120 likes | 268 Views
Neuromuscular junction. By Amar Kahlon. What is Neuromuscular J unction?.
E N D
Neuromuscular junction By Amar Kahlon
What is Neuromuscular Junction? • It is junction of the axon terminal of a motor neuron with the motor end plate, the highly-excitable region of muscle fibres plasma membrane responsible for initiation of action potentials across the muscle's surface, ultimately causing the muscle to contract.
Anatomy • Synatic knobs - ending of a nerve • Synaticcleft - a gap filled with extracellular fluid • Motor end plate - muscle membrane • Palisades - Muscle membrane thrown into folds
Myasthenia Gravis Disease • which literally means "serious muscle-weakness is a neuromuscular disease leading to fluctuating muscle weakness and fatigue. It is an autoimmune disorder, in which weakness is caused by circulating antibodies that block acetylcholine receptors.
Lambert-Eaton myasthenic syndrome • is a rare autoimmune disorder which affects voltage-gated calcium channels on the pre-synaptic membrane. The inhibition of the voltage-gated calcium channels prevents acetylcholine from being released from the presyntaptic terminal and the subsequent stimulation of the post-synaptic terminal which would lead to muscle contraction. • While children and young adults may be affected, the disease is usually observed in middle aged and older individuals. The incidence of the disease is difficult to determine due to its low frequency.