Anatomy Flashcards
Order of Abdominal Wall Muscles
External Oblique
Internal Oblqiue
Transversus Abdominis
Upper Middle Region
Epigastric
Middle Middle Region
Umbilical
Lower Middle Region
Pubic
Upper Right/Left Region
Right/Left Hypochondrium
Middle Right/Left Regions
Right/Left Flank
Lower Right/Left Region
Right/Left Groin
Planes Dividing into R/M/L Regions
Midclavicular
Planes Dividing into U/M/L
Subcostal and Intertubercular
Nerves to Abdominal Muscles
Anterior Rami of Thoracic Spinal Nerves
External Oblique Fibre Direction
Inferomedial “hands in pockets”
Internal Oblique FIbre Direction
Inferolateral
External Oblqiue movement
Flex Trunk
Turn to OPPOSITE side
Internal Oblqiue Movmeent
Flex trunk
Turn to SAME side
Linea Alba
Line where left and right aponeuroses of abdominal muscles meet
Transversus Abdominis Fibre Direction
Transverse / Horizontal
Rectus Abdominis is ___________ in the upper 3/4
Fully surrounded by all Abdominal wall muscles
Rectus Abdominis is __________ in the lower 1/4
Only covered by the front
Meaning behind is the transversalis fascia and periotneum
When does the posterior aponeuroses end, meaning rect ab is only covered in front
Arcuate Line
Arterial Supply to Abdominal Wall Muscles
Superior Epigasric and Inferior Epigastric (anastomose together)
Where do sup/inf epigastric arteries run
Within the Rectus sheath, underneath Rectus abdominis
Why is there an arcuate line / end of posterior aponeurose
So that the epigastric arteries can get back to the desired plane without penetrating the aponeurose
Venous Drainage Upper Abdominal Wall
Axillary Vein
Venous Drainage Lower Half Abdominal Wall
Femoral Vein
Where are nerves and veins found abdominal wall
Neurovascular Plane - between int Oblqiue and trans abd
Nerve Supply Abdominal Wall
Intercostal nerves (lateral and anterior branches) 7-12
Superficial Lympathic Drainage Abdominal Wall
Upper half = Axillary Nodes
Lower half = Superifical Inguinal Nodes
_______ Periotoneum forms _____ by folding back on itself
Visceral, Mesentery
Parietal Peritoneum sense
pain touch temp etc = somatic nerves
Visceral Perioneum senses
Stretch = autonomic nerves
Midgut and hindgut are suspended by _____ mesentery
One (dorsal)
Foregut is suspended by ______ mensnetry
Both ventral and dorsal
Intraperitoneal =
Suspended by mesentery = mobile
Retroperitoneal =
Stuck to back wall, only partial visceral peritoneal cover as no mesentery
Why do we have some retroperitoneal structures
To ensure that when mobile not all gut structures just fly around as there are attachments
All the Retroperitoneal Structures
Distal Duodenum
Ascending Colon
Descending Colon
Rectum
All the Intraperitoneal Structures
Stomach
Proximal Duodenum
Jejunum
Ilium
Transverse Colon
Sigmoid Colon
Name of mesentery for transverse colon
Transverse Mesocolon
Name of mesentery for Sigmoid Colon
Sigmoid Mesocolon
Name of mesentery for small bowel and stomach
Just called mesentery
Lesser Sac
Behind the lesser omentum and stomach
Greater sac
Peritoneal cavity except the lesser sac
Omental Foramen
Connection between lesser and greater sacs (contains important things eg portal triad)
Paracolic Gutter
Path for peritoneal fluid to move around abdomen
Foregut Structures
Pharynx -> Proximal 1/2 Duodenum
- Incl, Pancreas, Liver, Biliary Tree (Spleen)
Midgut Structures
Distal 1/2 Duodenum -> Proximal 2/3 Transverse Colon
Hindhut Strcutreus
Distal 1/3 Transverse Colon -> Proximal 2/3 Anal Canal
What is lateral folding
Ectoderm and Mesoderm folding laterally and centrally = closes off the endoderm as a seperated tube
Endoderm Becomes
Epithelial lining of gut tube
Mesoderm becomes
Supporting structures and smooth muscle
Space between mesoderm becomes
Body cavity
Longitudinal Folding is
Folding head to toe, dividing into foregut and hindgut
Foregut supply
Celiac Trunk
Midgut Supply
Superior Mesenteric
Hindgut Supply
Inferior Mesenteric
Celiac Trunk branches at
T12
SMA branches at
L1
IMA branches at
L3
Membranes of the gut tube
Cranial - Oropharyngeal
Caudal - Anal
They rupture soon after formation lol
What fills the lumen for a little bit during embryo development
Epithelium
Oesophageal Atresia
Blockage
Oesophageal Fistula
Connection (eg oesophagus and trachea)
How does the stomach form
Dilation
Rotation on long and coronal axes
Greater Omentum formation
Posterior mesogastrium dragged round = ant and post fuse = 4 layered peritoneal structure
What is the greater omentum
4 layered fused peritoneum that covers the stomach and intestines then wraps back around (ie bag containing stomach and intestines)
Congenital Pyloric Stenosis
Thickening of muscular wall pylorus = blocks exit of stomach contents = non-bilious vomiting
Hepatic Diverticulum is the precursor for
Liver - Larger part, cranial
Biliary Appartus - Smaller part, caudal
Larger bud of embryonic pancreas
Dorsal
What is Lesser Omentum
Peritoneum between liver and stomach
What is Falciform Ligament
Connects liver to abdominal wall peritoneum
What happens if pancreatic ducts dont fuse
Main duct going through minor papilla = blockage = pancreatic enzymes autodigest pancreas, and less enzymes in small int = less digestion
Midgut Shape
U (but upside down so should really be n lol)
What does the midgut do during embryonic dev
LOTS!! Of rotation
Herniation to migrate into umbilical cord
Fistula
Gut herniates through weekend region of body wall = gut outside of body
Ileal Diverticulm
Basically an ileal appendix where things can get stuck
Urorectal Septum
Seperates rectum and urogenital sinus
Pectinate Line
Boundary between outer ectoderm and inner endoderm (ie end of hindgut).
