GI Anatomy Flashcards
outline the morphology of the diaphragm
double doomed
central tendon
two recesses: costo-diaphragmatic and costo-mediastinal
what are the 3 attachments of the diaphragm
sternal- xiphoid process
costal- lower 6 cartilages
vertebral- left and right crurae & lumbercostal arches
what are the 3 main apertures and their vertebral level
caval -T8
oesophagal -T10
aortic- T12
what structures are superiorly related to the diaphragm
pleural cavities
what structures are inferiorly related to the diaphragm
stomach- under left dome
liver- under right dome
oesophagus
what is the motor innervation of the diaphragm
phrenic nerve C3-C5 (mainly C4)
what is the sensory innervation for the diaphragm
centrally- phrenic nerve
laterally- lower 5 intercostal nerves
where do intercostal nerves arise from
the anterior rami of the thoracic spinal nerves T1-T11
what are the function of the diaphragm
muscles of ventilation
aids micturition(urinating), defaecation(discharge of faeces) and parturition(giving birth)
aids lifting
what structures accompany the aorta as it passes through the aortic opening
sympathetic chains and thoracic duct
what is the central muscle of the anterior abdominal wall and where does it attach
rectus abdominis
between the rib cage and pubic bone
what are the other insertions are there of the rectus abdominous
3 tendinous insertions on the ant wall
2 transverse tendinous bands
- linea alba
- linea semilunaris
what are the lateral muscles of the anterior abdominal wall
external oblique
internal oblique
transversus abdominis
transversalis fascia
what are the attachments of the external oblique
lower 8 ribs linea alba inferiorly- iliac crest pubic bone inguinal ligament
what muscle does the external oblique oppose the action of
internal oblique
what is the function of the muscles of the abdominal wall
involved in flexion of the abdomen vertebral column.
It increases intra-abdominal pressure (contract when urinating)
active during expiration in lowering the vertebral column particularly in speech
from where does the internal oblique originate
iliac crest & pelvis
where does the internal oblique muscle insert
cosal margin
linea alba
pubis
what are origins & attachments of the transversus abdominis
lower 6 ribs origin - lumbar fascia - iliac crest - inguinal ligament forms part of the rectus sheath
what is the transversalis fasica
layer of deep fascia in which the fibres run in a transverse direction
deep to anterolateral abdominal muscles and the rectus sheath
what is the order of the muscles above the arcuate line
ext oblique int oblique *rectus abdominis* transversus abdominis transversalis fascia
what is the order of the muscles below the arcuate line
ext oblique int oblique transversus abdominis *rectus abdominis* transversalis fascia
what is the innervation of the anterior abdominal wall
intercostal nerves T7-L1
they travel between int oblique and transversus abdominis
lowest nerve: iliohypogastric nerve (L1)
what is peritoneum
the serous membrane forming the lining of the abdominal cavity
what are the 2 layers separated by peritoneal fluid contained in the peritoneal space
parietal- lining the abdomen
visceral- covers the surfaces of the viscera
what are the functions of the peritoneum
fixes organ in place
provides mobility
has immune function
explain how peritoneum has immune function
recruitment of leukocytes from the blood to the peritoneum
payas patches carry out an immune function (prevent growth of pathogenic bacteria)
what are mesenteries
peritoneal folds- connect different parts of the gut tubes carrying blood to & from the gut
what are retroperitoneal organs (extraperitoneal layer)
organs that lie on the back of the abdominal cavity and do not posses a mesentery (peritoneum only on one side)
what are intraperitoneal organs
covered with visceral peritoneum folded away from the abdominal wall (have a mesentery)
name some retroperitoneal organs
kidney
most of duodenum except for the first part
pancreas
ascending and descending parts of the colon
what are peritoneal ligaments
not actual ligaments
it is a name given to refer to a specific part of the mesentery
what is omentum
ligament that divides abdominal cavity into greater and lesser sacs
greater ligament that the rest
greater sac divides into supracolic and infracolic
what is the arterial blood supply & venous drainage of the stomach
arterial- all 3 br of the coeliac trunk
venous dr- via hepatic portal vein to the liver
what are the 3 major branches of the coeliac trunk
splenic
common hepatic
left gastric
what are the 3 distinct regions of the small intestine
duodenum- thickest
jejunum
ileum- thinnest (continuous superiorly with jejunum & inf with caecum part of colon. attached via mesentery to the abdominal wall)
