Yesterday's Physiology class, we talked about "mammalian diving reflex" and "static apnea." Static apnea is simply holding your breath, more of a mental challenge, in which the person fights against the urge to breathe for as long as possible.
"Marine mammals such as dolphins and whales cannot breathe underwater. How is it possible that such animals can descend so deep and remain so long underwater? Marine mammals have developed a set of physiological reactions, known as the mammalian diving reflex ,which enables them to stay underwater for extended periods of time. Humans also experience the mammalian diving reflex when immersed in water.
When submerged in water, 2 physiologic reactions occur:
1. Vasoconstriction is the narrowing of blood vessels to reduce blood flow, and is accomplished through a muscular contraction in the blood vessel walls. This reduces the amount of blood that flows to peripheral organs, which do not need a high level of oxygen to function, while conserving blood and oxygen for the body's vital organs such as the heart, lungs, and brain, which need high levels of oxygen. Aquatic mammals, humans, and diving birds all experience vasoconstriction when submerged.
2. Heart Rate Reduction:
The second physiological reaction occurring during the mammalian diving reflex is heart rate reduction (bradycardia). Interestingly, a diver does not need to be completely submerged to trigger this response. Simply wetting the face is enough to drop a diver's heart rate. For the average human, exposure of the face to water will trigger a 10 -30% reduction in heart rate. Individuals such as freedivers who have trained to augment their mammalian diving reflex may experience a heart rate reduction of up to 50%. The intensity of the reaction is also related to temperature. The colder the water, the greater the heart rate reduction.
Heart rate reduction may sound frightening, but it is actually beneficial for freedivers. It is a natural adaptation of the human body to conserve oxygen, which allows freedivers to make longer dives.
Aquatic mammals and humans are born with the necessary adaptations to spend long periods of time underwater. The mammalian diving reflex is natural physiological reaction that occurs when a human, mammal, or diving bird is submerged in water, and includes vasoconstriction and heart rate reduction. These reactions help to reduce a diver's consumption of oxygen while continuing to provide sufficient quantities of oxygen to his vital organs."
Referring back to your question, what the hell I was doing underwater; I was 'experimenting' if I could hold my breath longer underwater to test the 'diving reflex,' compared to holding my breath on land w/o being submerged in water.
Surveillance camera? Psssh... Playing Devil's Advocate, what if a contemporary ninja (not pirate) stalker cuts the electricity to your home?... Perhaps, you could get a vicious dog like a pitbull/rottweiler, or one of those DOOM monster dogs; get a gun, like a bazooka; or like a true Mafiosi, don a beautiful, elastic black lace garter holster with a garter belt/retention strap carrying a 9mm, 38mm or 22mm (looks sexy, but dangerous)...
Thanks for the question. I might earn some Medits for my reply. Perhaps, I could spend my Medits on some TIM training module, or a fancy, eye-catching 'colored' name? Lol.
I have the urge to create a big snowman, or make snow angels, on our driveway. Freakin' snow!
