Follow US:

Practice English Speaking&Listening with: Integrative Biology 131 - Lecture 13: Hematology

Normal
(0)
Difficulty: 0

MARIAN DIAMOND: Now, leukocytes are

very different from RBCs in that they function

outside of blood vessels.

So they live outside of blood vessels.

They live in connective tissue, in what we

call connective tissue proper--

CT proper.

Because we know we have lots of connective tissues,

that CT proper just equals CT cells and fibers.

So these white cells live out there,

waiting to be called upon.

There are many kinds of white blood cells.

There are five types.

And they're classified according to the granules

in the cytoplasm--

granules in cytoplasm.

And they're called granular leukocytes--

granular leukocytes.

And then there are those that have no granules.

So what are you going to call them?

Agranular-- a, without--

agranular leukocytes.

But we can also type leukocytes according

to the shape of the nucleus.

And they're called polymorphonuclear leukocytes.

Polymorpho-- all one word--

--nuclear leukocytes.

And that's easily deciphered, because poly is

many; morpho, shape; nuclear.

And when you work in the field, you're

going to be a technician in a hospital, they just call--

they're going to do a polymorph count.

So you understand which cells they're looking at.

Abbreviated to polymorphs.

So let's just name these now, and then

take each one individually to see why we need so many.

So they differ in size, as well.

So we'll just list them according to size.

The largest, then, will be the neutrophil.

And it will be from 12 to 15 micro in diameter.

And a neutrophil will be granular polymorph.

The next size is the monocyte--

monocyte.

And it's about 10 to 12 micro.

And it is agranular--

agranular.

The next one-- acidophil.

Acidophil.

And it's going to be a granular polymorph.

These will all fit together as soon as we describe them

and make it easier for you.

And 4 will be the basophil.

And it's also a granular polymorph.

And the last one is the lymphocyte.

Most people in today's world know lymphocytes.

And this is down, then, to about 8 micro in diameter--

almost the size of an RBC.

And it is agranular.

And an easy way--

all of these that have "phil" in-- what does "phil" mean?

Philadelphia-- what's it mean?

STUDENT: Love.

MARIAN DIAMOND: Love.

Love.

So loves neutral dyes.

Loves acid dyes.

Loves basic dyes.

So they're easy to remember, right?

We'll discuss each one at a time.

But just to help you with the big picture--

why they're called what they're called.

So let's begin, then, with the lymphocyte.

A lymphocyte has a large nucleus.

As we said, it's only 8 mu.

It has a large nucleus that almost fills the whole cell.

So a large nucleus is characteristic here.

It's not many-shaped, it's just roughly spherical.

And there's always a little indentation here.

It's not abnormal.

And it has just a simple rim of cytoplasm around the nucleus.

Not lots, just very little.

Simple cell.

And these cells deal with antibody-antigen reactions.

And there are many types of them.

We're going to follow B cells and T cells,

briefly get an introduction to them.

The B cells attack bacteria--

attack bacteria.

And the T cells attack substances larger than

bacteria, including-- example--

cells with nuclei-- cells with nuclei.

So quite a bit larger.

Now, B cells are formed in bone marrow.

B for B-- formed in bone marrow.

They then leave the bone marrow and go to lymph nodes--

lymph nodes-- which are collections of lymphocytes

throughout your body.

And from lymph nodes, they go out into the connective tissue

and become plasma cells.

Plasma cells secrete globulins.

And they then form antibodies, which

will interact with antigens--

or get marked with antigens, if you like--

and begin their process of the main function

in defending the body.

Now, the T cells--

by the way, you can't differentiate--

with a light microscope-- between these two types.

I mean, you look at lymphocyte with a light microscope,

it looks like this whether it's a T cell or a B cell.

The T cells, then, will be originating in bone marrow.

We had said that all blood cells have the same type

of initial stem cell.

And from the bone marrow, where are they going to go?

They go to the thymus gland, right.

Where's your thymus gland?

Right, everybody has a good idea.

Heart's as big as your fist, fits right in there--

on the big vessels coming and going to your heart--

fits your thymus gland.

So it's on large vessels of heart,

for those who've not studied it.

And here they're going to get an antigen marker

to carry out their function.

Now, there are many kinds of T cells.

Examples-- killer T cells, helper T cells, memory T cells,

and so forth.

