gastric arteries
Which structure is anterior to portal vein
Pancreatic neck
The ligamentum teres develops from which embryological structure?
Umbilical Vein
Remember - oxygenised blood passes from umbilicus via Umbilical vein (becomes ligamentum teres) > Ductus Venosum (Ligamentum Venosum) > IVC > Right Atrium > Foramen Ovale > systemic circulation
https://mypastest.pastest.com/newvideos/146/MediaView?subscriptionId=1454551&mediaItemId=68&index=3
The ligamentum venosum develops from which embryological structure?
Ductus Venosum
What is the origin of the external oblique muscle?
5-12th ribs
What nerves innervate the external oblique?
5-11th intercostal nerves
Subcostal nerve
Iliohypogastric nerves
What are the insertions of the external oblique muscle?
Pubic tubercle
Iliac crest
Linea alba
What are the insertions of the rectus abdominis muscle?
Xiphoid process of sternum
Costal cartilages of 5-7th ribs
Genital branch of genitofemoral nerve
Subcostal nerve
The aorta bifurcates at ___ which is in line with ____ . This plane is called _____ .
L4
The summits of the iliac crests
Supracristal plane
Borders of the epiploic foramen? - connection between the greater and lesser sac
Superior - Liver (caudate lobe)
Inferior - First part of duodenum (hepatic artery runs over this)
Anterior - Hepatoduodenal ligament (CBD , Hepatic artery and portal vein posteriorly)
Posterior - IVC
The peritoneal cavity contains NO organs and periotneal fluid to fight infection and prevent friction. The peritoneum can be divided in two ways ____ and ____
Greater sac vs Lesser Sac (communicate with one another via epiploic foramen)
and
Supracolic vs Infracolic (above and below transverse mesocolon)
What is a mesentery?
The mesenteries within the abdomen connect the viscera to the posterior abdominal wall. These include ___
4 layer fold of peritoneum responsile for connecting the abdominal viscera to the posterior abdo wall and also repsonsible for the nerve, lymphatic and blood supply to these viscera/
The mesentery of the small intestine
The transverse mesocolon
The sigmoid mesocolon
The mesoappendix
The ligaments that derive from the embryological ventral mesentery are?
The falciform ligament
The coronary ligament
The hepatoduodenal ligmanent
The hepatogastric ligament
The ligaments that arise from the embyrological dorsal mesentery include____
Gastrophrenic ligament
Gastrosplenic ligament
Phrenicocolic ligament
The transverse mesocolon
The greater omentum
The anatomical relations of the stomach
Anteriorly:
* abdominal wall
* left costal margin
* diaphragm
* left lobe of liver
Posteriorly:
* lesser sac
* Pancreas
* transverse mesocolon
* left kidney
* left adrenal
* Spleen
* splenic artery
Superiorly:
* Left dome of diaphragm
Arterial supply to the stomach
Lymphatic supply stomach
All drainage ends up in the aortic nodes.
However each area takes a different path:
- Via the right and left gastric vessels
- Via the subpyloric nodes and the gastro-epiploic vessels
- Via the suprapancreatic nodes and splenic vessels
This makes gastric cancer technically very difficult if lymph nodes are involved. If the aortic lymph nodes are metastatic then the cancer is often deemed incurable.
The vagal supply to the stomach
The anterior branch supplies the cardia and lesser curvature and also a large hepatic branch
The posterior branch supplies anterior and posterior branches to the stomach but importantly supplies the coeliac axis as it runs along the left gastric artery - where it is then distributed to the intestine and pancreas as far as the mid transverse colon
Barium swallow
Duodenal cap or first part of the duodenum is where the majority of duodenal ulcers occur
The relations of the duodenum
Anteriorly: Liver and gall bladder
Posteriorly: Portal vein , CBD , gastroduodenal artery, and further behind lies the IVC
Differences between the jejunum (upper 1/2) and ileum (lower 1/2).
- Jejunum has a thicker wall as the circular folds of mucosa (valvulae conniventes) are larger and thicker more proximally
- The proximal intestine is of a larger diameter
- The jejunum tends to lie at the umbilical region - the ileum in the suprapubic region and pelvis
- The mesentery becomes thicker and fatter more distally
- The mesenteric vessels for only one or two arcades to the jejunum, with long and relatively infrequent terminal branches passing to the gut wall. The ileum is supplied by shorter and more numerous terminal vessels arising from complete series of 3/4/ or even 5 arcades.
