Cell-Cell Communication Flashcards
What are 4 main classes of receptors?
Whats the difference?
Endocrine- through bloodstream
Paracrine- from signalling cell to target cell, local mediator
Synaptic - neurone to neurone
Contact-dependent - membrane bound signal molecule
Gap junctions are examples of what kind of signalling?
Contact dependent
Gap junctions made out of what proteins?
Connexin
6 Connexin= hexameric channel
Embolic stroke
When blood clot that forms elsewhere in body breaks loose and travels to brain via bloodstream
What is atrial fibirllation?
Fast heart and irregular heart rate
Upper chamber beat out of syncronisation with lower chambers- chambers connected via connexin
Decreased expression of connexin can lead to what?
Atrial fibrillation/heart failure
What problems with connecin can lead to atrial fibirllation?
Decreased number
Normal but mutated form so decreased channel activity
Change in connexin localisation (change place)
Lead to less functional channels , lower transfer of ions along length of fibres
Symptoms of Charcot Marie Tooth Neuropathy
Muscle weakness in feet, ankles and legs Feet high arched, make ankle unstable Or very flat feet Curled toes (hammer toes) Gait problems in infancy or later in childhood Awkward way of walking Reflexes lost at ankles and knees
What is Charcot Marie Tooth Neuropathy
Group of inherited conditions that damage the peripheral nerves
Causes for LQTS (Long QT syndrome)
Decrease in repolarising cardiac membrane currents or increase in depolarising cardiac currents late in cardiac cycle
Delayed repolarisation due to reduction in K+ current channels
Prolonged depolarisation due to small persistent inward “leak” in cardiac sodium current
Cholera symptoms
Severe water loss
Vomiting
Muscle Cramps
receptor tyrosine kinase
Adds phosphate to tyrosine
