What is the Main Function of Blood?

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What is the main function of blood?Ray Schilling:

Blood has many functions.

1. Most of all, blood transports oxygen from the lungs to all the tissues by way of hemoglobin that is embedded in the red blood cells. On the way back to the heart and lungs it transports CO2, which is exhaled by the lungs.

2. Nutrients are taken up in the capillaries of the gut, transported via the portal vein into the liver. Here many metabolic pathways are followed and the nutrients are further transported through the blood to all of the body cells.

3. Clotting factors in the plasma of the blood together with platelets contained in the blood see to it that any tiny tears or holes are immediately plugged. Blood has a certain blood pressure, so any defect cannot be tolerated or this could lead to a major bleed. It is interesting that coagulation from clotting factors/platelets and fibrinolysis are constantly balancing each other automatically.

4. Infection is being contained by white blood cells (lymphocytes for viruses, neutrophils for bacteria) on the one hand and antibodies from plasma cells on the other hand. This is quite an effective system to fight infection. Occasionally antibiotics are needed when our immune system is overwhelmed.

5. Hormones and other signaling molecules (e.g. nitric oxide) integrate the function of various organs. As long as all hormones are present and balanced we have energy and all our organs function perfectly. But when hormones are missing, we feel miserable. As we age, some hormones are not produced sufficiently. Having reviewed the literature, bioidentical hormone replacement will allow our system to get rebalanced.

6. Heat distribution and blood redistribution are other aspect of perfusion of our limbs with blood, our abdominal organs, the head and skin. After a meal the blood is rushing to the gut and the liver as we start to digest our meal. We may get tired, because some of the blood from the brain gets pulled away to the stomach, small intestine and the liver. On a hot day our skin veins open up wide, we sweat and lose some of our body heat through our skin. It’s the body’s way to keep us cool inside.

7. There is one aspect that seems to be out of our control. When we get excited or a person is extremely shy, the head, neck, and the ears will turn red. This is out of our control. Some people have this more than others and some don't have it at all. It comes from dilated skin blood vessels. When they dilate, blood rushes into that region giving your skin a reddened appearance.

This post originally appeared on Quora. Click here to view.

10 of the Most Popular Portable Bluetooth Speakers on Amazon

Altech/Bose/JBL/Amazon
Altech/Bose/JBL/Amazon

As convenient as smartphones and tablets are, they don’t necessarily offer the best sound quality. But a well-built portable speaker can fill that need. And whether you’re looking for a speaker to use in the shower or a device to take on a long camping trip, these bestselling models from Amazon have you covered.

1. OontZ Angle 3 Bluetooth Portable Speaker; $26-$30 (4.4 stars)

Oontz portable bluetooth speaker
Cambridge Soundworks/Amazon

Of the 57,000-plus reviews that users have left for this speaker on Amazon, 72 percent of them are five stars. So it should come as no surprise that this is currently the best-selling portable Bluetooth speaker on the site. It comes in eight different colors and can play for up to 14 hours straight after a full charge. Plus, it’s splash proof, making it a perfect speaker for the shower, beach, or pool.

Buy it: Amazon

2. JBL Charge 3 Waterproof Portable Bluetooth Speaker; $110 (4.6 stars)

JBL portable bluetooth speaker
JBL/Amazon

This nifty speaker can connect with up to three devices at one time, so you and your friends can take turns sharing your favorite music. Its built-in battery can play music for up to 20 hours, and it can even charge smartphones and tablets via USB.

Buy it: Amazon

3. Anker Soundcore Bluetooth Speaker; $25-$28 (4.6 stars)

Anker portable bluetooth speaker
Anker/Amazon

This speaker boasts 24-hour battery life and a strong Bluetooth connection within a 66-foot radius. It also comes with a built-in microphone so you can easily take calls over speakerphone.

Buy it: Amazon

4. Bose SoundLink Color Bluetooth Speaker; $129 (4.4 stars)

Bose portable bluetooth speaker
Bose/Amazon

Bose is well-known for building user-friendly products that offer excellent sound quality. This portable speaker lets you connect to the Bose app, which makes it easier to switch between devices and personalize your settings. It’s also water-resistant, making it durable enough to handle a day at the pool or beach.

Buy it: Amazon

5. DOSS Soundbox Touch Portable Wireless Bluetooth Speaker; $28-$33 (4.4 stars)

DOSS portable bluetooth speaker
DOSS/Amazon

This portable speaker features an elegant system of touch controls that lets you easily switch between three methods of playing audio—Bluetooth, Micro SD, or auxiliary input. It can play for up to 20 hours after a full charge.

Buy it: Amazon

6. Altec Lansing Mini Wireless Bluetooth Speaker; $15-$20 (4.3 stars)

Altec Lansing portable bluetooth speaker
Altec Lansing/Amazon

This lightweight speaker is built for the outdoors. With its certified IP67 rating—meaning that it’s fully waterproof, shockproof, and dust proof—it’s durable enough to withstand harsh environments. Plus, it comes with a carabiner that can attach to a backpack or belt loop.