- a greater number of arcades may simply facilitate greater flexibility in the distribution of arterial blood flow to the intestine, which may be more relevant in the ileum than in the jejunum where the majority of digestion occurs.
The small intestine is on average about ___ long.
The large intestine/ colon is on average about ____ long.
6m
1.5m
The colon (but not the ___, ___, or ___) bear characteristic fat filled peritoneal tags called ____ scattered over its surface. These ____ can undergo torsion which is a rare unusual cause of acute abdominal pain.
The appendix, caecum, or rectum
appendices epiploicae
The colon and caecum (but not the ___ or ____ ) are marked by the taeniae coli. These are 3 flattened bands of _____ that run from the base of the appendix all the way to the end of the sigmoid colon. Because these bands of muscle are shorter than the bowel itself, they give rise to the bowels sacculated shape in the abdomen, forming the haustra of the colon which are the shelf-like intraluminal projections.
appendix or rectum
longitudinal muscle tissue
The ileocaecal fold is often termed the _____. It however often contains a vessel that can be a site of significant haemorrhage.
bloodless fold of Treves.
Relations of the rectum (anterior/posterior/lateral)
Posterior:
* Extraperitoneal tissue containing the rectal vessels and lymphatic
and then
- Sacrum cocyx and middle sacral artery
(a growth from the rectum extending from the rectum posteriorly can thus lead to severe sciatic pain due to compression of the lower sacral nerves emerging from the anterior sacral foramina
Anteriorly:
* A layer of fascia (Denonvilliers) - the plane for excision of the rectum
and then
- Upper 2/3 of rectum is covered by peritoneum and in the female there is a recto-uterine space called the pouch of douglas
- Lower 1/3 lies the prostate, bladder base, and seminal vesicles or vagina in females
Laterally:
* The rectum is supported by the levator ani muscle
______ valves (or transverse folds of rectum) are semi-lunar transverse folds of the rectal wall that protrude into the anal canal. Their use seems to be to support the weight of fecal matter, and prevent its urging toward the anus, which would produce a strong urge to defecate.
Houston’s
Relations of the rectum (anterior/posterior/lateral)
Posterior:
* Extraperitoneal tissue containing the rectal vessels and lymphatic
and then
- Sacrum cocyx and middle sacral artery
(a growth from the rectum extending from the rectum posteriorly can thus lead to severe sciatic pain due to compression of the lower sacral nerves emerging from the anterior sacral foramina
Anteriorly:
* A layer of fascia (Denonvilliers) - the plane for excision of the rectum
and then
- Upper 2/3 of rectum is covered by peritoneum and in the female there is a recto-uterine space called the pouch of douglas
- Lower 1/3 lies the prostate, bladder base, and seminal vesicles or vagina in females
Laterally:
* The rectum is supported by the levator ani muscle
The mid anal canal represents the junction between the ____ of the hidgut and the _____ of the cutaneous invagination termed the ____ ( the embryonic posterior ectodermal part of the digestive tract)
endoderm
ectoderm
proctodaeum
The pectinate or dentate line demarcates the upper and lower half of the anal canal embrylogically, which differ in both structure and neurovascular and lymphatic supply.
The lower half of the anal canal is lined by ____
The upper half is lined by _____
Squamous epithelium (stratified)
Columnar epithelium
A carcinoma of the upper anal canal is thus an adenocarcinoma and the lower canal forms squamous carcinoma
The oesophagus and Anal canal are the only parts of the alimentary canal that are squamous epithelium and not columnar
The anal columns, also known as columns of ____ are a number of longitudinal folds of the anal mucosa.
The columns unite inferiorly to form crescentic shaped anal valves. Shallow clefts of mucosa are formed in between the columns and valves, termed the ____ . The anal valves aka (the valves of ____) form a complete ring around the anal canal, called the ___ (pectinate) line, which marks the position of the embryological anal membrane - failure of breakdown of this separating membrane results in imperforate anus or anorectal malformations
Morgagni
Anal sinuses
The valves of ball
Dentate
What is the arterial and venous blood supply to the upper and lower anal canal?
