1. What is different about activities on the two
sides of the synapse (axon next to muscle or
dendrite of other nerve)?
SALMAN UL ISLAM
2013298039
31.03.2014

2. Contents
o Introduction
o Nerve Cell
o Synapse
o Transmission across the synapse----- Neuromuscular
junction (NMJ)
o Summary

3. Introduction
o Neuron-----electrically excitable cell-----processing and
transmitting information through electrical and chemical
signals.
o Neurons communicate with each other by synaptic
transmission.
o Synapses transmit, process, and store information in
brain.
Courtesy of the Südhof lab. See Südhof, T.C. 2008. Nature 455:903-911 for details.

4. NERVE CELL
Three parts of a nerve cell are:
o dendrites: branches that receive sensory input and
bring it to the neuron’s cell body;
o cell body: contains the nucleus, mitochondria, and
ribosomes. The cell body carries on the normal metabolic
cellular functions of the nerve cell.
o axon: a long fiber extending from the cell body. The role
of the axon is to transmit a nerve impulse to another cell.
http://highered.mcgraw-hill.com/sites/dl/free/0073403474/858357/answers2e_ch25.doc.

5. Parts of a Nerve cell
http://cnx.org/content/m44731/latest/?collection=col11448/latest

6. SYNAPSE

7. SYNAPSE
 The presynaptic cell ends in an axon terminal that contains
calcium channels and synaptic vesicles with
neurotransmitters.
 The postsynaptic cell has ion channels with receptors for
the neurotransmitters.
 Between the two cells is a small gap called the synaptic
cleft.
http://highered.mcgraw-hill.com/sites/dl/free/0073403474/858357/answers2e_ch25.doc.

9. Transmission across the synapse-----
Neuromuscular junction (NMJ)
o “ The place where the motor neuron makes a functional
contact with the skeletal muscle cell is called
NEUROMUSCULAR JUNCTION or MYONEURAL
JUNCTION”

10. Neuromuscular Junction

11. What is the
mechanism of
Neuromuscular
Transmission

12. Myasthenia Gravis, A Seminar Report Posted: September 21, 2010 in Physiology, Toxic Med

13. From LIFE: The Science of Biology (Sadava et al., 2010)

14. Fate of Acetylcholine

15. Summary
 The synapse is a connection between a neuron and its
target cell (which is not necessarily a neuron).
 The presynaptic element is the synaptic end bulb of the
axon where Ca2+ enters the bulb to cause vesicle fusion
and neurotransmitter release.
 The neurotransmitter diffuses across the synaptic cleft to
bind to its receptor.
 Resulting action potential leads to muscle contraction.
 The neurotransmitter is cleared from the synapse either
by enzymatic degradation or neuronal reuptake.