کد خبر : 138481
تاریخ انتشار : دوشنبه 28 مارس 2022 - 20:21

چرا مار‌های بوآ به هنگام فشار دادن طعمه تا سر حد مرگ، خود خفه نمی‌شوند؟

چرا مار‌های بوآ به هنگام فشار دادن طعمه تا سر حد مرگ، خود خفه نمی‌شوند؟

مارهای بوآ برای شکار به دور طعمه خود می‌پیچند و با عضلات شکمی چنان فشاری به آن وارد می‌کنند که استخوان‌های شکار را درهم‌شکسته و آن را بکشند. با این حال برای محققان سوال بود که چطور این فرآیند، که در حالت طبیعی باید مجرای تنفسی مار را مسدود کند، منجر به خفگی خود حیوان

مارهای بوآ برای شکار به دور طعمه خود می‌پیچند و با عضلات شکمی چنان فشاری به آن وارد می‌کنند که استخوان‌های شکار را درهم‌شکسته و آن را بکشند. با این حال برای محققان سوال بود که چطور این فرآیند، که در حالت طبیعی باید مجرای تنفسی مار را مسدود کند، منجر به خفگی خود حیوان نمی‌شود؟

دانشمندان اکنون می‌گویند سرانجام دریافته‌اند که چطور مارهای بوآ از راهی استفاده می‌کنند که به هنگام منقبض کردن شدید عضلات بتوانند نفس بکشند و جریان هوا را در ریه‌های خود داشته باشند.

یک مطالعه جدید در دانشگاه براون آمریکا نشان می‌دهد مارهای بوآ با تنظیم بخش‌هایی از قفسه سینه‌ خود که برای تنفس استفاده می‌کنند، از خفگی خود در طول این فرآیند جلوگیری می‌کنند. در واقع بر خلاف انسان‌ها که از عضلات دیافراگمی تنها در زیر قفسه سینه برخوردارند، مارها به طور کامل و دقیقی بر بخش‌های مختلف قفسه سینه خود کنترل دارند و هنگام پیچیدن دور شکار و بلع و هضم وعده غذایی می‌توانند آن‌ها را به دلخواه به خدمت بگیرند.

دانشمندان برای تحقیق خود نشانگرهای فلزی کوچکی به دو دنده این خزنده چسباندند تا بتوانند نحوه حرکت دنده‌ها را با استفاده از اشعه ایکس تعقیب و مجسم کنند. سپس یک «کاف» دستگاه فشار خون، یا همان بالشتک‌های پلاستیکی بادشونده، روی دنده‌ها در هر دو ناحیه قرار دادند و فشار را به تدریج بالا بردند تا مارها در آن نقاط بی‌حرکت شوند.

بی‌حرکت شدن مارها بر اثر فشار روی دنده‌هایشان دقیقا همان مکانیزم پیچیدن به دور طعمه و فشار به آن را بازتولید کرد. محققان می‌گویند زمانی که مارها نهایت فشار را روی شکار خود می‌آورند دنده‌های درگیر دیگر نمی‌توانند حرکت کنند. در نتیجه مارها دنده‌های بخش عقب را فعال کرده و با حرکات موجی هوا را داخل خود می‌کشد.

با بازسازی حرکات دنده‌های مارها، دانشمندان دریافتند که منقبض‌کننده‌های عضلانی بوآ می‌توانند به طور مستقل حرکات دنده‌ها را در قسمت های مختلف قفسه سینه کنترل کنند و با حرکت دادن دقیق و جابجایی دنده‌ها بخش‌های فوقانی آن‌ها را سمت سر حیوان متمایل می‌کنند تا هوا به داخل ریه‌ها جریان یابد.

دانشمندان می‌گویند دنده‌های انتهایی ریه در حالت عادی حرکتی ندارند و تنها زمانی شروع به تحرک می‌کنند که دنده‌های جلویی قفل شده باشند.

به اینستاگرام یورونیوز فارسی بپیوندید

پژوهشگران همچنین در جریان این مطالعه از سیگنال‌های عصبی که ماهیچه‌های دنده را کنترل می‌کنند تصویربرداری کردند. این داده‌ها نشان داد که دنده‌های زیر فشار سیگنال‌های عصبی را دریافت نمی‌کردند و در عوض مارها دنده‌های بیشتر دیگری را فعال می‌کنند تا تنفس بتواند روال طبیعی خود را ادامه دهد.

از آنجایی که کشتن طعمه و هضم آن یکی از انرژی‌برترین فعالیت‌ها برای مارهای بوآ است، دانشمندان می‌گویند توانایی تنظیم جایگاه تنفس یک ویژگی در این حیوانات است تا بتوانند تکامل پیدا کنند.

نتایج مطالعات جدید در ژورنال علمی «بیولوژی تجربی» (Experimental Biology) منتشر شده است.

