Abdomen Flashcards
Foregut
oesophagus to 1st part of duodenum
Midgut
2nd part of duodenum to proximal 2/3rd of transverse colon
Hindgut
distal 1/3rd of transverse colon to rectum
Transpyloric plane
L1 verterbrae
Midway through jugular notch and pubic symphysis
ninth costal cartilage
pyloric orifice (opening of stomach into duodenum)
Body of pancreas
Hila of kidney - inferior pole of left kidney, superior pole of right kidney
Coeliac artery
anterior unpaired branch from abdominal aorta at upper border of L1
Superior mesenteric artery
anterior unpaired branch from abdo aorta at lower border of L1
Inferior mesenteric artery
anterior unpaired branch from abdo aorta at LIII
left renal vein
drains left kidney, suprarenal gland and gonad on left side. Left suprarenal vein, left gonadal vein and left lumbar vein drains into left renal vein. THis then drains into IVC.
Left common iliac vein
crosses at midline at approximately L5 to join with partner on right to form IVC.
left lumbar vein
drains back and posterior abdominal wall on left side
portocaval anastomoses
inferior end of oesophagus
inferior part of rectum
where liver is in direct contact with diaphragm (bare area of liver)
where wall of GI tract in direct contact with posterior abdominal wall (retroperitoneal areas of large and small intestine)
posterior surface of pancreas
rectus sheath contents
rectus abdominis
pyramidalis
superior and inferior epigastric vessels
lower 6 thoracic nerves and accompanying branches of the posterior intercostal vessels
transversalis fascia - deep to transversus abdominus
Continuous layer of deep fascia that lines abdominal cavity and continues deep into pelvic cavity. Continuous with fascia on inferior surface of diaphragm.
Continuous posteriorly with deep fascia covering muscles of posterior abdo wall and attaches to thoracolumbar fascia.
Attaches to iliac crest.
Ilioinguinal nerve cutaneous supply
anterior surface of scrotum/labia majora, small cutaneous branch to thigh
intercostal nerves to abdomen
runs in between internal oblique and transversus abdominis muscle, appears lateral to rectus sheath and pass posterior to rectus abdominis. Midline anterior cutaneous branch passes through rectus abdominis to supply skin.
Arterial supply to superficial layer of anterolateral abdominal wall
Musculophrenic artery - branch of internal thoracic
Superior epigastric artery and superficial circumflex iliac artery - both branches of femoral artery
Arterial supply to deep layer of abdominal wall
Superior epigastric artery
Intercostal arteries T10-T11 and subcostal artery T12
Inferior epigastric artery and deep circumflex iliac artery - both branches of external iliac artery
superior and inferior epigastric arteries
passes posteriorly to rectus abdominis throughout their course and anastomose with each other
lymphatic drainage of anteriolateral abdo wall
Superficial
superior to umbilicus - axillary nodes
below umbilicus - superficial inguinal nodes
Deep
Parasternal nodes, lumbar nodes and external iliac nodes
layers of processus vaginalis
transversalis fascia forms deepest covering
second covering - internal oblique
most superficial -external oblique
transversus abdominis covering not acquired because PV passes under arching fibers of this muscle
processus vaginalis
forms basic structure of inguinal canal
anterior to gubernaculum
inguinal canal
4cm long. Contents: Genital branch of genitofemoral nerve spermatic cord (men), round ligament (women) Ilioinguinal nerve
deep inguinal ring
mid-inguinal point
lateral to inferior epigastric vessels
continues as internal spermatic fascia of spermatic cord
superficial inguinal ring
superior to pubic tubercle
Triangular opening in the aponeurosis of external oblique. Apex pointing superolaterally and base formed by pubic crest. Two side of triangle attached to pubic symphysis and pubic tubercle.
continues as external spermatic fascia.
borders of inguinal canal
anterior - aponeurosis of external and internal oblique
posterior - transversalis fascia and conjoint tendon
roof - transversus abdominis and internal oblique muscles
floor - inguinal ligament
Contents of spermatic cord
ductus deferens artery to ductus deferens (from inferior vesical artery) testicular artery (from abdominal aorta) testicular veins cremasteric artery and veins genital branch of genitofemoral nerve sympathetic and visceral afferent fibers lymphatics
Fascia of spermatic cord
internal spermatic fascia - deepest, from transversalis fascia
cremasteric fascia - internal oblique
external spermatic fascia - external oblique
cremasteric muscle
supplied by genital branch of genitofemoral nerve.