And some of these will have numerical markers.

So we can have T4 cells, T8 cells--

as examples.

And the 4 and 8 refer to receptors.

Now, T4 cells will help T8 cells,

and T8 cells will destroy invaders.

In what disease is the ratio of T4 to T8 important?

Pardon?

STUDENT: [INAUDIBLE]

MARIAN DIAMOND: In AIDS, right.

T4 and T8-- important in AIDS.

In AIDS, the T4 decreases.

So if you've had a test for AIDS and you

find that you have decreased T4, immediately

request that you have a recount, because T4 fluctuates.

Don't just go home and cry.

So let's, then, go on to another agranular leukocyte--

which is it?

If it doesn't have a "phil" with it,

it doesn't have granules, right?

So the monocyte's the next one.

It's agranular, and it's going to be a little larger

than the lymphocyte.

And it'll have a kidney-shaped nucleus, lots of cytoplasm.

Easy to distinguish, on the whole--

monocytes from lymphocytes.

So we can call this either bean-shaped or kidney-shaped--

whichever you prefer.

And then lots of cytoplasm.

Just simple definitions here.

The monocyte is a phagocytic cell.

And again, these will be out in the connective tissue.

So if you have an infection, they migrate.

But they're slow migrators to the infection.

So maybe that's enough about a monocyte.

Let's start with our polymorph granular leukocytes.

Polymorph granular-- repeat, repeat--

leukocytes.

And start with the neutrophil that likes neutral dyes.

Neutrophil-- neutral dyes.

The neutrophil is the most common white blood cell--

most common white blood cell.

Anybody know what percentage it amounts to--

for your total lymphocytes?

I mean, white blood cells?

60% of total white blood cells.

Now, this cell-- as we said, it has a polymorph nucleus.

It has from three to five masses of chromatin--

three to five masses of chromatin--

that are connected.

So let's just make a three-nuclear leukocyte here,

take this over.

Three masses of chromatin that are connected.

And it will have neutral granules throughout--

so we'll color them the color of chalk.

Neutral stained-- it's very clever

when they can design a stain that will stain

all of these in one smear.

It's called Wright's stain--

very beautiful stain.

And what do we see attached to the female chromatin?

Little body here-- this is called a Barr body.

It's seen only in the female--

Barr body.

What does it represent?

It represents an inactive chromosome--

inactive chromosome.

When does this Barr body become useful in the Olympics?

When you're not sure that the contestant is male or female,

take a sample of blood, look at the neutrophils.

Interesting.

All right, these granules are filled

with an alkaline phosphatase--

these neutral granules.

The cells are phagocytic.

So say they can phagocytize a substance,

and then the alkaline phosphatase will break it down.

So eat a substance-- that's what phagocytize is.

And then broken down with the alkaline phosphatase.

Now, these move fast in contrast to your monocytes,

so they're fast movers.

So if you have an infection, they're the first to get there.

As you know-- we've all had infections at one time

or another--

we see that some of the symptoms there would be red, swelling,

soreness.

And if you're really infected, you develop pus as well.

Has anybody ever had pus?

Have you ever had an infection that gets a yellow pus?

I can see one hand.

So what's pus?

Yes, pus is nothing more than dead neutrophils and bacteria.

So these are busy cells.

Now, the next kind of polymorph granular leukocyte

is the acidophil, which loves its acid dyes.

Acidophil.

So its granules are going to be red.

And it has lots of big ones.

Let's first put in its nucleus, however.

It has a bilobed nucleus.

So you don't mix it up with the neutrophil,

[? which we ?] will define by lobes.

And then fairly large red granules-- quite clearly

a different cell.

And these granules contain an acid phosphatase.

These cells become active with allergies--

active with allergies.

Examples of allergies-- hay fever.

How many have hay fever this spring season?

Not too many, just a few.

Hay fever.

And also, they become prevalent with asthma.

How many have asthma?

A few more.

Some very strongly-- I can see by the way

you raised your hand.

So these are your acidophils.

What do they secrete?

They secrete a histaminase.

So you know it's an enzyme, because it ends in "ase."

So it can break down substances.

How are you going to remember the functions in this cell?

Let's start-- the name is acidophil.

They have acid phosphatase.

They're prevalent with asthma, allergies.

And histaminase-- how do we do a little cheating here?

