Please enable JavaScript.
Coggle requires JavaScript to display documents.
Embryology + some anatomy GIT (Anterior Abdominal wall (Superficial fascia…
Embryology + some anatomy GIT
Anterior Abdominal wall
Superficial fascia
Above umbilicus
: (single sheet connective tissue)
Below umbilicus
(
2
layers: Camper's & Scarpa's - vessels & nerves run between these 2)
The fat Camper tries to sit on the Scarpa
Muscles & associated fascia (sup-deep)
External Oblique
Internal Oblique
Transversus abdominus
Skin
Parietal peritoneum
Posterior Abdominal wall
Muscles
Quadratus lumborium
Psoas major - (HIP FLEXOR)
Psoas minor
Iliacus (joins psoas major - iliopsoas)
Fascia
Separates
Parietal peritoneum
from
above muscles
Psoas fascia
Thoracolumbar fascia
Gut tube
Comes from
ENDODERMAL
layer
Midgut
Superior mesenteric artery (lower border of L1)
What's in the midgut?
2nd part of duodenum to 2/3 along traverse colon
Includes part of gut tube
Duodenum (part 3 onwards)
Jejunum
Ileum
Caecum
Appendix
Ascending colon
Proxmal 2/3 transverse colon
Hindgut
Inferior mesenteric artery (body of L3)
Distal 1/3 transverse colon
Descending colon
Sigmoid colon
Rectum
From 2/3 transverse colon to rectum
Includes part of gut tube
Foregut
Abdomen: Coeliac trunk (T12/upper border of L1)
Includes parts of
gut tube:
Oesophagus
Stomach
Duodenum - till part 2
Includes
accessory organs
Liver
Pancreas
Gall bladder
Respiratory system
: from ventral outgrowth of the foregut 'respiratory diverticulum' to lower respiratory tract (larynx onwards)
Contains:
From oesophagus to where common bile duct joined with pancreatic duct to form ampulla of Vater (major duodenal papilla 2nd part of duodenum)
Pancreas
Bile duct
Accessory pancreatic duct
Major duodenal papilla
Hepatopancreatic ampulla
Main pancreatic duct
Liver embryology
Growth of liver
Liver growing in 2 parts: R lobe outwards and L lobe outwards . Dip created in middle, where the falciform ligament will 'reflect inwards'
Contained within it: umbilical vein (in adult is fibrous tissue 'ligamentum teres/round ligament of liver)
Ligaments
As liver grows rapidly, it breaks out of overlying peritoneum and bursts out of top. Leads to formation of
BARE AREA
, Boundaries:
Coronary
Triangular ligaments
Liver pushed up against diaphragm, bare area being part in contact with it
Falciform Ligament
Divides R & L liver lobes
Connects anterior abdominal wall to liver
Derivative of ventral mesogastrium
Stomach
Rotation
Stomach grows
Stomach rotates
90 clockwise
Greater curvature from back facing to side facing
Omental Bursa* + Lesser Sac
(same thing)
Area where peritoneum (Greater omentum) has folded to form a small pocket
Epiploic Foramen I
Area of communication between lesser and greater sacs
Epiploic Foramen 2
Anterior:
Free edge of lesser omentum (hepatoduodenal ligament): two layers and within these layers are the common bile duct, heaptic artery and portal vein (DAVE)
Free border of Lesser Omentum: derivation:
Ventral Mesogastrium
D
(Bile
D
uct)
A
(Hepatic
A
rtery)
V
(Hepatic portal
V
ein)
E
piploic foramen
Posterior:
Peritoneum covering IVC and Aorta
Medial
Gastrosplenic ligament and spleen
Superior
Peritoneum covering caudate lobe of liver
Inferior:
Peritoneum covering commencement of duodenum and hepatic artery, latter passing forward below foramen before ascending between two layers of lesser omentum (
duodenum
)
Greater Omentum
Guards the peritoneal cavity, containing infections in abdominal cavity: NO SPREADING
Filled with variable amount of fat
Extends from
greater curvature
of stomach to hangs
over transverse colon
Gastrosplenic ligament
Derived from
dorsal mesogastrium
dorsal mesogastrium
attaches posterior backwall (aorta etc) to the
Stomach's greater curvature
Short gastric artery
L gastroepiploic artery
Intestines
Grow faster than the abdominal cavity
U shaped of intestines (midgut) protrudes out of anterior abdominal into vitelline duct (duct connecting yolk sac to foetus):
herniation
Whilst herniated, midgut loop rotates 90
Anticlockwise
(around axis of superior mesenteric artery)
Once abdominal cavity grows large enough, intestines get pulled back into cavity
Large intestine portion of midgut loop, rotates again. Further
180 Anticlockwise
Intestine rotates: 90 (anticlockwise) + 180 (anticlockwise) = 270
anticlockwise
Retroperitoneal Organs
SAD PUCKER
Suprarenal glands
Aorta (& IVC)
Duodenum (parts 2 and 3 only)
Pancreas
Ureters
Colon (ascending and descending)
Kidney
Esophagus
Rectum
Behind the peritoneum
Fused to posterior abdominal wall
Lack of mesentery
Tend to cause back pain instead of abdominal pain