Other Flashcards
What is the lymphatic drainage of the vagina?
Superior aspect of the vagina - internal and external iliac nodes
Inferior aspect of the vagina - superficial inguinal nodes
Where do tumours of the uterine body metastasise to? As in, which nodes?
External Iliac lymph nodes
What type of hypersensitivity reaction is a organ rejection over years and what cell mediates this?
Type IV hypersensitivity
T lymphocyte mediated
When HLA typing for renal transplant, which are the most important antigens?
DR > B > A
What is the mechanism of action of neostigmine?
They prolong the action of acetylcholine by inhibiting the action of the enzyme acetylcholinesterase
Features of MEN IIB
Medullary thyroid cancer
Phaeochromocytoma
Mucosal neuroma
Marfanoid appearance
Features of Gardner’s syndrome
AD disorder
Mutation of APC gene located on chromosome 5
Colonic polyps (FAP)
Supernumerary teeth
Jaw and skull osteomas
Congenital hypertrophy of retinal pigment.
Papillary Thyroid cancer
Epidermoid cysts, fibromas and sebaceous cysts
How does tranexamic acid work?
Antifibrinolytic
Competitively inhibits the activation of plasminogen to plasmin
Prevents fibrin degradation
What type of tumour causes hypervascular metastases?
Renal cell carcinoma
What substance is commonly used to sterilize endoscopic equipment?
Glutaraldehyde solution
Also used for laparoscopic equipment
What type of biopsy is used for a suspected lymphoma?
Excision biopsy
Define metaplasia
Conversion to a different cell type
Eg Gastric mucsoa in the duodenum
What are the symptoms of Wernicke encephalopathy?
Triad of ophthalmoplegia, acute confusion and ataxia
Marfan’s disease is due to a defect on the gene for which protein?
Fibrillin
Features of a giardia infection
Abdominal pain
Diarrhoea - floats as fat not absorbed
Bloating
Resistant to chlorination so found in swimming pool
What skin lesion has the following characteristics:
Solitary dermal nodules
Usually affect extremities of young adults
Lesions feel larger than they appear visually
What is their histology?
Dermatofibroma
Histologically they consist of proliferating fibroblasts merging with sparsely cellular dermal tissues
What is Choanal atresia?
Congenital disorder where posterior nasal airway occluded by soft tissue or bone.
Babies with unilateral disease may go unnoticed.
Presents with episodes of cyanosis during feeding, which improve when the baby cries
They can only breathe through their mouth
What is the Koebner phenomenon?
It describes skin lesions which appear at the site of injury. It is seen in:
Psoriasis
Vitiligo
Warts
Lichen planus
Lichen sclerosus
Molluscum contagiosum
What type of immunoglobulin is responsible for hyperacute organ rejection?
IgG - antibody mediated
What type of ulcer base is heaped up?
SCC - Marjolin’s ulcer
What causes hydatid cyst?
Tapeworm parasite Echinococcus granulosus
What is the medical management of hydatid cysts?
Albendazole or mebendazole.
Praziquantzel in pre-operative stages
What are the radiological features of achondroplasia?
Large skull with narrow foramen magnum
Short, flattened vertebral bodies
Narrow spinal canal
Horizontal acetabular roof
Broad, short metacarpals
What is the mechanism of action of glucocorticoids?
By binding to intracellular receptors that are then transported to the nucleus where they affect gene transcription
What cancers are associated with EBV?
Burkitt’s lymphoma
Hodgkin’s lymphoma
Post transplant lymphoma
Nasopharyngeal carcinoma
What oesophageal malignancy is associated with achalasia?
SCC
What are Burton’s lines?
Blue lines on gum, indicative of lead poisoning
Acute intermittent porphyria is due to deficiency in what enzyme?
Porphobilinogen deaminase
What are the symptoms of acute intermittent porphyria?
Abdominal: Abdo pain, vomiting, constipation
Neurological: motor neuropathy
Psychiatric: depression
Autonomic: hypertension, tachycardia
Dark red urine
What sort of genetic inheritance is acute intermittent porphyria?
Autosomal dominant
What sort of genetic inheritance is achondroplasia?
Autosomal dominant
What is seen on histology for actoinomycosis?
Gram positive organisms with sulphur granules
What cells make up the islets of langhans and what do they secrete?
Beta cells - insulin
Alpha cells - Glucagon
Delta cells - somatostatin
F cells - pancreatic polypeptide
Causes of hypomagnaesaemia
Diuretics
Total parenteral nutrition
Diarrhoea
Alcohol
Hypokalaemia, hypocalcaemia
What is the half life of insulin?
<30 mins
What is seen on microscopic evaluation of amyloid tissue?
birefringence under polarised light
What is the commonest cause of filariasis (elephantiasis)?
