nervous system day 3-

the synapse

• areas where a nueron in another cell comes together

presynaptic cell- neuron

postsynaptic cell- any

• muscle : cardiac, smooth, skeletal

• gland :

• adipose :

the synaptic knob

• expanded area of axon

• contains synaptic vesicles

  • neurotransmitters

classification of neurons

1. unipolar (there)

   • dentrites - long dentrites - body - axon - teledentries

   • sesnsory nerons of body →general

2. multipolar (everywhere except senses)

   • dentrites to cell body to teledentrites

   • all neurons in brain and spinal cord and motor neurons (skeletal)

   • what we’ll label on the test

3. bipolar (very few)

   • end - axon - body - axon - end

   • specific sense organs

     • eyes → retina

     • ears → hair

Afferent: 10 million

• carry info to CNS

• sensory neuron

Efferent- 500,000

• brain to body

• motor

20 interneurons = brain and spinal cord = multipolar

Neuroglia: ependymal cells

• form epithelium called ependyma

• Cerebrospinal Fluid (CSF)

  • mananjidis

  • cushions brain and spinal cord

  • diffuses nutrients into brain and waste out

Neuroglia: Astrocytes

Neuroglia: Oligodentrocytes

myelin shealth- white lipid, insulates axon, action potential goes faster

Internodes:

• myelinated segments of axon

Nodes:

• gaps between internodes

• where axons may branch