GI anatomy Flashcards
name the 4 quadrants that the abdomen is split into
Right upper
left upper
right lower
left lower
The 2 imaginary lines that are used to divide the abdomen into 4 are
transumbilical line (across the belly button) median line (down the middle through belly button)
Name the 9 regions of the abdomen
Right hypochondriac - epigastric - Left hypochondriac
Right lumbar - umbilical - Left lumbar
Right iliac - hypogastric - Left iliac
Name the imaginary lines used to divide the abdomen into 9
Right and left midclavicular planes (down each side) transtubercular line (along the bottom below belly button) subcostal line (along top above belly button)
External oblique muscle actions and innervation
compresses and supports abdominal viscera
innervated by intercostal nerves and subcostal
Internal oblique muscle actions and innervation
flex and rotate trunk
innervated by intercostal nerves and subcostal nerve
Transversus abdominis muscle actions and innervation
Compresses and supports abdominal viscera
innervation is first lumbar nerve
Rectus abdominus muscle actions and innervation
Flexes trunk and depresses the ribs.
innervated by intercostal nerves and subcostal nerves
What is the rectus sheath and what is it made up of
Aponeurosis - flat tendon
made up of aponeurosis of external and internal oblique
How does the sheath differ above and below the umbilicus
above - incomplete
below - complete
Which thoracic spinal segments enervate the anterior abdominal wall
T 7-11
At what vertebral level is the umbilicus and why is this a good surface land mark
L4 - bifurcation of the aorta
The inguinal ligament is attached to which 2 bony points of the hip bone
iliac spine and pubic tubercle
inguinal canal anterior wall
external oblique aponeurosis
inguinal canal posterior wall
transversals fascia
inguinal canal roof
transversals fascia
inguinal canal floor
inguinal ligament
deep inguinal ring lies
superiorly
superficial inguinal ring lies
inferiorly
branches of the superior and inferior epigastric vessels superiorly
interior thoracic artery
branches of the superior and inferior epigastric vessels inferiorly
exterior iliac artery
contents of male inguinal canal
spermatic cord
blood vessels
ilio-inguinal nerve
contents of female inguinal canal
vestigial round ligament of the uterus
blood vessels
ilio-inguinal nerve
4 distinct functional layers throughout the GI tract
1. Mucosa - made up of 3 layers: epithelium, lamina propria, muscularis mucosa 2. submucosa 3. muscular propria 4. serosa (adventitia)
Protective mucosa is found where
oral cavity, pharynx, oesophagus, anal canal
secretory mucosa is found where
only in the stomach
absorptive mucosa is found where
typical of entire small intestine
absorptive/protective mucosa is found where
lines the whole of the large intestine
What is the peritoneum
transparent serous membrane that covers body walls and organs
What are the 2 subdivisions of peritoneum
Visceral and Parietal
What else can the peritoneum form
folds, mesenteries and omen,ligaments - vascular or avascular.
what is the peritoneal cavity
Space of capillary thinness between parietal and visceral layers
What are the 2 major divisions of the peritoneal cavity (sacs)
Greater sac
Lesser sac
Through which passage do the lesser and greater sac communicate
omental (epiploic) foramen
Organs that are intraperitoneal are described as what
completely surrounding by visceral peritoneum
Organs that are retroperitoneal are described as what
only covered on their anterior surface and therefore firmly attached to the posterior wall
organs that are intraperiotneal
stomach and spleen
organs that are retroperitoneal
kidneys and liver
What is present in the peritoneal cavity
peritoneal fluid
what is the greater omentum
greater curvature of the stomach to transverse colon
What is the lesser omentum
lesser curvature of the stomach to liver
posterior abdominal wall muscles
illiacus muscle, posts major, quadratus lumborum
posterior abdominal wall organs/tubes
diaphragm, kidneys, ascending colon
posterior abdominal wall main vessels
IVC and abdominal aorta
posterior abdominal wall nerves
subcostal and lumbar plexus
3 major openings in the diaphragm
caval, oesophagus, aortic
at what vertebral level do these 3 openings occur
T8, T10 and T12
What are the 3 main branches of the abdominal aorta which supplies blood to the gut tube within the abdominopelvic cavity
Celiac T12
superior mesenteric L1
inferior mesenteric L3
How is the IVC formed in the abdomen
by the union of the common iliac veins
Foregut structures
