weird facts about the body

WTF Fun Fact 13344 – Humans Can’t Feel Wetness

The fact that humans can’t feel wetness seems ridiculous at first. You may have even read that it’s a misconception. But, technically speaking, we do not have the right “gear” to directly sense wetness – even though we all know when something is wet.

But how does that work?

Why humans can’t feel wet

Humans lack dedicated hydroreceptors – the specialized sensory receptors solely responsible for detecting wetness. As a result, wetness is not a distinct sensation for us, but rather an interpretation of multiple sensory inputs.

When a liquid, such as water, comes into contact with the skin, several different types of sensory receptors are activated. These include thermoreceptors, mechanoreceptors, and nociceptors. Thermoreceptors respond to temperature changes and can detect the cooling effect of the liquid on the skin. However, this response alone does not convey the specific quality of wetness.

Mechanoreceptors, responsible for sensing pressure and touch, provide information about the physical presence of the liquid. They detect the pressure exerted by the liquid and signal the brain accordingly. However, the activation of mechanoreceptors alone does not differentiate between wet and dry sensations.

Nociceptors, which detect pain and discomfort, may also play a role in the perception of wetness. If the liquid is extremely hot, cold, or otherwise causes discomfort, nociceptors are activated, contributing to the overall sensation. However, this response is not exclusive to wetness and can be triggered by other stimuli as well.

How we sense “wet”

Due to the absence of dedicated hydroreceptors, the brain must integrate and interpret these various signals to create the perception of wetness. It combines the inputs from thermoreceptors, mechanoreceptors, and nociceptors, along with other contextual cues, to generate the subjective experience of being wet.

While humans can recognize and differentiate wet sensations, it is important to note that wetness itself is not a distinct sensory modality. Rather, it is a perception resulting from the brain’s processing of multiple sensory inputs related to temperature, pressure, and even discomfort.

— WTF fun facts

Source: “Humans Technically Can’t Feel Wetness, And People Are Confused” — IFL Science

WTF Fun Fact 13273 – Men’s Nipples Lactate

It’s extremely rare unless something is wrong with the body, but technically, men’s nipples lactate. That is, they are capable of producing milk, which is the function of a nipple.

All fetuses develop nipples. Male, female, and intersex fetuses develop nipples during the early stages of fetal development, typically around 6 to 7 weeks gestation. This is because nipples are a fundamental part of the human anatomy. It is only later in fetal development that sex-specific features begin to emerge, such as the development of genitalia.

How, when, and why do men’s nipples lactate?

While lactation in men is a rare occurrence, it is not something that should be dismissed as a mere anomaly. Despite being uncommon, men can and do produce breast milk in certain circumstances. For example, it may happen during hormonal imbalances or after frequent stimulation of the nipples. This phenomenon has been documented in a variety of mammalian species, including humans. Yet much remains to be understood about the underlying biology and mechanisms driving male lactation.

Male lactation is also known to occur in response to the hormonal changes brought about by certain medical conditions. For example, in some cases, male lactation is triggered when a man experiences a rise in the hormone prolactin.

The role of prolactin

The hormone responsible for milk production in females plays a similar role in males. Prolactin stimulates milk production in the mammary glands, and in males, it is secreted by the anterior pituitary gland.

However, the prolactin levels in males are much lower than in females. This is why milk production in males is rare, and the amount produced is usually not enough to sustain an infant. The biology involved in male lactation involves the mammary glands, which are present in both men and women.

While these glands are not fully developed in men, they still have the potential to produce milk. The process of male lactation can also be triggered by stress, certain medications, or a tumor in the pituitary gland.

Stimulating lactation in men

Another cause of male lactation is the use of medications that can mimic the hormonal effects of pregnancy and breastfeeding. For example, medications containing estrogen can cause an increase in prolactin production, leading to milk production in men’s mammary glands.

Despite the rarity of male lactation, some men have been able to nurse their infants successfully. One example is a man named Jack Newman. After adopting a child, Newman was able to induce lactation through a combination of hormone treatments and frequent nursing sessions.

Male lactation may seem like a strange and abnormal occurrence. But the rare phenomenon of male lactation is a fascinating subject. And it has captured the interest of scientists and laypeople alike. While much remains to be discovered, continued research into male lactation could have significant implications for our understanding of infant nutrition and lactation science as a whole. The underlying mechanisms that allow men to produce milk could help to improve our understanding of the biology of lactation in general. This could lead to breakthroughs in lactation-related issues such as mastitis and low milk supply.

Despite these potential benefits, male lactation remains a largely unexplored field of study.

— WTF fun facts

Source: “Strange but True: Males Can Lactate” — Scientific American