GI anatomy Flashcards
organs of the hepatobilary system
liver and gallbladder
organs of the urinary system in the abdomen
kidneys and ureters
organs of the endocrine system in the abdomen
pancreas and adrenal glands
what is the spleen?
haematopoetic and lymphoid organ
lining of the abdominal wall
parietal peritoneum
boundaries of the abdominal cavity
xiphisternum
costal margin
iliac crests
ASIS
pubic tubercles
pubic symphysis
which lines divide the abdomen into 4 quadrants
vertical line running down the midline through the lower sternum, umbilicus and pubic symphysis
horizontal line running across the abdomen through the umbilicus
name the quadrants
RUQ, LUQ, RLQ, LLQ
which lines divide the abdomen into 9 regions?
The right and left midclavicular lines, which extend vertically from the midclavicular point to the mid-inguinal point (halfway between the anterior superior iliac spine and the pubic symphysis)
The subcostal line - horizontal line drawn through the inferior most parts of the right and left costal margins (through 10th costal cartilage)
The intertubercular line (transtubercular) - a horizontal line drawn through the tubercles of the right and left iliac crests and the body of L5
what is the midinguinal point?
halfway between ASIS and pubic symphysis
what is the subcostal line?
horizontal line drawn through the inferior most parts of the right and left costal margins (through 10th costal cartilage)
what is the intertubecular/ transtubecular line?
horizontal line drawn through the tubercles of the right and left iliac crests and the body of L5
what are tubercles?
Tubercles - small elevations on a bone
Iliac tubercles are not the same as pubic tubercles
Iliac tubercles - small elevations found in the iliac crest of the iliac bone
transpyloric plane
Horizontal line passing through the tips of the right and left ninth costal cartilage
Halfway between the suprasternal notch and the pubic symphysis
Halfway between the umbilicus and the xiphisternum
Transects the pylorus of the stomach, fundus of gallbladder, pancreas, duodenojejunal flexure and hila of kidneys
L1, level of 9th costal cartilages
transumbilical plane
Unreliable as position varies depending on the amount of subcutaneous fat present
Lies at L3 in a slender individual
intercristal plane
Horizontal line drawn between the highest points of the right and left iliac crests
Cannot be palpated from the anterior aspect of the abdominal wall
Used to guide procedures on the back e.g lumbar puncture and epidural
McBurney’s point
The surface marking of the base of the appendix
Lies two thirds of the way along a line drawn from the umbilicus to the right anterior superior iliac spine
Guide for the location of the caecum
identify the nine regions of the abdomen
top right to left - right hypochondriac/ epigastric/ left hypochondriac (‘below chondriac’ = below costal cartilages)
middle right to left - right lumbar/ umbilical/ left lumbar
bottom right to left - right iliac region/ suprapubic or hypogastric/ left iliac region
muscles of the anterolateral abdominal wall
rectus abdominis
external oblique
internal oblique
transversus abdominis
line in the middle of rectus abdominis
linea alba
attachments of rectus abdominis
sternum, costal margin, pubis
what surrounds rectus abdominis?
aponeurotic rectus sheath
structure of rectus abdominis
muscle segments interspersed with horizontal tendinous bands
muscles orientated straight down
orientation of external oblique muscle
inferiorly and medially - down and towards the midline
orientation of internal oblique muscle
superiorly and medially
orientation of transverses abdominis
horizontally
is rectus abdominis paired?
yes
describe how the rectus sheath is formed
As it approaches the midline, the aponeurosis of IO splits into anterior and posterior layers
The EO aponeurosis and the anterior layer of the IO aponeurosis form the anterior wall of the rectus sheath
The posterior layer of the IO aponeurosis and the transversus abdominis aponeurosis form the posterior wall of the rectus sheath
what lies deep to transversus abdominis?
The transversalis fascia lies deep to transversus abdominis
Deep to the fascia lies the parietal peritoneum
what does the rectus sheath contain?
Rectus abdominis
Superior and inferior epigastric arteries
Superior and inferior epigastric veins
Nerves
Lymphatics
how is the inguinal ligament formed?
most inferior part of external oblique aponeurosis is attached to the:
Anterior superior iliac spine laterally
Pubic tubercle medially
to form the inguinal ligament
where is the inguinal canal?
The inguinal canal is just above the inguinal ligament
which arteries supply the anterior abdominal wall?
Internal thoracic artery - branch of the subclavian artery
Supplies the anterior chest
Abdominal wall
Breasts
Musculophrenic artery - branch of the internal thoracic
Superior epigastric artery - continuation of the internal thoracic artery. Descends in the rectus sheath
Inferior epigastric artery - branch of the external iliac artery. Ascends in the rectus sheath and anastomoses with the superior epigastric
innervation of the muscles and skin of the anterior abdominal wall
Thoraco-abdominal nerves T7-T11(Continuation of the intercostal nerves T7-T11)
- These somatic nerves contain sensory and motor fibres
Subcostal nerve
- Originates from T12 spinal nerve
Name is because it runs along the inferior border of the 12th rib
Iliohypogastric and ilioinguinal nerves
- Branches of the L1 spinal nerve
Dermatomes of the abdominal wall T7-L1
hernias
Abnormal protrusion of tissues or organs from one region into another through an opening or defect
Herniae of the anterior abdominal wall may occur if the muscles are weak or have been incised during surgery
A segment of the small intestine may protrude through a defect in the wall, forming a visible and palpable lump under the skin
laparotomy
Surgical opening of the anterior abdominal wall undertaken for major operations where good access to the abdomen is needed
A midline sagittal incision of the linea alba involves minimal risk to nerves and muscles
Ideally, muscles are split rather than cut
Where possible, laparoscopy (keyhole surgery) is performed, as it is associated with less post-operative pain, faster wound healing and a smaller risk of wound infection and post-operative hernia
what is an AAA?
Abdominal aortic aneurysm (AAA/ triple A)
An abnormal swelling in the aortic wall
Affected portion becomes distended, weak and prone to rupture
Detected as a pulsatile mass on an abdominal examination
organs deep to the right upper quadrant
liver, gallbladder, duodenum, right kidney,
ascending colon, hepatic flexure and transverse colon
organs deep to the right lower quadrant
ileum, caecum, appendix, ascending colon
organs deep to the left upper quadrant
liver (left lobe), stomach, jejunum, spleen, left
kidney, transverse colon, splenic flexure, descending colon
organs deep to the left lower quadrant
descending colon, sigmoid colon
organs deep to the epigastrium
liver, pancreas, stomach, transverse colon
organs deep to the umbilical region
small intestine, transverse colon
organs deep to the suprapubic region
small intestine, sigmoid colon, rectum, bladder
organs deep to the right hypochondrium
liver, gallbladder, ascending and transverse
colon
organs deep to the left hypochondrium
stomach, spleen, tail of the pancreas, transverse
and descending colon
organs deep to the right lumbar region
small intestine, ascending colon
organs deep to the left lumbar region
small intestine, descending colon
organs deep to the right iliac fossa
small intestine, caecum, appendix, right ovary and
right uterine tube in females
organs deep to the left iliac fossa
descending and sigmoid colon, left ovary and left
uterine tube in females
describe the anatomy of a six pack
The right and left rectus abdominis muscles lie either side of the linea alba.