But just to give you all the A's with your acidophil.

Did I forget anything here?

No, that's about it.

Now the basophil-- please.

STUDENT: [INAUDIBLE]

MARIAN DIAMOND: I'm sorry?

STUDENT: [INAUDIBLE]

MARIAN DIAMOND: Yes, two lobes of chromatin

with the acidophil.

Basophil-- a whole new world for many of you, isn't it?

Knowing this is going on in your bodies.

Muscles, bones-- you've heard of most of them.

This is all new.

So love basic dyes.

Basic dyes are usually blue.

They'll have a S-shaped nucleus.

And very irregular, basophilic.

I don't have another blue, because I

didn't know it's the same blue.

So we'll just use irregular nuclei

all over the granules, all over the place.

So they mask the nucleus.

So if you see a cell that's definitely not

a lymphocyte but lots of granules--

lots of granules.

These cells are less than 1% of your white blood cells.

Very infrequent.

Have you ever tried to do a cell count on blood-- on your blood?

No.

Well, the medical school--

teaching histology, you all had to take your blood,

and then you had to do a cell count.

And every time you found one of the white cells,

you raise your hand and the professor--

there are five professors in the lab,

can you imagine those days?

They were there.

And they'd come around and check you off.

And I could not find a basophil, so I never forgot that.

When it's less than 1% and your grade

depends on having a basophil--

how many years ago was that?

You remember that class.

All right, I got an A in the class,

but I still didn't find a basophil.

But those were days when they really

scrutinized to be sure you knew your blood cells, because they

are important.

So now, what are these cells secreting?

They're putting out heparin--

produce heparin.

What is heparin?

It's an anti-coagulant, right.

Forming blood clots.

In many diseases you do, you have to take heparin

to dissolve those blood clots.

Anti-coagulant.

What else do they form?

Anybody know?

Histamine.

Histamine-- they produce heparin and histamine.

And what does histamine do?

It increases the permeability of your blood vessel--

increases permeability of blood vessel.

So these little fellows are important.

Now we have another type of formed element in our plasma.

What is it?

Thrombocytes, right.

Thrombocytes.

Another name for thrombocytes--

platelets.

Another name for platelets--

cell fragments.

You'll see these used different places,

different parts of the country.

When I left Berkeley and went east,

found they use different terms.

There's some schools use one and not the other.

So I give them all to you, and you can take your choice--

or cell fragments.

These are all thrombocytes.

These are little fellows.

They're only 3 micra.

And again, a misnomer.

They're called cells-- thrombocytes--

yet they're fragments of a cell.

Where do they come from?

They come from a very large cell that has a large nucleus.

Mega is large.

Karyo is nucleus.

Cyte-- large, nucleated cells.

Megakaryocytes.

Megakaryocytes.

So mega is large.

Karyo refers to the nucleus and cell.

But they're not, they're cell fragments.

There's no nucleus in these thrombocytes.

So if we draw a megakaryocyte, we'll

find it's a large, irregular cell

with a large, irregular nucleus.

So this is our megakaryocyte.

Say it-- megakaryocyte, sure.

And so how does it form a little cell fragment?

That little fragment will bud off of a little bud here,

and then it'll break off.

This bud becomes a thrombocyte.

So it has no nucleus.

It's just the budding of little bits of protoplasm.

And what do they do?

They form thromboplastin.

And they aid in blood clotting.

So you wonder how all of these get designed to carry out

all these specific functions, and they're all

formed elements in your blood.

Let's see if we've got everything on that one.

Yes.

Now, a question came up at the end

of lecture last time of-- what happens to the reticulocyte

in forming an RBC?

So remember, we went from a normal blast--

do you remember?

Does it sound familiar, at least?

OK, a normal blast to a reticulocyte.

And then we went, right away, to the RBC.

And they said, what happened?

Well, the reticulocyte obviously has

to lose its reticulum, right?

I mean, if it's going to form it.

But that was a question that came up.

So we went from a normal blast [INAUDIBLE] forming an RBC.

We went to our reticulocyte.

I appreciate your input.

So if it's not clear, normal blast to a reticulocyte.

What does a reticulocyte count tell you?

STUDENT: [INAUDIBLE]

MARIAN DIAMOND: Right, the rate of production of your RBCs.

That's why they're so important.

