L.1 Flashcards
(22 cards)
What are the parts of nerve cells
Cell body
Dendrites
Axon
Ions can move in three different ways mention them ?
Diffusion
Active transport
Facilitated diffusion
What makes the membrane potential of nerve
Voltage difference across the membrane
What is the value of resting membrane potential
-60 to -80
The resting membrane potential value is close to ………
Ek+ and Ecl-
What are the types of ion channels
Voltage gated
Ligand gated
Mechanosensitive
What is the value needed to initiate an action potential
15+ mv
Voltage gated Na+ channels and voltage gated K+ channels cause what ?
K+ channels cause repolarisation
Na+ channels cause depolarisation
In the absolute refractory period what happen to the gates ? Both Na+ and K+
Na+ inactivated
K+ open
In the relative refractory period what happen to the gates ? Both Na+ and K+
Both are closed
What are the functions of myelin ?
- increase the speed of conduction
-Trap the positive charges inside the cell which lead to Saltatory conduction
What are the glial cell that produce myelin in PNS AND CNS
PNS : Schwann cell
CNS: oligodendrocytes
Where does the stimulation begin in the saltatory conduction
Nodes of ranvier
Class of nerves ? General and sensory
General ( A , B , C )
Sensory ( I , II , III , IV )
both from fast and big to slow and small
What are the two types of receptors?
Intropic ( protein subunits- fast action and activation)
Metatropic ( G-protein coupled receptor, slow action and activation)
What are glial cell ?
They are protectors and supporters of neurones and they increase their functional capacity
What are the types of glial cells
- Schwann cell
-oligodendrocytes
-ependyma
-astrocytes
-radial cell
-microglia
Function of each glial cells ?
- Schwann cell and oligodendrocytes is the production of myelin
- ependyma and astrocyte is control the extra cellular environment and produce CSF
- Radial cell is the development of brain they reduce overtime
- microglia immune function
Where does microglia and macroglia derived from ?
Microglia from macrophages outside CNS
macroglia from stem cells
What are the functions of macroglia ( 8) ?
Structural support
Insulate axons
Blood brain barrier
Promote efficient signalling between neurones
Release growth hormones
Guid the migrating neurones and axons
Synaptogenesis
Anatomical development of the brain
How does Astrocyte regulate synaptogenesis ?
By Regulating Synapse number , functions and stability
What is the role of glial cell in synaptic activity ?
They produce gliotransmitters
