practice questions Flashcards
what is Zollinger-Elison syndrome
Zollinger-Ellison Syndrome is a Gastrin Secreting Tumour caused by non beta cells in the islets of langerhans
this leads to increased HCL and villous hyperplasia
what is the threshold potential for GI smooth muscle
-40mV
resting is -50 -60mV
where is the tail of the pancreas
in the lienorenal ligament, intraperitoneal
what is the lower oesophageal sphincter controlled by
VIP nerves
this is the basis for alchalasia
what does the cranial limb of the intestinal loop become
the jejenum and ileum
what are the lengths of the parts of the colon
Ascending 13cm
Transverse 38cm
Descending 25cm
Sigmoid 25-38cm
what drug is used to treat nematodes such as hook worm by may cause liver failure
albendazole
what is barretts oesophagus
long standing reflux leading to risk of adenocarcinoma of the oesophagus
what disorder is characterised by high serum amylase
acute pancreatitis
what drug can be used to treat peptic ulcers but may have the side effect of galactorrhoea and gynaecomastia
cimetidine
H2 receptor antagonist
antagonises testosterone
what GI tumour would look like a sheet of similar cells that have scant pink and granular cytoplasm
carcinoid
name two steroid drugs effective against chemo induced emesis and nausea
methylprednisolone and dexamethazone
what can hep C cause
acute liver inflammation
what can schistomiasis cause
chronic liver inflammation
what causes inhibition of gastric emptying
ph less than 3.5
hypertonic solution
fatty acid with long chain
tryptophan
where is secretin synthesised
S cells in duodenal mucosa
what is the intestinointestinal inhibitory reflex
inhibition of contractions in the adjacent regions of the small intestine
what does hypotonic mean
water from the solution will tend to osmose into the cell
describe the features of colonic carcinoid tumour
large intramural masses with polypoid excavations.
describe a colonic adenoma
napkin ring encircling and exophytic growths
describe a villous adenoma
1-3 cm velvety masses
describe leimyosarcomas
large bulky intra mural masses that may ulcerate
what hormones mediate the efferent limb of the gastrocolic reflex
cholecystokinin and acetylcholine
what NSAID is best for a patient with GI problems
paracetamol
what vertebral level is the subcostal plane
L3
what structures does the sigmoid mesocolon cross in the left iliac fossa
bifurcation of the left common iliac artery
left ureter
where does the base of the mesentery begin
left of the L2 vertebra
what is the purpose of a paramedian incision
avoids cutting the linea alba
which artery enters the rectus sheath between the sternal and costal attachments of the diaphragm
superior epigastric
what is a feature of the rome 3 criteria of IBS
reccurent abdo pain within the last 3 months
what drugs absorption is slowed by food in the stomach
paracetamol
what factors can affect oral drug absorption
GI motility
particle size
splanchnic blood flow
what microbiota are commonly found in the duodenum
lactobacili
what hormone inhibits glucagon
somatostatin
what cells secrete secretin
S cells
what is the only essential secretion of the stomach
intrinsic factor -vitamin b12
what is the function of somatostatin
inhibits glucagon and insulin secretion
inhibits gastric acid production
what causes secretion of secretin
drop in pH
what cells produce somatostatin
delta cells in pylorus, duodenum and pancreas
what embryonic tissue gives rise to the liver
endoderm
what percentage of colon cancers does hereditary nonpolyposis coli account for
1-5%
how many life years are lost by a woman with a BMI of 30 as oppose to 25
7 years
which antiemetic causes sedation
haloperidol
what are the histological features of ulcerative colitis
crypt abscesses
crypt atrophy
inflammatory infiltration of lamina propria
what are the features of duodenal ulcer
even distrubution amongst social classes
high or normal acid levels
which antihelminthic acts by increasing permeability of the nematode to calcium ions
praziquantel
what is a risk factor for adenocarcinoma of the oesophagus
smoking
what neoplasm accounts for 98% of colorectal cancers
adenocarcinoma
