A 45-year-old man who has worked for 20 years in a textile mill in Surat without ear protection has difficulty following conversation in noisy places. His audiogram shows a bilateral sensorineural dip at 4,000 Hz with better hearing at 8,000 Hz. Which cells are damaged first?

Outer hair cells in the basal turn

Spiral ganglion cells in the apex

Inner hair cells in the apical turn

Outer hair cells in the apical turn

A 45-year-old teacher recovered from herpes simplex encephalitis that damaged both medial temporal lobes. He cannot remember the people he met that morning, but his memories of childhood are intact, and over several days he gets faster at a new jigsaw puzzle without recalling having seen it. Which memory function is impaired?

Formation of new declarative memory

Holding of immediate working memory

Learning of procedural skill memory

Retrieval of remote long-term memory

Higher functions, sleep and special senses physiology

27 NEET-PG practice questions on Higher functions, sleep and special senses physiology, part of Physiology. The first 25 are below; the first 5 with answers and explanations (tap Show answer after you have chosen), the rest in Learn with a free account.

Question 1 · Medium
A 32-year-old nurse in a Delhi hospital who has worked rotating night shifts for 2 years cannot sleep during the day and feels drowsy on duty. The master circadian clock that is out of step with her schedule lies in which structure?
1. APineal gland
2. BParaventricular nucleus
3. CSuprachiasmatic nucleus
4. DVentrolateral preoptic nucleus
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Answer: C · Suprachiasmatic nucleus
The suprachiasmatic nucleus of the hypothalamus is the master circadian pacemaker. It is set by light through the retinohypothalamic tract from melanopsin-containing retinal ganglion cells, and it controls the pineal gland's night-time melatonin secretion. Shift work exposes the clock to light at the wrong time, which causes shift-work sleep disorder; bright light at work, a dark room for daytime sleep and regular schedules help.
- A: The pineal gland secretes melatonin under the control of the SCN; it is not the master clock.
- B: The paraventricular nucleus controls CRH, TRH and oxytocin output.
- D: The ventrolateral preoptic nucleus promotes sleep but does not keep circadian time.
Question 2 · Medium
A 7-year-old boy is found walking about the house about an hour after going to bed, eyes open but not responding to his parents. He returns to bed and next morning remembers nothing. In which stage of sleep does this behaviour most likely arise?
1. AN3 slow-wave sleep
2. BN2 sleep
3. CREM sleep
4. DN1 sleep
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Answer: A · N3 slow-wave sleep
Sleepwalking, like night terrors, is a disorder of partial arousal from N3 (slow-wave) sleep. N3 is concentrated in the first third of the night and is most abundant in children, which explains the timing and age. Because the child is in deep non-REM sleep there is no dream recall. Parents are reassured and asked to make the house safe; most children outgrow it.
- B: N2 is not the usual stage for sleepwalking.
- C: REM-related events occur later in the night and come with vivid dream recall.
- D: N1 is a brief transition stage, not the source of complex arousal behaviours.
Question 3 · Medium
A 45-year-old man who has worked for 20 years in a textile mill in Surat without ear protection has difficulty following conversation in noisy places. His audiogram shows a bilateral sensorineural dip at 4,000 Hz with better hearing at 8,000 Hz. Which cells are damaged first?
1. ASpiral ganglion cells in the apex
2. BOuter hair cells in the basal turn
3. CInner hair cells in the apical turn
4. DOuter hair cells in the apical turn
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Answer: B · Outer hair cells in the basal turn
The cochlea is tonotopic: high frequencies are detected near the base, where the basilar membrane is narrow and stiff, and low frequencies near the apex. The noise-induced notch at about 4 kHz lies in the basal turn, and the outer hair cells, which amplify basilar membrane motion, are the first to be damaged by noise. The loss is permanent, so hearing conservation with ear protection and periodic audiometry is the answer in noisy industries.
- A: Spiral ganglion loss is not the first change in noise damage, and the apex serves low tones.
- C: Apical inner hair cells serve low frequencies, which are spared.
- D: The apical turn serves low frequencies, not 4 kHz.
Question 4 · Medium
A 10-year-old boy was operated on for a craniopharyngioma involving the floor of the third ventricle. Since then he eats constantly, searches for food at night and has gained 12 kg in 6 months. Damage to which hypothalamic area best explains this?
1. ALateral hypothalamic area
2. BSuprachiasmatic nucleus
3. CVentromedial nucleus
4. DSupraoptic nucleus
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Answer: C · Ventromedial nucleus
The ventromedial hypothalamus acts as a satiety centre, integrating signals such as leptin and insulin relayed through the arcuate nucleus. Bilateral damage removes satiety, so the patient overeats and becomes obese (hypothalamic obesity), a recognised complication of craniopharyngioma and its surgery. Lesions of the lateral hypothalamus, the feeding centre, have the opposite effect.
- A: Lateral hypothalamic damage causes loss of appetite and weight loss.
- B: Suprachiasmatic damage disturbs circadian rhythm, not satiety.
- D: Supraoptic damage causes diabetes insipidus, not hyperphagia.
Question 5 · Medium