منبع: یورنیوز

برچسب ها :

ناموجود
ارسال نظر شما
مجموع نظرات : 6 در انتظار بررسی : 0 انتشار یافته : 6
  • نظرات ارسال شده توسط شما، پس از تایید توسط مدیران سایت منتشر خواهد شد.
  • نظراتی که حاوی تهمت یا افترا باشد منتشر نخواهد شد.
  • نظراتی که به غیر از زبان فارسی یا غیر مرتبط با خبر باشد منتشر نخواهد شد.

Jerrold جمعه , 30 می 2025 - 16:55

These include UV light remedy, retinoids, and disease-modifying antirheumatic
medicine (DMARDs). Topical corticosteroids come as creams,
foams, gels, ointments, or solutions in quite a lot of strengths.

Prescriptions commonly embrace clobetasol, triamcinolone, and
hydrocortisone. Obtainable by prescription, these medications
assist to relieve the itching and discomfort of a psoriasis
rash.
If you may have plaques on delicate areas, similar to your face or groin, you’ll most likely need to stick with the gentle or medium steroid lotions.

That mentioned, you’ll need to maintain making use of the
cream to replenish the medication in your skin. As the steroids maintain off the psoriasis process,
the patches should progressively shrink, allowing your pores and
skin to heal. When you apply a steroid cream, the steroids sink
into the layers of your skin and enter various cells.
If you could have psoriasis, your immune system will get confused and starts attacking your skin. Antibodies flood the area to defend
in opposition to the attack, and the surrounding tissue turns into infected.

This will help him in providing a fuller look on stage as he
will be succesful of absolutely maximize his carb
load. This is without query a extra superior method and one many individuals will want to keep away from.
If you could have by no means used Anadrol earlier than the final thing you need is to make use
of it for contest prep purposes.
Winsol, however, is a steroid different that has potent elements built
to extend power, enhance fats loss and workout harder for longer.

For those that need extra Anadrol and have enjoyed
a optimistic response in a previous cycle, that means they have been capable of management side effects, doses that reach
the 100mg per day vary could be thought of. Nevertheless,
this will significantly enhance the chance of unwanted effects; caution is suggested.
Not solely are such doses harmful they have been shown to have very
little positive impact of an increasing nature. With most anabolic pills steroids the more you take the larger the
outcomes.
The ability to purchase Anadrol on-line is with out question the best way to
purchase this powerful anabolic steroid. There are seemingly numerous suppliers of anabolic steroids, and you’ll easily discover
practically any model you need. Anabolic androgenic steroids are categorised as
Schedule III managed substances and any violation of the regulation carries with
it sturdy consequences. While many countries carry much more lenient legal guidelines, many are similarly strict; excessive warning is suggested.

Due to the nature of such a purchase, in case you
are to remain throughout the safety of the legislation you would possibly be inspired to go to the sponsors right here at Steroid.com.
The ultimate time for a performance enhancing athlete to
make use of Anadrol is during a cutting cycle; nonetheless,
this can solely apply to a select group. Anadrol is normally
a great steroid for a aggressive bodybuilder at the tail finish of his contest prep.

Masteron is prized for its capability to harden muscle
tissue, enhance vascularity, and enhance general athletic
efficiency with out causing vital water retention. It is usually utilized by bodybuilders and athletes throughout competition prep.
Regardless Of its benefits, Masteron can lead to unwanted aspect effects corresponding to hair loss, aggression, and liver
strain.
Testosterone undecanoate is very distinctive in comparability with other
oral steroids as a result of it is suspended in an oil-based capsule.
This esterification permits testosterone undecanoate to be
absorbed through the lymphatic route, avoiding the liver and considerably reducing hepatotoxicity (4).
Superdrol is rarely stacked with other steroids due to its extreme antagonistic effects.
Thus, a Superdrol-only cycle is often utilized by bodybuilders trying to
overcome plateaus.
For example, 500mg of Testosterone would provide far much less outcomes for them than it would for
a newbie. Earlier Than we delve into the energy of steroids, it’s essential to assume
about a couple of key elements that may affect their effectiveness.

In the world of bodybuilding, many individuals ask, “Which steroid is the strongest? A Quantity Of factors have an result on a steroid’s energy and safety for every person, making it a fancy topic.

Adolph چهارشنبه , 4 ژوئن 2025 - 15:45

Low-density lipoprotein (LDL)—the bad—cholesterol levels enhance, and high-density lipoprotein (HDL)—the good—cholesterol levels
decrease. Extreme cardiovascular complications, together with hypertension,coronary
heart assault, and blood clots, are reported with the utilization of anabolic steroids.
Some athletes, bodybuilders and others misuse these medicine in an try
to reinforce efficiency and/or improve their physical appearance.
Anabolic steroids are the most common appearance- and performance-enhancing medication (APEDs).
Approximately three to four million people within the United States use anabolic steroids for nonmedical functions.
Anabolic steroids also upregulate and enhance the number of
androgen receptors, thus enabling increased training intensity
and indirectly contributing to elevated muscle dimension and energy.

