mock papers Flashcards
3 examples of a secondary cartilagenous joints
intervertebral disc
pubic symphesis
manubriosternal joint
the tunica intima of arteries is made up of ?
endothelium
layers of artery walls
Tunica intima - endolthelial
tunica media - smooth muscle, elastic tissue, collagen
Tunica externa/adventitia - connective tissue, collagen
what is an inverse agonist
a drug that binds to the same receptor as an agonist but induces a pharmacological response opposite to that of the agonist
they reduce constitutive activity as a receptor
the concept of a spare receptor describes
that it is possible to elicit a maximal biological response at a concentration of agonist that does not result in full occupancy of available receptors
EC50 is
concentration of a drug that produces 50% maximal effect
ED50 is
the dose for 50% of the population to obtain the therapeutic effect
what is the rate limiting step of glycolytic pathways
phosphofructokinase
Absorption of iron from the GI tract is best in what form
ferrous form
origin and termination of popliteal artery
Origin; continuation of femoral artery when it passes through the adductor hiatus
termination; lower border of popliteus muscle
You review a recent angiogram and note the patient had multiple collateral vessels. If two vessels are connected in parallel, their total resistance to blood flow is
less than the resistance of either vessel alone
Heparin biological activity is dependent on
endogenous antithrombin III
The initial event in atherosclerosis is
endothelial dysfunction
suprascapular nerve supplies
Suprspinatous
infraspinatous
long thoracic nerve supplies
serratus anterior
expiration is assisted by what muscles
subcostal muscles
with salbutamol when will it show a peak bronchodilator effect
15-30 mins
what is the clinical effect of ipratropium
blockage of airway smooth muscle contraction via reduced vagal activity
at the hilum of the lung visceral pleura becomes continuous with which part of the parietal pleura
mediastinal part
Elderly patients have physiological changes that affect the prescribing of medication. The greatest change in the liver is
changes to phase 1 reactions
two patients have different clinical response to the same drug, what is the most important mechanism for variation in drug responses
differences in active transport systems
bioavailability of diazepam
100%
Ficks law describes
passive flux of molecules down a concentration gradient
patient with HTN and diabetic nephropathy, initiating antihypertensive therapy would be with
ACEi
A patient presents with profound hypertension and headache of acute onset. They were on opiate withdrawal maintenance regime and had ceased all medications 4 days ago. What drug likely caused this
Clonidine
mechanism of action of furosemide
blockade of Na/K/Cl transporter in loop if henle
what part of the vasculature is most sensitive to the vasodilating effects of nitrates
Veins
Flecainide is what class of drug in Vaughan-Williams classification
1c
what time post stroke should thrombolysis be given ideally
<3 hours
warfarins mechanism of action is via
Inhibition of gamma-carboxylation of factors II VII IX X
paraesthesia of index finger and thumb is damage to what dermatome
C6
the major pathological mechanism causing ‘nutmeg’ liver in CCF is?
hepatic hypo-perfusion
what type of underlying genetic abnormality is most commonly seen in CF
deletions
pathology of ACS primarily involves
mural thrombosis of an epicardial artery
most common site of origin of emboli causing cerebrovascular disease is
heart
a factor that stimulates the proliferation of smooth muscle cells also relates to the pathogenesis of athersclerosis is
platelet derived growth factor
several days post STEMI a patient develops a new pansystolic murmur and increased left atrial pressures from late systole to early diastole. Which lesion is most likely to have caused this?
rupture of the papillary muscle
Successful immune response to HIV during the acute phase of infection results from?
development of CD8+ virus specific cytotoxic cells
organ transplant rejection is what type of hypersensitivity reaction
type IV, II and III
Excitatory amino acids in the brain are
GABA
glycine
major site of airway resistance is ?
medium sized bronchi
as a red cell passes through systemic capillaries its size will…
increase
because of increases intracellular osmoles
Immediately after inspiration commences what pressure changes would you expect?
intrapleural pressure and intrapulmonary pressure both fall
third heart sound is
turbulence during rapid ventricular filling in early diastole
turbulence is most likely to occur in blood vessels if
the velocity of blood within the vessels increases
A patient with abdominal pain that is visceral in origin, true visceral pain arises from?
