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💯 Which Of The Following Is Least Likely To Increase The Rate Of Diffusion?

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💯 Which Of The Following Is Least Likely To Increase The Rate Of Diffusion?

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Q which of the following is least likely to increase the rate of...

Q which of the following is least likely to increase the rate of… – Q: In general, to maintain homeostasis the relationship between our intracellular and extracellular fluid should be which of the following? Q: if a person is severely dehydrated, their extracellular fluids will become hypertonic to the intracellularfluid. What do you predict will happen to the person's cells?Which of the following blood components provide the major defense for our bodies against invading bacteria and viruses? plasma. 5. Which of the following are likely to increase in quantities when the body is under attack from bacteria?Multiple Choice Quiz. Which of the following is not a determinant of a consumer's demand for a commodity? a. inverse relationship between the price of a commodity and the quantity demanded of the commodity per time period. b. direct relationship between the desire a consumer has for a…

Practice Quiz for Blood Components – Which of the following are likely to increase in quantities when the body is under attack from bacteria? a) erythrocytes b) leukocytes c) Immediately following strenuous and vigorous exercise, which of the following is most likely to occur? a. blood will be rapidly diverted to the digestive…Which of the following minerals has a low solubility and therefore is least susceptible to chemical weathering at the Earth's surface? The rate of chemical weathering is increased by acids. Which of the following minerals would be most likely to form a clay mineral during chemical weathering?Which Of The Following Is Least Likely To Increase The Rate Of Diffusion?

Practice Quiz for Blood Components

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Electrotonic and Action Potentials – In the last video, we talked
about how the cell uses a sodium potassium pump and ATP
to maintain its potential difference between the inside
of the cell or the inside of the neuron and the outside– and
in general, the outside is more positive than the inside.
You have a -70 millivolt
potential difference from the inside to the outside. It's minus because the outside
is more positive. Less positive minus more
positive, you're going to get a negative number
and it's by -70. Now, I said that this was the
foundation for understanding how neurons actually
transmit signals. And to understand that, I'll
kind of lay a foundation over that foundation. I think then just the actual
neuron transmission will make a lot of sense. Even better, it'll make a lot
of sense why they even have these myelin sheaths and these
nodes of Ranvier and why we have all of these dendrites. Hopefully it'll all
fit together. So there are two types of
ways that kind of a potential can travel. So there's two types
of signal transfer. I'll just call it
signal transfer. I don't know what the
best word for it is. The first one I'll talk
is electrotonic. It sounds very fancy,
but you'll see it's a very simple idea. And the other one I'm
going to go over is an action potential. And they both have their own
positives and negatives in terms of being able to
transmit a signal. We're talking about within the
context of in a cell or across a cell membrane. Let's understand what
these mean. So let me get my membrane
of a cell. Let's say it's a nerve cell or
a neuron, just to make it all fit together in this context. And we know it's more
positive on the outside than the inside. We know that there's a lot of
sodium on the outside or a lot more sodium on the outside
than on the inside. There might be a little bit. And we know there's a lot more
potassium on the inside than the outside, but we know
generally that the outside is more positive then the inside
because our sodium potassium pump will pump out three
sodiums for every two potassiums it takes in. Now in the last video, I told
you that there are these things called– well, we could
call them a sodium gate. A sodium ion gate, right? These are all ions. They're charged. Now let's say that there's some
reason, some stimulus– let me label this. That right there is my
sodium ion gate. And it's in its closed position,
but let's say something causes it to open. We'll talk maybe in this video
or maybe this video and the next about the different
things that could cause it to open. Maybe it's some type of stimulus
causes this to open. Actually, there's a whole bunch
of different stimuluses that would cause it to open. But let's say it opens. What's going to happen
if it opens? So let's say we open it. Some stimulus opens– what's
going to happen? We have more positive on the
outside than the inside, so positive things want
to move in. And this is a sodium gate so
only sodium can go through it. So it's kind of a convoluted
protein structure that only sodium can make its
way through. And on top of that, we have a
lot more sodium on the outside than on the inside. So the diffusion gradient's
going to want to make sodium go through it. And the fact that sodium's a
positive ion, the outside is more positive, they're going to
want to run away from that positive environment. So if you open this, you're just
going to have a lot of sodium ions start to
flood through. Now as that happens, what's
going to happen if we go further down the membrane? Let's zoom out. So let's say that this is
my membrane right there. Let's say that this is my open
gate right here and that it's open for some reason and a bunch
of sodium is flowing in. So all of this is becoming
much more positive. Let's say we had a voltmeter
right here. We're measuring the potential
difference between the inside of the membrane a
and the outside. Let me do a little chart. I'm going to do the chart
here on my voltmeter. And this is going to be the
potential difference– or we'll call it the membrane
