Fichas
H&N2: Section 2
Fichas del conjunto (37)
- 1Passage of the optic nerveIt passes from the eyeball through the optic canal. Within the anterior cranial fossa it meets its partner at the optic chiasm just superior to the pituitary gland
- 2What does the oculomotor provide motor supply to?Superior, Inferior and Medial Recti
Inferior Oblique
Levetator Palpebrae Superioris - 3Passage of the oculomotor nerveIt arises from a nucleus in the midbrain and passes through the subarachnoid space to enter the cavernous sinus (one of the dural sinuses
- 4How does the oculomotor nerve enter the orbit?It enters the orbit via the superior orbital fissure to reach the muscles it supplies
- 5What other structures does the oculomotor nerve innervate?The oculomotor nerve contains parasympathetic nerve fibres which supply the iris of the eye
- 6Function of the parasympathetic innervation to the iris?To constrict the pupil when exposed to light
- 7Passage of parasympathetic nerve fibres of the oculomotor nerve (Pre-ganglionic)Pre-ganglionic parasympathetic axons arise from the Edinger- Westphal nucleus in the midbrain and travel through the oculomotor nerve
- 8Passage of parasympathetic nerve fibres of the oculomotor nerve (Post-ganglionic)The pre-ganglionic axons synapse in the ciliary ganglion and post- ganglionic axons run in short ciliary nerves from the ganglion to supply the sphincter pupillae muscles
- 9Type of innervation to the dilator papillae muscleSympathetic post- ganglionic axons can travel in either short or long ciliary nerves to supply this muscle
- 10Sympathetic fibres in the skullSympathetic nerves fibres are not associated with cranial nerves and reach their destination by travelling with blood vessels
All sympathetic fibres inside the skull are post- ganglionic. They do not synapse at ganglia in the skull. This is because their synapses took place in the sympathetic chain beforehand - 11Pressure on the oculomotor nerve may result from an aneurysms of the posterior communicating artery. The patient will have ptosis (droopy eyelid) and diplopia (double vision), can you explain this?Ptosis occurs because the oculomotor nerve innervates the levetator palpebrae superioris muscle in the eyelid
Diplopia occurs when the healthy eye can move in all directions but the eye which has non- functional oculomotor nerve cannot. Both eyes are required for binocular vision so when the eyes move together to focus on an object and 1 eye is restricted in movement double vision occurs. It is a very common symptom - 12What test can be carried out to test for oculomotor nerve palsy?H Test
- 13What extra-ocular muscle does the trochlear nerve innervate?Superior Oblique Muscle
- 14Passage of the trochlear nerveIt originates from the back of the brainstem on a level with the inferior colliculi. It passes forwards just beneath the edge of the tentorium and enters the lateral wall of the cavernous sinus just below CNIII
It enters the orbit by the superior orbital fissure - 15Does the trochlear nerve contain parasympathetic fibres?No
- 16What extra- ocular nerve does the abducent nerve supply?Lateral rectus muscle
- 17Passage of the abducent nerveArises from the brainstem between the pons and the pyramids of the medulla oblongata
It pierces the dura and runs in the cavernous sinus lateral to the internal carotid artery
It enters the orbit via the superior orbital fissure - 18How can the abducent nerve be damaged or compressed?By blood vessels or tumours, and by traction if intracranial pressure rises and pushes the brainstem caudally
- 19Ophthalmic NerveIt is not a cranial nerve but a divion of CNV
It's the superior and smallest division of the trigeminal nerve - 20What does the ophthalmic nerve supply?It is wholly sensory supplying the eyeball, lacrimal gland, conjunctiva, eyelids, forehead and part of the scalp and part of the nasal mucosa
The region of the face supplied by this nerve corresponds to the frontonasal process in development thus the ophthalmic nerve supplies the nose to the tip - 21Branches of the ophthalmic nerve?Lacrimal Nerve
Frontal Nerve
Nasociliary Nerve - 22Lacrimal NerveIt is sensory but it also carries parasympathetic post ganglionic secretomotor fibres from the pterygopalatine ganglion (located in the fossa) to the lacrimal gland
These parasympathetic fibres comes from elsewhere and are not associated with trigeminal function - 23What does the lacrimal nerve provide sensory innervation to?The skin of the lateral part of the upper eyelid and the conjunctiva
It is the sensory input tested in the blink reflex - 24Where can the frontal nerve be seen clearly?On the superior surface of the levatator palpebrae superioris muscle
- 25What does the frontal nerve supply?Supplies the skin of the forehead and the scalp
- 26Nasociliary NerveIt enters the orbit and passes inferior to the medial rectus
- 27Divisions of the nasociliary nerve?Anterior ethmoidal nerve
Infratrochlear nerve
Ciliary Nerves - 28What does the Anterior ethmoidal nerve supply?Ethmoidal air sinuses
- 29What does the infratrochlear nerve supply?Part of the skin and mucous membrane of the nose, and the conjunctiva
- 30What does the ciliary nerve supplyIt carries the sensory and sympathetic fibres to the eyeball
- 31How does the ophthalmic artery enter the orbitThrough the optic canal with the optic nerve
- 32What branch does the ophthalmic artery give off?Central artery of the retina which continues forwards to enter the eyeball
- 33What does the blockage of central artery cause?The central artery of the retina is an end artery and blockage of this artery results in complete blindness of the affected eye
- 34How can the central artery and accompanying veins be seen?Ophthalmoscope
- 35What does the engorgement of the central and artery and accompanying veins indicate?Arterial disease or raised intracranial pressure
- 36Why is the ophthalmic artery important?It constitutes an important anastomosis between the internal and external carotid arteries of the face and scalp
- 37Transmission of infection from the face to the cavernous sinusThe 2 ophthalmic veins communicate with the veins of the face and therefore provide a possible channel for transmission of infection from the face to the cavernous sinus
Información
- Descripción
- MBBS (Anatomy H&N2) Nervous and Locomotor Fichas sobre H&N2: Section 2, creado por Krishna Patel el 07/12/2019.
- Creado por
- Krishna Patel · dic 2019
- Actualizado
- 8 dic 2019
- Visitas
- 2
- Valoración