Distension
in normal circumstances largest volume of blood is located in ?
large veins
in hypokalaemia what would you see on ECG
U waves
widespread ST depression
Twave inversion
bradycardia
prolonged PR
Cushing triad of raised ICP
Bradycardia
Wide pulse pressure
irregular respirations
which hormone/ factor will result in an increase in pH of duodenal contents
secretin
a patient has a deep laceration to the arm which structure lies deepest and is least likely to be injured;
median nerve
basilic vein
flexor pollicis longus
ulnar nerve
flexor pollicis longus
nerve supplying skin over femoral triangle is
genitofemoral
oesophageal opening is at what level
T10
the anterior triangle of the neckhas a floor made up with which strucutres
submandibular gland
mylohyoid and hypoglossus muscles
the alar ligaments of the cervical spine connect what
dens to the foramen magnum
blood supply to the SA node is from?
SA nodal artery which arises from the RCA in 60% people
at the 4th finger PIPJ, flexion is primary the role of
flexor digitorum superficialis only
which subset of type A fibres is most sensitive to local anaesthetic
A delta
how long does paralysis with rocuronium last
25-35 mins
superior mesenteric artery and vein cross which part of the duodenum
inferior part
thoracic constriction of the oesophagus can be caused by its crossing which structure?
arch of aorta
left main bronchus
the styelomastoid foramen transmits the stylomastoid artery and ?
facial nerve
surface anatomy of the superior vena cava is best described as being related?
right border of the manubrium and upper 1/3 of the body of the sternum
type of cell injury seen in the myocardium following MI
coagulative necrosis
how much more potent is fentanyl compared to morphine
100 times more potent
on what vessels does angiotensin II principally act
arterioles
a week post fracture what stage of the pathology process would it be
fusiform uncalcified tissue uniting the fracture ends with no structural rigidity
where is responsible for the basic rhythm of ventilation
medullary respiratory centre
what IV fluid in large volumes of infusion can cause a normal anion gap metabolic acidosis
Normal saline
which IV fluid is considered to be a balanced solution
Hartmanns
which IV fluid is used to treat toxicity of drugs with a sodium channel blocking effect
sodium bicarbonate 8.4%
which organism do you need to consider specifically for burns
Pseudomonas aruginosa
Vasopressin’s antidiuretic effect is mediated by what mechanism
Binding V2 receptors and inducing insertion of aquaporin 2 into apical membranes of collecting ducts
Hydrogen ion secretion in the distal tubules and collecting ducts is controlled by what
Aldosterone control of ATP driven H+ pump
In nephrogenic diabetes insipid is what can the two genetic disorders be
- mutation to V2 receptor (X linked recessive)
- Mutation of the gene aquaporin 2 (autosomal)
Regarding diuretics what is the mechanism of action for ethanol
Inhibits vasopressin secretion
Type of diuretic and mechanism of action- acetazolomide
Carbonic anhydrase inhibitor
Profoundly decreases sodium bicarbonate reabsorption in the proximal tubule
Clinical application of acetazolamide
Acute mountain sickness
Glaucoma
Urinary / metabolic alkalosis
Pharmacokinetics of acetazolomide
