​dr Gawad Physiology Course Online Exams – EEG, Sleep, Thalamus, Hypothalamus, Limbic System

During non-REM sleep, dreams are not consolidated. Non-REM sleep is characterized by a decrease in brain activity and is typically dreamless. Dreaming usually occurs during REM (rapid eye movement) sleep, which is a different stage of sleep. Therefore, the statement "dreams are consolidated" is false in relation to non-REM sleep.

During REM (Rapid Eye Movement) sleep, the brain is highly active, and this is the stage where most dreaming occurs. Consolidation refers to the process of strengthening and integrating newly acquired information into long-term memory. Research has shown that REM sleep plays a crucial role in consolidating memories and facilitating learning. Therefore, it is true that dreams can be consolidated during REM sleep.

The destruction of the ventromedial nucleus of the hypothalamus can lead to obesity. This is because the ventromedial nucleus plays a crucial role in regulating satiety and controlling food intake. When this area is damaged, it disrupts the normal signaling process that tells the body when it is full, leading to overeating and weight gain.

The hypothalamus is responsible for regulating various bodily functions, including feeding behavior. The feeding center in the hypothalamus is indeed chronically active, meaning it is constantly involved in regulating hunger and satiety. This activity is crucial for maintaining a balance in food intake and energy expenditure. The hypothalamus receives signals from different parts of the body, such as hormones and nutrient levels, to determine when to initiate or suppress feeding behavior. Therefore, the statement that the feeding center is chronically active accurately describes the function of the hypothalamus in relation to feeding.

In thalamic syndrome, pain is following the "all or nothing" principle. This means that the patient either experiences severe pain or no pain at all, with no middle ground. This is due to the disruption of the thalamus, a part of the brain that is involved in processing pain signals. The other statements provided in the question are not related to the concept of thalamic syndrome and are therefore not true.

The anterior hypothalamus is responsible for regulating heart rate. Stimulation of the anterior hypothalamus leads to a decrease in heart rate, resulting in a low heart rate.

The anterior hypothalamus is considered as a sleeping center. It plays a crucial role in regulating sleep-wake cycles and promoting sleep. Damage to this area can lead to insomnia or other sleep disorders. The anterior hypothalamus contains neurons that release the neurotransmitter GABA, which inhibits wake-promoting neurons in the brain. This inhibition helps to initiate and maintain sleep. Additionally, the anterior hypothalamus receives input from other sleep-regulating regions of the brain, such as the suprachiasmatic nucleus, further contributing to its role as a sleeping center.

During REM (Rapid Eye Movement) stage of sleep, the most accepted explanation is that there is an increase in the release of acetylcholine. Acetylcholine is a neurotransmitter that plays a crucial role in regulating various brain functions, including arousal, attention, and memory. Its release during REM sleep is believed to be responsible for the activation of the brain and the occurrence of vivid dreaming. GABA (gamma-aminobutyric acid) and histamine are also involved in sleep regulation, but they are not specifically associated with the physiology of REM stage.

During the sleep-wake cycle, REM (Rapid Eye Movement) sleep is followed by stage 2 Non-REM sleep. This means that after the initial period of REM sleep, the individual transitions into stage 2 Non-REM sleep. This pattern repeats throughout the night, with multiple cycles of REM and Non-REM sleep. The statement "REM is followed by stage 2 Non-REM" accurately describes this sequence in the sleep-wake cycle.

The given answer "None of the above" is correct because none of the statements provided accurately describe the functions of the thalamus. The thalamus does not solely receive sensation from the same side limb, as it receives sensory information from both sides of the body. ILN (Intralaminar Nuclei) is not specifically concerned with the motor function of the thalamus, as it has a more general role in regulating consciousness and attention. Arousal is not solely the function of the post-ventral nucleus, as multiple thalamic nuclei contribute to arousal and wakefulness. Therefore, none of the statements are true regarding thalamus function.