Clinical Sciences Flashcards
5 Factors stimulating renin secretion
hypotension causing reduced renal perfusion
hyponatraemia
sympathetic nerve stimulation
catecholamines
erect posture
Factors reducing renin secretion
drugs: beta-blockers, NSAIDs
Actions of Angiotensin II
stimulates thirst(via the hypothalamus)
stimulates aldosterone and ADH release
increases proximal tubule Na+/H+activity
causes vasoconstriction of vascular smooth muscle leading to raised blood pressure and vasoconstriction of efferent arteriole of the glomerulus→ increased filtration fraction (FF) to preserve GFR.
Remember that FF = GFR / renal plasma flow
Actions of Aldosterone
released by the zona glomerulosa in response to raised angiotensin II, potassium, and ACTH levels
causes retention of Na+ in exchange for K+/H+ in distal tubule
elfin-like facies
characteristic like affect - very friendly and social
learning difficulties
short stature
transient neonatal hypercalcaemia
supravalvular aortic stenosis
Features of
William’s syndrome
William’s syndrome is an inherited neurodevelopmental disorder caused by a microdeletion on chromosome ….
chromosome 7
Fatty casts associated with
Nephrotic syndrome
Waxy casts associated with
Advanced chronic kidney disease
Epithelial casts associated
Acute tubular necrosis
White blood cell casts associated
Acute pyelonephritis
Interstitial nephritis
Red blood cell casts associated with
Glomerulonephritis
Renal ischaemia and infarction
Hyaline casts
Common and non-specific
May be seen following exercise or dehydration
Formula of Sensitivity
TP / (TP + FN )
Specificity formula
TN / (TN + FP)
Positive predictive value
TP / (TP + FP)
Negative predictive value
TN / (TN +FN)
Likelihood ratio for a positive test result
sensitivity / (1 - specificity)
Likelihood ratio for a negative test result
(1 - sensitivity) / specificity
Which sleep stage is stage be associated with hypnic jerks?
Non-REM stage 1 (N1)
In which sleep stage, Dreaming occurs
Loss of muscle tone, erections
REM stage
EEG & sleep stages
N1 → N2 → N3 → REM
Theta →Sleep spindles/K-complexes →Delta →Beta
TheSleepDoctor’sBrain
- ghrelin stimulates
- ghrelin stimulates hunger
Noonan syndrome is an autosomal ………..condition associated with ………. karyotype.It is thought to be caused by a defect in a gene on chromosome …..
Noonan syndrome is an autosomal dominant condition associated with a normal karyotype.
chromosome 12
characteristic clinical signs may also be seen in Noonan syndrome
pulmonary valve stenosis
ptosis
triangular-shaped face
low-set ears
coagulation problems: factor XI deficiency
Causes of metabolic alkalosis
Vomiting
diuretics
liquorice,carbenoxolone
hypokalaemia
primary hyperaldosteronism
Cushing’s syndrome
Bartter’s syndrome
Interferon-alpha
1. bind to type …. receptors
- produced by ……….
- useful in …….
- bind to type 1 receptors
- produced by leucocytes
- useful in hepatitis B & C, Kaposi’s sarcoma, metastatic renal cell cancer, hairy cell leukaemia
Interferon-beta
- bind to type ………. receptors
- produced by ……….
- reduces the frequency of ………
- bind to type 1 receptors
- produced by fibroblasts
- reduces the frequency of exacerbations in patients with relapsing-remitting MS
Interferon-gamma
- binds to type ….. receptors.
- Produced by ……
- may be useful in ……….
- binds only to type 2 receptors.
- Produced by natural killer cells and T helper cells
- may be useful in chronic granulomatous disease and osteopetrosis
Achondroplasia is an autosomal ………..disorder associated with short stature. It is caused by a mutation in ………
Achondroplasia is an autosomal dominant disorder associated with short stature. It is caused by a mutation in the fibroblast growth factor receptor 3 (FGFR-3) gene.
There are two main causes of ATN
- ischaemia
- shock
- sepsis
- nephrotoxins
- aminoglycosides
- myoglobin secondary to rhabdomyolysis
- radiocontrast agents
- lead
tubular epithelium necrosis: loss of nuclei and detachment of tubular cells from the basement membrane
dilatation of the tubules may occur
necrotic cells obstruct the tubule lumen
Histopathological Features of….