voltage or the voltage difference across the
membrane– and let's say this is time. Let's say I haven't opened
this gate yet. So it's in its resting state. Our sodium potassium
pumps are working. Things are leaking back and
forth, but it's staying at that minus 70 millivolts. So that right there is
minus 70 millivolts. Now as soon as this gate that's
way down some other part of the cell opens, what's
going to happen? And let's say that's the
only thing that's open. So this, all of a sudden, is
going to become more positive. So positive charges that's
already here– so other positive charges, whether
they're sodiums or potassiums, they're going to want to run
away from that point because this area hasn't had a flood
of positive things. So it's less positive
than this over here. So maybe we have some potassiums
and maybe we have some sodiums. Everything is
going to want to move away from the place where
this is opened. The charge is going to
want to move away. So as soon as this happens, as
soon as we open this gate, we're going to have a
movement of positive charge in this direction. So all of a sudden– this was
at minus 70 millivolts. So more positive charge
is coming its way. Almost immediately, it's going
to become less negative or more positive. The potential difference between
this and this is going to become less. So this is this point
over here. Now if we took this point, if we
did the same thing– if we measured the voltage at this
point right here, maybe it was at minus 70 millvolts, maybe a
fraction of a minute amount of time later, the positive charge
starts affecting it so it becomes more positive, but
the effect is diluted, right? Because these positive charges,
they're going to radiate in every direction. So the effect is diluted. So the effect on this thing
is going to be less. It's going to become
less positive. So an electrotonic potential–
what happens is at one point in the cell, a gate opens,
charge starts flooding in, and it starts affecting the
potential at other parts of the cell. But the positive of it is, it's
very fast. As soon as this happens. further down the cell, it starts
becoming more and more positive, but the further you
go, the effect gets dissipated with distance. So if you care about speed,
you'd want this electrotonic potential. As soon as it happens, it'll
start affecting the rest of the cell, but if you wanted
this potential change to travel over large distances–
for example, let's say if we got all the way to this point of
the neuron and we wanted to measure it, it might not
have any impact. Maybe a little bit later, but
it's not having any impact because all of this gets diluted
by the time it gets– it's increasing the charge
throughout the cell. So it's a impact far away from
the initial place where the gate opened. It's going to be a lot less. So it's really not good for
operating over distance. Now let's try to figure
out what's going on with an action potential. And you might understand, this
might involve more action. So let's start off with
the same situation. We have a sodium gate that gets
opened by some stimulus. What I'm going to do– let me
draw two membranes here. So this is the outside. This is the inside. And let me draw– maybe we're
dealing with a– and we'll go in more detail. Maybe this is an axon or
something, but let me– let's say we have another sodium
gate right here. And then they're alternating,
essentially. So they're alternating so then
I have another sodium gate. I don't want to do
a bunch of these. I think I just have to draw one
round of it for you to get what's going on. Let me draw another
potassium gate. And let's say that they
all start closed. So they're all in the
closed position. Now let's say that this sodium
gate gets stimulated. It gets opened. Let's say that guy right
there gets opened. It gets stimulated by something
to get opened. We'll talk about the things
that– let's say in particular this thing gets opened– let's
say the stimulus– it has to be a certain voltage. And let's say they become open
when we are at minus 55 millivolts. So when we're just in our
resting state, the potential difference between the inside of
the cell and the outside is minus 70, so it's not
going to be open. It's going to be closed, but if
for whatever reason, this becomes positive enough to get
to minus 55 millivolts, all of a sudden this thing
will be open. Let's write a couple of other
rules that dictate what happens to this gate. Let's say it closes– and these
are all rough numbers, but the main idea is for you
to get the general idea. Let's say it closes at–
I don't know– plus 35 millivolts. And let's say that our potassium
gate opens at plus 40 millvolts, just to give
an idea of things. Let's say it closes at–
I don't know– minus 80 millivolts. So what's going to happen? Lets say that, for whatever
reason, the voltage here has now become minus 55. Let me do a chart just
like I did down here. So I want to have space
to draw my chart. This is membrane voltage. And this is time down here. And let's say we're measuring
it– let's say this is the membrane voltage at– let's say
right by the sodium gate right here. So we're measuring this voltage across this right here. So if it's not stimulated any
way, we're just here, flatlining at minus 70
millivolts– and let's say some stimulus, for
whatever reason, makes this more positive. Maybe it's some type of
electrotonic effect that's making it more positive here. Maybe some positive charges
are floating by. So this becomes more positive. So let's say this becomes more
positive and then the ATP pumps– the sodium potassium
pumps pump it out so it doesn't get to the threshold of
minus 55, so then nothing will happen, right? It didn't get to
the threshold. But then let's say there's
another electrotonic or maybe a bunch of them and just there's
a lot of positive charge here so we get to
the minus 55 millvolts. Remember, when positive
charge comes by, we become less negative. The potential difference
becomes less negative. We get to that minus
55 volts– this thing opens then, right? This was closed before. It was closed when we were