abdominal part of oesophagus and stomach
midgut structures
distal part of duodenum, jejunum, ileum, ascending colon, caecum
hindgut structures
descending colon and sigmoid colon
artery supplying the foregut
celiac
artery supplying the midgut
superior mesenteric
artery supplying the hindgut
inferior mesenteric
The portal vein is formed by the union of which 2 major veins
splenic and superior mesenteric
List the 4 sites of portocaval anastomosis (communication between portal and systemic venous system) in the body
- in the distal oesophagus
- between rectal veins
- paraumbilical veins
- bare area of the liver
Nerve supply to abdominal viscera: sympathetic
abdominopelvic splanchnic nerves
pre vertebral sympathetic ganglia
abdominal aortic plexuses
Nerve supply to abdominal viscera: parasympathetic
anterior and posterior vagal trunks (vagus nerve)
pelvic splanchnic nerves (S2,S3 and S4)
How is GI secretion affected: parasympathetic:
increased
How is GI secretion affected: sympathetic:
decreased
how is Peristalsis or GI motility affected: parasympathetic:
stimulation
how is Peristalsis or GI motility affected: sympathetic:
inhibitory
what happens to Blood vessels: parasympathetic:
vasodilation
what happens to Blood vessels: sympathetic:
vasoconstriction
Where do the kidneys lie
on the posterior abdominal wall at the level of T12-13 vertebrae
What are the 3 main structures entering or leaving the hilum of the kidney
Renal artery
Renal vein
Pelvis of the ureter
what is the anatomical location of the suprarenal gland, and what type of gland is it
between superomedial aspects of kidney and crura
endocrine
What are ureters
muscular ducts carry urine from the kidneys to the urinary bladder
ureter is constricted at 3 places, what are they?
at the junction of the ureters and renal pelvis
ureters cross the brim of the pelvic inlet
during passage through wall of urinary bladder
The oesophagus has 3 constrictions - where are they
Cervical
thoracic
diaphragmatic
At what vertebral level is the oesophageal opening
T10
List the structures that go through the oesophageal opening
Oesophagus
vagus nerve
Branches of the left gastric artery
Blood supply to the abdominal part of the oesophagus
branches of left gastric artery
venous drainage of the abdominal part of oesophagus
Left gastric vein to the portal venous system
Lymphatic drainage of the abdominal part of oesophagus
Left gastric lymph nodes to the celiac lymph nodes
where is the cardinal notch located
between the oesophagus and fundus
What are the 2 orifices of the stomach
cardinal
pyloric
what are the 2 curvatures of the stomach
Greater
Lesser
What are the 2 surfaces of the stomach
anterior
posterior
What is pyloric sphincter
band of smooth muscle between pylorus and duodenum
What is the function of the pyloric sphincter
acts as valve to control flow of partially digested food from stomach to small intestine
Lesser omentum extends from where to where
Extends from lesser curvature to liver
Greater omentum extends from where to where
extends from greater curvature to spleen
what are the gastric rugae formed from
series of ridges from folding of stomach wall
in what portions of the stomach are rugae most apparent
pyloric part and along the greater curvature
Which sphincter controls the discharge of food from the stomach to the duodenum
pyloric sphincter
Stomach lies on several structures in abdominal cavity - what are they
left dome of diaphragm left kidney and suprarenal gland spleen pancreas transverse mesoderm colon splenic artery all form the stomach bed
What nerve is key in controlling gastric motility
vagus
What is the effect of increased vagal stimulation on
- the pylorus
- gastric secretion
- increases the opening
2. incarnation secretion
Where does the small intestine extends to
extends from the pylorus of the stomach to the ileoecal junction
What are the 3 parts of the small intestine
duodenum
jejunum
ileum
Which part of the small intestine receives the opening of the bile and pancreatic duct
descending (second) part
where is the foregut/midgut boundary in the small intestine
where bile duct enters duodenum
How is the 1. Duodenum 2. Jejunum 3. Ileum peritonised
- Retroperitoneal
- Intraperitoneal
- Intraperitoneal
Which part of the small intestine is the shortest, widest and most fixed part
Duodenum
Distinguishing factors of jejunum and ileum in life:
colour, wall, vascularity, vasa recta, arcades, fat in mesentery, circular folds:
Jejunum - Deeper red, thick and heavy, greater, long, a few large loops, less, large tall and closely packed.
