2 answers left
Full Access

(1). Why does having cold hands create apainful sensation?

Is it a physical effect, maybe a protection mechanism fromevolution?

(2). Why, if one's hands are cold, does it feelas if they are more susceptible to pain?

Note: I have (2) as a separate question because the painfulsensation in (1) refers to that from the coldness, whereas in (2),I mean that certain 'ordinary tasks' would feel painful, forexample, holding a shopping bag.

Posted Aug 26 2019

Answered on Aug 28 2019
For question 1, it is only a biochemical response from thermoreceptor nerves in the skin, temperatures that are likely to cause lasting damage from prolonged exposure cause a neurological response - in this case it is pain. In response to question 2, it is most likely due to the physiological response of vasoconstriction. When the body is cold, the body undergoes a constriction of the blood vessels in the extremities to preserve the core temperature, which is more essential for the proper functioning of vital organs. By restricting blood flow to the extremities (in this case the hands), there is less blood, because the nerves in the hand are closer to the surface and therefore more sensitive to pain.

A student determines that the field of view with a 10x ocular lens and a 4x objective lens is 2.5 in diameter.What is the diameter if the student changes the objective lens to 10x?

14 Feb 2019

Plant Physiology:

Greenhouse producers often supplement the atmospheres in their facilities with extra CO2. This addition increases plant growth, leading to more rapid plant production for sale. Describe (1) how this supplemental CO2 benefits growth and the physiological and biochemical level and (2) what drawbacks the plant might face upon transplanting to a homeowner’s garden.

30 Jun 2019

What genotypes does a person with AB blood have

14 Feb 2019