There are three types of  ion channels in cells of human body. They are as follows: 1. Ungated Ion Channels or leak channels     These channels are always open and there is free diffusion of ions through these channels along the concentration gradient of the ions. Leak channels are responsible for maintenance of Resting membrane potential of a cell. 2. Voltage gated Ion Channels Voltage gated ion channels respond to the change in resting membrane potential of the cell. These channels either open or close based on the voltage of the resting membrane potential. 3. Ligand gated ion channels These ion channels have a additional binding site for ligands and open or close based on weather the ligand is attached or not. Ligands act as keys and the channels act as locks.   A receptor can act as one of the types. NMDA receptor is an exception. NMDA receptor can act both as voltage gated and ligand gated channel.

  X-ray : basic interpretation X rays are one of the most frequently requested investigations and their interpretation is one of the fundamental skills of every doctor. In this blog series, we look into the basic interpretation of chest x-ray. If you have no or little knowledge regarding the interpretation of x rays   then it will give you a solid foundation upon which you can build your further knowledge. figure. x-ray source, detector, patient in between less dense like air=black,  more dense like bones=white,  moderate dense like water=grey   parts of the film -                 where x ray struck: black     where x rays are blocked/ no x ray struck: white     where some amount of x ray struck: shade of grey spectrum: radiolucent to radiopaque ( air, fluid, and soft tissue, bone, metal) there are 3 types of views for x ray:  ·         anteroposterior or AP view is used in bed-ridden patients who are unable to stand. AP view magnifies the size of the heart and medias

  Syncope An abrupt loss of consciousness or loss of postural tone which is of short duration and is followed by spontaneous recovery is known as syncope.  There are four components of syncope An abrupt and transient loss of consciousness  Loss of postural tone Short Duration Spontaneous recovery Prodrome A constellation of symptoms like lightheadedness, diaphoresis, visual distrubances that can  precede the loss of consciousness. Prodrome can last for several seconds to minutes.     Chest pain, palpitations or dyspnea point to cardiac cause     Aura , Headache, Dysarthia, and limb weakness point to CNS causes Pre-syncope Occurance of prodromal symptoms of syncope without the subsequent loss of consciousness is known as pre-syncope. During Attack Is there a pulse? Limb jerking, Tongue biting, Urinary Incontinence? Hypoxic Seizures After Attack Rapid recovery: Arrythmia, VAsovagal syncope Prolonged, with drowsiness: Seizures Questions to Ask of a Patient presenting with syncope What wa