A 45-year-old teacher recovered from herpes simplex encephalitis that damaged both medial temporal lobes. He cannot remember the people he met that morning, but his memories of childhood are intact, and over several days he gets faster at a new jigsaw puzzle without recalling having seen it. Which memory function is impaired?
1. AHolding of immediate working memory
2. BLearning of procedural skill memory
3. CFormation of new declarative memory
4. DRetrieval of remote long-term memory
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Answer: C · Formation of new declarative memory
The hippocampus and adjacent medial temporal cortex are needed to consolidate new declarative (explicit) memories of facts and events. Bilateral damage causes anterograde amnesia while older memories, already stored in the neocortex, remain. Procedural memory depends on the basal ganglia and cerebellum, which is why he still improves with practice. Working memory depends on the prefrontal cortex and is usually spared.
- A: Immediate working memory depends on prefrontal cortex and is usually preserved.
- B: Procedural learning is preserved, shown by his improving jigsaw speed.
- D: Remote childhood memories are intact.
Question 6 · Medium
A 35-year-old woman has gradually reduced hearing in the left ear. With a 512 Hz tuning fork, the Rinne test is negative on the left and positive on the right, and the Weber test is heard louder in the left ear. What does this show?
1. ALeft sensorineural hearing loss
2. BLeft conductive hearing loss
3. CRight sensorineural hearing loss
4. DRight conductive hearing loss
Answer and explanation in LearnFree account
Question 7 · Medium
A 19-year-old engineering student falls asleep in lectures and even during meals. When he laughs at a joke, his knees buckle and he slumps to the floor while fully conscious. A sleep study shows REM sleep within minutes of falling asleep. Loss of which neurons underlies his illness?
1. ADopaminergic neurons of the substantia nigra
2. BHistaminergic neurons of the posterior hypothalamus
3. COrexin neurons of the lateral hypothalamus
4. DSerotonergic neurons of the raphe nuclei
Answer and explanation in LearnFree account
Question 8 · Easy
A 4-year-old girl from a tribal hamlet is brought to an anganwadi health camp because she stumbles about after dusk and cannot find her toys in dim light. There are dry, foamy grey patches on the bulbar conjunctiva. Which photopigment is affected?
1. AMelanin in the pigment epithelium
2. BPhotopsins in the cones
3. CRhodopsin in the rods
4. DMelanopsin in ganglion cells
Answer and explanation in LearnFree account
Question 9 · Easy
A 35-year-old man undergoes overnight polysomnography for loud snoring. The report notes sleep spindles and K-complexes on the EEG during part of the night. Which sleep stage do these features define?
1. AStage N3
2. BStage N1
3. CREM sleep
4. DStage N2
Answer and explanation in LearnFree account
Question 10 · Medium
A 64-year-old retired bank officer punches and kicks in his sleep in the early morning hours, shouting as if in a fight. When woken, he describes a vivid dream of being attacked. Polysomnography shows raised chin muscle tone during REM periods. Loss of which normal feature of sleep explains his behaviour?
1. AEye movements during REM sleep
2. BSleep spindles during N2 sleep
3. CSlow waves during N3 sleep
4. DMuscle atonia during REM sleep
Answer and explanation in LearnFree account
Question 11 · Hard
A 60-year-old man in the ICU receives large, rapid IV boluses of furosemide for acute pulmonary oedema. Next day he complains of reduced hearing and ringing in both ears. The drug impairs hearing chiefly by reducing which of these?
1. AStiffness of the basilar membrane near the apex
2. BNumber of inner hair cells in the organ of Corti
3. CEndocochlear potential made by the stria vascularis
4. DSodium concentration of perilymph in scala tympani
Answer and explanation in LearnFree account
Question 12 · Easy
An EEG is recorded from a 22-year-old medical student lying relaxed with her eyes closed. Regular waves of about 10 Hz are seen over the occipital region; they are replaced by low-voltage, faster waves when she opens her eyes. What are the 10 Hz waves called?
1. ADelta waves
2. BBeta waves
3. CAlpha waves
4. DTheta waves
Answer and explanation in LearnFree account
Question 13 · Hard
A 30-year-old man has overnight polysomnography for suspected obstructive sleep apnoea. Consider these statements about REM sleep in such a study: 1. The EEG is low-voltage and fast, resembling the awake state. 2. Tone is lost in limb and chin muscles, but the diaphragm and extraocular muscles keep working. 3. REM periods are longest in the first third of the night. 4. Obstructive apnoeas tend to be worse in REM than in N3 sleep. Which statements are correct?
1. A1, 2 and 4 only
2. B1, 2 and 3 only
3. C2 and 4 only
4. D1 and 2 only
Answer and explanation in LearnFree account
Question 14 · Hard
A 38-year-old man has a right anterior temporal lobectomy for drug-resistant epilepsy. Two weeks later, visual field testing shows a new defect. Which field defect is expected?
1. ARight homonymous superior quadrantanopia
2. BLeft homonymous inferior quadrantanopia
3. CBitemporal superior quadrantanopia
4. DLeft homonymous superior quadrantanopia
Answer and explanation in LearnFree account
Question 15 · Medium
Recovering from herpes simplex encephalitis that involved both temporal lobes, a young man has become strangely placid and fearless, puts coins and soap into his mouth, and makes inappropriate sexual advances to ward staff. He no longer recognises common objects by sight. Bilateral damage to which structure chiefly explains his behaviour?