ATN
Phases of ATN
oliguric phase
polyuric phase
recovery phase
pigmented sclera
urine turns black if left exposed to the air
intervertebral disc calcification may result in back pain
renal stones
Features of……?
Alkaptonuria
Treatment of Alkaptonuria
high-dose vitamin C
dietary restriction of phenylalanine and tyrosine
Alkaptonuria (ochronosis) is a rare autosomal …… disorder of ……….. metabolism caused by a lack of the enzyme ……….. which results in a build-up of toxic homogentisic acid.
Alkaptonuria (ochronosis) is a rare autosomal recessive disorder of phenylalanine and tyrosine metabolism caused by a lack of the enzyme homogentisic dioxygenase (HGD) which results in a build-up of toxic homogentisic acid.
ADH promotes water reabsorption in ………….of the kidneys by theinsertion of ……….
promotes water reabsorption in the collecting ducts of the kidneys by the insertion of aquaporin-2 channels.
drugs should be avoided during breastfeeding
antibiotics:ciprofloxacin,tetracycline, chloramphenicol,sulphonamides
aspirin
amiodarone
benzodiazepines , lithium
carbimazole
cytotoxic drugs
clozapine
methotrexate
sulfonylureas
Actions of parathyroid hormone
increases plasma calcium, decreases plasma phosphate
- increases renal tubular reabsorption of calcium
- increases osteoclastic activity*
- increases renal conversion of 25-hydroxycholecalciferol to 1,25-dihydroxycholecalciferol
- decreases renal phosphate reabsorption
Actions of 1,25-dihydroxycholecalciferol
- increases plasma calcium and plasma phosphate*
- increases renal tubular reabsorption and gut absorption of calcium
- increases osteoclastic activity
- increases renal phosphate reabsorption
osteoclasts don’t have …… receptors
PTH receptors
Calcitonin
- Secreted by …….
- Inhibits ……….
- Inhibits………..
- Secreted by C cells of thyroid
- Inhibits osteoclast activity
- Inhibits renal tubular absorption of calcium
Factors which increase pulse pressure
less compliant aorta (this tends to occur with advancing age)
increased stroke volume
The cerebral perfusion pressure (CPP) =
CPP= MAP - ICP
Non-modifiable Risk factors for developing diabetic nephropathy
- Male sex
- Duration of diabetes
- Genetic predisposition (e.g. ACE gene polymorphisms
Regulation of growth hormone
Increases secretion by ……
sleep (particularly delta sleep)
exercise
Fasting
*SEF
Regulation of growth hormone
Decreases secretion by ……
glucose
somatostatin
American College of Rheumatology guidelines recommend a temporal artery biopsy if:
- Age of onset older than 50 years
- New-onset headache or localized head pain
- Temporal artery tenderness to palpation or reduced pulsation
- ESR > 50 mm/h
Contraindication of temporal artery biopsy
Glucocorticoid therapy > 30 days
Vitamin K acts as a cofactor in the carboxylation of clotting factors ……
II, VII, IX, X
- 1972
failure to thrive
normal serum calcium, low phosphate, elevated alkaline phosphotase
x-ray changes: cupped metaphyses with widening of the epiphyses
Features of….
Vitamin D-resistant rickets
Vitamin D-resistant rickets, Diagnosis is made by
increased urinary phosphate
Management of Vitamin D-resistant rickets
high-dose vitamin D supplements
oral phosphate supplements
Vitamin D-resistant rickets is inherited in
X-linked dominant
Features vitamin C deficiency
gingivitis, loose teeth
poor wound healing
bleeding from gums, haematuria, epistaxis
general malaise
Consequences of vitamin B6 deficiency
peripheral neuropathy
sideroblastic anemia
Consequences of niacin deficiency:
pellagra: dermatitis, diarrhoea, dementia
Consequences of ( B2) riboflavin deficiency:
angular cheilitis
Conditions associated with thiamine deficiency
- Wernicke’s encephalopathy:nystagmus, ophthalmoplegia and ataxia
- Korsakoff’s syndrome:amnesia, confabulation
- dry beriberi: peripheral neuropathy
- wet beriberi: dilated cardiomyopathy
What is a measure of the spread of scores away from the mean.