Sensory fibres enter spinal cord at L1
Hesselbach triangle boundaries
inferiorly inguinal ligament
laterally inferior epigastric vessels
medially rectus abdominis
Omental bursa
smaller subdivision of peritoneal cavity posterior to stomach and liver, connected to greater sac through epiploic foramen
Epiploic foramen
anteriorly - portal vein, hepatic artery proper, bile duct
posteriorly - IVC
superiorly - caudate lobe of liver
inferiorly - first part of duodenum
greater omentum
derived from dorsal mesentery from greater curvature of stomach and first part of duodenum draping over transverse colon and coils of jejunum and ileum
contains two arteries and accompanying veins - right and left gastro-omental vessel between this double-layered peritoneal apron
lesser omentum
lesser curvature of stomach and first part of duodenum to inferior surface of liver. derived from ventral mesentery
Divided into
medial hepatogastric ligament - between stomach and liver
lateral hepatoduodenal ligament - between duodenum and liver
Right and left gastric vessels are in between the layers of lesser omentum
Oesophagus
25cm long, from C6 behind cricoid cartilage to cardia of stomach (around T11)
vagus nerve through T10 of diaphragm - anterior trunk from left vagus, posterior trunk from right vagus
Regions of stomach
cardia - opening of oesophagus into stomach
fundus - area above level of cardial orifice
body - largest region
pyloric - pyloric antrum and pyloric canal and is the distal end of stomach
Arterial supply of oesophagus
branches from left gastric (from coeliac trunk)
branches from left inferior phrenic artery (from abdo aorta)
arterial supply to stomach
lesser curvature:
left gastric artery from celiac trunk
right gastric artery from hepatic artery proper
greater curvature:
right gastro-omental artery from gastroduodenal artery
left gastro-omental artery from splenic artery
posterior gastric artery from splenic artery (not always present)
duodenum
20-25cm long
above level of umbilicus, adjacent to head of pancreas
retroperitoneal except for its beginning, which is connected to liver by hepatoduodenal ligament
4 parts of duodenum
superior part
descending
inferior
ascending
Superior part of duodenum
pyloric orifice of stomach to neck of gallbladder. just right of L1 and passes anteriorly of bile duct, gastroduodenal artery, portal vein and IVC. Most duodenal ulcers occur here.
2nd part (Descending part) of duodenum
Right of midline and from neck of gallbladder to lower border of LIII. Anterior surface crossed by transverse colon, posterior to it is right kidney, and medial is head of pancreas. Contains major duodenal papilla (entrance for bile and pancreatic ducts) and minor duodenal papilla (entrance for accessory pancreatic duct).
inferior part (3rd part) of duodenum
longest section, crossing IVC, aorta and vertebral column. Crossed anteriorly by SMA and SMV.
Ascending part (4th part) of duodenum
passes upward and left of aorta to approximately upper border of LII and terminates at duodenojejunal flexure.
arterial supply to duodenum
branches of gastroduodenal artery
first jejunal branch of SMA
Jejunum
proximal 2/5ths of small intestine, larger in diameter and thicker wall than ileum.
walls has plicae circulares.
less prominent arterial arcades and longer vasa recta
arterial supply - jejunal arteries from SMA
Ileum
distal 3/5ths of small intestine.
Thinner walls, fewer and less prominent mucosal folds, shorter vasa recta, more arterial arcades.