1. AMammillary bodies
2. BCingulate gyrus
3. CAmygdala
4. DVentromedial hypothalamus
Answer and explanation in LearnFree account
Question 16 · Hard
Bilateral medial temporal lobe damage from hypoxia after a cardiac arrest has left a former accountant unable to remember anything that has happened since his illness; each morning he greets his therapist as a stranger, though he recalls his school years well. Over two weeks of daily sessions he becomes steadily faster and more accurate at a mirror-tracing task, while insisting each time that he has never tried it before. His attention span, digit span and conversation in the moment are normal, and his mood is good. Which statement best explains this?
1. AOld memories stored before the injury are preserved
2. BEpisodic memory is stored in the amygdala
3. CWorking memory in the prefrontal cortex is intact
4. DProcedural memory uses striatal and cerebellar circuits
Answer and explanation in LearnFree account
Question 17 · Medium
Polysomnography is done for a bank clerk with 3 months of low mood, early-morning waking, loss of interest and poor appetite. 1. REM latency is shortened. 2. Slow-wave (N3) sleep is reduced. 3. The density of eye movements in REM is increased. 4. Total sleep time is increased. Which findings are typical of his illness?
1. A1, 2, 3 and 4
2. B1 and 4 only
3. C2 and 3 only
4. D1, 2 and 3 only
Answer and explanation in LearnFree account
Question 18 · Medium
After surgery for a craniopharyngioma, a patient's body temperature drifts with the room: it falls to 34 °C in the air-conditioned ICU and rises to 38.5 °C when covered with blankets, without shivering or sweating in response. Infection screens are negative. Damage to which region best explains this?
1. AAnterior hypothalamus alone
2. BPosterior hypothalamus
3. CSupraoptic nucleus
4. DArcuate nucleus
Answer and explanation in LearnFree account
Question 19 · Hard
In the neurosurgical ICU, a road traffic accident victim has been deeply comatose for 12 hours, with a GCS of 5, equal reactive pupils and spontaneous breathing. The cervical spine has not yet been cleared, so the oculocephalic (doll's eye) test is avoided. CT shows diffuse swelling without a mass lesion. To assess brainstem function, the intact tympanic membranes are checked and 50 mL of ice-cold water is run slowly into the right external ear canal with the head raised 30 degrees. If the brainstem pathways are intact, what eye response is expected?
1. ANystagmus with the fast phase to the right
2. BNystagmus with the fast phase to the left
3. CNo movement of either eye
4. DSlow tonic deviation of both eyes to the right
Answer and explanation in LearnFree account
Question 20 · Easy
When the eye focuses on a near object, the ciliary muscle contracts. What happens to the zonules and the lens?
1. AZonules slacken and the lens flattens
2. BZonules tighten and the lens becomes more convex
3. CZonules slacken and the lens becomes more convex
4. DZonules tighten and the lens flattens
Answer and explanation in LearnFree account
Question 21 · Medium
A chronic alcoholic recovering from Wernicke encephalopathy at a de-addiction centre in Kozhikode cannot remember the doctor who saw him an hour earlier, and he fills the gaps with invented stories of a recent trip to Dubai. His attention span, language and general intelligence are preserved. Damage to which structures is most typical of this condition?
1. AMammillary bodies and dorsomedial thalamus
2. BPrefrontal cortex and cingulate gyrus
3. CCaudate nucleus and putamen
4. DAmygdala and uncus
Answer and explanation in LearnFree account
Question 22 · Easy
After a left middle cerebral artery stroke, a shopkeeper understands everything said to him and follows commands, but his speech is slow, effortful and telegraphic, and he is visibly frustrated by it. Repetition is poor and his right arm is weak. Which area is damaged?
1. ALeft arcuate fasciculus
2. BLeft inferior frontal gyrus
3. CLeft superior temporal gyrus
4. DLeft angular gyrus
Answer and explanation in LearnFree account
Question 23 · Medium
Speaking rapidly and fluently but with many invented words, an elderly man in the stroke unit cannot follow simple spoken commands and seems unaware of his errors. Repetition is also impaired, his hearing is normal, and there is no limb weakness. Where is the lesion most likely?
1. ALeft inferior frontal gyrus
2. BRight posterior superior temporal gyrus
3. CLeft posterior superior temporal gyrus
4. DLeft precentral gyrus
Answer and explanation in LearnFree account
Question 24 · Medium
Audiometry before ossicular reconstruction shows a 45 dB air-bone gap in the right ear of a teacher whose chronic otitis media has eroded the long process of the incus; the tympanic membrane is intact. The surgeon explains that the normal middle ear amplifies sound pressure so that it can pass from air into cochlear fluid. Which feature contributes most to this pressure gain?
1. AResonance of the external ear canal
2. BLever action of the malleus and incus
3. CArea ratio of tympanic membrane to stapes footplate
4. DContraction of the stapedius muscle
Answer and explanation in LearnFree account
Question 25 · Medium
Small, irregular pupils that do not constrict to light but constrict briskly when he looks at a near object are found in a lorry driver with positive treponemal serology, shooting leg pains and absent ankle jerks. Vision is normal in both eyes. Where does the lesion lie?
1. ACiliary ganglion
2. BOculomotor nerve trunk
3. COptic nerve
4. DPretectal area of the dorsal midbrain
Answer and explanation in LearnFree account