just at minus 70. So let me write here. So at this point, our
sodium gate opens. Now, what's going to happen when
our sodium gate opens? When that opens– we've seen
this show before– all the positively charged sodium is
going to go down there, both electric gradient and diffusion
gradient, and there's going to flood
into the cell. There's so much sodium out
there, it's so positive out there, they just want
to come in. So as soon as they hit that
threshold, even though this might've only gotten us to minus
55 or maybe minus 50, all of a sudden that gate opens
and we have all of this positive charge flooding
into the cell. So the potential difference
becomes much, much more positive. So they keep flooding in,
becomes much, much more positive, but as it gets
more positive, it closes at plus 35 millvolts. So let's say that we're dealing
here– let's say that this up here is plus
35 millvolts. So here it closes and at the
same time, that stuff I just deleted– I set at plus 40
millvolts– or let's say at plus 35, just for the
sake of argument. Let's say at plus 45
millvolts, our sodium gates open. So what's happened here? All of a sudden, we're at plus
35 or maybe plus 40 millivolts so this is– let's just say plus
40, I think you get the idea either way so we'll say
plus 40– either way. So at plus 40, this guy's
going to close. No more positive ions are coming
in, but now we are at more positive inside, at least
locally at this point on the membrane, than we are outside. And so this gate will open. So then our sodium
gate will open. K-plus ion gate opens. Now when that opens,
what happens? We have all of these
sodium ions here. We already saw from the sodium
potassium pump that the potassium– we have all of these
potassium ions here. We saw from the sodium potassium
pump that it makes the sodium concentration on
the outside higher and the potassium concentration
on the inside higher. And now that we've gotten to
this plus 40 millvolt range, we're also now more positive
on the inside. So this opens. These guys want to escape
because there's less potassium outside. They want to go down their
concentration gradient. It's also very positive
on the inside. We're at plus 40 millvolts. So they also want to escape. So they start escaping
the cells. So positive charges starts
exiting the cell from the inside to the outside. So we become less
positive again. So let me write what
happens here. So at this point, our sodium
gate closes and our potassium gate opens. And then the positive charge
starts flooding out of the cell again and maybe it'll
overshoot because it's only going to close maybe once we
get to minus 80 millvolts. So maybe our potassium gate
closes at minus 80. And then our sodium potassium
pump might get us back to our minus 70 millvolts. So, this is what's happening
just at this point in the cell, just near that
first sodium gate. But what's going to happen
in general, right? As this became very positive–
we went to 40 millivolts over here. We went to 40 millvolts in
this area of the cell. Because of– I guess you could
almost view it as a short term or very short distance
electrotonic potential, this area is going to become
more positive, right? This is going to become
more positive. These positive charges
are going to go where it's less positive. So this is going to become
more positive. This was at minus 70, but it's
going to become more positive. It'll go to minus 65, minus 60,
minus 55– and then bam. This guy will get
triggered again. Then this guy gets opened. Then this guy gets opened. Sodium floods in through here. So if you wanted to plot this
guy's, the potential difference of what's going on
across this, this all happened as soon as– maybe as soon as a
sodium started going in this first dude, the second guy– he
gets triggered here because the second guy a little bit
later in time– because of all this flow a little bit to
the left of him, his potential goes up. He gets triggered, same exact
thing happens to him, right? When the sodium flows in here,
becomes really positive around here, that makes the cell
around here, the voltage around here, the charge around
here a little bit more positive, triggers this next
sodium gate to open and then this whole same thing
happens, same cycle. Then the potassium gates open to
make it negative again, but by the time that's happened,
it's become positive over here to trigger another
sodium gate. So one after another, you have
these sodium gates opening and closing, but it's transmitting
that information, it's transmitting that potential
change. So what's going on here? So this is slower and it
actually involves energy. So this was– the electrotonic
was very fast. This is slow. An action potential is slower. I don't want to say it's slow. It's slower because it has to
involve these opening and closing of gates and it
also involves energy. It also requires more energy. And you're also going to have to
keep changing the potential in your cell and you actively
have your sodium potassium pumps being very active. But it's good. The positive is, it's good
at covering distance. When you have something like
this– we saw with the electrotonic, as we get further
and further away from where the stimulus happened,
the change in potential becomes more and more
dissipated. It actually exponentially
declines. It becomes more and more
dissipated as we get further and further away so it's not
good for long distance. This thing can just continue
forever because every time it stimulates the next gate, it's
like we're starting all over again and so this gate– it's
going to have a flood of ions come in and those ions are going
to make it a little less negative over here. Then the next gate's
going to open. We're going to have the cycle
over and over again. So this is really good for
traveling long distances. So now we have really the
foundation to understand exactly what's happening in a
neuron and I'm going to go over that in the next video to
show you how electrotonic potentials and action potentials
can combine to have a signal travel through
a neuron. .