* Rectus abdominis is comprised of muscle segments (typically three)
interspersed with horizontal tendinous bands.
* When the muscle segments hypertrophy with exercise, they bulge either side
of the tendinous bands and can been seen on the anterior abdominal wall as bulges – the ‘six-pack’
are intra or retroperitoneal organs mobile?
intraperitoneal
which peritoneum can be seen?
parietal, not visceral
innervation of the parietal peritoneum
Receives the same somatic nerve supply as the region of the abdominal wall that it lines
Innervated by the somatic nerves that supply the overlying muscles and skin of the abdominal wall
how does injury to the parietal peritoneum present?
Pain is sharp, severe and well localised to the abdominal wall
how does injury to the parietal peritoneum present?
Pain is sharp, severe and well localised to the abdominal wall
can visceral peritoneum be seen?
no
innervation of visceral peritoneum
visceral sensory nerves which convey painful sensations back to the CNS along the path of the sympathetic nerves that innervate the organ/ structure it covers
how does injury to visceral peritoneum present?
Pain can be severe, but usually dull and diffuse (cannot be pinpointed to a specific location)
Painful sensations may be perceived as nausea or distension
what is the peritoneal cavity?
Potential space between the parietal and visceral peritoneum
Thin film of peritoneal fluid lies in the cavity, allowing the viscera to slide freely alongside each other
Peritoneal fluid consists of water, electrolytes, leukocytes and antibodies
what does intraperitoneal mean?
almost completely covered by the peritoneum suspended in the peritoneal cavity
name intraperitoneal organs
Sigmoid colon
Appendix
Liver
Transverse colon
Stomach
Small intestine
(SALTSS)
what does retroperitoneal mean?
posterior to the peritoneum, hence only covered by peritoneum on their anterior surface
name retroperitoneal organs
Duodenum
Ascending colon
Descending colon
Pancreas
Oesophagus
Kidneys
(DADPOK)
what does secondarily retroperitoneal mean?
intraperitoneal in early development but came to be ‘stuck down’ onto the posterior abdominal wall
features of mesenteries, omenta, ligaments and folds
All composed of peritoneum
Connect organs to each other and the abdominal wall
May carry blood vessels, nerves and lymphatics to the viscera
Contain a variable amount of fat - omenta is usually very fatty
what is a mesentery?
Folds of peritoneum that contain fat and suspend the small intestine and parts of the large intestine from the posterior abdominal wall
Arteries that supply the intestine from the posterior abdominal wall (from abdominal aorta) and veins that drain the gut (tributaries of the portal venous system) are embedded in the mesenteries
what is the greater omentum?
hangs from the greater curvature of the stomach and lies superficial to the small intestine
usually very fatty
what is the lesser omentum?
connects the stomach and duodenum to the liver. hepatic artery, hepatic portal vein and bile duct (portal triad) are embedded within its free edge
extends from the liver and attaches to the lesser curvature of the stomach and the first part of the duodenum
usually very fatty
what organ do the omenta connect to?
stomach
what are ligaments?
Folds of peritoneum that connect organs to each other or to the abdominal wall
what is the falciform ligament?
connects the anterior surface of the liver to the anterior abdominal wall
what are the coronary and triangular ligaments?
Coronary and triangular ligaments - connect the superior surface of the liver to the diaphragm
what are peritoneal folds?
Raised from the internal aspect of the lower abdominal wall and are created by the structures they overlie, like carpet running over a cable
what does the median umbilical fold represent?
Represents the remnant of the urachus, an embryological structure that connected the bladder to the umbilicus
where does the median umbilical fold lie?
in the midline
what do the medial umbilical folds represent?
Represent the remnants of the paired umbilical arteries, which returned venous blood to the placenta in foetal life
where do the medial umbilical folds lie?
Lateral to the median umbilical fold
what do the medial umbilical folds represent?
remnants of the paired umbilical arteries, which returned venous blood to the placenta in foetal life
what do the lateral umbilical folds overlie?
inferior epigastric arteries which supply the anterior abdominal wall
what sections is the peritoneal cavity divided into?
lesser and greater sac
what is another name for the omental bursa?
lesser sac
where does the lesser sac lie?
posterior to the stomach and anterior to the pancreas
posterior to the stomach and lesser omentum
what connects the lesser and greater sac?
epiploic foramen/ omental foramen
where does the epiploic foramen lie?
posterior to the free edge of the lesser omentum
embryology of the viscera
The viscera do not develop in the locations we see them in an adult
The gastrointestinal system develops from the embryonic gut tube
Lies in the midline of the abdominal cavity
Suspended from the posterior abdominal wall by the dorsal mesentery
Major branches of the abdominal aorta that supply the developing gut tube travel through the dorsal mesentery
The ventral mesentery connects the stomach to the anterior abdominal wall
As the liver grows within it, the anterior part of the ventral mesentery becomes the falciform ligament and the posterior part becomes the lesser omentum
During development, organs grow, migrate and rotate towards their final positions
As they do so, they pull their peritoneal attachments with them
Growth, migration, and rotation of organs during development is responsible for the formation of the lesser sac and results in some organs being pushed onto the posterior abdominal wall and becoming retroperitoneal
The umbilical vein is the embryological structure that forms the ligamentum teres
what does the GI system develop from?
embryonic gut tube
what suspends the embryonic gut tube from the posterior abdominal wall?
dorsal mesentery
which embryological structure forms the ligamentum teres?
umbilical vein
carries oxygenated blood from the placenta to the foetus
the veins enters the liver
after birth, the umbilical vein closes, the remnant is the ligaments teres
what is peritonitis?
Inflection and inflammation of the peritoneum
May be localised (to the region of peritoneum adjacent to the inflamed organ)
Or generalised (affecting the whole peritoneum)
Caused by inflammation of an organ or rupture of a hollow viscus
Rupture of the intestine allows faecal matter and bacteria to contaminate the peritoneum
As the peritoneum has a large surface area and is semi-permeable, peritonitis can lead to sepsis and is hence a life-threatening condition
Extremely painful
what are peritoneal adhesions?