Buy it: Amazon

7. Tribit XSound Go Bluetooth Speaker; $33-$38 (4.6 stars)

Tribit portable bluetooth speaker
Tribit/Amazon

Tribit’s portable Bluetooth speaker weighs less than a pound and is fully waterproof and resistant to scratches and drops. It also comes with a tear-resistant strap for easy transportation, and the rechargeable battery can handle up to 24 hours of continuous use after a full charge. In 2020, it was Wirecutter's pick as the best budget portable Bluetooth speaker on the market.

Buy it: Amazon

8. VicTsing SoundHot C6 Portable Bluetooth Speaker; $18 (4.3 stars)

VicTsing portable bluetooth speaker
VicTsing/Amazon

The SoundHot portable Bluetooth speaker is designed for convenience wherever you go. It comes with a detachable suction cup and a carabiner so you can keep it secure while you’re showering, kayaking, or hiking, to name just a few.

Buy it: Amazon

9. AOMAIS Sport II Portable Wireless Bluetooth Speaker; $30 (4.4 stars)

AOMAIS portable bluetooth speaker
AOMAIS/Amazon

This portable speaker is certified to handle deep waters and harsh weather, making it perfect for your next big adventure. It can play for up to 15 hours on a full charge and offers a stable Bluetooth connection within a 100-foot radius.

Buy it: Amazon

10. XLEADER SoundAngel Touch Bluetooth Speaker; $19-$23 (4.4 stars)

XLeader portable bluetooth speaker
XLEADER/Amazon

This stylish device is available in black, silver, gold, and rose gold. Plus, it’s equipped with Bluetooth 5.0, a more powerful technology that can pair with devices up to 800 feet away. The SoundAngel speaker itself isn’t water-resistant, but it comes with a waterproof case for protection in less-than-ideal conditions.

Buy it: Amazon

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What Should You Do In the Unlikely Event You Meet An Alien?

If you ever find yourself in a Mac and Me-type situation, it's best to know what to do.
If you ever find yourself in a Mac and Me-type situation, it's best to know what to do.
Shout! Factory

What do you do if you encounter an alien? It’s obviously fairly unlikely, but nothing is impossible—after all, you can’t spell meet without ET. If there’s a stray dog in your backyard, there’s a set procedure to follow. But what if, rather than a mere hound, it’s a creature from another world?

“If you meet an alien in your backyard, my recommendation is to get out of town,” Seth Shostak, senior astronomer at the SETI Institute, an organization seeking to explore, understand, and explain the origin and nature of life in the universe, tells Mental Floss. “If they have the technology to come here, they’re so far beyond us that whatever they want to do, they're going to do. If they’re here to take over the planet, it’s going to be pretty hard to stop them.”

A creature from another planet lurking on your property means not only that there is intelligent life elsewhere, but that it is at a significantly more technologically advanced stage than humanity. A species with the ability to not only travel the enormous distances involved (the closest star to our sun, which does have some potentially life-supporting planets, is 4.2 light years away), but also land undetected in your flowerbed would simply have us outclassed.

As you flee, however, you might want to contact the emergency services. If, for instance, the alien is aflame—and given that we know nothing about what form such a creature might take, there’s no real reason it wouldn’t be—you might want to give the fire department a call, for example. Moving up a notch, the FBI and Department of Defense are frequently contacted with flying saucer sightings, as are the UK’s Royal Air Force and Ministry of Defence and, well, pretty much every other emergency service in every country. This is because there is no set protocol, no universally agreed-upon decree of exactly what to do in the event of a close encounter.

“As far as I know, there is no policy for that, because that would be like Neanderthals having a policy for if the U.S. military decided to take them on,” Shostak says. “If aliens were actually landing here, we could have whatever policy we wanted and it wouldn’t be likely to help much.”

A scene from E.T.
Universal Pictures Home Entertainment

Whatever Hollywood might tell us, the likelihood is that any contact we have with beings from another world will be limited to picking up a signal from deep space, rather than encountering the long fingers and warm heart of a charming 3-foot-tall alien rustling around in shrubbery. As luck would have it, there is a protocol for that; it's known as the Declaration of Principles Concerning Activities Following the Detection of Extraterrestrial Intelligence [PDF] and was put together by the International Academy of Astronautics with input from Shostak.

The protocols are also entirely voluntary, with no force of law behind them and nobody under any obligation to adhere to them. What if you don’t want to tell everybody? What if you fancy keeping information about life beyond Earth to yourself for a while? You’re the one talking to aliens, after all—surely you can make a few bucks out of the situation ...

As Shostak points out, this kind of thinking is unlikely to get you anywhere. Given the distances involved, and the power required to transmit information that far, you aren’t going to be in any kind of dialogue. Secondly, revealing that you have detected a transmission is useless without it being verified and studied—the process of which, by necessity, involves making that information available to the world. Thirdly, interpreting any alien message will be a mammoth task involving a lot of work from a lot of people, a task unlikely to ever reach a definitive conclusion. “It would depend on whether they were trying to make it easy,” Shostak says.

Anything you discovered would belong to humanity as a whole, as we collectively tried to figure out what the signal meant, both literally and existentially, knowing we are not alone in the universe. You’d get to be the first person to prove there was intelligent life beyond Earth, which might be mildly less exciting in the short term than getting attacked by a little green man while taking the trash out, but at least you’d live to tell the tale.