Nerves - brain Flashcards
(23 cards)
What makes up the brain stem
midbrain - high level functions
pons
medulla oblongata - vital involuntary functions
What is the four cerebrum lobes
frontal lobe - thoughts and feeling
temporal lobe - language and auditory
parietal lobe - sensation an touch
occipital lobe - visual
How many pairs of spinal nerves are there
31
How many cervical, thoracic, lumbar, sacral, coccygeal
8 cervical 12 thoracic 5 lumbar 5 sacral 1 coccygeal
What are the three types of neurons related to the CNS
afferent neurone
efferent neurone
interneurons
What are the different gial cells in the CNS and their functions
Astrocytes -maintain the external environment for the neurones and surround blood vessels & produce the blood brain barrier
Oligodendrocytes - form myelin sheaths in the CNS
Microglia - immunity
ependymal cells - produce CBF
what are the gial cells in the PNS
Schwann cells - form myelin sheath
Satellite cells - support
Name three different types of potentials
RMP
graded
AP
What is a gyrus
a ridge or fold between two clefts on the cerebral surface in the brain
what is a sulcus
a groove or furrow, especially one on the surface of the brain
What does cerebellum regulate
muscular activity
What is the function of the corpus callous
joins the two hemispheres, helping in communication
What is the purpose of the RMP
keep cells ready to respond
what is an indirect cause of RMP
NA/K pump
What causes RMP
leaky K
What is the equilibrium constant
the membrane potential at which the electrical gradient is exactly equal and opposite to the concentration gradient
What does the Nernst equation predict
the equilibrium potential for a single ion species
What protects the brain from K changes
blood brain barrier
What is the normal RMP
-70mV
What causes the tight blood brain barrier
Due to astrocytes & tight junctions between endothelial cells
Why is RMP -70mV and not theoretically -90mV
due to other leaky channels between Na and Cl
When is depolorisation, repolarisation, hyperpolorisation
d- when cells become positive
r - when cells return make to RMP
h- cells go below RMP e.g. -90mV
What is refractory period
cells is at rest and unresponsive to stimuli