Pathological fibrous connections between the parietal and visceral peritoneum
Irritation e.g by infection, causes peritoneum to produce fibrin which adheres the parietal and visceral peritoneum
Cause chronic abdominal pain
Increase the risk of volvulus (twisting) of the intestine, as it can no longer move freely
what is ascites?
An increased volume of peritoneal fluid
Occurs secondary to other pathology, such as heart failure, liver failure or intra-abdominal malignancy
Abdomen is distended and uncomfortable
Ascitic drain removes the fluid and relieves symptoms, but fluid reaccumulates
why would a surgeon want to avoid cutting lateral umbilical folds?
overlie inferior epigastric vessels, which bleed profusely if cut
what is peritoneal dialysis?
Peritoneal dialysis is a form of dialysis for patients who have end-stage renal failure. It is an alternative to haemodialysis.
* A tube is inserted into the abdomen (which remains permanent) and dialysis
solution is introduced.
* The solution draws waste products and excess fluid across the peritoneum
and into the fluid over several hours. The fluid is then drained out and discarded.
at which level is the oesophageal hiatus?
T10
what passes through the oesophageal hiatus?
oesophagus
vagus neves
inferior oesophageal arteries and veins
what artery supplies the oesophagus?
branches from the left gastric arteries
venous drainage of the oesophagus
Systemic system of veins (via oesophageal veins that drain into the azygos vein)
Portal venous system (via the left gastric veins)
what is the left border of the stomach?
greater curvature
what is the right border of the stomach?
lesser curvature
folds on the internal aspect of the stomach
rugae
sphincters of the stomach
inferior oesophageal sphincter
pyloric sphincter
name the parts of the stomach
cardia
fundus
body
antrum
pyloric antrum
pyloric canal
most superior part of the stomach
fundus
largest part of the stomach
body
which part of the stomach contains the pyloric sphincter?
pyloric canal
name structures lying posteriorly to the stomach
pancreas
diaphragm
splenic artery and vein
where does the lesser sac lie?
posterior to the stomach and lesser omentum
which quadrant does the stomach lie in?
left upper quadrant
which surface of the stomach is related to the anterior abdominal wall, diaphragm and left lobe of liver?
anterior
what does the posterior surface of the stomach form?
anterior wall of lesser sac
name structures forming the posterior wall of the lesser sac
pancreas
left kidney
spleen
which structures does the lesser omentum connect?
lesser curvature of the stomach and liver
name structures contained within the free edge of the lesser omentum
hepatic artery, hepatic portal vein, bile duct - portal triad
what is posterior to the free edge of the the lesser omentum?
entrance to the lesser sac
at which level does the coeliac trunk leave the abdominal aorta?
T12
name the branches of the coeliac trunk
left gastric
splenic artery
common hepatic artery
blood supply of the foregut
coeliac trunk
blood supply of the midgut
superior mesenteric artery
blood supply of the hindgut
inferior mesenteric artery
organs of the foregut
stomach
first half of duodenum
liver
gallbladder
pancreas
spleen - technically not a foregut structure (develops in the dorsal mesentery and is mesodermal in origin) but derives its blood supply from the coeliac trunk
blood supply of the lesser curvature
left and right gastric arteries
anastomose
where does the left gastric artery arise from?
coeliac trunk directly
where does the right gastric artery arise from?
common hepatic artery
blood supply of the greater curvature of the stomach
left and right gastro-omental (gastroepiploic) arteries
anastomose
where does the left gastro-omental arise from?
splenic artery
where does the right gastro-omental arise from?
gastroduodenal
which is a branch of the common hepatic
what do the short gastrics supply?
greater curvature
venous drainage of the stomach
left and right gastric veins and right and left gastro-omental veins
which drain into the hepatic portal vein
which blood vessel carries nutrient rich venous blood from the GI tract to the liver?
HPV
parasympathetic innervation of the stomach
vagus
effect of parasympathetic stimulation of the stomach?
peristalsis
gastric secretion
effect of sympathetic stimulation of the stomach
contraction of the sphincters
sympathetic innervation of the stomach
greater splanchnic nerve
formed of preganglionic sympathetic fibres from T5-T9
pass through sympathetic trunk without synapsing
the fibres synapse in prevertebral ganglia around the coeliac trunk
postganglionic fibres travel to the stomach and inhibit peristalsis and secretion
hiatus hernia
Abdominal oesophagus and upper part of stomach herniate through oesophageal hiatus into thorax
If contents of the stomach reflux into the oesophagus - heartburn, acid reflux
what is a gastric ulcer?
Mucosal lining of stomach breaks down
Usually due to infection with Heliobacter pylori which erodes the mucosal lining
Muscular wall exposed to gastric acid and enzymes
Erosion through wall and into blood vessels leads to intra-abdominal bleeding
pyloric stenosis
Congenital malformation
Hypertrophy of the circular smooth muscle of the pyloric sphincter
Presents six weeks after birth
Vomiting
Treated surgically
gastric cancer
Presents late as symptoms are non specific
Abdominal discomfort, early satiety, loss of appetite, nausea, weight loss, difficulty swallowing, indigestion
which structures lie anterior to the stomach?
left lobe of the liver
anterior abdominal wall
what lies posterior to the stomach?
The lesser sac.
Posterior to the lesser sac lies the pancreas and diaphragm.
function of the small intestine
digestion and absorption of food
folds of mucosa inside small intestine
plicae circulares
name the parts of the small intestine, proximal to distal
duodenum, jejunum, ileum
what is the duodenum curved around?
head of pancreas
is the duodenum intraperitoneal or retroperitoneal?
mostly retroperitoneal
what is the major duodenal papilla?
opening of the bile duct and main pancreatic duct into the duodenum
embryological origin of the first and second half of the duodenum?
first - foregut
second - midgut
when does the duodenum become jejunum?
when a mesentery begins to develop
artery of the foregut
coeliac trunk
artery of the midgut
superior mesenteric artery
are the jejunum and ileum retroperitoneal or intraperitoneal?
intraperitoneal
what suspends the jejunum and ileum from the posterior abdominal wall?
mesentery of the small intestine
blood supply of the jejunum and ileum
superior mesenteric artery
(artery of the midgut)
adaptations of the small intestine for nutrient absorption
villi and microvilli
plicae circulares
long and coiled
vast surface area
internal differences between jejunum and ileum
plicae circulares more pronounced in jejunum
internal ileum contains Peyer’s patches
what are Peyer’s patches?
large submucosal lymph nodes of the internal ileum
what is Meckel’s diverticulum?
Blind-ended diverticulum approximately one metre from the ileum’s termination
Embryological remnant of the connection that was present between the midgut loop to the yolk sac
Mimics appendicitis when inflamed
which abdominal region does the terminal ileum become the caecum?
what is this called?
right iliac fossa
ileocaecal junction
where does blood from the jejunum and ileum drain?
superior mesenteric vein
which veins combine to form the hepatic portal vein to the liver?
splenic and superior mesenteric vein
what are haustrations?
sacculations produced from where the teniae coli contract to shorten the wall of the bowel
what are tenia coli?
