Lecture 3 Flashcards
sensory stimulus
activation of cutaneous mechanoreceptors by skin deformation
neural code
action potential, post-synaptic potential
interpretation/action
flexor withdrawal reflec
extracellular and cytosolic fluid
-neurons are in an extracellular milieu that is water-based
-ions: atoms or molecules with a net electrical charge
the concentration gradient is the product of:
- the imermeability of the plasma membrane to the movement of ions
- the presence of proteins that maintain actively the gradient of concentration
- the presence of proteins that allow ions to passively cross the membrane (into or out of the cell)
ion channels
control of resting and action potentials
receptors-channels
neurotransmitters and post-synaptic potentials
metabotropic receptors
neurotransmitters and neuromodulators
ion pumps
-producers of electrochemical gradients
-formed by transmembrane proteins
-catalyze ATP for energy (active transport)
-push ions against the concentration gradient (from more diluted to concentrated)
-produces the ion concentration gradients (neuronal signaling)
proteins-channels
-voltage dependent
-polar R groups
-non polar R groups
-transmembrane domains
-ion selectivity
-mechanism of activation (gating)
Na/K ATPase ion exchange pump
-catalyze ATP into ADP
-drives 3 Na+ out, brings 2 K+ in
-forms a concentration gradient of more Na outside and more K inside
K+ equilibrium potential
-80mV
Na+ equilibrium potential
62mV
Ca2+ equilibrium potential
123mV
Cl- equilibrium potential
-65mV