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How Mosquitoes Use Six Needles to Suck Your Blood | Deep Look

7 vistas· 03/04/20
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Seen up close, the anatomy of a mosquito bite is terrifying. The most dangerous animal in the world uses six needle-like mouthparts to saw into our skin, tap a blood vessel and sometimes leave a dangerous parting gift.

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DEEP LOOK is a ultra-HD (4K) short video series created by KQED San Francisco and presented by PBS Digital Studios. Explore big scientific mysteries by going incredibly small.

Scientists have discovered that the mosquito’s mouth, called a proboscis isn’t just one tiny spear. It’s a sophisticated system of thin needles, each of which pierces the skin, finds blood vessels and makes it easy for mosquitoes to suck blood out of them.

Male mosquitoes don’t bite us, but when a female mosquito pierces the skin, a flexible lip-like sheath called the labium scrolls up and stays outside as she pushes in six needle-like parts that scientists refer to as stylets.

Two of these needles, called maxillae, have tiny teeth. The mosquito uses them to saw through the skin. They’re so sharp you can barely feel the mosquito biting you.

“They’re like drill bits,” said University of California, Davis, biochemist Walter Leal.

Another set of needles, the mandibles, hold tissues apart while the mosquito works.

Then the sharp-tipped labrum needle probes under the skin, piercing a vessel and sucking blood from it.

The sixth needle – called the hypopharynx – drools saliva into us, and delivers chemicals that keep our blood flowing. Mosquito saliva also makes our blood vessels dilate, blocks our immune response and lubricates the proboscis. It causes us to develop itchy welts, and serves as a conduit for dangerous viruses and parasites.

---+ Read the entire article on KQED Science:
http://ww2.kqed.org/science/20....16/06/07/how-mosquit

---+ What is the deadliest animal in the world?
Mosquitoes are the deadliest animals in the world to us humans. The diseases they transmit kill hundreds of thousands of people each year.

---+ How many people get malaria each year?
In 2015, malaria, the deadliest mosquito-borne disease, killed roughly 635,000 people, mostly children under the age of five and pregnant women in sub-Saharan Africa.

---+ What diseases do mosquitoes transmit?
Malaria, dengue, yellow fever, West Nile and Zika are some of the diseases that mosquitoes transmit.

Dengue fever, transmitted Aedes aegypti mosquitoes, is estimated to make almost 400 million people sick with jabbing joint pain each year.

Scientists also believe that Aedes aegypti mosquitoes are the main culprit for more than 350 confirmed cases of congenital malformations associated with the Zika virus in the northeastern Brazilian state of Pernambuco. Since last October, an unusually high number of babies have been born there with small heads and a host of health problems like convulsions, suspected of being caused by a Zika virus infection early in their mother’s pregnancy.

---+ What diseases can I get from mosquitoes in the United States?
West Nile virus is the most important of several mosquito-transmitted viruses now native to the U.S., according to the Centers for Disease Control.

---+ More Great Deep Look episodes:

The Bombardier Beetle And Its Crazy Chemical Cannon
https://youtu.be/BWwgLS5tK80

--- See also this new Zika video from PBS Digital Studios:

Should You Be Worried About Zika? | It's Okay to Be Smart
https://www.youtube.com/watch?v=rZ9S_3RFBgc

---+ About KQED

KQED, an NPR and PBS affiliate in San Francisco, CA, serves Northern California and beyond with a public-supported alternative to commercial TV, Radio and web media.

Funding for Deep Look is provided in part by PBS Digital Studios and the John S. and James L. Knight Foundation. Deep Look is a project of KQED Science, which is also supported by HopeLab, the David B. Gold Foundation, the S. D. Bechtel, Jr. Foundation, the Dirk and Charlene Kabcenell Foundation, the Vadasz Family Foundation, the Gordon and Betty Moore Foundation, the Smart Family Foundation and the members of KQED.

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Video of mosquito labrum probing under mouse skin from:
Choumet V, Attout T, Chartier L, Khun H, Sautereau J, et al. (2012) Visualizing Non Infectious and Infectious Anopheles gambiae Blood Feedings in Naïve and Saliva-Immunized Mice. PLoS ONE 7(12): e50464. doi:10.1371/journal.pone.0050464 .
Used under the terms of: http://creativecommons.org/licenses/by/4.0/

Animations based on drawing in Choo Y-M, Buss GK, Tan K and Leal WS (2015) Multitasking roles of mosquito labrum in oviposition and blood feeding. Front. Physiol. 6:306. doi: 10.3389/fphys.2015.00306
Used under the terms of: http://creativecommons.org/licenses/by/4.0/
#deeplook #mosquito #mosquitobite

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