Question

1. List the steps of muscle contraction from the brain to muscle fiber

2. List the steps of muscle relaxation

3. List steps of synaptic transmission of nerves

4. List Five glial cells and their functions

5. What is excitatory post synaptic potential or facilitation?

6. What is inhibitory post synaptic potential or inhibition?

Define the following!

1. Sarcolemma

2. Troponin

3. Tropomyosin

4. Myosin

5. Actin

6. Cross Bridge

7. Titin

8. H zone

9. I band

10. A band

11. M line

12. Sarcomere

13. Motor Unit

14. Resting Membrane Potential

15. Depolarization

16. Repolarization

17. Hyperpolarization.

18. Saltatory Nerve Conduction

19. Acetylcholinesterase

20. Neuromuscular junction

21. Sarcoplasm

22. Multinucleated

23. Motor end plate

24. Acetylcholine

25. Sarcoplasmic Reticulum

26. Nissl Bodies

27. Z line or Disk

Answer 1

1. The motor skill impulse is sent from the CNS to muscle via motor neuron. Action potential travels down the axon of the motor neuron and when it reaches the terminal, it releases the Ach from presynaptic neuron contained in synaptic vesicle at neuromuscualr junction which diffuses to the post synaptic muscle cell and bind to its AchR.

2. Muscle relaxation:

• Stimulation stops.
• Calcium pumped back to SR.
• Actin and myosin dissociates.
• Causing the muscle to relax.

3. Synaptic transmission:

• Begins with initiation of action potential via:
• Depolarization of the terminal membrane.
• Activation of voltage-gated Ca²⁺ channels.
• Ca²⁺ entry.
• Conformational change of docking proteins.
• Fusion of the vesicle to the plasma membrane.
• Subsequent release NT release.

4. Glial cells:

CNS glial cells:  

Oligodendrocytes - Create myelin in CNS axon.

Astrocytes - Maintain ECM and induce BBB.

Ependymal cells - Create and circulate CSF.

Microglia - Immune survelliance

Peripheral nervous system glial cells

Schwann cells -  Create myelin in PNS axon.

satellite cells - MAintain ECM, remove excess NT.

5. EPSP: Facilitate.

EPSP triggers postsynaptic neuron more likely to fire an action potential.

6. IPSP: Inhibitory.

IPSP prevent post synaptic cell fro firing AP.