Absorption - 100% oral bioavailability
Not metabolised
Excreted in urine
Contraindications of acetazolomide
Renal failure - worsens metabolic acidosis
Liver failure - decreases excretion of already elevated NH4 = hepatic encephalopathy
Mechanism of action of mannitol
Osmotic diuresis
Osmotic effect at proximal tubule and descending loop of henle
Pharmacokinetics of mannitol
Administered parenterally
Rapidly distributed
Not metabolised
Excreted in urine within 30-60 minutes
Clinical uses of mannitol
Increasing urine volume
Reduction of ICP
Mechanism of action of furosemide
Loop diuretic acting in the thick loop of henle
Blocks the Na K Cl co transporter
Increases Ca and Mg excretion
Pharmacokinetics of frusemide
Oral bioavailability 45-70% , IV
Rapid onset
Metabolised and excreted in the kidney
Clinical uses of furosemide
Oedema
Acute hypercalcaemia (with IV fluids)
Hyperkalaemia
Anion ingestion (bromide, fluoride, iodide)
Toxicity of furosemide
Hypokalaemic metabolic alkalosis
Ototoxicity
Hyperuricaemia - may precipitate gout
Hypomagnesaemia
Mechanism of action of chlorothiazide
Thiazide diuretic
Blocks Na Cl cotransporter in the distal tubule
Inhibits NaCl reabsorption = diuresis
Clinical uses of thiazide diuretics
Htn
Heart failure
Neohrolithiasis due to idiopathic hypercalciuria
Neohrogenic diabetes insipidus
Mechanism of action of spironalactone
A synthetic steroid and aldosterone antagonist
Competitive antagonist to aldosterone at its receptor in the collecting ducts
Inhibit NaK exchange by inhibiting aldosterone
Clinical uses of spironolactone
Primary hyper secretion - Conns syndrome, ectopic ACTH production
Secondary aldosteronism - heart failure, hepatic cirrhosis, nephrotic syndrome
Pharmacokinetics of spironolactone
Orally absorbed 70%
Extensive first pass metabolism
90% protein bound
Excreted urine and small amount in bile
Mechanism of action of amiloride and triamterene
Interfere directly with Na entry through the ENaC ion channel in the collecting tubule
At what gestation do ectopic pregnancies typically rupture
6 weeks
What is the urinary lower pH
4.5
A 6 year old indigenous male presents with joint pain, rash, new murmur 2 weeks following from a strep sore throat. What type of hypersensitivity is this?
Type II reaction
(Rheumatic fever)
Describe and give examples of type 1 hypersensitivity
IgE mediated
Mast cells and basophils
Results in allergy, anaphylaxis, atopic disease
Describe and give examples of type II hypersensitivity
Cytotoxic reaction mediated IgG or IgM
Mediated by antibodies directed towards antigens present on cell surfaces or extra cellular matrix
Eg blood transfusion reactions, rheumatic fever,
Describe and give examples of type 3 hypersensitivity
Antigen antibody complexes
Eg post strep glomerulonephritis
Sle , RA, serum sickness
Describe and give examples of type 4 hypersensitivity
Cell mediated
Eg transplant rejection, infectious contact dermatitis
Regarding cholera how does the toxin cause chloride secretion
The cholera toxin binds to epithelial cells
Opens CFTR channel that secretes chloride ions into the lumen
Massive Cl Na and HCO3 secretion
Osmotic H20 loss
Secretary diarrhoea
Which hormone is responsible for stimulating the acinar cells of the pancreas to release zymogen granules and pancreatic juice rich in enzymes?
