a

2-3 Glandular epithelium

hey we've got the next set of notes 2-3

glandular epithelium glandular refers to

glands things that secrete stuff and

epithelium is because they're all

derived from epithelial type tissue so

we're going to look a little more

in-depth as to what epithelia can do for

you so let's take a look at the

definition of a gland a gland is one or

more cells that secrete a product so any

cell that can produce something all by

itself and secreted into your blood or

into an organ is considered a gland and

the secretion is the thing that it

squeezes out of itself it's an aqueous

fluid which means it's got water as this

main solvent and it contains usually

proteins or some combination of fats and

oils and other things there are two main

types of glands that we find endocrine

and exocrine so from the words you can

kind of get a basic idea that endo means

inside so these secrete internally to

your body

EXO crin EXO exit means outside and so

they secrete externally to your body so

here's just some pictures of different

types of glands but we'll get into those

in just a moment alright let's start

with endocrine glands because they're

pretty simple endocrine glands do not

have any ducts they don't have any tubes

that the secretion comes out of not like

your salivary glands where you have the

saliva and a tube and it dumps out into

your mouth these guys they just kind of

ooze out their product so imagine your

hypothalamus and pituitary and your

brain just start sweating hormones

that's pretty much what it looks like

your pancreas your testes your ovaries

your adrenal gland your thyroid they

just kind of ooze out their product

directly into the bloodstream so what do

they do they produce hormones amino

acids peptides and steroids directly

into the blood example like I just said

thyroids adrenals ovaries and testes so

they just kind of ooze

but you have to remember you see like

that word is I'm gonna say that a lot

use alright so endocrine glands babes

exocrine glands these guys are a little

bit more detailed and a little fancier

in their structure and so these guys are

a tad more complicated exocrine exit

liquids head means that it exits out of

either a body surface or something and

it goes into an organ so directly into a

target organ or it goes into a cavity an

empty hollow place in your body exocrine

glands aren't any more common of the two

types of glands you have certain amount

of endocrine but you have tons of

exocrine glands of the exocrine glands

again two types there's unicellular and

multicellular the unicellular ones are

like this it's made out of one cell with

one nucleus and that says own little

booger making factory these guys are

called goblet cells due to the shape is

like a goblet or an old-style

kind of like a wineglass almost they

refer to that as a goblet their job is

to secrete mucin mucin eventually turns

into mucus which is boogers and nasty

gross stuff that you you know get back

in your throat like that and so that's

what their job is to do so imagine

you've got a lot of these up in your

nasal cavity down your trachea

as well and they also secrete into the

intestines because your stomach needs a

mucus to protect itself from eaten

itself so you've got a lot of mucus in

there as well you gross boogers in your

stomach so they secrete mucin into the

intestine and the respiratory tracts and

that's pretty much it that's all they do

they're just a little like I said booger

making factories then we have the

multicellular ones kind of like this so

this was one cell one nucleus as you can

cell see that this is a multiple cells

and they all work together to secrete

now there's three main parts to a

multicellular exocrine gland the first

part is called the duct and the duct is

this too but right here that is just a

passageway nothing exciting goes on

there the cells around it don't produce

anything they merely just provide a

passageway out then we have the

secretory unit which is made up of

cells that actually do the secreting so

they're the ones making the milk making

the oil making the sweat so they're

doing the work and then we have

supporting connective connective tissue

the yellow stuff all the way around it

that helps to give it its shape okay now

the multicellular ones come in two

varieties called simple and compound the

simple ones have no branching ducts it's

just a single tube one duct and it goes

in a straight line and other the simple

glands there's three types tubular

alveolar and tubular to below alveolar

they got really creative in naming that

one the tubular ones remind me of test

tubes so if you look down here kind of

looks like a test tube that's a tubular

forms tubes it's slender it's straight

they're really really simple then we add

up an alveolar with or otherwise known

as a cenar which is kind of funny

because it's got the word ass in it and

acinar looks like a small round bottom

flask so it's got the little skinny

tubes and then big fat ones right there

and then we have tubular alveolar which

is just a mix in the both so it's got

the nice single row of cells like this