what IBD is more common among non smokers
ulcerative colitis
what proportion of bile salts are reabsorbed
95%
all in the small intestine
what can cause gastroenteritis
salmonella
what is active helminth transmission
lavae penetrate the skin
what is intermediate transmission
ingestion of the parasite
what do parietal cells secrete
acid and intrinsic factor
omeprazole
PPI
Ranitidine
histamine receptor antagonist
pepto bismol
antacid and anti inflammatory
skip lesions
crohns disease- patchy mucosal inflammation
what part of the intestine is most commonly infected in crohns
terminal ileum and ascending colon
what layers does UC affect
superficial layer
crohns disease can affect all layers
in what disease is crypt hypertrophy and villous atrophy seen
coeliac disease
what bacteria is associated with food esp rice
B. cereus
what bacteria cause rice water stools with severe dehydration and often caused by shellfish consumption
V. cholerae or V.volnificus
what bacteria causes haemolytic uraemic syndromw
enterohaemorrhagic e. coli
what is the most common cause of viral enteritis in infants
rotavirus
what is the most common cause of viral enteritis in adults
norovirus
where is the pain of diverticulitis usually felt
LIF
what enzyme is released in bile duct disease
ALP
what enzymes are released by damaged hepatocytes
aspartamate and alanine aminotransferase
what is normal body temperature
36.5 - 37.2
what bacteria might cause bloody stools and severe septic shock and haemolytic uraemic syndrome
e. coli
what bacteria is associated with antibiotic therapy
c. diff
what is the surface marker for the femoral pulse
along the inguinal ligament, midway
what is the function of secretin
increases volume and alkalinity of pancreatic juice
what is the function of substance P
increases peristalsis
what are the immune functions of the liver
protein synthesis
kupffer cells which phagocytose bacteria
pro inflammatory cytokines
what percentage of secretions are formed in the cephalic phase
30%
what do cheif cells produce
pepsinogen
what receptors does the vomiting centre contain
muscarinic and Histamine1
what receptors does the CTZ contain
dopamine 2 receptors
what are antimuscarinics used for
vestibular apparatus stimulated vomiting but not CTZ induced
what is swan neck deformity of the oesophagus a sign of
alchalasia
may show dilation of the oesophagus
what type of mesoderm do the kidneys develop from
intermediate mesoderm
what do the glomruli develop from
the mesonepros
what do the gonads develop from
intermediate mesoderm
what do the adrenal glands develop from
intermediate mesonephros
when does organogenesis happen
6 weeks
what are the features of extrahepatic jaundice
pale stools due to bile not entering the intestine conjugated bilirubin (water soluble) - dark urine pruritis due to increased bile salts raised ALP
what is pre hepatic jaundice
increased haemolysis
how long does it take food to reach the stomach
9 seconds
what hormone stimulates ECL cells and gastric acid secretion
gastrin
what is the function of the posterior fibres of temporalis
retraction of the mandible
what is the function of medial pterygoid
elevation and protrusion
what is the function of lateral pterygoid
depression and protrusion
what does coeliac disease predispose to
small bowel lymphoma
where in the stomach is mucin secreted
pylorus and cardia
what nerves are carried to the hindgut along the IMA
least splanchnic nerve and parasympathetic from S2-4
what is an omphacele
herniation of the stomach through the umbilicus. covered by peritoneum
what does the ventral mesentery form
lesser omentum and falciform ligament
what structures form the stomach bed
central tendon of diaphragm
left colic flexure
spleen
what may result from a patent tunica vaginalis
cytocele
hydrocele
indirect hernia
how much rotation of the intestine happens around the SMA
270 degrees anticlockwise
which of the forces in the nephron is the weakest
oncotic pressure of the tubule
what is tubuloglomerular feedback
increased flow rate of sodium past the macula densa sends a message to afferent arterioles when BP increases
what ion is found a lot in saliva