Any contribution from exogenous DHEA or androstenedione will be largely moderated by the
massive amount of testosterone contributed by
the testis. In ladies, a rise in efficiency could additionally be possible following
ingestion of these supplements, as circulating testosterone can be anticipated to extend.
The plasma focus of endogenous testosterone is approximately 1/10th that present in men and the relative
proportion arising from peripheral conversion of
weaker androgens is far larger.
Sure, utilizing steroids, particularly anabolic ones, can increase the possibility of blood clotting.
This happens as a end result of steroids can have an result on how blood clots type and how do steroids build muscle (Anya) the center and blood
vessels work. If you take steroids, it’s necessary to learn about this
risk and talk to a well being care provider when you’re nervous.
Nevertheless, it might possibly result in dependency, with people feeling the necessity
to keep using steroids to take care of muscle features and facing
withdrawal symptoms during breaks. Steroids, particularly
within the realm of efficiency enhancement, usually suggest artificial compounds that resemble
and act like the male hormone testosterone. It Is made in several components of their our bodies
and helps with muscle energy, bones, and intercourse drive.

However if there’s too little or too much, it could trigger health issues like polycystic ovarian syndrome (PCOS) or symptoms
like too much hair (hirsutism).
These supplements purpose to help enhance testosterone levels in the body, selling various health benefits and improvements in general well-being.
Not Like anabolic steroids, which introduce artificial testosterone, testosterone boosters work by
stimulating the body’s capacity to produce its personal
male intercourse hormone. Anabolic steroids work
by binding to androgen receptors in the body, leading to increased protein synthesis and
muscle progress. They usually are available a number
of forms, together with injectables, oral tablets, and transdermal patches.
Some of the frequent anabolic steroids include nandrolone, testosterone,
and trenbolone.
By No Means stop taking your treatment and by no means change your dose or frequency with
out consulting your doctor. Non-pharmaceutical water-based testosterone suspensions for injection are advertised on bodybuilding web pages and
cheats in sport may discover these engaging as, in principle, these ought to be comparatively quick appearing.
Non-pharmaceutical-based preparations, whether or not oil or water based mostly, could additionally be a
selected hazard to well being as the contents could not
have been ready under sterile circumstances.
Estrogen— Any of several steroid hormones, produced primarily in the ovaries, that stimulate estrus
and the development of feminine secondary sexual characteristics.
That’s why ongoing monitoring and proactive well being administration are important to any stacking plan.
In addressing illicit use, all members want to pay attention to the indicators of steroid misuse and be prepared to counsel as essential to aim to
resolve the problem. In reliable therapeutic use, the clinician will
prescribe an agent based mostly on clinical necessity for a specific symptom or indication, and
the pharmacist can verify applicable dosing and verify for drug interactions.
Nurses can provide counseling on administration together with the pharmacist and monitor for antagonistic results on follow-up visits.
These actions present the potential effectiveness
of an interprofessional group method to anabolic steroid use or misuse.
Users must additionally perceive that the psychoactive results
of anabolic steroids could be lethal, resulting in sudden bouts
of anger, suicidal thoughts, rage, loss of judgment, and
extreme violence.[122] The abuse of anabolic steroids
is a problem at all ranges of education and consists of both genders.

Generally, it’s only used for medical reasons under a
healthcare professional’s supervision. Moreover, testosterone also can direct the physique to
make other things, corresponding to development components, such as insulin-like growth
factor 1 (IGF-1) and growth hormone (GH).
These substances work in conjunction with
testosterone to advertise muscle development and repair.
In the body, steroids act as hormones that control processes like metabolism, copy, and
preventing infections.
The authors of an early study63 investigated methandrostenolone use
at 10 mg/d and resistance coaching by university college students over 4 weeks.
Training with AAS increased performance in the 1-repetition most (1RM) bench
press and squat. Others64 studied the utilization of
10 mg/d of methandrostenolone and a protein complement by faculty
students. This randomized, double-blind, placebo-controlled research lasted 7 weeks, together with the
3-week remedy section. The authors reported increases in 1RM bench press and squats by the treatment group over each the
placebo and control groups. Other authors36 reported an analogous association between AAS abuse and physical train in European adolescents.

Jodi یکشنبه , 8 ژوئن 2025 - 19:18

70918248

References:

natural Steroids for bodybuilding – https://www.themirrored.com

Gary پنج‌شنبه , 12 ژوئن 2025 - 16:08

70918248

References:

steroids for muscle growth for sale (http://Www.lumia360.com)

Christoper دوشنبه , 18 آگوست 2025 - 7:27

can i take creatine while intermittent fasting

References:

creatine while fasting (https://pad.stuve.uni-ulm.de/RWmp-JxHTfuyPp4AkO3WTg)

Rhonda چهارشنبه , 20 آگوست 2025 - 0:45

dianabol cycle length

References:

valley.md