In the anal canal
Megacolon
No nervous control in gut = can’t dilate = can’t defecate
V serious
Imperforated Anus
Anal membrane doesn’t perforate = can’t defecate
Easy surgery
Rectal Atresia
Anal canal and rectum not connected
Normally rectum connects to urinary system instead = bad
Foregut Referred Pain
Epigastric
Foregut Venous Drainage
Direct to Portal Vein (NO SUCH THING AS COELIAC VEIN)
Oesophagus enters stomach at
Costal cartilage of Rib 7/8
Fundus of stomach at
Rib 5/6
Generally, if left of the midline what branch of the coeliac trunk will be involved
Splenic
Generally, if right of the midline what branch of the coeliac trunk
Common Hepatic
Blood supply lesser curvature
Left Gastric (Coeliac -> )
Right Gastric (Coeliac -> Com Hepatic -> )
Blood supply greater curvature
Left Gastro-omental (Coeliac -> Splenic -> )
Right Gastro-omental (Coelaic -> Com Hep -> Gastroduodenal -> )
Blood Supply Fundus
Short Gastric (Coeliac -> Splenic -> )
Duodenal Shape
G
1st part of duodenum
Trans-pyloric plane
2nd Part Duodenum
Wraps head of pancreas
3rd Part Duodenum
Crosses over IVC and Aorta
4th part Duodenum
Duodenojejunal Flexure
Duodenum Parts Intraperitoneal
1st
Duodenum Parts Retroperitoneal
2nd 3rd 4th
Foregut Duodenal Blood Supply
Superior Pancreaticoduodenal (Coelaic -> Com Hep -> Gastroduodenal ->)
Midgut Duodenal Blood Supply
Inferior Pancreaticoduondeal (SMA branch)
Midgut Referred Pain
Umbilical
Identifying Jejunum vs Ilium
Jejunum: 1-2 arterial arcades with long branches
Ileum: Many arcades with short branches
Jejunum Artery Supply
Jejunum Arteries (via SMA)
Ilium Blood Supply
Ileal (via SMA)
Hepatic Flexure
Retro -> Infra
Ascending Colon to Transverse Colon name
Hepatic Flexure
Splenic Flexure
Infra -> Retro
Transverse to Descedning COlon name
Splenic Flexure
Midgut to Hindgut Transition
2/3 Along Transverse Colon
Caecum Blood Supply
Caecal (SMA -> Ileocolic -> )
Appendix Blood Supply
Appendicular (SMA -> Ileocolic -> )
Ascending Colon Blood Supply
Right Colic (SMA)
Proximal 2/3 Transverse Colon Blood Supply
Middle Colic (SMA)
Marginal Artery
Distal 1/3 Transverse Colon Blood Supply
Left Colic (IMA)
Marginal Artery
What is the marginal aretry
Anastomosis between SMA and IMA
Descending Colon Blood Supply
Left Colic (IMA)
Sigmoid Colon Blood Supply
Sigmoid (IMA)
Sigmoid Colon transition to rectum at
S3
Rectum becomes anal canal when
Pierces pelvic floor/diaphragm at tip of coccyx
Rectum Blood Supply
Superior Rectal (IMA)
Middle/Inferior Rectal (Internal Iliac) = NOT TO PORTAL VEIN
Proximal Rectum Supply Nervous
Inf Mesenteric Plexus (ANS)
Distal Rectum Nervous Supply
Hypogastric Plexus = Somatic not Autonomic therefore can feel anus
Portal Vein formed at
L1 on Transpyloric plane
Portal Vein direct constitutents
SMV and Splenic Vein
IMV goes to Portal Vein via
Splenic
Hindgut Referred Pain
Suprapubic
Hindgut Parasympathetic Supply
Pelvic Splanchnic S2-4
Foregut Parasympathetic Supply
Vagus
Midgut Parasympathetic Supply
Vagus
Foregut Sympethic Supply
Greater Splanchnic T5-9
Midgut Sympaethic Supply
Lesser Splanchnic T10-11
Hindgut Sympathetic
Lumbar/Sacral Splanchnic L1-2
Liver Blood Supply (incl proportions)
Portal Vein 3/4
Hepatic Artery 1/4
Gallbladder Surface Anatomy Level
Transpyloric Plane at 9th costal cartilage
Largest anatomical liver lobe
Right
What divides right and left anatomical liver lobe
Falciform ligament
What is Ligamentum teres
Part of falciform ligament (inferior)
Posterior Surface Liver Lobes
Left, right, caudate, quadrate
Caudate and right lobe separator
IVC
Quadrate and right lobe separator
Gall Bladder
