What happens during ciliospinal reflex?
The ciliospinal reflex (pupillary-skin reflex) consists of dilation of the ipsilateral pupil in response to pain applied to the neck, face, and upper trunk. If the right side of the neck is subjected to a painful stimulus, the right pupil dilates (increases in size 1-2mm from baseline).
Is the ciliospinal reflex sympathetic or parasympathetic?
In the absence of anesthesia, this response has been called the ciliospinal reflex and is primarily mediated by the sympathetic nervous system in both humans [1,2]and cats.
What causes Horner’s syndrome?
Horner syndrome is caused by damage to a certain pathway in the sympathetic nervous system. The sympathetic nervous system regulates heart rate, pupil size, perspiration, blood pressure and other functions that enable you to respond quickly to changes in your environment.
What nerve is involved in Horner’s syndrome?
In most cases, the physical findings associated with Horner syndrome develop due to an interruption of the sympathetic nerve supply to the eye due to a lesion or growth. The lesion develops somewhere along the path from the eye to the region of the brain that controls the sympathetic nervous system (hypothalamus).
How does blink reflex protect the body?
The ocular reflexes are the simplest ocular motor responses. Ocular reflexes compensate for the condition of the cornea and for changes in the visual stimulus. For example, the eye blink reflex protects the cornea from drying out and from contact with foreign objects.
How does Horner syndrome affect the pupils of the eye?
Eyelids: patients have a mild (less than 2 mm) ptosis of upper lid and inverse ptosis of the lower lid (lower lid rests at a higher level than normal) which produces a decreased palpebral aperture compared to the fellow eye. Pupils: Patients have anisocoria (difference in the pupillary size) with the ptotic eye having the smaller pupil (miosis).
Which is the most common symptom of Horner’s syndrome?
Horner’s Syndrome is a rare syndrome that is based upon findings that are due to an alteration in the sympathetic neuro-pathway. Approximately 60% of cases studied are from known causes and the other 40% are idiopathic 1 .The main and most common characteristics of this syndrome are ptosis of the eyelids and ipsilateral miosis of the pupil.
Where does the sympathetic trunk originate in Horner’s syndrome?
It is characterized by miosis (a constricted pupil), partial ptosis (a weak, droopy eyelid), apparent anhydrosis (decreased sweating), with apparent enophthalmos (inset eyeball ). The nerves of the sympathetic trunk arise from the spinal cord in the chest, and from there ascend to the neck and face.
What causes miosis and ptosis in Horner’s syndrome?
Horner’s syndrome is a rare condition characterized by miosis (constriction of the pupil), ptosis (drooping of the upper eyelid), and anhidrosis (absence of sweating of the face). [1] [2] It is caused by damage to the sympathetic nerves of the face. The underlying causes of Horner’s syndrome vary greatly and may include a tumor, stroke, injury,