arterial supply - ileal arteries from SMA and ileal branch from ileocolic (from SMA)
duodenal ulcers
posterior - erode into gastroduodenal artery or more commonly onto posterior superior pancreaticoduodenal artery
anterior - peritoneal cavity causing peritonitis
appendix
arterial supply - anterior cecal artery, posterior caecal artery and appendicular artery. All branches of ileocolic artery from SMA
colon structure locations
ascending and descending are secondarily retroperitoneal
transverse and sigmoid are intraperitoneal
arterial supply to ascending colon
colic branch from ileocolic (from SMA)
anterior cecal artery, posterior caecal artery both from ileocolic (from SMA)
right colic artery from SMA
arterial supply to transverse colon
right colic from SMA
middle colic from SMA
left colic from IMA
arterial supply to descending colon
left colic from IMA
arterial supply to sigmoid
sigmoidal artery from IMA
Rectosigmoid junction
level of vertebra S3, rectum is a retroperitoneal structure
Arterial supply to rectum and anal canal
superior rectal artery from IMA
middle rectal artery from internal iliac artery
inferior rectal artery from internal pudendal artery (from internal iliac artery)
Visceral surface of liver in contact with
oesophagus,, right anterior part of stomach, superior part of duodenum, lesser omentum, gallbladder, right colic flexure, right transverse colon, right kidney and right suprarenal gland
Ligaments of liver
Liver attached to anterior abdominal wall by falciform ligament, except for a small area against diaphragm (bare area of liver).
Hepatoduodenal ligaement
Hepatogastric ligament
Anterior and posterior coronary ligaments - attached to diaphragm.
Bare area of liver
Anterior boundary - anterior coronary ligament
Posterior boundary - posterior coronary ligament
Where coronary ligaments come together laterally they form right and left triangular ligaments
Quadrate lobe of liver
Visible on anterior part of visceral surface, bounded on left by fissure for ligamentum teres and right by gallbladder. Functionally related to left lobe of liver
Caudate lobe of liver
Visible on posterior part of visceral surface. Bounded on left by fissure for ligamentum venosum and right by IVC
arterial supply of liver
right and left hepatic artery - branch of hepatic artery proper - branch of common hepatic artery from coeliac trunk
arterial supply of gallbladder
cystic artery from right hepatic artery
Pancreas
Lies mostly posterior to the stomach. Extends from duodenum (on R) to spleen (on L)
Mostly retroperitoneal except for some parts of its tail.
Develops from ventral and dorsal buds from foregut.
Ventral - head and uncinate
Dorsal - head, neck and body.
Parts of pancreas
Head, uncinate process, neck, body and tail
Head of pancreas
C-shaped concavity of duodenum
Uncinate process of pancreas
passes posterior to superior mesenteric vessels
Neck of pancreas
anterior to superior mesenteric vessels.
SMV and splenic veins join to form portal vein behind neck of pancreas
Tail of pancreas
passes between layers of splenorenal ligament
arterial supply to pancreas
gastroduodenal artery (branch of common hepatic artery)
inferior pancreatic artery (branch of splenic artery)
inferior pancreaticoduodenal artery (branch of SMA)
Bile duct relative structure
Lies to the right of hepatic artery proper, and usually to the right/anterior of portal vein.
Continues inferiorly and passes posterior to superior part of duodenum
Spleen
Develops from dorsal mesentery
From rib 9 to 10
Spleen connected to
greater curvature of stomach by gastrosplenic ligament which contains short gastric and gastro-omental vessels
left kidney by splenorenal ligament which contains splenic vessels
arterial supply to spleen
splenic artery (a branch of coeliac trunk)
Liver
8 lobes, Caudate lobe = Segment I and moves clockwise.
Principal plane = parasagittal plane across IVC and gallbladder
Coeliac trunk
anterior branch of abdominal aorta - anterior to L1.
Divides into left gastric, splenic and common hepatic arteries
Left gastric artery
Smallest branch of coeliac trunk.
Has oesophageal branches to abdo part of oesophagus.
Descends along lesser curvature of stomach and anastomose with right gastric artery.
Splenic artery
largest branch of coeliac trunk.
Travels to the left along superior border of pancreas, travels in splenorenal ligament and enters hilum of spleen.
Branches into short gastric arteries (fundus of stomach)
Branches into left gastro-omental artery which runs along greater curvature of stomach and anastomose with right gastro-omental artery
Common hepatic artery
Divides into 2 terminal branches - hepatic artery proper and gastroduodenal artery
Hepatic artery proper
runs to left of bile duct and anterior to portal vein, and divides into left and right hepatic artery
Gastroduodenal artery
Give off posterior superior pancreaticoduodenal artery
Terminates into 2 branches - right gastro-omental artery and anterior superior pancreaticoduodenal artery
Superior mesenteric artery
anterior branch of abdominal aorta, lower part of LI
Crossed anteriorly by splenic vein and neck of pancreas
Posterior to it - left renal vein, uncinate process and inferior part of duodenum.