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Higher functions, sleep and special senses physiology

A 32-year-old nurse in a Delhi hospital who has worked rotating night shifts for 2 years cannot sleep during the day and feels drowsy on duty. The master circadian clock that is out of step with her schedule lies in which structure?

A 7-year-old boy is found walking about the house about an hour after going to bed, eyes open but not responding to his parents. He returns to bed and next morning remembers nothing. In which stage of sleep does this behaviour most likely arise?

A 45-year-old man who has worked for 20 years in a textile mill in Surat without ear protection has difficulty following conversation in noisy places. His audiogram shows a bilateral sensorineural dip at 4,000 Hz with better hearing at 8,000 Hz. Which cells are damaged first?

A 10-year-old boy was operated on for a craniopharyngioma involving the floor of the third ventricle. Since then he eats constantly, searches for food at night and has gained 12 kg in 6 months. Damage to which hypothalamic area best explains this?

A 35-year-old woman has gradually reduced hearing in the left ear. With a 512 Hz tuning fork, the Rinne test is negative on the left and positive on the right, and the Weber test is heard louder in the left ear. What does this show?

A 19-year-old engineering student falls asleep in lectures and even during meals. When he laughs at a joke, his knees buckle and he slumps to the floor while fully conscious. A sleep study shows REM sleep within minutes of falling asleep. Loss of which neurons underlies his illness?

A 4-year-old girl from a tribal hamlet is brought to an anganwadi health camp because she stumbles about after dusk and cannot find her toys in dim light. There are dry, foamy grey patches on the bulbar conjunctiva. Which photopigment is affected?

A 35-year-old man undergoes overnight polysomnography for loud snoring. The report notes sleep spindles and K-complexes on the EEG during part of the night. Which sleep stage do these features define?

A 60-year-old man in the ICU receives large, rapid IV boluses of furosemide for acute pulmonary oedema. Next day he complains of reduced hearing and ringing in both ears. The drug impairs hearing chiefly by reducing which of these?

An EEG is recorded from a 22-year-old medical student lying relaxed with her eyes closed. Regular waves of about 10 Hz are seen over the occipital region; they are replaced by low-voltage, faster waves when she opens her eyes. What are the 10 Hz waves called?

A 38-year-old man has a right anterior temporal lobectomy for drug-resistant epilepsy. Two weeks later, visual field testing shows a new defect. Which field defect is expected?

When the eye focuses on a near object, the ciliary muscle contracts. What happens to the zonules and the lens?

After a left middle cerebral artery stroke, a shopkeeper understands everything said to him and follows commands, but his speech is slow, effortful and telegraphic, and he is visibly frustrated by it. Repetition is poor and his right arm is weak. Which area is damaged?

Speaking rapidly and fluently but with many invented words, an elderly man in the stroke unit cannot follow simple spoken commands and seems unaware of his errors. Repetition is also impaired, his hearing is normal, and there is no limb weakness. Where is the lesion most likely?

Small, irregular pupils that do not constrict to light but constrict briskly when he looks at a near object are found in a lorry driver with positive treponemal serology, shooting leg pains and absent ankle jerks. Vision is normal in both eyes. Where does the lesion lie?