3 strips of longitudinally running muscle on the outer surface of the large intestine
what are appendices epiploicae?
Small pouches of fat filled peritoneum
Mark where blood vessels enter the bowel to supply the mucosa
function of the large intestine
Water absorption from faecal material to form semi-solid faeces
name the components of the large intestine in order
Caecum
Appendix
Ascending colon
Transverse colon
Descending colon
Sigmoid colon
Rectum
Anal canal
which parts of the large intestine are intraperitoneal?
Caecum, transverse colon and sigmoid colon are intraperitoneal
describe the structure of the large intestine?
Outer longitudinal muscle layer organised into three bands - taeniae coli
Inner circular muscle layer forms bulges called haustra (haustrations)
Bears fatty tags called epiploic appendages that mark the point at which blood vessels penetrate the intestinal wall
what is the first part of the large intestine?
caecum
where does the appendix arise from?
caecum
what connects the appendix and caecum?
mesoappendix
on which side of the posterior abdominal wall does the ascending colon run?
what is this place called?
right
right paracolic gutter
where is the hepatic flexure (right colic flexure), and what is it?
right upper quadrant
the 90 degree turn in the ascending colon where it becomes the transverse colon
named so because it bends under the liver
what connects the transverse colon to the posterior abdominal wall?
transverse mesocolon
where is the splenic flexure (left colic) and what is it?
left upper quadrant
the 90 degree turn in the transverse colon where it becomes the descending colon
named because of location relative to the spleen
what connects the splenic flexure and diaphragm?
phreniocolic ligament
which part of the large intestine marks the transition point between the embryological midgut and hindgut?
transverse colon
where does the midgut end?
after the proximal two thirds of the transverse colon
where does the hindgut start?
distal third of the transverse colon
where does the descending colon run?
left paracolic gutter
vertically on the left side of the posterior abdominal wall
where does the sigmoid colon run?
left lower quadrant
what mesentery does the sigmoid colon lie in?
sigmoid mesocolon
what is the bend in the sigmoid colon called?
rectosigmoid junction
which three large arteries supply the GI tract, and where do they originate?
coeliac trunk
superior mesenteric artery
inferior mesenteric artery
abdominal aorta
what does the coeliac trunk supply?
foregut
oesophagus, stomach, first half of duodenum, liver, gallbladder, bile ducts, pancreas, spleen
where does the superior mesenteric artery leave the abdominal aorta?
L1
what does the superior mesenteric artery supply?
midgut
second half of duodenum, small intestine, large intestine as far as first two thirds of transverse colon
branches also supply part of the pancreas
what does the inferior mesenteric artery supply?
hindgut
distal third of transverse colon, descending ind sigmoid colon, rectum, upper third of anal canal
where does the inferior mesenteric artery leave the abdominal aorta?
L3
name some branches of the SMA
jejunal branches - supply jejunum
ileal branches - supply ileum
ileocolic artery - supplies caecum, appendix, ascending colon
right colic artery - supplies ascending colon
middle colic artery - supplies the transverse colon
describe the blood supply of the small intestine
jejunal and ileal branches are embedded in the mesentery of the small intestine
they anastomose with each other, forming loops of arteries called arcades
from these arcades run the vasa recta (straight vessels) which supply the intestinal walls
name branches of the inferior mesenteric artery
left colic artery - supplies transverse colon and descending colon
sigmoid branches supply the sigmoid colon
superior rectal artery - terminal branch of the IMA, supplies the upper rectum
what is the marginal artery?
Branches of the middle colic artery (from the SMA) and the left colic artery anastamose along the distal third of the transverse colon and the splenic flexure forming the marginal artery
blood supply of the lower rectum
blood vessels originating from the internal iliac arteries in the pelvis
venous drainage of the hindgut
inferior mesenteric vein
which accompanies IMA
drains into the splenic vein
where does the IMV ascend?
left side of the abdomen
what vessels form the hepatic portal vein?
superior mesenteric vein and splenic vein
origin of hepatic veins, and can they be seen externally?
after nutrients have been removed, blood enters small hepatic veins which unite within the liver - cannot be seen externally
parasympathetic innervation of the foregut and midgut
vagus
parasympathetic innervation of the hindgut
pelvic splanchnic nerves
where do the cell bodies of preganglionic parasympathetic neurone lie?
S2-S4
The axons of these neurons leave the spinal cord and form the pelvic splanchnic nerves
where are parasympathetic ganglia located?
very close to or within the walls of the viscera
sympathetic innervation of the abdominal viscera
greater lesser and least splanchnic nerves
which splanchnic nerve innervates the foregut? which spinal segments is this?
greater
T5-T9
which splanchnic nerve innervates the midgut?
which spinal segments is this?
lesser
T10-T11
which splanchnic nerve innervates the hindgut?
which spinal segments is this?
least
T12
describe the dermatomes of the abdominal region, and referred pain
Segments T5-T9 receive information from dermatomes T5-T9 - upper abdomen and epigastrium
Segments T10-T11 receive information from dermatomes T10-T11 - umbilical region
Segment T12 receives information from dermatome T12 - suprapubic region
Pain from abdominal viscera is referred to the body wall
Epigastric pain - foregut pathology
Central abdomen/ umbilical - midgut pathology
Lower abdomen/ suprapubic - hindgut
appendicitis
Inflammation of the appendix
Pain begins in the umbilical region and is poorly localised
Result of irritation of the visceral peritoneum
Visceral sensory afferents returning to spinal cord segment T10
As inflammation progresses, the adjacent parietal peritoneum becomes involved
Causes severe, well localised pain in the right iliac fossa (which is conveyed to the CNS via somatic nerves that innervate the body wall)
History is of diffuse umbilical pain that ‘moves’ to the right iliac fossa
Symptoms vary depending on where the appendix lies
Maximal tenderness over McBurney’s point
Rupture of the appendix leads to peritonitis
Appendectomy usually performed via laparoscopy
mesenteric ischaemia
Mesenteric arteries occluded by a thrombus
Results in ischaemia of the intestine which may progress to infarction
Acute mesenteric ischaemia is a surgical emergency
Gut must be revascularised and necrotic intestine removed
High mortality, even when the condition is recognised and treated
IBD
Crohn’s disease and ulcerative colitis are two types of IBD
Flare ups of both can be serious and lead to life-threatening conditions
Affected parts of the gut may be removed if medication does not work
Crohn’s
Inflammation of the gut mucosa
Affects any part of the GI tract but typically affects the small intestine
Abdominal pain, diarrhoea, bloody stools, weight loss and tiredness
Ulcerative colitis
Affects the colon and rectum
Mucosa becomes inflamed and ulcerated
Abdominal pain, bloody diarrhoea, weight loss, tiredness
colon cancer
Bowel cancer
Change in bowel habits, bloody stools, abdominal pain, bloating
Colonoscopy allows visualisation of the colon and biopsies can be taken if a mass is seen
volvulus
Twisting of the gut
Affects mobile parts of the gut (i.e have a mesentery)
Most common at the sigmoid colon
Twisting obstructs the passage of faeces
May cause ischaemia and infarction of the affected part of the gut
venous drainage of the spleen
splenic vein
Which veins drain blood from the large intestine and where does it flow to?
