What cranial nerve controls lacrimation?
Lacrimation (tearing) and salivation are also stimulated by the 7th cranial nerve. The 7th cranial nerve also has some sensory component including the sense of taste (anterior 2/3 of the tongue).
Which ganglion controls lacrimation?
The ciliary ganglion is a bundle of nerve parasympathetic ganglion located just behind the eye in the posterior orbit. It is 1–2 mm in diameter and in humans contains approximately 2,500 neurons. The ganglion contains postganglionic parasympathetic neurons….
| Ciliary ganglion | |
|---|---|
| FMA | 6964 |
| Anatomical terms of neuroanatomy |
What is reflex lacrimation?
An index of reflex lacrimation, defined as the percentage decrease in fluorescein concentration as a result of stimulation, was calculated by forward and backward extrapolation of the steady state decay of the fluorescein concentration in tears, relative to the time of stimulation.
What are the causes of crocodile tears syndrome?
The crocodile tears syndrome occurs most often following facial paralysis when nerve fibers destined for a salivary gland are damaged and by mistake regrow into a tear gland. Also called Bogorad’s syndrome, gustatolacrimal reflex, paroxysmal lacrimation.
What nerves affect the face?
The trigeminal nerve is one set of the cranial nerves in the head. It is the nerve responsible for providing sensation to the face. One trigeminal nerve runs to the right side of the head, while the other runs to the left. Each of these nerves has three distinct branches.
What is lacrimal system?
The lacrimal system is made up of a secretory system, which produces tears, and an excretory system, which drains the tears. The lacrimal gland is primarily responsible for producing emotional or reflexive tears. The tears that are drained through the punctum will eventually be drained through the nose.
What is excessive lacrimation?
Tearing Disorders Excessive tearing (lacrimation) or defective drainage of tears may cause epiphora, with resultant chronic annoyance, irritation and social awkwardness.
Why do crocodiles tear in Bell’s palsy?
The diagnosis of crocodile tears syndrome should be considered after excluding common differential diagnosis such as simple epiphora following Bell’s palsy. [9] This occurs due to loss of tone of the orbicularis oculi muscle, which leads to sagging of the lower eyelid.
Where are lesions along the efferent arm of lacrimation?
lesions along efferent arm of lacrimation pathway: –parasympathetic nucleus of facial nerve –main trunk of facial nerve –near geniculate ganglion –major petrosal nerve –nerve of the pterygoid canal –pterygopalatine ganglion –postganglionic parasympathetic fibers xeromycteria (dry nasal mucosa) common finding
What are the cranial nerves involved in lacrimation?
Relevant Cranial Nerves Trigeminal nerve (CN V) – sensory afferent and parasympathetic efferent Facial nerve (CN VII) – parasympathetic efferent Abducens nerve (CN VI), Glossopharangeal nerve (CN IX) – proximity to pathway Trigeminal Nerve and Lacrimation
What kind of injury can cause facial nerve damage?
The facial nerve is affected in 7 to 10% of temporal bone fractures. These injuries typically occur from falls, motor vehicle accidents, and assault, as well penetrating trauma, such as gunshot wounds.
Where is the parasympathetic efferent of the lacrimal gland?
Parasympathetic Efferent to Lacrimal Gland Facial Nerve (CN V II) parasympathetic nuclei Greater Petrosal nerve (petrous temporal bone) Nerve of Pterygoid Canal (with post ganglionic sympathetics) synapse in Pterygopalatine Ganglion (ventral periorbital region, near apex of orbit)