The arterial supply to the upper half of the anal canal is from the superior rectal artery derived from the inferior mesenteric artery.
The venous supply to the upper half of the anal canal is from the superior rectal vein which drains into the inferior mesenteric vein and then the splenic, and further the portal vein.
In contrast the blood supply of the lower anal canal (and surrounding perianal skin) is from the inferior rectal vessels, derived from the internal pudendal and ultimately the internal iliac artery and vein.
The two venous systems communicate and anastamose the portal and systemic venous system
What is the blood supply to the lower anal canal?
Below the pectinate line, the anal canal is served by the middle and inferior rectal arteries.
The middle rectal artery is a branch of the internal iliac artery, while the inferior rectal artery is a branch of the internal pudendal artery that arises from the internal iliac artery
The anorectal ring is formed by the fusion of the internal anal sphincter, external anal sphincter and ____ muscle
puborectalis (part of levator ani muscle group)
What is the drainage of the lymphatics of the anal canal above and below the pectinate line
Above - lumbar nodes
Below - Inguinal nodes
A carcinoma of the lower anal canal may thus metastasize to the inguinal nodes or groin.
Anal sphincter anatomical relations (anterior / lateral posterior)
Anterior: Perineal body - which separates anal canal from the bulb of the urethra in men and the lower vagina in females
Lateral: Ischioanal fossa (containing fat)
Posteriorly: Fibrous tissue and coccyx (the anococcygeal body)
The Coeliac axis/SMA/IMA arise from the aorta at which verterbral levels?
Coeliac axis - T12
SMA - L1
IMA - L3 (Can be L2-L4 - about 2cm above the bifurcation)
List the 5 locations of portal–caval anastomoses that enlarge during increased portal hypertension?
- Oesophagus (Azygous - Oesophageal and gastric veins - Left gastric vein - portal vein)
- Mid rectum (Inferior rectal vein - internal pudendal - internal iliac vein)
- Anterior body wall, via umbilical veins along the falciform ligament, which may reopen under pressure (caput medusae)
- Where the liver connects to the diaphragm (bare area)
- Where superficial veins of colon drain to the body wall.
Lymphatic drainage of the intestine drains into the ___
Cisterna chyli
Lymphatic drainage of the intestine drains into the ___
Cisterna Chyli
What are the layers of mucosa of the alimentary canal?
Mucosa
Submucosa
Muscularis
Serosa aka adventitia (absent when the gut is extraperitoneal)
The mucosa and submucosa form longitudinal folds, or rugae, that contain funnel-shaped invaginations at the mucosal surface. These invaginations, which are referred to as gastric pits, or foveolae, form the openings for ducts into which the gastric ‘crypt like’ glands empty.
Which anatomical part of the stomach is mostly responsible for producing gastrin?
Antrum (also duodenum and pancreas)
Gastrin is a peptide hormone that stimulates secretion of gastric acid by the parietal cells of the stomach and aids in gastric motility.
Which mucosal cells of the stomach are responsible for the secretion of HCL/Intrinsic factor?
Parietal/Oxyntic cells
Parietal cells (also known as oxyntic cells) are epithelial cells in the stomach that secrete hydrochloric acid (HCl) and intrinsic factor
Which cells of the stomach mucosal crypts produce pepsin?
Gastric chief cells
Chief cells secrete pepsin as an inactive zymogen called pepsinogen. Parietal cells within the stomach lining secrete hydrochloric acid that lowers the pH of the stomach. A low pH (1.5 to 2) activates pepsin.
The duodenum and small intestine also contain crypt like gland invaginations. However, they also contain many villous processus which extend into the lumen of the bowel - greatly increasing its surface area.
The duodenum has a distinguishing characteristic in that its crypts extend deep into the ______ and open into an extensive system of acini in the submucosa termed _____
Muscularis mucosa
Brunners glands
Brunner’s glands are located in the submucosa of the duodenum. They secrete an alkaline fluid containing mucin, which protects the mucosa from the acidic stomach contents entering the duodenum.
The mucosa of the large intestine is lined almost entirely by mucous secreting _____ cells ; there are NO VILLI
Goblet cells
Goblet cells reside throughout the length of the small and large intestine and are responsible for the production and maintenance of the protective mucus blanket (mucins)
The muscle coat of the alimentary canal is made up of an inner circular layer and an outer (think of taenia coli on outside) longitudinal layer.