Wuchereria bancrofti
What type of cancer is linked to working with PVC (vinyl chloride)?
Hepatic angiosarcoma
Causes of oxygen dissociation curve moving left?
Increased affinity for oxygen
Due to decreased oxygen requirement by the tissue such as
1. Alkalosis
2. Hypothermia
3. Reduced levels of DPG
4. Polycythaemia
5. HbF
What is the Bohr effect?
Hemoglobin’s oxygen binding affinity is inversely related both to acidity and to the concentration of carbon dioxide
i.e. a decrease in carbon dioxide provokes an increase in pH, which results in hemoglobin picking up more oxygen.
and an increase in CO2 provokes a decrease in pH and subsequent decrease in oxygen affinity
Causes of decreased oxygen binding affinity?
Increased CO2
Increased H+ (lower pH)
Increased DPG
Increased temp
What receptors does ondansetron act on?
5HT3 chemoreceptor of the area postrema (medulla oblongata)
What are popcorn cells?
They are a variant of reed sternburg cells that are seen in nodular lymphocyte predominant hodgkins lymphoma.
They appear as a hyper nodulated nucleus with a small nucleoli
What are the 5 parts of the JVP waveform?
Upwards
A - atrial contraction (missing in AF)
C - ventricular contractionand tricuspic closure
V - atrial filling
Downwards
X - atrium relaxes and tricuspid moves down
Y - ventricular filling/atrial emptying
Why does hyperventilation lead to circumoral parasthesia and muscular twitching?
Hyperventilation -> Respiratory alkalosis -> lowers ionised calcium levels
What substance is released from the sympathetic nervous system to stimulate the adrenal medulla?
Acetylcholine
What sort of gene is p53 and where is it located?
Tumour suppressor gene located on chromosome 17
What is the formula for mean arterial pressure?
MAP = DP + 1/3(SP – DP)
What is the formula for systemic vascular resistance?
SVR = ((MAP-CVP)/CO ) x80
Which cell type is the only one to not have mitochondria?
Erythrocyte
How do erythrocytes generate energy?
Glycolytic pathways
What amino acids are collagen made up by?
Glycine and prolene
What are the 3 main features of MENII
Medullary thyroid cancer
Hyperparathyroidism (hypertrophy)
Phaeocromocytoma
Which factors are affected by warfarin?
II, VII, IX, X and protein C
What are the 2 classes of potassium sparing diuretics and where do they act in the kidney?
Aldosterone antagonists eg spironolactone and eplerenone
Epithelial sodium channel blockers eg amiloride and triamterene
Collecting ducts
What cells secrete pepsinogen?
Chief cells
What factors increase and decrease renin secretion?
Increase:
Catecholamines
Erect posture
Sympathetic nerve stimulation
Hypotension
Hyponatraemia
Decrease:
NSAIDs
Beta blockers
What factors cause release of glucagon from alpha cells in the islets of langherhans?
Decreased plasma glucose
Increased catecholamines
Increased plasma amino acids
Sympathetic nervous system
Acetylcholine
Cholecystokinin
What are the ECG features of hypokalaemia?
U waves
Small or absent T waves (occasionally inversion)
Prolonged PR interval
ST depression
Long QT interval
Which infectious organism demonstrates both worms and eggs within faeces? What are other features of it?
Ascaris lumbricoides
No anal pruritus
Sub-saharan africa or asia
What parasitic organism causes anal pruritus?
Enterobius vermicularis
What renal condition is associated with muddy brown casts and increasing creatinine?
Acute tubular necrosis
What substances are tested for in blood and urine for carcinoid syndrome?
Blood - chromogranin A, neuron-specific enolase (NSE), substance P, and gastrin
Urine - 5 HIAA (metabolite of serotonin)
Features of keratoacanthoma
Rapid growing dome shaped erythematous lesion
Central keratin which begins to necrose and slough off
Where does aldosterone act on the nephron?
Distal convoluted tubule and collecting duct
Where does parathyroid hormone act on the nephron?
Proximal and distal convoluted tubule
How do thiazide diuretics work?
Inhibits the reabsorption of sodium in the distal convoluted tubule.
Examples incude bendroflumethiazide, chlortalidone, cyclopenthiazide, indapamide and xipamide.
Where does furosemide act on the nephron? And how does it work?
It acts on the sodium/potassium/chloride co-transporter on the thick ascending loop of henle
What hormone inhibits ADH?
Anti natriuretic peptide release from stretched cardiac atria due to increased BP
What is the action of ADH?
Increases aquaporin 2 channels in collecting ducts and therefore water reabsorption
What is the equation to for anion gap? And what is the normal anion gap?
