[Ottehg Star (OP)]

When you get in a hot bath your skin, even the bits submerged get goosebumps. Why? Goosebumps are a reflex action for when the skin is cold. Explain ............

[harryneild]

Here i found this on a site. Hope it answers your question:

quote:The smooth muscle that is responsible for "goose bumps" is called arrector
pili or pilimotor muscles.  The are attached to the hair follicle and when
contacted, raise the hair and pull the skin down in an "attempt" to
insulate us from cold via trapping air between the hair.  The "bumps" are
really the indentions due to the muscle pulling the epidermis down and we
notice the difference in height along the skin.  Since these muscles are
smooth, they are innervated by the Autonomic Nervous System (ANS).  The
sympathetic branch of the ANS is the only branch that is connected to these
muscles.  When activated by the ANS, contraction occurs.  In the dermis of
the skin, there are at least 2 types of temperature receptors, one for hot
& one for cold.  Both of these are "phasic", meaning that they react to a
range of temperatures.  For example, the cold receptors, sometimes called
Bulbs of Krause, reach threshold between 12 and 35 degrees C whereas the
hot receptors (Ruffini organs) are activated between 25 & 47 degrees C.
Below 12 and above 47, pain receptors reach threshold.  Both the cold and
hot receptors use the same sensory pathway to the brain called the lateral
spinothalamic tract.  This tract goes through the thalamus and terminates
in the appropriate location of the post central gyrus of the cerebrum.  
This helps us to locate the area of the body that is being stimulated.
Temperature changes are mediated by nuclei in the hypothalamus which
has connections to the thalamus and which then sends messages to the
medulla.  From there, impulses go down the spinal cord and out spinal
nerves, which make up the sympathetic division or thoracolumbar outflow.  
These send a nerve impulse to the arrector pili muscles and they contract.
 It would therefore seem to me that if one gets "goose bumps" from hot
temps it is due to this pathway being stimulated by a temperature that is
an overlapping one so that both hot and cold receptors are being activated.

"Knowledge has to be improved, challenged, and increased constantly, or it vanishes." Peter F. Drucker

[Hadrian]

Buoyancy aid?

 


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What you do speaks so loudly that I cannot hear what you say.