6.2.4 / 6.2.5 Factors that affect the rate of reaction / Maxwell- Bolztmann distribution curves – .

The menstrual cycle – Learning medicine is hard work!
تعلم الطب عمل شاق! Osmosis makes it easy.
أوزموسس تجهله سهلا. It takes your lectures and notes to create
a personalized study plan with exclusive videos,
يأخذ دروسك ومحاضراتك ليقدم لك
خطة دراسية خاصة بك مع فيديوهات حصرية، practice questions and flashcards, and so
much more.
،أسئلة تختبر بها نفسك وبطاقات تعليمية
والكثير المزيد. Try it free today!
جربه اليوم مجانا! The menstrual cycle refers to the regular
changes in the activity of the ovaries and
الدورة الطمثية تعني التغيرات المنتظمة
بنشاط المبيضين the endometrium that make reproduction possible.
وبطانة الرحم لتسمح بالتكاثر The endometrium is the layer of tissue lining
the inside of the uterus.
بطانة الرحم هي طبقة النسيج التي
تحد سطح الرحم الداخلي. This lining consists of a functional layer,
which is subject to hormonal changes and is
،هذه البطانة تتألف من طبقة وظيفية
تستجيب للتغيرات الهرمونية shed during menstruation, and a thin basal
layer which feeds the overlying functional
وتتمزق خلال الطمث، و من طبقة قاعدية رقيقة،
تعوض الطبقة الوظيفية الأعلى منها. layer. The menstrual cycle actually consists of two
interconnected and synchronized processes:
الدورة الطمثية تتكون بالواقع من
:عمليتين متداخلتين معا ومتزامنتين the ovarian cycle, which centers on the development
of the ovarian follicles and ovulation, and
الدورة المبيضية التي تتمحور حول تطور
الجريبات المبيضية والإباضة، the uterine or endometrial cycle, which centers
on the way in which the functional endometrium
والدورة الرحمية او البطانية، التي تتمحور حول
الطريقة التي يتم بها thickens and sheds in response to ovarian
activity.
تثخن وتسلخ البطانة الوظيفية استجابة
لنشاط المبيض. Menarche, which refers to the onset of the
first menstrual period, usually occurs during
بدء الإحاضة، الذي يشير لبداية أول دورة طمثية
يحدث عادة خلال early adolescence as part of puberty.
خلال المراهقة الباكرة كجزء من البلوغ) Following menarche, the menstrual cycle recurs
on a monthly basis, pausing only during pregnancy,
وتبعا لبدء الطمث، تحدث الدورة وفق
نظام شهري و تتوقف فقط أثناء الحمل until a person reaches menopause, when her
ovarian function declines and she stops having
حتى الوصول لسن اليأس، عندما
تنتهي وظيفة المبيض ويتوقف menstrual periods.
حدوث الدورات الطمثية. The monthly menstrual cycle can vary in duration
from 20 to 35 days, with an average of 28
الدورة الطمثية الشهرية يمكن ان تختلف في مدتها
من عشرين الى خمسة وثلاثين يوم، وسطيا ثمانية وعشرين يوم. Each menstrual cycle begins on the first day
of menstruation, and this is referred to as
كل دورة طمثية تبدأ مع اليوم الأول للطمث
الذي غالبا ما يشار إليه day one of the cycle.
باليوم الأول للدورة Ovulation, or the release of the oocyte from
the ovary, usually occurs 14 days before the
الإباضة أو انبثاق الخلية البيضية من المبيض
عادة يحدث قبل اليوم الأول للطمث first day of menstruation (i.e., 14 days before
the next cycle begins).
