A&P Lect 3 part 1

afferent- going toward CNS

efferent- going away from CNS

dendrite- some- trigger zone- axon- synaptic knob

excitability, conductivity, secretion

to sum up local graded potentials

CSF production and circulation

immune cells

myelin sheathes for CNS

• form scaffolding of CNS
• provide nutrients and growth factors to neurons
• take up wastes and neurotransmitters
• provide frame to direct nerve growth during development and new synapse formation after birth
• attach to capillaries to tighter them into a blood- brain barrier

a wrap of cell membrane around an axon that speeds transmission of an action potential and allows axons to regenerate

the action potentials have a skipping

• old schwann cells produce growth factors that cause the axon to elongate
• new schwann cells wrap the axon as it grows
• can only occur in peripheral axons

• neurotransmitters bind to ligand-gated channels
• open channels allow ions to enter cell causing a change in resting membrane potential locally 
• local changes are summed up at the trigger zone
• if the sum reaches threshold, voltage gated sodium channels open sequentially down the axon 

• acetylcholine
• monoamines
• amino acids
• neuropeptides
• lipids

made in the soma of each neuron

they are discharged from their transport vesicles at the synaptic knob by the interaction with calcium.

diffusion, re-uptake by presyanptic cell, uptake by astrocyte, enzyme degradation

bind to receptors on the  membrane of the post synaptic cell

• ligand- gated sodium channel
• voltage- gated sodium channel
• voltage- gated calcium channel

a second messenger membrane protein

one post neuron receives input from three pre-synaptic neurons

three post, synaptic neurons receive input from pone pre-synaptic neuron