Feeds

What lies without

Life on the human body

Next gen security for virtualised datacentres

Also in this week's column:

What lies without: Life on the human body

The skin of the human body is alive with life - microscopic life of all kinds. In his classic work, Life on Man (1969), Theodor Rosebury estimates that there are 10m individual bacteria living on the average square centimeter of human skin (155,000 per sq inch).

Rosebury describes all of these robust, active, fertile microscopic creatures as like a "teeming human population during Christmas shopping". The population of bacteria on the 2 sq meters (21.52 sq feet) of the skin surface of the human body varies depending upon what part of the body you examine.

The most bacteria-prone parts of the body are the armpits, the anal region, the pubic region, and the oily sides of the nose. For example, the armpit is the home of up to about 203,000 bacteria per square cm (516,000 per sq inch). Each square cm of human skin consists of about four million cells (10m per sq inch), 24 hairs (60 per sq inch), 35 oil glands (90 per sq inch), 6.1 meters of blood vessels (20 feet per sq inch), 246 sweat glands (625 per sq inch), 7,480 sensory cells (19,000 per sq inch), 23,622 pigment cells (60,000 per sq inch), more than 393 nerve endings (1,000 per sq inch), and all of that microscopic life.

Although all the microscopic life is high in numbers, it is small in size and weight. Rosebury estimates that all of the bacterial life on the human skin surface would fit into a medium-sized pea and possibly weigh about as much.

It is not just bacteria that live on the human skin. We can also become infested with a variety of creatures that set up household on our skin and dine there to their little heart's content.

According to Dr Jonathan Kantor of the Department of Dermatology at the University of Pennsylvania Medical Centre in Philadelphia, there are three types of louse (Pediculus humanus corporis) that can live on humans. They are head lice (Pediculus capitis), body lice (Pediculus humanus), and pubic lice (Pthirus pubis). No prizes for figuring out where on the body each type lives.

There are also the follicle mite (Demodex folliculorum) that lives on the eyebrows, the scabies mite (Sarcoptes scabiei) that lives everywhere, and several other Trombiculae mites (chiggers, redbugs, rougets, harvest, and scrub) that camp out everywhere. In addition there are the tropical rat mite (Ornithonyssus bacoti), the human bot (Dermatobia hominis), the primary screwworm (Cochliomyia hominivorax), and of course ticks, fleas, bed bugs, and a few others. Our skin is a veritable United Nations of tiny critters.

Stephen Juan, Ph.D. is an anthropologist at the University of Sydney. Email your Odd Body questions to s.juan@edfac.usyd.edu.au

Secure remote control for conventional and virtual desktops

More from The Register

next story
Our LOHAN spaceplane ballocket Kickstarter climbs through £8000
Through 25 per cent but more is needed: Get your UNIQUE rewards!
LOHAN tunes into ultra long range radio
And verily, Vultures shall speak status unto distant receivers
NASA to reformat Opportunity rover's memory from 125 million miles away
Interplanetary admins will back up data and get to work
SpaceX prototype rocket EXPLODES over Texas. 'Tricky' biz, says Elon Musk
No injuries or near injuries. Flight stayed in designated area
EOS, Lockheed to track space junk from Oz
WA facility gets laser-eyes out of the fog
Volcanic eruption in Iceland triggers CODE RED aviation warning
Lava-spitting Bárðarbunga prompts action from Met Office
LOHAN Kickstarter breaks NINETEEN THOUSAND of your EARTH POUNDS
That's right, OVER 9,000 beer tokens - and counting
prev story

Whitepapers

Endpoint data privacy in the cloud is easier than you think
Innovations in encryption and storage resolve issues of data privacy and key requirements for companies to look for in a solution.
Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Advanced data protection for your virtualized environments
Find a natural fit for optimizing protection for the often resource-constrained data protection process found in virtual environments.
Boost IT visibility and business value
How building a great service catalog relieves pressure points and demonstrates the value of IT service management.
Next gen security for virtualised datacentres
Legacy security solutions are inefficient due to the architectural differences between physical and virtual environments.