بأربعة عشرة يوما، (بكلمات أخرى 14 يوم
قبل بدء الدورة التالية) So, for an average 28-day menstrual cycle,
this means that there are usually 14 days
اذا، بمعدل ثمانية وعشرين يوما للدورة
هذا يعني غالبا أربعة عشر يوما leading up to ovulation (i.e., the preovulatory
phase) and 14 days following ovulation (i.e.,
تؤدي للإباضة(بكلمات أخرى الطور قبل الإباضي)
وأربعة عشر يوما بعد الإباضة the postovulatory phase).
(الطور بعد الإباضي) During these two phases, the ovaries and the
endometrium each undergo their own set of/Nخلال هذين الطورين، كل من المبيض وبطانة الرحم يخضعان
لمجموعة من التغيرات الخاصة بهما changes, which are separate but related./المنفصلة عن بعضها لكن متعلقان ببعضهما As a result, each phase of the menstrual cycle
has two different names to describe these
وبالتالي، كل طور من الدورة الطمثية
له اسمان مختلفان يصفان two different parallel processes.
العمليتان المختلفتان For the ovary, the two weeks leading up to
ovulation is called the the ovarian follicular
بالنسبة للمبيض، الأسبوعان قبل الإباضة
يطلق عليهما الطور الجريبي المبيضي phase, and this corresponds to the menstrual
and proliferative phases of the endometrium.
وهذا الطور يوافق الأطوار
التكاثرية والطمثية لباطن الرحم Similarly, the two weeks following ovulation
is referred to as the ovarian luteal phase,
بشكل مشابه، الأسبوعان بعد الإباضة
يطلق عليهمها الطور اللوتيئيني which also corresponds to the secretory phase
of the endometrium.
الذي أيضا يوافق الطور الإفرازي
لبطانة الرحم So, let’s first focus on the preovulatory
period, starting with the ovarian follicular
حسنا، لنركز أولا على فترة قبل الإباضة
بدءا من الطور الجريبي المبيضي phase. This phase starts on the first day of menstruation
and represents weeks one and two of a four-week
هذا الطور يبدأ من اليوم الأول للطمث
ويمثل الأسبوعين الأول والثاني من أربع cycle.
أسابيع للدورة The whole menstrual cycle is controlled by
the hypothalamus and the pituitary gland,
الدورة الطمثية بأكملها مضبوطة
من قبل الوطاء والغدة النخامية which are like the masterminds of reproduction.
الذين يعملان كمدبرين لعملية التكاثر The hypothalamus is a part of the brain that
secretes gonadotropin-releasing hormone, or
الوطاء هو جزء من الدماغ
الذي يحرر الهرمون الموجه للأقناد GnRH, which causes the nearby anterior pituitary
gland to release follicle stimulating hormone/N أو الGnRHالذي يحرض النخامى الأمامية المجاورة
ويحثها على تحرير or FSH, and luteinizing hormone, or LH.
الهرمون المنبه للجريبات والهرمون اللوتيئيني Before puberty, gonadotropin-releasing hormone
is released at a steady rate, but once puberty
قبل البلوغ يفرز الهرمون الموجه للأقناد
بشكل مستقر مستتب، حتى البلوغ hits, gonadotropin-releasing hormone is released
in pulses, sometimes more and sometimes less.
يصبح إفراز الهرمون الموجه للأقناد
بشكل نبضاني أحيانا أقل وأحيانا أكثر The frequency and magnitude of the gonadotropin-releasing
hormone pulses determine how much follicle
كمية وتكرار إفراز هذه النبضات
تحدد كمية الهرمونات stimulating hormone and luteinizing hormone
will be produced by the pituitary.
المنبهة للجريبات واللوتيئيني
التي سنتنتج من النخامى These pituitary hormones control the maturation
of the ovarian follicles, each of which is
هذه الهرمونات المبيضية تتحكم بنضج
الجريبات المبيضية التي كل منها initially made up of an immature sex cell,
or primary oocyte, surrounded by layers of
تتكون بدئيا من خلايا جنسية غير ناضجة
(بيضية أولية) محاطة بطبقات theca and granulosa cells, the hormone-secreting
cells of the ovary.
من الخلايا الحبيبية والقرابية
الخلايا المفرزة للهرمونات بالمبيض Over the course of the follicular phase, these
oocyte-containing groups of cells, or follicles,
خلال الطور الجريبي هذه الجريبات
او مجموعات الخلايا المحتوية خلايا بيضية أولية grow and compete for a chance at ovulation.
