Capture or Tethering Increased vascular permeability and vasodilation are mediated by inflammatory mediators like histamine released by inflammatory cells in response to PAMPs expressed by pathogens. Hemoconcentration (owing to increased vascular permeability) and decreased velocity of blood flow (owing to vasodilation) leads to peripheral pooling of the leukocytes (i.e. towards…
Tag: General concepts
PGMEE, MRCS, USMLE, MBBS, MD/MS 
Amino Acids Mnemonics
What are amino acids ? Amino acids are molecules containing: An amine group A carboxylic acid group A side chain that varies between different amino acids Assign the names of these amino acids to 20 different alphabets The technique that you are going to use to remember all these are given…
PGMEE, MRCS, USMLE, MBBS, MD/MS 
VDJ (Somatic) Recombination Made Easy
Many students feel that, this is one of the most difficult to explain topic in Immunology. Here, we will try to explain the process and clinical relevance of V(D)J or Somatic recombination in simple and interactive way. Question your mind Humans only have about 25,000 genes. Since, an antibody made…
PGMEE, MRCS, USMLE, MBBS, MD/MS 
Cell Cycle Made Easy
Stages of Cell Cycle Interphase Mnemonic: Go Sally Go! Make Children 1. G1 phase 2. S phase 3. G2 phase 4. Mitosis 5. Cytokinesis 1. G1 (Gap 1) phase: Early and late phase divided by Restriction (R) point Functions: Preparation for DNA replication (synthesis of replication proteins cyclin D) Thymidine…
PGMEE, MRCS, USMLE, MBBS, MD/MS 
Apoptosis Made Easy
Definition of Apoptosis Apoptosis is: Origin of the word “apoptosis”: Caspases – Central Regulators of Apoptosis Caspases = Cysteine Aspartate Specific Proteases 2 types of caspases: Initiator caspases: Executioner caspases: 3 Pathways of Caspase Activation 1. Activation of Initiator of Extrinsic Pathway Receptor-ligand interaction mediated: Can mediate intrinsic (mitochondrial) pathway…
PGMEE, MRCS, USMLE, MBBS, MD/MS 
Cellular Adaptations
Hypertrophy, Hyperplasia, Atrophy and Metaplasia are the main four types of cellular adaptations. Adaptations are: Reversible changes In the number, size, phenotype, metabolic activity or functions of cells In response to the changes in the environment (stress). Hypertrophy Definition: Increase in cell size Occurs in: non-dividing (permanent) cells: cardiac and…
PGMEE, MRCS, USMLE, MBBS, MD/MS 
Complement Pathway – Explained
The complement system is composed of about 20 different proteins released into the blood after production in the liver. They interact in coordinated and regulated way to produce biologically active protein products. ACTIVATION OF COMPLEMENT CASCADE The complement cascade can be activated in 3 ways: C3 and C3 CONVERTASE All of…
PGMEE, MRCS, USMLE, MBBS, MD/MS 
Electron Transport Chain (ETC) and Oxidative Phosphorylation : Mnemonic
General concepts of ETC and Oxidative Phosphorylation: 1. Occurs in cell cytosol: Glycolysis 2. Occurs in mytochondrial matrix: Kreb’s (TCA) cycle 3. Occurs in mitochondrial inner membrane: ETC – Stepwise movement of electrons from high energy to low energy that activates proton pump which transports proton from the mitochondrial matrix to mitochondrial inter-membrane and…