CCK
What cells secrete CCK
Secreted by I cells in the mucous of the upper small intestine
What does CCK do/cause
Contraction of gall bladder
Stimulate acinar cells of pancreas to release pancreatic juice rich in enzymes
What cells produce Gastrin
Produced in G cells in the gastric antrum
What does Gastrin do / stimulate
Stimulation of gastric acid and pepsin secretion, growth of mucosa in stomach and large intestine , gastric motility
What type of laxative is docusate
Stool softener
Main mechanism of action of gliclazide
A sulfonylurea
Stimulating release of performed insulin from pancreatic islet cells
Examples of first and second generation sulfonylureas
1st - tolbutamide
2nd - glipizide glimipiride
Adverse effects of sulfonylureas
Hypoglycaemia
Flushing with alcohol
Dlutional hyponatraemia
Where is glucose maximally absorbed
Jejunum
Shoulder addiction myotome
C7/C8
Finger abduction myotome
T1
Elbow extension myotome
C7
Finger extension myotome
C7
Finger abduction myotome
T1
A weak acid is defined as
A neutral melecule that can reversibly dissociate an anion with a proton
What are on the axis of frank starling curve
Stroke volume ml
LV end diastolic pressure mmHg
Pathology of Graves’ disease
Type II hypersensitivity reaction
Autoantibodies to TSH receptors in the thyroid
Treatment for sulfonylurea induced hypoglycaemia
Octreitide
It inhibits insulin secretion
Central cord syndrome neurological findings
Variable loss of touch sensation with loss motor function in upper limbs > lower limbs
What is benztropine
A centrally acting anti muscarunic in Parkinson’s
How is bilirubin delivered to the liver
Bound to serum albumin
Which class of organisms is most sensitive to chlorhexidine
Gram positive cocci
ICF contributes to what % of total body weight and what % of total body water
40% total body weight
66% total body water
ECF contributes to what % total body weight and what % of total body of water
20% total body weight
33% total body of water
Type of hypersensitivity for post strep glomerulonephritis
Type 3
What organism causes post strep glomerulonephritis
Group A strep
Mechanism of action of digoxin
Inhibits action of Na/K ATPase pump
This increases sodium in the cell
Causing the sodium calcium channel to not bring Na in or move Ca out
So intracellular Ca increases
Increases contractility
Positive inotrope
Also increases vagus nerve supply to heart - negative chronotrope
Pharmacokinetics of digoxin
65-89% orally absorbed
Poorly lipid soluble
Widely distributed including to CNS
NOT extensively metabolised
2/3 excreted by kidneys
Half life 60 hrs
What two cell types are in the adrenal medulla
Adrenaline secreting 90%
Noradrenaline secreting 10%
What cells release renin
Juxtaglomerular cells
When is renin released and where does it go/what does it do
Released with low BP
Travels to the liver
Converts angiotensinogen to angiotensin I
What does angiotensin II do to the cns
Causes posterior pituitary to secrete ADH (vasopresssin) which causes water retention in collecting ducts
Also creates thirst
What does angiotensin II do to the adrenal gland
Causes aldosterone release from zona glomerulosa in the adrenal cortex
This increases Na and H2O reabsorption in the DCT
What does angiotensin II do to the kidneys
Causes vasoconstriction in efferent arteriales > afferent arterioles
Increases GFR
What inhibits renin
Increases pressure within the afferent arterioles
What are the vitamin k dependent clotting factors
II VII IX X
Attachment actions and innervation of superior rectus
Originated from superior part of the common tendinous ring
Attaches to the superior and anterior aspect of sclera
Main movement is elevation.
Also contributes to adduction and medial rotation
CN III
Attachments action and innervation of inferior rectus
Originates from the inferior part of the common tendinous ring
Attaches to inferior and anterior aspect of sclera
Main movement is depression
Contributed to addiction and lateral rotation
CN III
Attachment action and innervation of medial rectus
Originates from medial part of common tendinous ring
Attaches to antereromedial aspect of the sclera
CN III
Attachment action and innervation of lateral rectus
Originates from the lateral part of the common tendinous ring
Attaches to anterolateral aspect of sclera
Abducts the eye ball
CN VI abducens
Attachments action and supply of superior oblique
Originates from body of the sphenoid bone
Depress abducts and Medially rotates eyeball
Innervated by trochlear nerve CNIV
Attachments actions and innervation of inferior oblique
Originates from anterior aspect of orbital floor
Elevated abducts and laterally rotates the eyeball
Innervation CN III
What part of the heart is not on the posterior surface
Right ventricle
A complication of hydralazine
Can cause sle in 10-20% patients
In pacemaker cells what happens at phase 4
Funny current ion channels open
Conduct slow inward Na current
In pacemaker cells in phase 4 what happens at -50mV
Transient T type Ca channels open
In pacemaker cells what happens in phase 4 at -40mV
Second type of L type Ca channel opens
More calcium enters cell until action potential reached at -30mV
In pacemaker cells what happens phase 0
Influx of calcium through L type Ca channels
In pacemaker cells what happens at phase 3 of the cycle
K channels open and k moved out of the cell
Ca channels close
At end slow inward Na funny channels open
