The corneal reflex, also known as the blink reflex, is an involuntary blinking of the eyelids elicited by stimulation of the cornea. Here's how it works:
The Corneal Reflex Arc
The corneal reflex is a protective mechanism involving a neurological loop between sensory and motor nerves. Here's a breakdown:
- Stimulation: Contact with the cornea (e.g., by a foreign object, puff of air) triggers the reflex.
- Sensory Input: Trigeminal sensory nerves detect the stimulation and send a signal. According to the reference, this is a crucial part of the loop.
- Brainstem Processing: The signal travels to the brainstem.
- Motor Output: The facial motor (VII) nerve is activated.
- Eyelid Closure: The facial nerve innervates the orbicularis oculi muscles, which contract, causing the eyelids to close in a blink. The reference highlights the orbicularis oculi muscle's involvement.
Reflex Components in a Table
| Component | Nerve Involved | Function |
|---|---|---|
| Sensory (Afferent) | Trigeminal Nerve (V) | Detects corneal stimulation |
| Motor (Efferent) | Facial Nerve (VII) | Contracts the orbicularis oculi muscle to blink |
Additional Reflexes
Besides the blink reflex, corneal stimulation also initiates tear production, contributing to the eye's protective response.
