1.
A patient with daytime sleepiness is sent to a sleep lab for analysis. Just after midnight, the EEG records K complexes and sleep spindles. What stage of sleep is being recorded?
Correct Answer
D. Stage 2
Explanation
The presence of K complexes and sleep spindles on the EEG indicates that the patient is in Stage 2 of sleep. K complexes are large, slow waves that occur during this stage, while sleep spindles are bursts of rapid brain activity. This stage is characterized by light sleep and is a transition between the initial drowsiness of Stage 1 and the deeper sleep of Stage 3 and REM sleep.
2.
Which of the following nuclei are most directly involved in narcolepsy?
Correct Answer
A. Dorsolateral hypothalamus
Explanation
The dorsolateral hypothalamus is most directly involved in narcolepsy. Narcolepsy is a sleep disorder characterized by excessive daytime sleepiness and sudden attacks of sleep. Studies have shown that there is a loss of hypocretin-producing neurons in the dorsolateral hypothalamus in individuals with narcolepsy. Hypocretin is a neuropeptide that plays a crucial role in regulating wakefulness and sleep. The loss of hypocretin leads to disruptions in the sleep-wake cycle and results in the symptoms of narcolepsy. Therefore, the dorsolateral hypothalamus is the most directly involved nucleus in narcolepsy.
3.
A healthy young medical student is trying not to fall asleep during a boring lecture. Suddenly, a high pitch loud noise makes him feel alert and very aware of his environment. Which part of his reticular formation (RF) is the most involved in this phenomenon?
Correct Answer
D. Lateral RF
Explanation
The lateral reticular formation (RF) is the most involved in this phenomenon. The RF is responsible for regulating arousal and attention. When the high pitch loud noise occurs, it stimulates the lateral RF, causing the medical student to feel alert and very aware of his environment. The lateral RF plays a crucial role in maintaining wakefulness and vigilance.
4.
Among all the structures involved in sleep, which one is receiving direct photic input?
Correct Answer
B. Suprachiasmatic nucleus
Explanation
The suprachiasmatic nucleus is receiving direct photic input. This is because the suprachiasmatic nucleus is located in the hypothalamus and is responsible for regulating the circadian rhythm, or the internal body clock. It receives direct input from the eyes through the optic nerve, allowing it to detect changes in light and darkness. This information helps the suprachiasmatic nucleus synchronize the body's internal clock with the external environment, helping to regulate sleep-wake cycles.
5.
As compared to wakefulness, which neurotransmitter is increased during all stages of sleep?
Correct Answer
C. GABA
Explanation
During all stages of sleep, the neurotransmitter GABA is increased compared to wakefulness. GABA (gamma-aminobutyric acid) is an inhibitory neurotransmitter that helps to regulate and reduce neuronal activity in the brain. It plays a crucial role in promoting sleep by inhibiting the release of other neurotransmitters that promote wakefulness, such as norepinephrine and acetylcholine. The increase in GABA levels during sleep helps to promote relaxation, reduce arousal, and facilitate the transition and maintenance of sleep.
6.
The suprachiasmatic nucleus projects
Correct Answer
B. Indirectly to the pineal gland
Explanation
The suprachiasmatic nucleus is a small region in the brain that is responsible for regulating the body's circadian rhythm. It receives information about light and darkness from the retina and then sends signals to various parts of the brain and body to synchronize their activities with the external environment. In the case of the pineal gland, the suprachiasmatic nucleus indirectly projects to it. This means that it sends signals to other brain regions, which in turn send signals to the pineal gland. The pineal gland then produces and releases the hormone melatonin, which helps regulate sleep-wake cycles.
7.
A young mother is concerned about her son's sleep walking. She wonders if this kind of behavior signifies deeper pathology and what she can do for treatment. Given what you know about this behavioral pattern you suspect that her child's sleep walking primarily occurs during which stage of sleep?
Correct Answer
D. Stage 3 sleep
Explanation
Sleepwalking, also known as somnambulism, is a parasomnia disorder that usually occurs during deep sleep, specifically in stage 3 sleep. During this stage, the brain waves are slow and large, and it is difficult to awaken the individual. Sleepwalking is believed to be caused by a disruption in the transition between sleep stages, leading to partial arousal and the performance of complex behaviors while still asleep. Therefore, based on the information provided, it is likely that the young mother's son's sleepwalking primarily occurs during stage 3 sleep.
8.
