402 



ANATOMY FOR NURSES 



[Chap. XIX 



Property 

 of nerve- 

 tissue 



I Irritability or the power to respond to stimulation. 

 Conductivity or the power to transmit stimuli. 



Neurone 

 or Nerve- ■ 

 ceU 



Cell- 

 body 



Cell- 

 processes 



Cell-body 



Dendrites. 



Axis cylinder process. 



Nerve-fibres. 



Collaterals. 



Nerve-endings. 



( Unipolar. 

 Varieties i Bipolar. 



i Multipolar. 



Nutrition. 



Gives rise to nervous impulses. 



- , vc • 1 f Inhibition. 

 Modifies impulses i „ 



[ Summation. 



Function ■ 



Dendrites 



■ Short, break up into many branches. 

 Rough outline — diminish in calibre. 

 May be one, or many. 



. Function — Collect and carry impulses to cell-body. 

 Synapse — Arborization of contiguous processes, not an anatomical 

 continuation. 



Axis 



Cylinder 



Process 



Nerve- 

 fibre 



Long, smooth outline, diminishes very little. 

 Gives off collaterals. 

 Continued as core of nerve-fibre. 

 Function — Carry impulses from cell-body. 



Mcdul- 

 lated 



Non- 

 medul- 

 lated 



Axis cylinder process. 



Medullary sheath-function 



Neurilemma. 



Axis cylinder process. 

 Neurilemma. 



I Protection. 



\ Non-conduction. 



Nodes of 

 Ranvier 



■ Ring-like constrictions in medullated fibres, due to absence of 

 medullary sheath. 

 Function — Render easier the passage of blood-plasma to 

 fibre. 



Collaterals — Minute side branches given off from axis cylinder processes, 

 usually at nodes of Ranvier. 



