Dental Physiology _ level 4 _ neurotransmitters

1. By: Olla BaEissa
Neurotransmitters (Synaptic transmitters):
1-The small molecular weight
rapidly acting transmitter
2- The large molecular weight
slow & prolonged acting transmitter
1-They are rapidly acting.
2-They act by activation of ion channels.
3- Responsible for transmission of sensory
impulses to the brain and motor signals to
the muscles.
4-They are synthesized in the pre-synaptic
terminals and stored in transmitter vesicles.
5-They are released in large quantities .
6- They are removed by active reuptake or
by enzymatic destruction.
1-Usually slow and prolonged action .
2- Act by second messenger system.
3-Include several families of peptides that
are present in other organs and systems
,beside the nervous system ,as endocrine
and gastrointestinal system.
4-Synthesized by neurons in the C.N.S and
so called neuropeptides .
5- Released in small quantities.
6-More potent.
A-Excitatory chemical transmitters as:
Glutamine , Enkephalin
Acetyl choline , Noradrenaline
Histamine , Nitric oxide
Serotonin , Aspartate
B-inhibitory chemical transmitters as:
Dopamine , Glycine
Gamma amino butyric acid (GABA).
A- Hypothalamic –releasing hormones
as: T.R.H & L.H.R.H .
B- Pituitary peptides
as: ACTH ,β-endorphin , prolactin, L.H ,
Thyrotropin, G.H, ADH & Oxytocin
C- GIT hormones
as: substance P , Gastrin , CCK , VIP