Portal Triad Positions
Hepatic Artery = Ant Left
Bile Duct = Ant Right
Portal Vein = Post
Do Hepatic Veins exist
Yes, but only inside the liver -> direct drainage to the IVC
Anterior and Posterior Coronary Ligaments organ
Liver
Left and right triangular ligaments organ
Liver (post and ant surfaces)
Suprahepatic Space
Between liver and diaphragm
What seperates L and R Suprahepatic space
left and right separated by falciform ligament
Subhepatic Space
Between liver and kidney
Dependent part
Lowest point (where fluid gathers)
Changes depending on if body erect, supine etc
When does common hepatic artery become proper hepatic artery
Once gastroduodenal artery given off
Anatomical definition of liver segment
Position of hepatic and portal veins
Physiological defintiion of liver segment
Own branch of portal triad
Do liver halves have blood supply communication
- No arterial / portal vein communication
- Some mixing of venous drainage communication
Principal Plane
Line between the IVC and gallbladder that seperates the liver into left and right PHYSIOLOGICAL LOBES
Why are the anatomical and physiological liver halve definitions different
Physiological - divided by principal plane (gall bladder IVC)
Anatomical - divided by falciform ligament
Which organ has the most lymph in the body
Liver (1/3-1/2 of total)
Gallbladder Regions
Fundus, body, neck
Biliary Tree
Cystic Duct (Gallbladder) + Common Hepatic Duct (Liver) —-> Common Bile Duct
Common Bile Duct + Pancreatic Duct —-> Ampulla of Vater —-> Sphincter of Oddi —-> Duodenum
Gall Bladder Blood Supply
Cystic Artery (from R Hepatic Artery)
Cystic Artery found in
Hepatobiliary Triangle
Pancreas regions
head neck body tail
Pancreas Head location
Duodenum concavity (at L1)
Pancreas Uncinate Process location
Wraps behind SM vessels
Pancreas Neck location
Anterior to SM vessel origins
Pancreas Tail location
In contact with spleen hilum at the splenorenal lig
Pancreas retro/intraperitoneal
Retro
Accessory Ducts (pancreas) drain into
Minor Duodenal Papilla
Sphincterotomy
Remove sphinchter of Oddi
(Fine as sphinchter has no real function)
Pancreas Blood Supply Origins
Predominantly Coeliac
Accessory SMA
Head/neck of pancreas predominant blood supply
Superior Pancreaticoduodenal (Coeliac -> Com Hep -> Gastroduodenal -> )
Tail/body pancreas blood supply
Dorsal Pancreatic and Great Pancreatic (Coeliac -> Splenic -> )
Pancreas pain referral
Posterior Epigastric
What is the spleen
Single largest mass of lymphoid tissue, filters and recycles blood
What is anterior to the spleen
Colon Splenic Flexure (Ie where the colon goes trans -> descending and retro -> infra)
Spleen ligaments
Splenorenal
Gastrosplenic
Spleen Blood Supply
Splenic (Coeliac -> )
Spleen Surfaces
Diaphragmatic and Visceral
Spleen Areas
Gastric
Colic
Renal
What travels through the splenorenal ligament
Splenic Vessels
What travels through the gastrospelnic ligament
Short gastric vessels
Splenomegaly
Abnormally enlarged spleen (normally should be 1x3x5inch)
Why does the IMV join splenic vein before joining the portal vein
So that it doesnt cross the midline as a small vessel, safer to cross the bony midline when in a bigger, higher pressure vessel (splenic)
Venous Blood Flow in the Liver
Portal Vein -> R/L Portal Vein -> Sinusoids -> R/M/L Hepatic Vein -> IVC
What is portosystemic shunting
Hypertension in the portal system = forces blood into the systemic system
Where are the main shunts of portosystemic shunting
Lower Oesophagus
Umbilicus
Rectum/Anus
Causes varices in each region
Varices in the umbicilis is called
Caput medusae