تنمو وتتنافس على فرصة الإباضة During the first ten days, theca cells develop
receptors and bind luteinizing hormone, and
خلال العشر أيام الأولى
تطور الخلايا القرابية مستقبلات
للهرمون اللوتيئيني وتربطه in response secrete large amounts of the hormone
androstenedione, an androgen hormone.
واستجابة لذلك تحرر كميات كبيرة
من الأندروستينيديون(هرمون أندروجيني) Similarly, granulosa cells develop receptors
and bind follicle stimulating hormone, and
بشكل مشابه، تطور الخلايا الحبيبية
مستقبلات للهرمون المنبه للجريبات وتربطه بها in response produce the enzyme aromatase.
وتنتج إنزيم الأروماتاز استجابة لذلك. Aromatase converts androstenedione from the
theca cells into 17β-estradiol, which is
الأروماتاز يحول الأندروستينيديون من
17-الخلايا القرابية الى استراديول بيتا a member of the estrogen family.
من عائلة الإستروجينات During days 10 through 14 of this phase, granulosa
cells also begin to develop luteinizing hormone\من اليوم العاشر وحتى الرابع عشر لهذه المرحلة
تبدأ الخلايا الحبيبية بتطوير مستقبلات للهرمون اللوتيئيني receptors, in addition to the follicle stimulating
hormone receptors they already have.
بالإضافة لمستقبلات الهرمون المنبه للجريبات
التي تملكها مسبقا As the follicles grow and estrogen is released
into the bloodstream, increased estrogen levels
بينما تنمو الجريبات ويتحرر الإستروجين إلى الدم
نسب الإستروجين المرتفعة هذه act as a negative feedback signal, telling
the pituitary to secrete less follicle stimulating
تعمل كإشارة تلقيم راجع سلبي
مخفضة من إنتاج النخامى hormone.
للهرمون المنبه للجريبات As a result of decreased follicle stimulating
hormone production, some of the developing
وكنتيجة لانخفاض إنتاج الهرمون المضاد للجريبات
بعض الجريبات المتطورة follicles in the ovary will stop growing,
regress and die off.
في المبيض، تتوقف عن النمو
تتراجع وتتلاشى The follicle that has the most follicle stimulating
hormone receptors, however, will continue
والجريب الذي يملك أكبر عدد لمستقبلات
الهرمون المنبه للجريبات سيكمل نموه بكل حال to grow, becoming the dominant follicle that
will eventually undergo ovulation.
ليغدو الجريب المسيطر
الذي يدخل الإباضة بالنهاية This dominant follicle continues to secrete
estrogen, and the rising estrogen levels make
هذا الجريب المسيطر يستمر بإنتاج الإستروجين
ونسب الإستروجين المرتفعة تجعل النخامى the pituitary more responsive to the pulsatile
action of gonadotropin-releasing hormone from
أكثر استجابة للهرمون الموجه للأقناد
النبضاني المفرز من the hypothalamus.
الوطاء As blood estrogen levels start to steadily
climb higher and higher, the estrogen from
وعندما ترتفع تراكيز الإستروجين في الدم
أكثر فأكثر فإن الإستروجين the dominant follicle now becomes a positive
feedback signal – that is, it makes the
من الجريب السائد يصبح الآن
إشارة تلقيم راجع إيجابي pituitary secrete a whole lot of follicle
stimulating hormone and luteinizing hormone
تحث النخامى على تحرير المزيد
من الهرمون اللوتيئيني والمنبه للجريبات in response to gonadotropin-releasing hormone.
استجابة للهرمون الموجه للأقناد This surge of follicle stimulating hormone
and luteinizing hormone usually happens a
هذا الارتفاع بنسب الهرمون اللوتيئيني
والمنبه للجريبات يحدث عادة قبل يوم أو يومين day or two before ovulation and is responsible
for stimulating the rupture of the ovarian
من الإباضة، ومسؤول عن
تمزق الجريب المبيضي follicle and the release of the oocyte.
وتحرير البويضة You can think of it this way: for most of
the follicular phase, the pituitary saves
يمكنك التفكير بهذه الطريقة:
خلال غالبية الطور الجريبي تحافظ النخامى its energy, then when it senses that the dominant
follicle ready for release, the pituitary
على طاقتها، ثم عندما يبدو الجريب
المسيطر جاهزا، تستخدم النخامى uses all its energy to secrete enough follicle
stimulating hormone and luteinizing hormone
كل طاقتها لتنتج الهرمون اللوتيئيني
والهرمون المنبه للجريب to induce ovulation.