The superior mesenteric vein drains the midgut part of the large intestine (as
far as 2/3 of the way along the transverse colon). The superior mesenteric vein unites with the splenic vein to form the hepatic portal vein, which enters the liver
The inferior mesenteric vein drains the hindgut part of the large intestine. The inferior mesenteric vein joins the splenic vein.
What four anatomical features ensure the small bowel has a high surface area for absorption of nutrients?
It is very long
* The mucosa is folded (plicae circulares)
* The mucosal folds bear villi and there are microvilli on the luminal surface of each epithelial cell.
* These features ensure that the jejunum and ileum, which are the sites of nutrient absorption, have a vast surface area
Where is the ‘junction’ between the midgut and the hindgut?
Approximately 2/3 of the way along the transverse colon. The proximal 2/3 are
derived from the midgut and the distal 1/3 is derived from the hindgut.
How might you distinguish a loop of large intestine from that of small intestine?
Large intestine is peripherally located; small intestine is centrally located
* The large intestine is of greater calibre (i.e. it has a wider lumen)
* The large intestine has epiploic appendages, haustrations and taeniae coli.
What do the following terms mean: colectomy, colostomy, ileostomy
A colectomy is removal of part of the colon (-ectomy means removal, e.g.
appendicectomy [removal of the appendix], mastectomy [removal of the
breast]).
* Colostomy is an operation in which, after part of the colon is removed, the
remaining, last part of the colon is connected to an opening (stoma) created in the anterior abdominal wall. The colon empties into a bag placed over the stoma.
* If the whole colon is removed, the terminal ileum is connected to a stoma created in the anterior abdominal wall. This procedure is called an ileostomy.
where does the liver lie?
right upper quadrant
where is bile produced?
liver
where is bile stored?
gallbladder
function of bile
emulsify lipids in the chyme entering the duodenum from the stomach
name the two surfaces of the liver?
diaphragmatic - anterosuperior, related to the inferior surface of the diaphragm
visceral - posteroinferior, related to other organs
where is the liver not covered by visceral peritoneum?
bare area - lies in contact with the diaphragm
region where the gallbladder lies in contact with the liver
region of the porta hepatis - where hepatic blood vessels and ducts of the biliary system enter and exit the liver (hilum of the liver)
what is the bare area of the liver?
where the liver lies in contact with the diaphragm
what separates the two anatomical lobes of the liver?
falciform ligament
how many lobes does the liver have?
two
which lobe of the liver is larger?
right
function of the falciform ligament
connect the anterior surface of the liver to the internal aspect of the anterior abdominal wall
name the two accessory lobes of the liver, and their relative positions
caudate and quadrate
caudate is superior to quadrate
On which surface are the accessory lobes of the liver located?
posteroinferior surface of the liver
how many functional segments of the liver are there?
8
Each segment is served by its own branch of the hepatic artery and portal vein, and by its own hepatic duct
do the lobes of the liver represent the internal, functional organisation of the liver?
no
name the three components of the portal triad
where are portal triads found?
bile duct
hepatic artery
hepatic portal vein
corners of the lobules
what does the common hepatic artery give rise to?
gastroduodenal artery
what is the common hepatic called after it gives off the gastroduodenal?
hepatic artery proper
what does the hepatic artery proper bifurcate into?
right and left hepatic arteries
venous drainage of the liver
two or three large hepatic veins
fate of the hepatic veins
unite with the inferior vena cava as it passes posterior to the liver
innervation of the liver
hepatic plexus
what forms the hepatic plexus?
parasympathetic fibres from the vagus nerves and sympathetic fibres
where is liver pathology referred?
epigastrium
what connects the liver to the diaphragm?
coronary and triangular ligamants
what connects the liver to the stomach and duodenum?
lesser omentum
where does the portal triad run?
free edge of lesser omentum
what forms the anterior boundary of the epiploic foramen?
portal triad and free edge of lesser omentum
what is the hepatorenal recess?
Lies between the right kidney and the posterior (visceral) surface of the right side of the liver
Fluid flows into this space in the supine position
what are the left and right subphrenic recesses?
Lie either side of the falciform ligament
Between the anterosuperior surface of the liver and the diaphragm
what part of the gut is the liver?
foregut
development of the liver
Develops from the embryological foregut
Grows from a tissue bud that develops in the ventral mesentery - peritoneal fold in the upper abdomen that connects the stomach to the anterior abdominal wall
Liver grows and migrates to the right side of the abdomen
Its peritoneal attachments are pulled with it
Remains of the ventral mesentery form the lesser omentum and the falciform ligament
Peritoneal attachments of the liver anchor it to surrounding structures, including the diaphragm superior to it
embryological remnants in the liver
Round ligament of the liver (ligamentum teres)
Contained in the free edge of the falciform ligament
Remnant of the umbilical vein - carries oxygenated blood from the placenta to the foetus
Ligamentum venosum
Lies on the posterior surface of the liver
Lies in the groove between the caudate lobe and the left lobe of the liver
Remains of the ductus venosus - diverts blood from the umbilical vein to the IVC in a foetus. Shunts oxygen rich blood to the heart and bypassing the liver
draw, label and describe the billary tree
Bile is continuously produced by hepatocytes
Excreted into bile canaliculi
Canaliculi drain into bile ducts of increasing calibre
Bile ducts converge to form right and left hepatic ducts that exit the liver at the porta hepatis
Left and right hepatic ducts converge to form the common hepatic duct
Common hepatic duct receives the cystic duct from the gallbladder
Distal to this point, the duct is called the (common) bile duct
The bile duct runs in the free edge of the lesser omentum
It lies posterior to the superior part of the duodenum and posterior to the head of the pancreas
Bile duct enters the duodenum
Bile enters the gallbladder for storage via the cystic duct
The spiral fold (spiral valve) lies at the junction between the gallbladder neck and the cystic duct
name the parts of the gallbladder
fundus, body, neck
Function of the gallbladder
stores and concentrates bile
on which surface of the liver is the gallbladder?