Ileum - Paler pink, thin and light, Less, short, many short loops, more, low and sparse absent in distal part
Distinguishing features of the large intestine
Tenia coli
Omental appendices
Haustra
How is the large intestine peritonised:
Caecum: intraperitoneal Ascending colon: retroperitoneal Transverse colon: intraperitoneal Descending colon: retroperitoneal Sigmoid colon: retroperitoneal
Where does the rectum pierce the pelvic floor and what does it become
Pierces at the and-rectal junction and becomes the anal canal which is located in the perineum
What is the role of the pelvic floor in maintaining faecal incontinence
the muscles support rectum and urinary bladder
* rectum and urinary bladder also involved in maintaining faecal incontenence
Visceral and somatic innervation of the anal canal differences
somatic = sensitive to pain, touch and temp - control voluntary external anal sphincter visceral = only sensitive to stretching
The hepatoduodenal and hepatogastric ligaments are parts of what
Lesser omentum
What is the falciform ligament
Round ligament of the liver
How many layers of peritoneum are present in the greater omentum
4 - double folded on itself
What function of the greater omentum makes it be called the abdominal policeman
fights intra-abdominal infection
what are paracolic gutters
spaces between colon and abdominal wall
List 3 abdominal viscera which lie in the free edge of a double layer of peritoneum described as the mesentery
Stomach
Spleen
Transverse colon
oesophagus - what type of muscle is the muscularis externa
skeletal
oesophagus - what type of muscle is the muscularis mucosae
smooth
oesophagus - what kind of epithelium is the surface epithelium
stratified squamous non-keratinised epithelium
what secretory cells are present in the gastric pits
mucus secreting, chief cells
Small intestine - what are the large folds extending into lumen called
pilae circularis
What kind of epithelium in small intestine
simple columnar
what do goblet cells do
secrete mucus
what type of cells are present in the surface epithelium
microvilli
where are payer’s patches located
within mucosa
Where is the transpyloric plane
approx L1 vertebral body - imaginary horizontal plane
What structures are present at transpyloric plane?
Neck of pancreas
Second part of duodenum
Pylorus of stomach
hilum of kidneys
What is one of the spleens main function
acts as a filter for blood and plays important role in the immune responses of the body
How is the spleen peritonised
intraperitoneal (except at hilum)
Name the structures in the hilum at the spleen
Splenic artery
splenic vein
lymphatics
the tail of which organ is closely related to hilum of spleen
pancreas
Functions of the spleen
storage of RBC’s
storage of WBC
storage of platelets
phagocytosis
Pancreas - exocrine or endocrine
partly exocrine - secrets the digestive pancreatic juice
partly endocrine - secretes hormones
Which vein is formed posterior to the neck of the pancreas
superior mesenteric vein
round ligament of the liver is the remnant of which embryological structure
umbilical vein
What is the bare area of the liver bare of
peritoneum
3 structures present in the porta hepatis
hepatic portal vein
hepatic artery
hepatic duct
The extra hepatic biliary apparatus consists of what
Right and Left hepatic duct Common hepatic duct Gall bladder Cystic duct Common bile duct
Where is bile produced
Liver
Where is bile stored
Gall bladder
where does bile enter the gut tube
cystic and bile ducts – duodenum
What is the function of bile
contains bile acids - critical for digestion, absorption of fats, and fat soluble vitamins
Main histological features of pancreas
islets of langerhans composed of clumps of small poorly stained cells
pure serous acini composed of large strongly stained cells
small lobules surrounded by connective tissue septa
Main histological features of liver:
cells are arranged in sheets and converging towards the centre
at the corner of the lobule connective tissue encloses tissue encloses 2-3 portal areas which contain blood vessels and ducts.
Spleen - what is the main content of White Pulp
lymphoid aggregation
Spleen - what is the main content of Red Pulp
vascular anastomosing cords of cells
Which costal cartilage is the surface marking of the gall bladder
7th left costal cartilage
Do the liver and spleen move with respiration
yes
Which ribs are related to the spleen
Left 9th - 11th
Which abdominal plane crosses the pancreas
transpyloric