Reticulocyte then goes to an RBC,

but it obviously has to lose all the reticulum, all

those ribosomes.

So it loses the reticulum.

Don't you find it fascinating?

Yep, good.

It's so amazing.

All these things are synchronized,

and you don't have to think about them.

Loses the reticulum and becomes the RBC.

All right, that gives you an introduction to blood.

You can take a whole course--

15 weeks-- on blood, right?

So let's look at what these cells look like.

First slide, please.

Can we dim the lights, please?

Thank you.

So what have we got here?

A lymphocyte-- you know that immediately, don't you?

Is it a polymorph?

No.

Is it a granule cell?

No.

I just want you to learn to identify.

What's this?

Whoops, I lost my pointer.

There we go.

Why does it go out there?

I think my battery's going out in my pointer.

Can you see where-- there it is.

Can you see it?

What's that?

Erythrocyte.

Why is it light in the middle?

Thanks very much.

Jill is so good.

I hope you have an assistant like her someday--

she and Evelyn.

What's this?

Say it!

STUDENT: Erythrocyte.

MARIAN DIAMOND: It's an erythrocyte,

but you can also call it a red blood cell.

Is that a correct term for it?

Why not?

No nucleus-- we learn these basics.

What are these?

Platelets.

They always look like--

this is not a platelet.

This is dirt.

And you have to learn to distinguish

between dirt and platelets.

They're about the same size.

In the next one--

so we've got a polymorph.

1, 2, 3, 4--

who's he?

A neutrophil.

How many lobes can it have?

What's its range?

STUDENT: Three to five.

MARIAN DIAMOND: Three to five, good.

And this one may be an older one,

because they have more with age.

And then the neutral granules that are filled with what?

An alkaline phosphatase, right?

And the next one?

Now, what's this?

A great, big nucleus.

What's it?

Is it a polymorph?

What?

No.

It's got big-- looks like a kidney shape.

Oh, can't you see that kidney shape?

It's not lobulated like the polymorphs.

So what is it?

It's a monocyte, sure.

That's a monocyte-- a big kidney-shaped nucleus,

lots of cytoplasm.

It's going to phagocytize.

What's this one?

Is it a polymorph?

Yes.

1, 2, 3, 4.

What is it?

A neutrophil.

They don't all fit textbook descriptions and drawing

descriptions, but it's definitely a polymorph.

What are these little fellows?

Platelets again.

Next one-- what's this bilobed one?

Acidophil, with lots of red granules.

So what conditions do you find in acidophil?

Asthma, hay fever, allergies, right?

Hay fever.

Well, when you see somebody's lung when have these,

there are lots of these around if they have asthma.

They really come to the rescue.

In the next one--

all right, this one's so dark you can barely see the nucleus.

What is it?

Basophil, right.

So when in doubt-- you can't see anything-- call it a basophil.

And then you don't remember it for a lifetime.

All right, what's it secreting?

Heparin.

What's heparin?

Anti-coagulant.

What else is it secreting?

Histamine.

What's histamine?

Blood vessel permeability, right.

The more you say it, the more you know it.

The next one-- ah-ha.

Where are we?

Who's this?

STUDENT: [INAUDIBLE]

MARIAN DIAMOND: We're in bone marrow, good for you.

And what do we see there?

Just this one.

What are these?

Erythrocytes.

What is this?

What's the precursor of the erythrocyte?

Waiting for somebody.

Normal blast-- say it.

Normal blast.

It loses, but here you see lots of these

have already lost theirs.

It's hard to make a preparation and catch one.

These are all ready to go out.

All right, when you go to medical school,

you have to learn all the precursors of all

of your white blood cells.

I just gave you the erythrocyte.

Next one-- next one, please.

Now, what's this big cell with this funny nucleus?

STUDENT: [INAUDIBLE]

MARIAN DIAMOND: I can hear mumbling.

Anybody see it clearly?

Megakaryocyte-- say it.

Megakaryocyte.

Mega-- large.

Look at how large that nucleus is, and lobulated.

Look how big the cell is in contrast to the other cells.

And here you see a little bud coming off.

That could go to be a platelet.

Let's try another one.

Next one, please.

Here-- this could have some little buddings, too.

Here's another stain entirely.

But this is a megakaryocyte.

All right, enjoy your afternoon.

The Description of Integrative Biology 131 - Lecture 13: Hematology