Editing Vulcan (section)

==Physiology==
Externally, Vulcans are generally similar to [[human]]s, the chief exceptions being the Vulcans' notably pointed ears and arched eyebrows. Most Vulcans have pale skin with a slightly greenish tinge, and straight, glossy black hair.

Some Vulcans, including [[Tuvok]], have darker skin, tightly coiled black hair, and physiognomic features similar to those found in humans of [[Africa]]n descent. Others share physiognomic features similar to those found in humans of [[Asia]]n descent.  However, most Vulcans have a vaguely Eurasian appearance.

Vulcans have body hair similar to humans, and some males can be very hirsute.  Vulcan males are also capable of growing facial hair (as evidenced by [[Soval (mirror)|Soval]] in the [[mirror universe]]), but rarely do so.

In contrast to their external similarities, Vulcan internal [[anatomy]] differs radically from that of humans. For instance, their [[heart]] is where a Human's liver would normally be, and beats several hundred times per minute.  Vulcan blood is copper-based and is green when oxygenated in the arteries and is copper or rust colored when deoxygenated in the veins.  Bruises and dermal abrasions also take on a green color.

The Vulcan [[digestive tract]] is highly adaptable. Although [[alien]] [[food]]s, notable Human food, will occasionally disagree with a Vulcan, given time, their body will evenually adapt to the alien food.

Vulcan hearing is very sensitive. Having evolved on a planet which is mostly desert, Vulcans have developed ways of surviving in desert conditions. For example, they can survive for several days without [[water]] and have [[inner eyelid]]s which protect their [[eye]]s. 

Vulcan females possess a heightened sense of smell.  Vulcans also have superior metabolism to humans. Caffeine has little effect on Vulcans.  They are also capable of surviving for long durations without [[food]] or sleep. Under stress, Vulcans can do without sleep for weeks.  Vulcans are on average three times physically stronger than humans and are noticably more agile.

One weakness of the Vulcans is their inability to metabolize [[nitrous oxide]]. After only a few minutes of exposure to the gas, a Vulcan will pass out.

Vulcans typically have a lifespan of 200 years or more.

===The Brain===
Perhaps the most interesting aspect of the Vulcan physiology is the [[brain]]. The Vulcan brain has been described as "a puzzle, wrapped inside an enigma, housed inside a cranium"; This has some basis in fact, as the Vulcan brain is composed of many layers. It is in direct control of most of the bodily functions, acting as a control unit for many organs. Unlike most humanoid brains, traumatic memories are not only psychologically disturbing to Vulcans, but have physical consequences as well. The Vulcan brain, in reordering neural pathways, can literally lobotomize itself.

Vulcans have learned to gain conscious control of many of these functions, allowing them to regulate their bodies to a high degree by simple will power. When injured a Vulcan can go into a trance-like state, using this ability to concentrate all of his or her energy onto repairing the injury. This trance can be self-induced and give the physical appearance of near-death. It is similar, in principle,  to Vulcan [[neuropressure]] techniques which can be used to relax the mind and body.

The substance [[trellium-D]] acts as a neurotoxin to Vulcans, destroying the [[neuron|neural]] pathways which control their [[emotion]]s.  Treatment must be provided quickly after exposure, otherwise the damage is irreversible.

Of course, the most famous aspect of the Vulcan brain is the inherent [[telepathy|telepathic]] abilities, such as the [[Vulcan mind meld]].  Many Vulcans are natural touch-telepaths, though considerable training is required to utilize this ability fully.  Stronger minds are capable of non-contact telepathy, usually over short distances and in a limited fashion.  Although, typically, Vulcans do not experience uncontrolled strong emotions they may sense them in others. Some Vulcans have telepathic abilities which are far stronger than those of most members of their race.  The rigorous mental training all Vulcans are given often allows such individuals to develop such abilities as emotional compulsion and psychic image projection.  Besides [[Rao Vantika]] (who achieved it through [[technology]]) and the [[Trill]] (who achieve it when performing the  [[Zhian'tara]] ritual on joined Trill) , Vulcans are the only other race capable of performing a [[synaptic pattern displacement]], or the transfer of one individual's consciousness into another.

The psycho-suppression system responsible for the Vulcan supression of emotions is located in the mesiofrontal cortex.

Approximately every seven years, adult Vulcans must endure [[pon farr]], the Vulcan mating period. It is marked by intense emotions and primal urges (known as [[plak tow]], or "blood fever") that can kill the Vulcan if not satisfied. For such an orderly society of quiet sobriety, the madness which accompanies the outbreak of ''pon farr'' is an unavoidable evil.