posteroinferior (visceral)
what is the main part of the gallbladder?
body
in which fossa does the gallbladder sit on the visceral surface of the liver?
gallbladder fossa
which part of the gallbladder communicates with the cyctic duct?
neck
what is the rounded end of the gallbladder?
fundus
surface marking of the fundus of the gallbladder
tip of 9th costal cartilage at the point where the right midclavicular line intersects the right costal margin
arterial supply of the gallbladder
cystic artery
venous drainage of the gallbladder
cystic veins
innervation of the gallbladder
visceral afferents
where is visceral gallbladder pain referred to? where else may gallbladder pain be referred to, and why?
epigastrium, spinal cord levels T5-T9
skin over the shoulder, if it irritates the diaphragm
diaphragm is innervated by phrenic nerve C3-5, which also receives somatic sensory information from the skin over the shoulder
if gallbladder pathology irritates the parietal peritoneum which is innervated by somatic nerves, pain is well localised to the right hypochondrium
hepatomegaly
Liver enlargement
Causes
-Hepatitis (liver inflammation from various causes)
-Malignancy
-Heart failure
Inferior border becomes palpable inferior to the right costal margin
liver metastases
As venous blood from the gut passes through the liver, bowel cancers often metastasise to the liver
Primary cancer of the liver can occur but is less common
liver cirrhosis
Scarring of the liver
Caused by
-Chronic excess alcohol consumption
-Chronic infection with hepatitis B or C
-Build up of fat in the liver
Hepatocytes are destroyed and replaced with fibrous tissue
Liver becomes shrunken, hard and nodular
Loss of hepatocytes impairs the function of the liver and liver failure may ultimately result
portal hypertension
High blood pressure in the portal venous system
Results when blood flow through the liver and portal vein is obstructed e.g in cirrhosis of the liver
oesophageal varices
Portosystemic anastomoses are communications between veins draining to the systemic circulation and veins draining to the portal circulation
In the distal oesophagus, venous blood drains into both the systemic veins (via the azygos) and the portal system (via the gastric veins)
If flow in the portal system is obstructed, pressure in the portal system increases and blood is diverted from the portal veins into the systemic veins
Systemic veins become distended and varicose - called oesophageal varices in the oesophagus
Rupture of these vessels leads to catastrophic bleeding
Gallstones, biliary colic and cholecystitis
Gallstones are mostly composed of cholesterol
Often asymptomatic
Cause symptoms when they migrate into the biliary tree
A gallstone lodges in the cystic duct causes pain when the gallbladder contracts - biliary colic
If the stone moves back into the gallbladder, the pain eases
If iit does not, the stone blocks the flow of bile into the cystic duct and the gallbladder becomes inflamed - cholecystitis
Cholecystectomy
Removal of the gallbladder
Usually performed laparoscopically
which artery gives rise to the cystic artery?
right hepatic artery
which structures are found in the porta hepatis?
Macroscopically – the hepatic portal vein, the right and left hepatic arteries,
the right and left hepatic ducts.
* Microscopically – lymphatics, branches of the vagus nerve and branches of the
greater splanchnic nerve.
What structure degenerates to form the ligamentum venosum?
The ductus venosus.
* In foetal life, the ductus venosus shunts most of the oxygenated blood in the
umbilical vein directly to the IVC. Only a small amount of blood enters the
developing liver.
* After birth, the ductus venosus closes and its remnant forms the ligamentum
venosum
With the patient in a supine position, where might fluid collect in the abdomen?
In the hepatorenal recess, which lies between the right kidney and the
posterior (visceral) surface of the right side of the liver.
What is the surface marking of the fundus of the gallbladder?
The tip of the right ninth costal cartilage.
* Where the right midclavicular line crosses the costal margin.
* At the point of the most lateral attachment of the rectus abdominis onto the
right costal margin.
Which nerves may relay pain from diseases of the gallbladder? For each nerve involved, where would the patient feel the pain?
Patients may experience gallbladder pain in the epigastrium (involves visceral
sensory (afferent) nerves), right hypochondrium (involves somatic nerves). or
the right shoulder (involves the phrenic nerve).
* The gallbladder is innervated by parasympathetic and sympathetic fibres.
* Visceral afferents from the gallbladder return to the CNS with the sympathetic fibres. Visceral pain from the gallbladder enters spinal cord levels T5 – T9 and is therefore referred to (i.e. felt in) the epigastrium.
* Gallbladder pain may be referred to the right shoulder if gallbladder pathology (e.g. inflammation) irritates the diaphragm. The diaphragm is innervated by the phrenic nerve (C3-5). Spinal cord segments C3-5 also receive somatic sensory information from the skin over the shoulder. Therefore gallbladder pathology involving the diaphragm may be felt in the right shoulder.
* If gallbladder pathology irritates the parietal peritoneum, which is innervated by somatic nerves, pain is well localised to the right hypochondrium
Where do the hepatic veins drain to?
Directly into the inferior vena cava
where does the coeliac trunk leave the anterior aspect of the aorta?
T12
what does the left gastric artery supply?
lesser curvature of the stomach
distal oesophagus
what does the common hepatic artery supply?
liver, stomach and duodenum
what does the splenic artery supply?
stomach, pancreas and spleen
what is the shortest part of the small intestine?
duodenum
is the duodenum mainly intraperitoneal or retroperitoneal?
retroperitoneal
describe the parts of the duodenum
superior, (first)
descending
inferior
ascending
name structures posterior to the first part of the duodenum
bile duct, gastroduodenal artery, hepatic portal vein
name the place where the jejunum meets the duodenum
duodenojejunal flexure
where is the major duodenal papilla?
halfway along the internal wall of the duodenum
what is the major duodenal papilla?
small elevation
marks where bile and digestive secretions (pancreatic juice) enter the duodenum
what is the embryological origin of the first half of the duodenum?
foregut
what is the embryological origin of the second half of the duodenum?
midgut
blood supply of the duodenum (2 parts)
gastroduodenal artery from the common hepatic artery
inferior pancreaticoduodenal arteries from the superior mesenteric artery
what do veins from the duodenum drain into?
hepatic portal vein
at which level does the pancreas lie?
Lies horizontally on the posterior abdominal wall at the level of L1
is the pancreas intra or retroperitoneal?
retroperitoneal
appearance of the pancreas?
bumpy
formation of the pancreas
Forms from dorsal and ventral pancreatic buds which fuse during development
name the parts of the pancreas
Head
Neck
Body
Tail
what is the hook-like projection of the head of the pancreas?
ucinate process
what forms part of the posterior wall of the lesser sac?
pancreas
which artery runs towards the spleen embedded in the upper border of the pancreas?
splenic artery
which vein lies posterior to the pancreas?
splenic vein
functions of the pancreas
Endocrine and exocrine function
Synthesises and secretes insulin and glucagon
Produces pancreatic juice that contains digestive enzymes
how does pancreatic juice reach the duodenum?
