This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Muscle relaxants, Subject name: Anaesthesia
Tubocurare affects which muscle first? 
Select and explain. 
A. Head and neck, B. Limbs, C. Respiratory muscles, D. Abdominal muscles
A: Head and neck
Answer: A: Head and neck 
Explanation: Sequence of blockade : face - jaw- pharynx - larynx - respiratory (including diaphragm) - trunk muscle - limb muscle. Face muscles are involved earliest. 1)in non-depolarising blocker (d-Tc), earliest clinical sign is Ptosis and diploia 2)In succinylcholine (depolarising blocker ),First clinical sign is Fasciculation of eye lids.