So here we have an example problem that says, if someone did not have a papillary layer in their dermis, which of the following would occur? And we've got these 4 potential answer options down below. Now option a says they would become more susceptible to skin cancer. However, the papillary layer of the dermis does not play a direct role in preventing skin cancer. The papillary layer does have blood vessels to help nourish the cells in the epidermis. But the papillary layer of the dermis lies underneath the epidermis, so it does not prevent UV light from the sun from hitting those epidermal cells. And therefore, it doesn't play a direct role in preventing skin cancer and that's why we can eliminate answer option a.
Now, option b says they would no longer be able to thermoregulate via the skin. Now, recall from our previous lesson videos that thermoregulation of the skin can occur via vasoconstriction and vasodilation of blood vessels. And we know that the papillary layer does have blood vessels. So, it does play a role in thermoregulation of the skin. However, thermoregulation of the skin is not unique to the papillary layer because the reticular layer of the dermis also has blood vessels that can vasoconstrict and vasodilate and contribute to thermoregulation of the skin as well. And so, for that reason, option b is not going to be the best answer for this example problem.
Now, option c says the epidermis would be more firmly anchored to the dermis. However, this is actually the exact opposite of what would happen. Recall that the papillary layer of the dermis has dermal papillae. And those dermal papillae actually increase the surface area of contact between the dermis and the epidermis, which actually allows for more firm anchoring. And so that means that without the papillary layer there would be less firm anchoring. And this is suggesting more firm anchoring without the papillary layer. So for that reason, we can eliminate answer option c.
And of course, this leaves answer option d as the only option and it is the correct answer. Which says, they would lose some sensation of touch. Now, recall that the papillary layer of the dermis has nerve endings, specifically in structures known as the tactile or Meissner corpuscles. And so, those are going to allow for sensations of touch. And without the papillary layer and without those tactile and Meissner corpuscles, there would be fewer sensations of touch. And so for that reason we can indicate that option d is the correct answer to this example problem and that concludes this example, so I'll see you all in our next video.