First branch - inferior pancreaticoduodenal artery
left branches - jejunal and ileal arteries
right branches - middle colic, right colic and ileocolic.
Inferior mesenteric artery
anterior branch of abdominal aorta, around LIII.
Branches - left colic, sigmoid and superior rectal artery
Portal vein
Union of splenic vein and superior mesenteric vein posterior to neck of pancreas at level LII.
Tributaries of portal vein
right and left gastric veins
cystic veins
paraumbilical veins
Tributaries of splenic vein
short gastric veins
left-gastro-omental vein
pancreatic vein
inferior mesenteric vein (usually)
portosystemic anastomoses
gastro-oesophageal junction at stomach - left gastric vein (portal) with azygos system (caval)
anus - superior rectal vein (portal) with middle and inferior rectal veins (systemic)
umbilicus - paraumbilical (portal) with veins of anterior abdominal wall. Causes caput medusae.
Sympathetic trunks route
As they pass through neck, lie posterior to carotid sheath.
In upper thorax, anterior to necks of ribs.
Lower thorax, lateral aspect of vertebral bodies.
Abdo, anterolateral to lumbar vertebral bodies.
In pelvis, anterior to sacrum.
The two trunks come together anterior to coccyx to form ganglion impar.
sympathetic trunk ganglias
cervical - 3
thoracic - 11/12
lumbar - 4
sacral - 4/5
Splanchnic nerves
thoracic, lumbar and sacral - sympathetic
pelvic - parasympathetic
thoracic splanchnic nerves
greater - T5-T9 - to coeliac ganglion
lesser - T10-11 - to aorticorenal ganglion
least - T12 - to renal plexus
lumbar splanchnic nerves
usually 2 to 4
passes from lumbar part of trunk to prevertebral plexus
sacral splanchnic nerves
pass from sacral part of trunk and enter inferior hypogastric plexus, which is an extension of prevertebral plexus into the pelvis.
Pelvic splanchnic nerves (parasympathetic)
Originate from anterior rami of S2-4 to inferior hypogastric plexus.
Innervates the hindgut.
Abdominal prevertebral plexus
3 major divisions - coeliac, aortic and superior hypogastric plexus.
Receives:
preganglionic parasympathetic and visceral afferent fibers from vagus nerves
thoracic and lumbar splanchnic nerves
pelvic splanchnic nerves
Boundaries of posterior abdominal region (muscle)
Medially - psoas major and minor
Laterally - quadratus lumborum
Inferior - Iliacus
Superior - diaphragm
Psoas major
Attachment - lateral surface of bodies of T12 and L1-5 vertebrae, travels under inguinal ligament to lesser trochanter of femur
Innervation - Anterior rami of L1 to L3
Function - flex thigh at hip joint
Psoas minor
Attachment - lateral surface of bodies of T12 and Li vertebrae.
Insertion - pectineal line of pelvic brim
Innervation - anterior rami of L1
Function - weak flexion of lumbar vertebral column
Quadratus lumborum
Origin - transverse process of L5, iliolumbar ligament and iliac crest
Insertion - transverse process of L1 -4 and inferior border of rib 12
innervation - anterior rami of T12 and L1-4
Function - depress and stabilise rib 12 some lateral bending of trunk
Iliacus
Origin - upper 2/3rd of iliac fossa and upper lateral surface of sacrum
insertion - lesser trochanter of femur
Innervation - femoral nerve (L2-4)
function - flexion of thigh at hip joint
Diaphragm phrenic nerve
Right phrenic nerve passes through with IVC
Left phrenic nerve passes through muscular part of diaphragm just anterior to central tendon on left side
Arterial supply to diaphragm
Superiorly, musculophrenic and pericardiocophrenic arteries (branches of internal thoracic) and superior phrenic artery (branch of thoracic aorta)
Inferiorly, inferior phrenic artery (branch of abdo aorta)
Transpyloric plane - between jugular notch and pubic symphysis
L1 vertebrae THrough ends of ninth costal cartilage Beginning and upper limit of end of duodenum Hila of kidneys Neck of pancreas Origin of SMA from aorta
Surface anatomy of kidneys
Left slightly higher than right, up to rib 11 whereas right reaches only rib 12
Lower poles around level of disc between L3-L4