Variance
Variance = ……?
Variance = square of standard deviation
3 Indications for surgery in secondary (renal) hyperparathyroidism:
Soft tissue calcifications
Bone pain
Persistent pruritus
*SPP = 2ry hyperparathyroidism
2ry : Soft tissue calcifications
Hy(p)er(p)arathyroidism P2: pain & pruritus
8 Primary hyperparathyroidism
Indications for surgery
- Creatinine clearance < 30% compared with normal
- Hypercalciuria > 400mg/day
- Elevated serum Calcium > 1mg/dL above normal
- Episode of life threatening hypercalcaemia
- Neuromuscular symptoms
- Age < 50 years
- Osteoporosis
- Nephrolithiasis
Homocystinuria is a rare autosomal …………. disease caused by adeficiency of …………………
Homocystinuria is a rare autosomal recessive disease caused by adeficiency of cystathionine beta synthase.
Investigations of Homocystinuria
increased homocysteine levels in serum and urine
cyanide-nitroprusside test: also positive in cystinuria
Treatment of Homocystinuria
Treatment is vitamin B6 (pyridoxine)supplements.
ocular features of Homocystinuria
downwards (inferonasal) dislocation of lens
severe myopia
learning difficulties
large low set ears, long thin face, high arched palate
macroorchidism
hypotonia
autism is more common
mitral valve prolapse
Features of…….
Fragile X syndrome, Features in males
Diagnosis of Fragile X syndrome
can be made antenatally by chorionic villus sampling or amniocentesis
analysis of the number of CGG repeats using restriction endonuclease digestion and Southern blot analysis
Drugs which interfere with folate metabolism
trimethoprim
methotrexate
pyrimethamine
Drugs which can reduce folate absorption
phenytoin
Fabry disease is inherited in…….1….
& deficiency of ……2……
1.X-linked recessive
- alpha-galactosidase A
burning pain/paraesthesia in childhood
angiokeratomas
lens opacities
proteinuria
early cardiovascular disease
Features of…..?
Fabry disease
the kidney receives up to …?……% of resting cardiac output
up to 25% of resting cardiac output
The thin ascending limb of the loop of Henle is impermeable to …..
water
Phases of Cardiac action potential
0 : Rapid Na influx
1: K efflux
2: slow Ca influx
3: K efflux
4: Resting potential is restored by Na+/K+ATPase
DiGeorge syndrome is a primary immunodeficiency disorder caused by……
deletion of a section of chromosome ……..
T-cell deficiency and dysfunction
chromosome 22
Features of DiGeorge syndrome
mnemonic CATCH22:
C -Cardiac abnormalities
A - Abnormal facies
T - Thymic aplasia
C -Cleft palate
H -Hypocalcaemia/ hypoparathyroidism
22 - Caused by chromosome 22 deletion
What is the commonest cause of Down’s syndrome
Nondisjunction. 94% of cases
Cardiac complications of Down’s syndrome
- VSD
- Secundum ASD
- tetralogy of Fallot
- isolated PDA
8 Later complications of Down’s syndrome
- subfertility
- learning difficulties
- short stature
- repeated respiratory infections(+hearing impairment from glue ear)
- acute lymphoblastic leukaemia
6.hypothyroidism
7. Alzheimer’s disease
8. atlantoaxial instability
Hirschprung’s disease is associated with
Down syndrome
Effects of nitric oxide
acts on guanylate cyclase leading to raised intracellular cGMP levels and therefore decreasing Ca2+ levels
vasodilation, mainly venodilation
inhibits platelet aggregation
What is the most common renal abnormality in Turner’s syndrome
horseshoe kidney
In Turner’s syndrome, There is also an increased incidence of autoimmune disease especially ………..
autoimmune thyroiditis and Crohn’s disease
Turner’s syndrome is denoted as…….
45,XO or 45,X.
Microtubules are found in all cells except ……
red blood cells.
Microtubules helpguide movement during
intracellular transport and also help bind internal organelles
dynein moves in
retrograde fashion, down the microtubule towards the centre of the cell (+ve → -ve)
kinesin moves in
anterograde fashion, up the microtubule away from the centre, towards the periphery (-ve → +ve)