A young man with a history of hypersomnia is easily driven into a cataplexic state when emotionally excited. Sometimes, on awakening from sleep, he cannot move his body. Which of the following pharmacological approaches would be effective in treating his hypersomnia?
Correct Answer
C. Drug that stimulates release of hypocretin from hypothalamus
Explanation
The young man's hypersomnia is likely caused by a deficiency in hypocretin, a neuropeptide that regulates wakefulness. This is supported by the fact that he experiences cataplexy, which is often associated with narcolepsy, a condition characterized by a lack of hypocretin. Therefore, a drug that stimulates the release of hypocretin from the hypothalamus would be effective in treating his hypersomnia.
9.
A mother consults with a general health practitioner because she is concerned that her child is talking in his sleep and sleep walking on a nightly basis. Such behavior is?
Correct Answer
F. Associated with a stage of sleep with high amplitude, low frequency wave forms
Explanation
The behavior of talking in sleep and sleepwalking is associated with a stage of sleep that has high amplitude, low frequency waveforms. This stage of sleep is known as slow-wave sleep or deep sleep. During this stage, the brain activity is characterized by slow, synchronized waves, which are different from the beta waveforms of the waking state. This behavior is not necessarily dangerous or a major health risk to the child, but it may indicate a disruption in the normal sleep cycle.
10.
A sleep histogram allows a sleep investigator to observe the stages of sleep. Imagine you were consulting with a patient who complains of intense hypersomnia during the day. Investigation of the airway reveals enlarged tonsils. Obstructive sleep apnea is suspected. Which of the following scenarios would you expect to be the major abnormal feature of this individual's sleep histogram?
Correct Answer
C. Increase in the number of microawakenings
Explanation
In individuals with obstructive sleep apnea, the airway becomes partially or completely blocked during sleep, leading to disruptions in breathing and frequent awakenings throughout the night. These awakenings, known as microawakenings, are brief and often go unnoticed by the individual, but they can significantly disrupt the normal sleep cycle. Therefore, in this individual's sleep histogram, an increase in the number of microawakenings would be expected as the major abnormal feature.
11.
Which neurotransmitter is involved in Restless Legs Syndrome?
Correct Answer
B. Dopamine
Explanation
Restless Legs Syndrome (RLS) is a neurological disorder characterized by an uncontrollable urge to move the legs, often accompanied by uncomfortable sensations. Dopamine, a neurotransmitter, is involved in RLS. It is believed that a dysfunction in the dopamine system may contribute to the development of RLS symptoms. Dopamine helps regulate movement and is involved in controlling muscle activity. Therefore, a deficiency or imbalance in dopamine levels can lead to the symptoms experienced in RLS.
12.
Among all the structures involved in sleep, which one is receiving afferents from the spinal cord?
Correct Answer
C. Pineal body
Explanation
The pineal body, also known as the pineal gland, is the structure that receives afferents from the spinal cord. The pineal gland is located in the brain and is involved in the regulation of sleep-wake cycles. It receives input from the spinal cord through the sympathetic nervous system, which helps to synchronize the body's internal clock with external cues such as light and darkness. Therefore, the pineal body is the correct answer to the question.
13.
When these cells are activated, REM sleep is turned OFF:
Correct Answer
E. Noradrenergic neurons of locus coeruleus, serotoninergic neurons of the RapHe
Explanation
When the noradrenergic neurons of locus coeruleus and serotoninergic neurons of the Raphe are activated, REM sleep is turned off. These neurons release neurotransmitters that inhibit the activity of the brainstem structures responsible for generating REM sleep, leading to its suppression.
14.
What is the part of the reticular formation (RF) that is dedicated to reception of somatosensory inputs?
Correct Answer
D. Lateral RF
Explanation
The lateral RF is the part of the reticular formation that is dedicated to the reception of somatosensory inputs. This means that it is responsible for processing sensory information related to touch, temperature, and pain from various parts of the body. The other options mentioned, such as the raphe nuclei, magnocellular RF, locus coeruleus, and paramedial RF, are not specifically involved in the reception of somatosensory inputs.
15.
What is the name of the nucleus involved in heartbeat modulation?
Correct Answer
D. Nucleus solitarius
Explanation
The correct answer is Nucleus solitarius. The nucleus solitarius is involved in heartbeat modulation. It is a part of the medulla oblongata in the brainstem and is responsible for receiving and processing sensory information related to cardiovascular function. It helps regulate heart rate and blood pressure by receiving input from baroreceptors and chemoreceptors and sending signals to other areas of the brain and spinal cord involved in cardiovascular control.