PHYSIOLOGY TUTORIAL

PHSL - 215

Graded Potential & Action Potential Neuron Nerve Conduction in Myelinated &

Unmyelinated Nerve Fiber Synapse Neuromuscular Junction

Topics

Q.1 What is graded potential?Q2. What is action potential?Q3. Give 4 differences between graded potential & action potential Q4. Draw diagram of AP of Neuron. Show depolarization, repolarization and hyper polarization phase and give the cause of each phase.

Q5. Nerve fiber can be stimulated easily, when it is at RMP or at hyper polarization stage. Give reason for your answer.Q6. What is absolute refractory period?Q7. What is relative refractory period? Q8. Draw AP and show absolute and relative refractory period? 

Q.9. Draw and label the parts of neuron

Q10. Where AP is generated in neuron?Q11. What are the differences between contiguous conduction and saltatory conduction?

Q12. What is myelin sheath?  Q13. What is node of Ranvier?  Q14. What factors affect nerve conduction?  Q15. What is synapse?Q16. Draw the diagram of chemical synapse 

Q17. What is excitatory post synaptic potential (EPSP)

Q18. What is inhibitory post synaptic potential (IPSP)  

Q19. What is neuromuscular junction?  

Q20. What is a neurotransmitter at neuromuscular

junction?  

Q21. How acetylcholine is destroyed?  

Q22. What is myasthenia gravis?   

Q23. What is the treatment of myasthenia gravis?

 

 

Q1. Abeer, a medical student, had a tooth ache. She went to the dentist and the dentist advised her “filling” in a cavity in tooth. The dentist injected a local anesthetic in the nerve pathway which carries the nerve impulses from the area of tooth. Due to injection, Abeer did not feel any pain during the drilling and filling procedure.

 

Information – local anesthetic block voltage gated Na+ channels.

Explain how this action of local anesthetic prevents the transmission of pain impulses to the brain?

 

 

(Reference – See page 131 in ‘Human Physiology’ by Lauralee Sherwood)

CASE HISTORIES

Q2. A person was driving the car very fast and had a road accident. He injured his Right Ulnar Nerve in the upper arm and had a spinal cord injury also.Later, Right Ulnar Nerve in the arm recovered but there was no return of function caused by spinal cord injury. Answer the following:  Why Ulnar Nerve (PNS) recovered?Why Spinal Cord (CNS) did not improve?As a Medical Student, with your knowledge of Physiology, what ways can you suggest to improve his Spinal Cord regeneration?  (Reference – See Page 103 in ‘Human Physiology’ by Lauralee Sherwood)