Question

Increases in which of the following hormones cause sleepiness? (A) Cortisol (B) Growth hormone (C) Melatonin (D) Oxytocin

Short answer

(C) Melatonin

Step-by-step solution

- Understand the Question

Determine which hormone is known to cause sleepiness when its levels increase.

- Review Hormones and Their Functions

This step involves recalling the primary functions of each hormone mentioned in the options: (A) Cortisol - Often related to stress and wakefulness.(B) Growth hormone - Primarily involved in growth and cell reproduction.(C) Melatonin - Known for regulating sleep-wake cycles.(D) Oxytocin - Linked to social bonding and reproduction.

- Identify the Hormone with Effects on Sleep

Among the options, identify which hormone directly affects sleep. Melatonin is the hormone that increases and induces sleepiness by signaling the body to prepare for sleep.

- Select the Correct Answer

Given the analysis, the correct answer is (C) Melatonin.

Key concepts

Melatonin Function

Melatonin is a hormone produced by the pineal gland in the brain. It's often called the 'sleep hormone' because it plays a key role in regulating sleep-wake cycles. Melatonin levels in the blood rise in response to darkness and fall in the presence of light.

Here are some pivotal functions of melatonin:

• **Induces Sleepiness**: When melatonin levels increase, it signals the body that it's time to sleep.
• **Regulates Sleep-Wake Cycles**: It helps synchronize the body's internal clock with the external environment's light-dark cycle.
• **Antioxidant Activity**: Melatonin acts as an antioxidant, protecting cells from damage caused by free radicals.

Understanding melatonin's function can help in managing sleep disorders and improving sleep quality. The production of this hormone can be influenced by factors such as light exposure, lifestyle, and age.
By ensuring a dark environment before bed, you can promote natural melatonin production.

Sleep-Wake Cycles

The sleep-wake cycle is a daily rhythm that governs our periods of wakefulness and sleep. It is often described as a circadian rhythm, which means it follows a roughly 24-hour cycle.

Key points about sleep-wake cycles include:

• **Circadian Rhythm**: This internal body clock helps regulate when we feel alert and when we feel sleepy. It is influenced by external cues like light and temperature.
• **Role of Melatonin**: Melatonin is crucial in promoting sleep within this cycle. Its release is triggered by darkness and helps prepare the body for rest.
• **External Influences**: Exposure to bright light, especially blue light from screens, can disrupt the sleep-wake cycle by suppressing melatonin production.

Maintaining a regular sleep-wake schedule can support better sleep quality and overall health. It's essential to create an environment conducive to sleep, which includes controlling light exposure and keeping a regular bedtime.

Endocrine System

The endocrine system is a network of glands and organs that produce, store, and release hormones. These hormones are crucial for regulating various bodily functions.

Here are essential aspects of the endocrine system:

• **Hormone Regulation**: Hormones control processes like growth, metabolism, and sleep. They act as messengers, sending signals to different parts of the body.
• **Major Glands**: Some key glands in the endocrine system include the pineal gland (melatonin production), the pituitary gland, the thyroid, and the adrenal glands (cortisol production).
• **Sleep and Hormones**: The pineal gland produces melatonin, regulating sleep patterns. Other hormones like cortisol also affect sleep and wakefulness but in different ways.

A well-functioning endocrine system ensures balanced hormone levels, contributing to overall health and well-being. Factors like stress, diet, and lifestyle can influence this system, so maintaining a healthy lifestyle is essential for hormone balance.