Sherrington’s Law

Sherrington’s Law is one of the laws that governs the movements of extraocular muscles

1. Sherrington’s Law

2. Sherrington’s Law of Reciprocal Innervation Whenever an agonist receives an impulse to contract, an equivalent inhibitory impulse is sent to its antagonist, which relaxes and actually lengthens

3. Agonist Muscles AKA prime mover On contracting it automatically is checked and controlled by the opposing simultaneous contraction of another muscle Antagonist Muscles An agent that acts in physiological opposition A muscle that contracts and limits the action of an agonist with which it is paired Important Concepts to Understand

4. Synergistic Muscles T wo muscles moving the eye in the same direction Yolk Muscles AKA Contralateral S ynergists Pair of muscles producing conjugate ocular movements Important Concepts to Understand

5. Right Eye Left Eye Movement Position of Gaze Lateral Rectus Medial Rectus Move the globe to the right Dextroversion   Medial Rectus Lateral Rectus Move the globe to the left Laevoversion Superior Rectus Inferior Oblique Move the globe upward Dextroelevation Inferior Oblique Superior Rectus Move the globe upward Laevoelevation Superior Oblique Inferior Rectus Move the globe downward Laevodepression Inferior Rectus Superior Oblique Move the globe downward   Dextrodepression Paired Agonist Muscles

6. Eye movements previously mentioned visible via motility test

7. P hysiologically and clinically important because it explains why strabismus occurs due to paralysis of extraocular muscle Importance of Sherrington’s Law

8. Measure electrical potential changes within a muscle based on muscle fibre contraction indicating overall neuromuscular activity Electromyography (EMG)

9. Uses: Strabismus Patients with Duane’s Syndrome Sherrington’s Law – Clinical Use

10. Duane’s Syndrome

11. Not only applicable to EOM It applies to all striated muscles of the body Something to Take Home

12. http :// www.cybersight.org/bins/content_page.asp?cid=735-2858-4397-4404-4654-4704-4707 http:// www.vestib.com/EOM-muscles-movements.html http:// onlinelibrary.wiley.com/doi/10.1111/j.1442-9071.1982.tb01632.x/pdf http://www.authorstream.com/Presentation/optom.rawaa-513087-4th-lecture / https://books.google.gy/books?id=DN60U5yZkyQC&pg=PA63&lpg=PA63&dq=sherrington+law+muscles&source=bl&ots=_ bIrlBf7_d&sig=mpcXewinO1L7NwpY6B84Q4h3tS0&hl=en&sa=X&ved=0CCEQ6AEwAjgKahUKEwiRgp2h8tzIAhXHGh4KHSheDNc#v=onepage&q=sherrington%20law%20muscles&f=false Reference