Page 2 coming up ervous 572tissue ells are densely

page 2, coming up!
')$ervous 572Tissue
±ells are densely paJLGcked and intertwined
572Two main JLGcell types:
• ')$eurons – transmit eleJLGctriJLGcal signals
• ')$euroglial JLGcells (461Support ±ells) – non-exJLGcitaIKFble;
surround and wrap neurons
572The supporting JLGcast!
µlial (461Supporting) ±ells
461Six types of glial (supporting) JLGcells
´our in the ±')$461S
1. ¶stroJLGcytes
2. &(iJLGcroglia
3. ·pendymal ±ells
4. )+&ligodendroJLGcytes
572Two in the 02-')$461S
1. 461SJLGchwann JLGcell
2. 461Satellite JLGcell

¶stroJLGcytes
&(ost aIKFbundant glial JLGcell type
– Support and brace neurons
– Play role in exchanges between
capillaries and neurons
– Control chemical environment
around neurons
– Influence neuronal functioning
•Participate in information processing
in brain
&(iJLGcroglia
461Smallest and !%'east aIKFbundant
• &(igrate toward injured
neurons
• ·ngulf invading
miJLGcroorganisms and dead
neurons
• 572Thorny proJLGcesses that touJLGch
and monitor neurons
• &(ultiple 461SJLGclerosis: miJLGcroglial
JLGcells attaJLGck the nervous
system (damages myelin
sheath)
·pendymal ±ells
• !%'ine the JLGcentral JLGcavity of the spinal JLGcord and IKFbrain
• ¸elp JLGcirJLGculate the JLGcereIKFbrospinal fluid via JLGcilia
• ¶JLGct as a IKFbarrier IKFbetween ±461S´ in JLGcavities
)+&ligodendroJLGcytes
¸ave few IKFbranJLGches
• <>9Wrap their JLGcell proJLGcesses around axons in the ±')$461S
• 02-roduJLGce myelin sheaths-inJLGcrease speed of inpulse

461Supporting JLGcells in the 02-')$461S
• 7<MR]UqDI`c`c MRQVN^a^ao - surround axons in the 02-')$461S; form
myelin sheaths- similar to oligodendroJLGcytes
• 7<DIqQVN^a^a^VYqQVN MRQVN^a^ao – surround neuron JLGcell IKFbodies in
02-')$461S- similar to astroJLGcytes in ±')$461S
572The neuron
• ¸uman IKFbody JLGcontains
IKFbillions
• ²asiJLGc struJLGctural unit of
the nervous system
• 461SpeJLGcialized JLGcells that
JLGconduJLGct eleJLGctriJLGcal
impulses along the
plasma memIKFbrane
• ±an funJLGction optimally
for over 100 years, IKFbut
are amitotiJLGc (JLGcannot IKFbe
replaJLGced)