Pancreatic juice is transported through main pancreatic duct and accessory pancreatic duct to the duodenum
do the main and accessory pancreatic ducts communicate?
yes
where do the bile duct and main pancreatic ducts merge?
hepatopancreatic ampulla
where does the hepatopancreatic ampulla open?
second part of the duodenum at the major duodenal papilla
what surrounds the hepatopancreatic ampulla?
smooth muscle
sphincter of Oddi
function of the sphincter of Oddi
contracts to prevent reflux of duodenal contents into the bile and main pancreatic ducts
where does the accessory pancreatic duct empty pancreatic juice into the duodenum?
minor duodenal papilla
where does the minor duodenal papilla lie?
just proximal to the major duodenal papilla
blood supply of the pancreas
vessels derived from the coeliac trunk and superior mesenteric artery
which artery runs along the upper border of the pancreas and gives rise to pancreatic arteries?
splenic artery
which artery gives rise to the superior pancreaticoduodenal artery?
gastroduodenal
which artery gives rise to the inferior pancreaticoduodenal artery?
superior mesenteric artery
which vein drains the pancreas?
splenic
which veins form the hepatic portal vein?
superior mesenteric vein
splenic vein
where is the hepatic portal vein formed?
posterior to the neck of the pancreas
what is the spleen?
haematopoetic and lymphoid organ
in which quadrant does the spleen lie?
left upper quadrant, protected by ribs 9-11
functions of the spleen?
breakdown of old erythrocytes
storage of erythrocytes and platelets
immune response e.g production of IgG
how many surfaces and borders does the spleen have?
2 surfaces - diaphragmatic and visceral
4 borders - anterior, superior (notched), posterior, inferior (smooth)
is the spleen palpable below the costal margin
shouldn’t be
arterial supply of the spleen
splenic artery from coeliac trunk
how many branches does the splenic artery divide into at the hilum?
5
where does the splenic artery run?
superior border of the pancreas, embedded within it
venous drainage of the spleen, and where does this vessel run?
splenic vein, which runs posterior to the pancreas
duodenal ulcer
common in the first part of the duodenum
may erode the duodenal wall and gastroduodenal artery which lies posterior to the first part of the duodenum
pancreatitis
chronic or acute
acute - emergency
causes can be excess alcohol intake or impaction of a gallstone at the hepatopancreatic ampulla
gallstone pancreatitis - impaction of the gallstone prevents pancreatic juice from leaving the pancreas, and it starts to break down the pancreas
pancreatic cancer
causes pain that radiates to the back
when it affects the head of the pancreas, it can obstruct flow of bile in the bile duct
leads to an accumulation of bile pigments in the blood resulting in jaundice
diabetes mellitus
insulin producing cells no longer produce enough insulin
sustained high blood glucose levels
can be developed secondary to pancreatitis
splenomegaly
enlarged spleen
caused by infection, malignancy and portal hypertension
spleen enlarges towards the midline in the direction of the right iliac fossa as the phreniocolic ligament prevents its direct descent towards the left iliac fossa
splenic rupture
spleen is soft and highly vascular so is vulnerable to blunt abdominal trauma or rib fractures
removal of the spleen - splenectomy
spleen is not essential for life but patients may be more prone to bacterial infections
what structures might a tumour of the head of the pancreas involve?
hepatic portal vein, bile duct, pancreatic duct
what structures join to form the bile duct, and what is its course?
The bile duct is formed by the union of the common hepatic duct and cystic
duct.
* The bile duct runs in the free edge of the lesser omentum and behind the first
part of the duodenum. It courses posterior to the head of the pancreas.
* It unites with the main pancreatic duct at the hepatopancreatic ampulla, which
opens into the duodenum at the major duodenal papilla.
where is the sphincter of Oddi?
It surrounds the hepatopancreatic ampulla. It is located in the medial wall of
the second part of the duodenum, where the hepatopancreatic ampulla opens into the duodenum at the major duodenal papilla.
which artery lies behind the first part of the duodenum?
gastroduodenal artery
what lies between the pancreas and stomach?
lesser sac
what forms the first part of the respiratory tract?
left and right nasal cavities
where is the spheno-ethmoidal recess?
superoposterior to the superior conchae
between the superior concha and cribriform plate
where are olfactory receptors found, and what do they form?
mucosa in the upper part of the nasal cavity
spheno-ethmoidal recess
axons form the olfactory nerves (CN I)
what separates the left and right nasal cavities?
thin midline septum, formed of cartilage and bone
what separates the nasal cavities and the oral cavity?
hard palate
what part of the pharynx does the nasal cavity communicate with posteriorly?
nasopharynx
what are paranasal sinuses?
cavities within the skull bones
what is the midline nasal septum formed of anteriorly and posteriorly?
cartilage anteriorly
two thin plates of bone posteriorly
which bone forms the superior part of the posterior septum?
perpendicular plate of the ethmoid bone
which bone forms the inferior part of the posterior septum?
vomer
projections of bone on the lateral wall of the nasal cavity
superior, middle and inferior conchae, or turbinates
what are the meatuses?
spaces INFERIOR to the conchae
in this way, the superior meatus lies inferior to the superior conchae
function of the meatuses?
warms, humidifies and filters air
what separates the nasal cavity and the cranium?
cribriform plate
what is the cribriform plate?
delicate section of bone that is perforated with tiny holes
separates nasal cavity and cranium
function of the cribriform plates
allow axons of olfactory neurones to pass through the perforations and form the olfactory nerves which travel to the brain
where is the spheno-ethmoidal recess?
superoposterior to the superior conchae
between the superior concha and cribriform plate
what are the paranasal sinuses?
cavities within skull bones
how are the paranasal sinuses named?
according to the bones within they are located
where is the frontal sinus?
anterior part of the frontal bone
where is the ethmoid sinus/ ethmoid air cells?
ethmoid bone
superior to nasal cavity and medial to orbits
where is the sphenoid sinus?
sphenoid bone
where is the maxillary sinus?
within the maxillae of the facial skeleton
lateral to the lateral walls of the nasal cavity
which sinuses are usually clearly seen in the bisected head?
frontal and sphenoid
where does the frontal sinus drain into?
middle meatus
where does the sphenoid sinus drain into?
spheno-ethmoidal recess
where do the ethmoid air cells drain into
superior and middle meatuses
where does the maxillary sinus drain into?
middle meatus
why can’t the maxillary sinus drain freely when the head is upright?
opening of the maxillary sinus lies superomedially
where does the nasolacrimal duct drain into?
