MLT GlobeAnatomy: Head, neck & special senses – page 2
35 Anatomy MCQs on Head, neck & special senses with answers and explanations.
Which statement about the choroid of the eye is correct?
The choroid is a highly vascular pigmented layer lining the posterior sclera, nourishing the outer retina. Extrinsic muscles insert into the sclera.
On fundoscopy, the central retinal artery and vein are seen emerging at which site, which lacks photoreceptors?
The optic disc is where the optic nerve and central vessels enter; having no rods or cones, it forms the blind spot. The fovea gives sharpest vision.
Which ocular structure is normally avascular, receiving nutrients by diffusion?
The cornea (like the lens) has no blood vessels, which keeps it transparent and contributes to corneal graft acceptance. Choroid, iris and ciliary body are vascular.
A patient cannot turn one eye outward (abduction). Which muscle and nerve are involved?
The abducent nerve supplies only the lateral rectus, which abducts the eye; its palsy causes inward deviation and double vision.
The masseter, temporalis and pterygoid muscles are all supplied by which nerve?
All muscles of mastication derive from the first pharyngeal arch and are supplied by V3. The facial nerve supplies muscles of facial expression.
The neurons that link rods and cones to ganglion cells in the retina are of which type?
Retinal bipolar cells carry signals from photoreceptors to ganglion cells. Pseudounipolar neurons are typical of dorsal root ganglia.
Skin over the back of the scalp is supplied mainly by the:
The greater occipital nerve (dorsal ramus of C2) supplies the posterior scalp. Infratrochlear and nasociliary supply the eye region and nose; the buccal nerve supplies the cheek.
The air-filled middle ear (tympanic cavity) is enclosed mainly by which bone?
The tympanic cavity lies within the petrous part of the temporal bone. It contains air and the ossicles; the utricle belongs to the inner ear.
The facial artery gives off a tonsillar branch. Which region besides the face does it therefore help supply?
Facial artery branches (tonsillar, ascending palatine) supply the tonsil and pharynx. Lower teeth are supplied by the inferior alveolar artery from the maxillary artery.
Which muscle receives motor supply from two different cranial nerves?
The digastric's anterior belly is supplied by the mandibular nerve (V3) and posterior belly by the facial nerve (VII), reflecting different arch origins.
Receptors that detect stimuli from a distance, such as light, sound and odour, are termed:
Teleceptors (distance receptors) are exteroceptors sensing remote stimuli. Proprioceptors monitor body position and interoceptors monitor internal organs.
The facial nerve passes from the posterior cranial fossa into the temporal bone through which opening?
The facial nerve enters the temporal bone through the internal acoustic meatus and leaves the skull through the stylomastoid foramen.
The utricle of the inner ear mainly senses which type of motion?
The utricle macula detects horizontal linear acceleration and head tilt; the saccule detects vertical acceleration and semicircular canals detect rotation.
A hemianopia with a pupillary light reflex absent when light falls on the blind half of the retina (Wernicke hemianopic pupil) localises to the:
Optic tract lesions interrupt fibres to the pretectal nucleus, so light on the affected hemiretina gives no pupil response. Occipital lesions spare the reflex.
Which extraocular muscle, acting alone from the primary position, turns the eye upward and laterally?
The inferior oblique elevates, abducts and extorts the eye. The superior oblique depresses and abducts; the superior rectus elevates and adducts.