(Na+ + K+) - (Cl- + HCO3-)
10-18 mmol/L
What are the causes of a normal anion gap acidosis?
Hyperalimentation/hyperventilation
A - Acetazolamide
R - Renal tubular acidosis
D - Diarrhoea
U - Ureteral diversion
P - Pancreatic fistula/parenteral saline
What amino acids are catecholamines derived from?
Tyrosine
What drugs impair wound healing?
Drugs: NSAIDs, chemotherapy, steroids, immunosuppressive drugs
What non drug factors impair wound healing?
D iabetes
I nfection, irradiation
D rugs eg steroids, chemotherapy
N utritional deficiencies (vitamin A, C & zinc, manganese), Neoplasia
O bject (foreign material)
T issue necrosis
H ypoxia
E xcess tension on wound
A nother wound
L ow temperature, Liver jaundice
What is the thin bluish - white margin that appears around a skin graft about a week later? At what rate does this process occur?
Re-epithelialisation
1mm/day
What cell type is associated with desmoid tumours?
Myofibroblasts
Name a type of anthracycline and describe their mechanism of action
Doxorubicin and epirubicin
Inhibits DNA and RNA synthesis by intercalating base pairs
When performing minor surgery in the scalp, which of the following regions is considered a danger area as regards spread of infection into the CNS? And why?
Loose connective tissue
Contains emissary veins which pass intracranially
What factors can cause a falsely elevated 5-HIAA 24 hours urinary level?
Food: spinach, cheese, wine, caffeine, tomatoes
Drugs: Naproxen, Monoamine oxidase inhibitors
Recent surgery
What is the correct diagnostic investigation for suspected lymphoma in the context of axillary lymphadenopathy?
Excision biopsy of lymph node
What are the features of Li-Fraumeni Syndrome?
Autosomal dominant
Due to germline mutations to p53 tumour suppressor gene
Sarcomas and leukaemias
What is plexiform neurofibroma?
A hallmark finding of neurofibromatosis type 1.
A sheet of neurofibromatosis tissue encases major nerves which attracts extra blood circulation and can accelerate growth of the affected limb
What is the mechanism of action of glucocorticoids?
binding intracellular receptors that are then transported to the nucleus where they affect gene transcription
How do catecholamines work?
Increasing cAMP levels by adenylate cyclase stimulation. This increases intracellular calcium ion mobilisation and thus the force of contraction.
What are the effects of binding to the following cell receptors:
a1 and a2
B1
B2
D1
D2
a1 and a2 - vasoconstriction
B1 - increased cardiac contractility and HR
B2 - vasodilatation and bronchodilation
D1 - renal and spleen vasodilatation
D2 - inhibits release of noradrenaline
What receptors do the following drugs act on:
Adrenaline
Noradrenaline
Dobutamine
Dopamine
Adrenaline - a1, a2, B1, B2
Noradrenaline - a1
Dobutamine - B1
Dopamine - D1, D2
What happens to cardiac output and systemic vascular resistance during hypovolaemia?
Cardiac output - Low
Systemic vascular resistance - High
What factors mediate vasodilation?
histamine
prostaglandins
nitric oxide
platelet activating factor
complement C5a (and C3a)
lysosomal compounds
What are the effects of cholecystokinin?
Increases secretion of enzyme-rich fluid from pancreas
Contraction of gallbladder and relaxation of sphincter of Oddi
Decreases gastric emptying
Trophic effect on pancreatic acinar cells
Induces satiety
What medicine is used to treat carcinoid syndrome?
Octreotide
What is Kartagener’s syndrome?
Triad of situs invertus, chronic sinusitis and bronchiectasis
The primary problem is of immotile cilia
What blood test is diagnostic of EBV infection?
EBV causes infectious mononucleosis
It is tested for with Paul Bunnell test
What condition are elliptical cells associated with?
Hereditary spherocytosis
What skin condition is glucagonoma associated with?
necrolytic migratory erythema
What are asteroid bodies indicative of?
sarcoidosis
Which 2 types of bacteria are most likely to cause a liver abscess?
E.coli
Klebsiella pneumoniae
Both are gram -ve rods
What is inulin used for?
To estimate glomerular filtration rate
What substance is used to determine renal plasma flow?
Para-amino hippuric acid
What paraneoplastic syndrome is seen with squamous cell carcinoma of the lung?
Hyperparathyoidism
Ca High
PTH High
PO4 low
What is the histological composition of a hamartoma?
A combination of cartilage, connective tissue, smooth muscle, fat, and respiratory epithelium
What virus is associated with Kaposi’s sarcoma?
Human herpes virus 8
What is the effect of beta blockers on insulin release?
Inhibits release of insulin
