Rubrospinal tract mediates flexor of the upper arm. Here is a way to remember these two postures and never forget again. Decerebrate has more “E” and more “R”. Extended upper limbs Rubrospinal tract transected (Red nucleus is above the level of lesion, i.e. below midbrain level) Decorticate has “COR”. Upper…
Category: PGMEE, MRCS, USMLE, MBBS, MD/MS
Medical knowledge in bullet points with understandable language, simplified images and graspable mnemonics.
PGMEE, MRCS, USMLE, MBBS, MD/MS 
15 “P”s of Lichen Planus
In your medical school, you must have heard about the 5 “P”s of Lichen planus representing the gross morphology of Lichen Planus. This 15 P mnemonic encompasses morphology, drug and other associations and histology of lichen planus. Morphology:PruriticPlanar (Flat-topped)PolygonalPurplePapulesPattern of white lines on papules (Wickham’s stria)Pterygium in nailsPhenomenon of Koebner…
PGMEE, MRCS, USMLE, MBBS, MD/MS 
HLA association mnemonics
The genes that encode HLA (Human Leukocyte Antigen) are on chromosome 6. MHC class Type Location Function I HLA-A, -B, -C All cells Recognized by CD8+ lymphocytes II HLA-DP, -DQ, -DR Antigen presenting cells Recognized by CD4+ lymphocytes III Complement components Plasma Chemotaxis, opsonization, lysis of bacteria and cells The…
PGMEE, MRCS, USMLE, MBBS, MD/MS 
Hypertensive Retinopathy Grading – Simplified
Hypertensive retinopathy has been classified by Keith, Wagener & Barker and Scheie (hypertensive and arteriosclerotic features). With this mnemonic, we will have a grading with combination of all these classifications. Mnemonic: SAFEs I – Slight Systemic (generalized) narrowing of arterioles II – AV deflection (at Angle) and focal narrowing of…
PGMEE, MRCS, USMLE, MBBS, MD/MS 
Visual cycle – Simplified
11-cis-retinal combines with opsin protein to form rhodopsin. Light stimulates conversion of rhodopsin bound 11-cis-retinal to all-trans-retinol (all-trans-retinol is transported from photoreceptor cells to retinal pigment epithelium), which subsequently dissociates from opsin (bleaching), leading to membrane depolarization and initiation of action potential in photoreceptors in the neural retina. Once in…
PGMEE, MRCS, USMLE, MBBS, MD/MS 
Differential Diagnoses of Bone Tumors : Mnemonic Approach
Lytic and Sclerotic Bone Lesions Mnemonic for Solitary lytic lesions: FEGNOMASHIC Fibrous dysplasia Enchondroma Eosinophilic granuloma Giant cell tumor Nonossifying fibroma Osteoblastoma, Osteosarcoma (telangiectatic) Metastases Myeloma Aneursymal bone cyst Simple bone cyst Hyperparathyroidism (brown tumor) Infection Chondroblastoma Chondromyxoid fibroma Mnemonic for Multiple lytic lesions: FEMHI Fibrous dysplasia Eosinophilic granuloma/Enchondroma Metastasis/Mutiple…
PGMEE, MRCS, USMLE, MBBS, MD/MS 
Errors and P-value
Statistical hypotheses Null hypothesis (H0): No difference or relation exists; e.g. Treatment A is not better than Treatment B Alternative or research hypothesis (H1): Some difference or relation exists, e.g. Treatment A is better than Treatment B Statistical errors Type I error (alpha): False positive (Falsely rejecting Null-hypothesis; i.e. null…
PGMEE, MRCS, USMLE, MBBS, MD/MS 
Baye’s theorem derived PPV and NPV
Let’s unveil the mathematics behind the relation between: Prevalence (Pre-test probability) Predictive value (Post-test probability) Sensitivity Specificity SYMBOLS: Total screened population = nPrevalence = PSensitivity = SnSpecificity = SpTrue positive = TPTrue negative = TNFalse positive = FPFalse negative = FNWith disease = D+Without disease = D-Positive predictive value =…