The muscle is voluntary in the ____ and the ____. Otherwise it is involuntary.
The stomach also has an additional innermost ____ layer.
upper 2/3 oesophagus
anal margin (below the dentate line in the anal canal)
Oblique layer
The autonomic nerve plexuses of Meissner and Auerbach lie in which which layers of the bowel wall?
Meissners plexus is also known as the ____
Auerbachs plexus is also known as the _____
Meissner’s plexus lies in the submucosal layer and is fittingly also named the submucosal plexus
Auerbach’s plexus lies between the inner circular and outer longitudinal layers and is also referred to as the myenteric
Remember Auerbach for OUTBACK
Define the anatomical relations of the foramen of winslow
(Superior/Inferior/Anterior/Posterior)
Foramen of winslow borders:
Superior - caudate lobe of the liver
Inferior - Duodenum
Anterior - Hepatoduodenal ligament (comprising the portal triad - Bile duct / hepatic artery proper/ Portal Vein)
Posterior - IVC
What are the anatomical relations of gall bladder?
Lies in a fossa separating the quadraste and caudate lobes of the liver
Inferiorly - duodenum and transverse colon (inflamed gall baldder can occasionally ulcerate into either of these structures)
Nerve supply of gall bladder?
Thoracic Splanchnic nerves/Coeliac or solar plexus ( arises from T7)
Carry sympathetic fibers that cause the gallbladder to relax, allowing bile to flow into the gallbladder
- Biliary pain is often referred to the right lower pole of the scapula
Vagus nerve (hepatic branch)
Carries parasympathetic fibers that assist the hormone cholecystokinin (CCK) in contracting the gallbladder and secreting bile.
- Stimulation of the vagus by sight smell and taste of food causes the gall bladder to contract
Gut emybryology
What are the borders of calots triangle?
Medial – common hepatic duct.
Inferior – cystic duct.
Superior – inferior surface of the liver.
[https://www.osmosis.org/learn/Development_of_the_gastrointestinal_system]
In performing a splenectomy the close relationship of the pancreatic tail to the splenic hilum and pedicle must be remembered as it is easily wounded
Posterior relations of the pancreas?
4 veins:
IVC
Commemcement of portal vein
Splenic vein
SMV
2 Arteries:
AORTA
SMA
4+1 others:
Crura of diaphragm
Coeliac plexus
Left Kidney
Suprarenal gland
Common bile duct - either lies in a groove in the right extremity of the gland or is embedded in its tissue - thus technically is in the same plane but is considered to be posterior
A neoplasm of the head of the pancreas will produce obstructive jaundice as it compresses the bile duct. An extesnive growth may also compress the portal vein and IVC.
Anterior relations of the pancreas?
Stomach
Lesser sac
The sac may become closed off and distended with fluid - either from a perforation of a posterior gastric ulcer or from the outpouring of fluid in acute pancreatitis - forming a pseudocyst of the pancreas. Such a collection may almost fill the abdominal cavity.
The pancreas lies at which spinal level?
L1
Note the splenic vessels are the principal blood supply to the pancreas (splenic artery and vein) along with the pancreaticoduodenal arteries
The gastrosplenic ligament carries which vessels?
Short gastric
Left gastro-epiploic vessels
The splenorenal ligament carries which structures?
Splenic vessels
Tail of the pancreas
Both the gastosplenic and splenorenal ligaments are part of the Greater Omentum (continuous with)
What are the anatomical relations of the spleen?
(Posterior/Anterior/Inferior/Medially)
Posterior - Left diaphragm (separating it from the pleura lung and ribs 9/10/11)
Anteriorly - Stomach
Inferior - Splenic flexure of colon
Medial - Kidney (left)
The close proximity of these structures means any injury to the upper abdomen may caause damage to any combination of these structures. A stab wound in the posterior left chest often penetrates the diaphragm and tears the spleen.
The spleen with its** tense capsule **is the commonest organ to be ruptured by blunt trauma
The spleen has a thin fibrous capsule to which the peritoneum adheres intimately. The fibrous tissue extends into the spleen to form a series of trabeculae between which lies the splenic ____ .
reticuloendothelial system (RES)
pulp