بنسب كافية لتحريض الإباضة While the ovary is busy preparing an egg for
ovulation, the uterus, meanwhile, is preparing
وبينما المبيض مشغول بتحضير البيضة للإباضة
فإن الرحم خلال ذلك the endometrium for implantation and maintenance
of pregnancy.
يحرض بطانته للغرس والحفاظ على الحمل This process begins with the menstrual phase,
which is when the old endometrial lining,
هذه العملية تبدء مع الطور الطمثي
والذي عندما تتمزق البطانة القديمة or functional layer, from the previous cycle
is shed and eliminated through the vagina,
او الوظيفية من الدورة السابقة
وتنزل عبر المهبل producing the bleeding pattern known as the
menstrual period.
مسببا شكل النزيف المعروف
بالفترة الحيضية(الطمثية) The menstrual phase lasts an average of five
days and is followed by the proliferative\الطور الطمثي يستمر وسطيا خمسة أيام
ويتبع بالطور التكاثري phase, during which high estrogen levels stimulate
thickening of the endometrium, growth of endometrial
الذي تحرض خلاله مستويات الاستروجين
المرتفعة بطانة الرحم لتتثخن glands, and emergence of spiral arteries from
the basal layer to feed the growing functional
، وخلايا الغدد البطانية لتنمو
والشرايين الحلزونية لتنشأ من الطبقة القاعدية endometrium.
لتغذي البطانة الوظيفية Rising estrogen levels also help change the
consistency of the cervical mucus, making
مستويات الاستروجين المرتفعة ايضا تساعد على
تغيير تماسك مخاطية العنق جاعلة إياها it more hospitable to incoming sperm.
أكثر قابلية لاستضافة النطفة القادمة The combined effects of this spike in estrogen
on the uterus and cervix help to optimize
التأثيرات المشتركة لارتفاع الاستروجين على الرحم
والعنق تساعد على تعزيز the chance of fertilization, which is highest
between day 11 and day 15 of an average 28-day
فرصة الإخصاب، التي تكتسب ذروتها
بين الأيام الحادي عشر والخامس عشر cycle.
من ثمانية وعشرين للدورة الوسطية Following ovulation, the remnant of the ovarian
follicle becomes the corpus luteum, which
بعد الإباضة، تتحول بقية الجريب
المبيضي ليتكون الجسم الأصفر is made up of luteinized theca and granulosa
cells, meaning that these cells have been
، الذي يتكون من خلايا قرابية وحبيبية
لوتيئينية، هذا يعني أن هذه الخلايا exposed to the high luteinizing hormone levels
that occur just before ovulation.
تعرضت للنسب المرتفعة من الهرمون اللوتيئيني
التي حدثت فقط قبل الإباضة Luteinized theca cells keep secreting androstenedione,
and the luteinized granulosa cells keep converting
الخلايا القرابية اللوتيئينية تستمر بإنتاج الأندروستينيديون
والحبيبية اللوتيئينية تواصل تحويله it to 17β-estradiol, as before.
الى 17-بيتا استراديول كما سابقا However, luteinized granulosa cells also respond
to the low luteinizing hormone concentrations
على كل حال، الخلايا الحبيبية اللوتيئينية
أيضا تستجيب لتراكيز الهرمون اللوتيئيني المنخفضة that are present after ovulation by increasing
the activity of cholesterol side-chain cleavage
التي تحدث بعد الإباضة
عبر زيادة فعالية انزيم enzyme, or P450scc for short.\تقسمات السلسلة الجانبية للكولسترول او (P450scc) This enzyme converts more cholesterol to pregnenolone,
a progesterone precursor.
هذا الانزيم يحول المزيد من الكولسترول الى
بريغنينولون (سليف بروجسترون) So luteinized granulosa cells secrete more
progesterone than estrogen during the luteal
اذا الخلايا الحبيبية اللوتيئينية تحرر بروجسترون
اكثر من الاستروجين خلال phase.
الطور اللوتيئيني Progesterone acts as a negative feedback signal
on the pituitary, decreasing release of follicle
البروجسترون يعمل كإشارة تلقيم راجع سلبي
على النخامى خافضاً تحرير الهرمونات stimulating hormone and luteinizing hormone.