what is arterial blood supply & venous drainage of the pancreas
A- coeliac trunk and sup mesenteric artery
V- sup mesenteric br of the hepatic portal vein
what are the branches of ht aorta that supply the gastrointestinal tract (3 unpaired)
coeliac trunk
superior mesenteric
inferior mesenteric
what is the anatomical route taken by the bile to reach the gastrointestinal tract
the right and left hepatic ducts unite forming the common hepatic duct. a short cystic duct joins the common hepatic duct to form the common bile duct transporting bile to the duodenum via the hepatopancreatic duct
what are the pelvic viscera
bladder and uterus
at what vertebral level does the aorta pierce the diaphragm
T12
what does the superior mesenteric artery suuply
midgut
i.e the second part of the duodenum, jejunum, ileum, caecum, appendix & transverse parts of the colon
what does the inferior mesenteric artery supply
the remainder of the colon and the gut as far as the proximal rectum
what does the hepatic br of the coeliac trunk supply
liver & gall bladder
what does the splenic br of the coeliac trunk supply
spleen & pancreas
what do the left gastric br of coeliac trunk supplly
oesophagus & stomach
what are the paired branches to the genitourinary system
renal arteries
testicular/ovarian arteries
what are the 2 routes of veins responsible for venous drainage of the aorta
inferior vena cava
hepatic portal system
where does the inferior vena cava pierce the diaphragm
T8
which 2 veins unite to form the inferior vena cava
common iliac veins
name the tributaries that drain into the vena cava
- hepatic veins
- inferior phrenic veins
- suprarenal veins
- renal (gonadal drain directly into renal)
- testicular veins
- 5 pairs of lumbar veins
what is the function of the hepatic portal system
directs blood from parts of the GI to the liver
what veins are part of the hepatic portal system
inferior mesenteric (drains hindgut joints)
splenic (drains foregut)
superior mesenteric
hepatic portal vein
what veins unite to form the hepatic portal vein
sup mesenteric joins inf mesenteric and splenic vein to form the portal vein
what is the function of hepatic portal vein
drain blood from the gut to liver transporting products of digestion
what are the muscles of the posterior abdominal wall (back)
psoas major
iliacus
quadratus lumborum
which vertebrae does the psoas major arise from, where does it attach & what is its function
T12- L5
inferiorly to the femur
flexes hip
on which muscles does the ureter lie
psoas muscle
urter drains urine from kidney to the bladder
where does the iliacus attach and what is its function
internal surface of pelvic bone and femur
flexes hip
where does the quadratus lumborum attach and what is its function
12th rib to tips of transverse processes of L1-L5
inferiorly to iliolumbar ligamnet and part of the iliac crest
lateral rotator and stabiliser of the hip
lateral flexor of of the vertebral column
how is is the quadratus lumborum important in ventilation
fixes the 12th rib during ventilation
what nerve provides the parasympathetic innervation to the gut
vagus nerve
at which vertebral level does the vagus n pierce diaphragm
T10- oesophageal opening
what is meant by intramural ganglia
br of the nerve (X) pass to ganglia within the walls of the viscera
what happens after CNX pierces the diaphragm
autonomic axons in it are preganglionic and synapse in intramural ganglion within the viscera they innervate
what happens after preganglionic fibres of CNX synapse in the intramural ganglion
the post ganglionic parasympathetic neurones innervate the GI tracrt
up to what part of the GI tract does CNX provide parasympathetic innervation
as far as the left colic flexure (where transverse colon becomes descending colon)
what nerve provides PS innervation to the gut beyond the left colic flexure
pelvic parasympathetic splanchnic nerves from S2, S3, S4
what nerves provide sympathetic innervation to the gut
T5-T13 spinal nerves to sympathetic chain splanchnic nerves to abdomen - lumbar -thoracic postganglionic fibres to the viscera
which nerves supply the hindgut and in which ganglion do they synapse
lumbar splanchnic nerves
inferior mesenteric ganglion
which nerves supply the fore and mid gut and in which ganglion do they synapse
thoracic splanchnic nerves
superior mesenteric ganglio
terminology for clinical examination of the midline
epigastric- stomach & foregut
umbilical- duodenum to colon
hypogastric- uterus bladder
terminology for clinical examination of the right & left
hypochondrium- liver on right, spleen on left
lumbar- lower poles of kidney and colon (on left)
inguinal- appendix on right colon cancer on sides