but instead of big fat cells in the

middle like this there are little skinny

cells and they make this nice big open

cavity like this so simple ones straight

tube directly to the outside

multi-cellular ones that come in

compound forms these tubes branch so

there's lots of little branches I should

probably draw but once again I left my

pen at home so I'm drawing with my

finger so it's not gonna look great

so single or simple just go straight out

but a branched would go like that that's

a beautiful drawing right there can we

get rid of that okay for the

multi-cellular same thing

tubular forms tubes alveolar small

flasks tubular alveolar mixes both but

the only difference being that they're

branched as opposed to unbranched so

here is a picture kind of explaining so

we have the simple ones at the top and

this yellow area is showing dang it the

light just went off

oh well not like you guys can really see

me anyway being backlit and all so we've

got this simple tubular so it looks like

a test-tube and it comes together and

there's just one one tube leading out

simple branched tubular is the test tube

has branched but not the passageway

simple alveolar one passageway simple

branched alveolar they're still out via

larvae again one branch now the compound

as you can see if we follow the yellow

which are the tubes there's one two

three tubes or the ducts and so what we

see is there's a branched one and since

the red area the secretory unit is looks

like a test tube that's how we know it's

tubular then alveolar which is like a

round bottom flask and again you can see

that the ducts are branched ducts are

branched so if there's one duct it's

simple if there's many ducks

crack crack then it is compound all

right exocrine glands they so they

classify them by what do they look like

are they branched are they not branch

but they also classify them by how they

secrete how do they get their stuff out

so they're classified functionally how

they secrete oh there's lights why as

either merocrine apocrine or holocrine

so they're based on how they secrete

their product so you're thinking well

how many ways are there well the first

way is the holocrine way holocron this

guy right here a what he does

I like loops I like this guy because he

is he's float he explode he makes his

product so these little polka dots right

here and the cell swells up and then

eventually I can't take it anymore and

it goes kablooey and the cell just marks

its contents out all over the place but

then that's okay because right here we

got mitosis going on and this like oh

you exploded don't worry I'll make you a

new one not that big of a deal and so

all the cells are always replaced by

mitosis and then we have a you know oil

glands all over your face so anytime you

get oily you know right here just

remember that

was because a cell gave up his life for

you so you could have nice shiny

complexion Yeah right whatever so here's

how I remember this one hole the whole

cell explode hole Loughran I know it's

not whle but you get the point the whole

cell exploit all right merocrine Marin

is the most common one that we find so

when in doubt merocrine you know like

you when in doubt see it out with glands

when in doubt it's merocrine so america

and are the most common glands that you

find all over your body and they are

constantly secreting and whatever they

make immediately pops out of them but

the cells do not get destroyed

so they secrete their substance it comes

straight out of the duct nothing happens

to the cells they don't explode or

anything and it's just a constant flow

so you don't really think you're

sweating right now but you really are so

there's a little experiment we do in the

next unit we're just sitting here we're

gonna put a card on our hand that

identifies sweat changes colors when it

comes in contact with sweat nobody

surprised just how much you sweat just

sitting here let's see so sweat is the

most common example of merocrine glands

I don't know how to remember yell

constantly marrow bone marrow constantly

makes blood merocrine constantly make

sweat I don't know you know whatever

works for you and then we have the

apocrine app cream glands are only found

in your memory glands and what they do

is a little bit of the cell breaks off

and secretes it's substance so notice

the cell doesn't explode like it does

here but it actually bits of the cell or

fragments of the cell take off with the

product in it and then kind of oozes and

secretes out there so you see right here

pinched off portion of cell secretion so

it's actually cell membrane wrapped

around the good stuff

so milk pretty much is the only one out

there that they have figured out they

think earwax but they're not sure yet

so so this milk comes out a little bitty

bags and weird to think

that way ooh milk bags gets ahold sorry

that was inappropriate of me all right

here's how I remember a procuring

Bland's being memory is because of the a

reminds me of the pointy bras that

Madonna used to wear and so now cocaine

bra milk boobs you get it okay I think

I've done yeah I'm done okay bye guys