المنبهة للجريبات والهرمون اللوتيئيني At the same time, luteinized granulosa cells
begin secreting inhibin, which similarly inhibits
بالوقت نفسه، تبدأ الخلايا الحبيبية اللوتيئينية
بتحرير الإنهيبين، الذي يثبط the pituitary gland from making follicle stimulating
hormone.
ويقلل انتاجها للهرمون المنبه للجريبات Both of these processes result in a decline
in estrogen levels, meaning that progesterone
كلا العمليتان تقللان من نسب الإستروجين
هذا يعني أن البروجسترون becomes the dominant hormone present during
this phase of the cycle.
أصبح الهرمون السائد خلال هذا الطور
من الدورة Together with the decreased level of estrogen,
the rising progesterone level signals that
جنبا إلى تناقص نسب الاستروجين،
البروجسترون المرتفع ينبه ovulation has occurred and helps make the
endometrium receptive to the implantation
أن الإباضة تمت، ويساعد على جعل
البطانة الرحمية أكثر تقبلا للغرس of a fertilized gamete.
للخلية التناسلية المنتشة(المشيجة) Under the influence of progesterone, the uterus
enters into the secretory phase of the endometrial
تحت تأثير البروجسترون يدخل الرحم الطور الافرازي
من الدورة cycle.\البطانية During this time spiral arteries continue
to grow, and the uterine glands begin to secrete
خلال هذا الوقت، تستمر الشرايين الحلزونية
بالنمو، وتبدأ الخلايا الرحمية more mucus./Nتفرز مخاطا أكثر After day 15 of the cycle, the optimal window
for fertilization begins to close.
بعد اليوم الخامس عشر للدورة،
تبدأ نافذة الإخصاب المثالية بالانغلاق The cervical mucus starts to thicken and becomes
less hospitable to the sperm.
حيث تتثخن مخاطية عنق الرحم، وتصبح
اقل قابلية لاحتواء النطفة Over time, the corpus luteum gradually degenerates
into the nonfunctional corpus albicans.
ومع الوقت،يتنكس الجسم الأصفر تدريجيا
ليتشكل الجسم الأبيض غير للوظيفي. The corpus albicans doesn’t make hormones,
so estrogen and progesterone levels slowly
الجسم الابيض لا ينتج أية هرمونات،
لذا تتناقص مستويات الاستروجين والبروجسترون decrease.
ببطئ When progesterone reaches its lowest level,
the spiral arteries collapse, and the functional
عندما يصل البروجسترون أقصى درجات الانخفاض
تنخمص الشرايين الحلزونية وتتحضر layer of the endometrium prepares to shed
through menstruation.
الطبقة الوظيفية لبطانية الرحم لتنسلخ وتنزف خلال الخيض This shedding marks the beginning of a new
menstrual cycle and another opportunity for
النزف يشير لبداية دورة جديدة
وفرصة أخرى جديد fertilization.
للإلقاح All right, so as a quick recap – the menstrual
cycle begins on the first day of menstruation.
حسنا، كخلاصة سريعة، الدورة الطمثية تبدأ
من اليوم الأول للنزف الطمثي For an average 28-day menstrual cycle, the
changes which occur in the ovary during the
لمدة ثمانية وعشرين يوم للدورة الوسطية
التغيرات المبيضية تحدث خلال first 14 days are called the follicular phase.
الأيام الأربعة عشرة الأولى تسمى
الطور الجريبي Ovulation usually occurs at day 14, as a result
of the estrogen-induced surge in luteinizing
الإباضة تحدث عادة باليوم الرابع عشر
استجابة لارتفاع الاستروجين المحرض بالهرمون hormone.
اللوتيئيني The last 14 days of the cycle are the luteal
phase, during which progesterone becomes the
الأيام الأربعة عشرة الأخيرة تدعى الطور اللوتيئيني)
خلالها يصبح البروجسترون dominant hormone.
الهرمون السائد While the length of the follicular phase can
vary, the luteal phase almost always precedes
بينما تختلف مدة الطور الجريبي،
فإن الطور اللوتيئيني تقريبا دائما يسبق the onset of menses by 14 days.
بداية الإباضة بأربعة عشر يوما The uterus also goes through its own set of
changes.
الرحم أيضا يخضع لتغيرات خاصة به During the first 14 days of the cycle, the
endometrium goes through the menstrual phase
خلال الأيام الأربع عشر الأولى تدخل البطانة
الطور الطمثي والتكاثري and the proliferative phase, and during the
last 14 days it goes through the secretory
وخلال الأيام الأربع عشر الأخيرة
تدخل الطور الإفرازي.
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phase. .