potassium
what factors decrease the rate of action potentials in slow waves
sympathetic
gastrin
gip
secretin
where is the second part of the duodenum
anterior to the hilum of the right kidney, right side of L2,3 vertebrae
what is an indicator of acute pancreatitis
low serum calcium
what are the features of pancreas secretion
amylase, lipase and protease
(cholecystokinin reduces secretion)
high bicarbonate content
isotonic
what is the blood supply to the lower pharynx
inferior thyroid
what percentage of gastric secretions is the gastric phase responsible for
60%
loose foul smelling fatty stools
giardiasis
what paracrines are secreted from the stomach
somatostatin
histamine
what is the only endocrine secretion of the stomach
gastrin
what are the exocrine secretions of the stomach
HCl
intrinsic fx
pepsinogen
ions
what are the borders of the epiploic foramen
porta hepatis- ant
IVC- post
duodenum-inf
caudate lobe-sup
what are vitamins
essential to life but cannot be made by the body
what is enterokinase
converts trypsinogen to trypsin
what is the ph of pancreatic juice
8
what is the nerve supply of the small intestine
lesser splanchnic nerve t10 and 11 and vagus nerve via the superior mesenteric plexus
referred pain is peri umbilical
where are the peyers patches
ileum
where does small intestinal wall lymph drain to
mesenteric nodes on the SMA and then the cysterna chyli
what is meckel’s diverticulum
a patent remnant of the vitello intestinal duct
2 inches long, 2 feet from the end of the ileum in 2% of people
it may ulcerate - feels like apendicitis
faecal discharge at the umbilicus
how big is the caecum
7.5 cm. covered by peritoneum but not on a mesentery. RIF
which part of the appendix contains lymphoid tissue
submucosa
what are the possible locations of the appendix
pelvic; subcaecal; retrocaecal; retro-ileal; pre-ileal
use the taenia coli to locate
what is the blood and nerve supply of the appendix
ileocolic branch of the superior mesenteric, from the aorta at L1 with nerves derived from T10/11,
what is the blood supply of the caecum
iliocolic, anterior and posterior caecal plus appendicular artery from posterior caecal
where does the sigmoid start and end
pelvic brim and s3
what are the ascending and descending colons related to
kidneys
what do the branches of the IMA cross
ureter and gonadal vessels
what is the nerve supply of the hindgut
least splanchnic nerves s2,3,4 -para
T12- sympathetic
referred pain is to t12 -supra pubic region
where is the rectum
S3
is alpha 1 antitrypsin dominant or recessive
recessive
what does scarpa’s fascia go on to form
fascia lata
and buck’s and colle’s in the penis and scrotum
what aponeurosis forms the inguinal ligament
external oblique
what is the most common cause of kidney stone
calcium oxalate
what is the most common cause of chronic renal failure
DM
what are the possible causes of kidney stones
uric acid
magnesium ammonium phosphate
cystine
what factors contribute to renal stones
poor urine output
infection
low pH
low concentration of factors that inhibit stones such as citrate
name some causes of metabolic acidosis
increased renal bicarbonate loss hypokalaemia increased fixed H+ production increased intake of dietary acid decreased renal H+ secretion
furosemide
loop diuretic
what proportion of an adult is water
60%
increased adiposity mean decreased water proportion
what proportion of water is intracellular
40%
what proportion of body water is extracellular
20%
what proportion of water is plasma
5%
what proportion of body water is interstitial fluid
15%
increases the tubular reabsorption of sodium
aldosterone
what hormone increases renal blood flow
dopamine
is tubular fluid in the distal tubule hypotonic or hypertonic
hypotonic
henderson hasselback equation
ph = pk + log10 base/ acid
what bacteria can reduce nitrates to nitrites
Most gram negs
S cells in duodenal mucosa
stimulates bicarbonate and fluid secretion by the pancreas
secretin
presence of hydrocholoric acid in the small intesting
D cells
somatostatin
itching, rectal pain and rectal bleeding
haemorrhoids
left iliac fossa pain, mass, nausea, bleeding
diverticulitis