inferior meatus
what does the nasolacrimal duct drain?
tears that lubricate the anterior surface of the eye
why do we get a runny nose when we cry?
excess fluid runs down the nasolacrimal duct, which drains into the inferior meatus
in which bone is the middle ear?
temporal bone
how many bones comprise the middle ear?
three
what connects the middle ear to the nasopharynx?
auditory tube (Eustachian tube)
where is the opening of the auditory tube, and how can it be identfied?
lateral wall of the nasopharynx
surrounded by a slight bulge which is formed of tonsillar tissue
function of the auditory (Eustachian) tube
connects the middle ear to the nasopharynx
allows air to pass into the middle ear so that the pressure on either side of the tympanic membrane (eardrum) is equal for optimal conduction of sound waves
where does the tympanic membrane lie?
between the middle and external ear
name an artery supplying the nasal cavity
branches of the maxillary artery
what is the maxillary artery a terminal branch of?
external carotid artery
medical name for nosebleed
epistaxis
innervation of the nose
trigeminal nerve (CN V)
anterior and posterior composition of the palate
anterior hard palate - bone
posterior soft palate - muscle
what forms the roof of the oral cavity?
the palate
which bones form the hard palate?
palatine bone of the maxilla
horizontal plate of the palatine bone
which bones form the hard palate?
palatine bone of the maxilla
horizontal plate of the palatine bone
why is the hard palate important?
prevents food or fluid entering the nasal cavity
we push our tongue up against the hard palate during the first phase of swallowing, which forces food and fluid backwards into the oropharynx
we push our tongue up against the hard palate to articulate certain sounds
cleft palate
bones of the hard palate do not develop properly or do not fuse in the midline
cleft remains that allows communication between the nasal and oral cavities
surgically repaired
what hangs from the posterior border of the soft palate?
uvula
what do the muscles of the soft palate do during swallowing?
contract to elevate the soft palate
the nasopharynx is closed off from the oral cavity, preventing reflux of food and fluid into the nasal cavity
innervation of the muscles of the soft palate
vagus
which muscles are in the cheeks?
buccinator
what is the oral cavity continuous with posteriorly?
oropharynx
how many teeth do adults have?
32
how many incisors, canines, premolars and molars are there in the upper/ lower jaw?
4 incisors
2 canines
4 premolars
6 molars
4,2,4,6
composition of the teeth
inner pulp containing blood vessels and nerves
dentin surrounding the pulp
outer enamel coating
what does the tongue bear on its superior surface?
papillae
where does the root of the tongue extend into?
oropharynx
what is the space between the posterior tongue and anterior aspect of the epiglottis?
vallecula
two types of muscles comprising the tongue
intrinsic and extrinsic
difference between intrinsic and extrinsic muscles
intrinsic muscles
- lie entirely within the tongue
- paired bilaterally and fuse in the midline
- they change the shape of the tongue
extrinsic muscles
- attached to the tongue but originate from outside it (from the mandible and hyoid bone)
- move the tongue
innervation of tongue muscles
hypoglossal
sensory innervation of the tongue
taste in the anterior two thirds - facial nerve
general sensation (touch, pain, temperature) in the anterior two thirds - trigeminal nerve
taste and general sensation in the posterior third - glossopharyngeal
which arteries supply the oral cavity, and which artery are these a branch of?
lingual, maxillary, facial
branches of external carotid
innervation of soft palate muscles
vagus
how many cranial nerves innervate the tongue?
four
which cranial nerves innervate the tongue and how?
hypoglossal
- innervation of the muscles of the tongue
facial
- taste to anterior two thirds
trigeminal
- general sensation to anterior two thirds
glossopharyngeal
- taste and general sensation to posterior third
name 4 tonsils
pharyngeal tonsils (adenoid)
tubal tonsils
palantine tonsils
lingual tonsils
which tonsils lie in the roof and posterior wall of the nasopharynx?
pharyngeal (adenoid)
where is the adenoid/ pharyngeal tonsil?
roof and posterior wall of the nasopharynx
where is the tubal tonsil?
surrounds the opening of the auditory tube on the lateral wall of the nasopharynx
where is the palatine tonsil?
lateral wall of the oropharynx
usually referred to as ‘the tonsils’, as they are visible on either side of the oropharynx when the mouth is open
where is the lingual tonsil?
in the posterior tongue
name places in the body where lymphoid tissue can be found
spleen, tonsils, lymph nodes, Peyer’s patches
what is lymphoid tissue?
support the immune response
treatment of epistaxis
applying pressure
cauterising the bleeding vessels
nasal tampon
which bone is vulnerable in nose fractures?
cribriform plate of ethmoid bone
sinusitis
which sinus is most problematic when affected by sinusitis and why?
inflammation or infection of the mucosa lining the paranasal sinuses
maxillary
- do not drain freely unless lying down on one side
- inflammation of the maxillary sinus may cause cheek pain as the sensory nerve that supplies the cheek runs in the roof of the maxillary sinus
which is the only contralateral cranial nerve?
trochlear
only cranial nerve where clinical findings are on the other side
which is the only cranial nerve to have a dorsal exit from the brainstem?
trochlear
symptoms of hypoglossal nerve palsy
injury to the left or right hypoglossal nerve results in:
atrophy and weakness of the ipsilateral tongue muscles
tongue deviates to the injured side when the patient protrudes their tongue
presentation of mouth cancer?
ulcers, lumps, patches of discolouration on the oral mucosa
tonsilitis and tonsillectomy
tonsillitis - inflammation of the tonsils
usually affects palatine tonsils
can be caused by a viral or bacterial infection
tonsils become enlarged, red and may be covered in pus appearing as white spots in the surface of the tonsils
painful swallowing
inflammation and enlargement of the pharyngeal tonsil (adenoid) is common in children
enlargement may obstruct nearby opening of the auditory tube, resulting in fluid accumulation in the middle ear and hearing impairment
recurrent infection of the tonsils may be managed by tonsillectomy - surgical removal of the tonsils
function of the auditory tube
equalise air pressure on either side of the tympanic membrane
important for optimal movement of the typanic membrane
why would an infant with a cleft palate have difficulty feeding?
Cleft palate allows reflux of liquid and food into the nasal cavity.
* The palate also plays an important role in swallowing as the first part of
swallowing involves pressing the tongue up against the hard palate to force
food backwards.
* For infants that are breast or bottle feeding, sucking also involves the tongue
being pressed up against the palate – this is obviously impaired (or even impossible) if there is a gap in the palate.
why may poor oral hygiene lead to a dental abcess?
Poor hygiene (ineffective or insufficient brushing) allows bacteria and
foodstuffs to erode the outer enamel layer of the tooth.
Decay and infection of the inner pulp may follow and can lead to infection of
the bone.
