[Script Info]
Title: 
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:02.04,0:00:04.54,Default,,0000,0000,0000,,Voiceover: Before we get to exactly how
Dialogue: 0,0:00:04.54,0:00:06.22,Default,,0000,0000,0000,,chronic bronchitis happens,
Dialogue: 0,0:00:06.22,0:00:07.49,Default,,0000,0000,0000,,I just wanted to review a quick
Dialogue: 0,0:00:07.49,0:00:09.53,Default,,0000,0000,0000,,rule of thumb about the body.
Dialogue: 0,0:00:09.53,0:00:11.24,Default,,0000,0000,0000,,So this is any opening,
Dialogue: 0,0:00:11.24,0:00:13.11,Default,,0000,0000,0000,,the body has to the outside.
Dialogue: 0,0:00:13.11,0:00:15.61,Default,,0000,0000,0000,,Let's label this as the outside.
Dialogue: 0,0:00:15.61,0:00:17.47,Default,,0000,0000,0000,,And anytime you have an opening
Dialogue: 0,0:00:17.47,0:00:20.76,Default,,0000,0000,0000,,and irritants get into\Nthe body, it could be,
Dialogue: 0,0:00:20.76,0:00:22.90,Default,,0000,0000,0000,,by irritants I mean anything\Nthat doesn't belong there
Dialogue: 0,0:00:22.90,0:00:25.24,Default,,0000,0000,0000,,that inflames a tissue.
Dialogue: 0,0:00:25.24,0:00:28.63,Default,,0000,0000,0000,,A common first defense\Nof the body is to call on
Dialogue: 0,0:00:28.63,0:00:31.99,Default,,0000,0000,0000,,the glands which are embedded in tissue.
Dialogue: 0,0:00:31.99,0:00:36.39,Default,,0000,0000,0000,,To secrete either liquid\Nor mucous into the space.
Dialogue: 0,0:00:36.39,0:00:40.06,Default,,0000,0000,0000,,And the goal is to have\Nthis fluid, this mucous
Dialogue: 0,0:00:40.06,0:00:42.11,Default,,0000,0000,0000,,mixed with the irritants and eventually
Dialogue: 0,0:00:42.11,0:00:44.31,Default,,0000,0000,0000,,flush them out or bring them out.
Dialogue: 0,0:00:44.31,0:00:46.18,Default,,0000,0000,0000,,I'm sure you can think of examples
Dialogue: 0,0:00:46.18,0:00:47.43,Default,,0000,0000,0000,,of what I'm talking about,
Dialogue: 0,0:00:47.43,0:00:48.97,Default,,0000,0000,0000,,like tears.
Dialogue: 0,0:00:49.20,0:00:50.74,Default,,0000,0000,0000,,If things get in your eye,
Dialogue: 0,0:00:50.74,0:00:52.54,Default,,0000,0000,0000,,it makes your eyes tear, right?
Dialogue: 0,0:00:52.54,0:00:53.82,Default,,0000,0000,0000,,So this is a mechanical thing
Dialogue: 0,0:00:53.82,0:00:56.93,Default,,0000,0000,0000,,the tears actually flush out\Nthe irritant in your eye.
Dialogue: 0,0:00:56.93,0:00:59.93,Default,,0000,0000,0000,,And we have snot.
Dialogue: 0,0:00:59.93,0:01:00.90,Default,,0000,0000,0000,,I'm sorry this is kind of gross,
Dialogue: 0,0:01:00.90,0:01:02.92,Default,,0000,0000,0000,,but if things get in your nose
Dialogue: 0,0:01:02.92,0:01:04.17,Default,,0000,0000,0000,,and it's not suppose to be there,
Dialogue: 0,0:01:04.17,0:01:06.28,Default,,0000,0000,0000,,the snot has to bring it out.
Dialogue: 0,0:01:06.28,0:01:08.79,Default,,0000,0000,0000,,And the third thing\Nwhich has to do with what
Dialogue: 0,0:01:08.79,0:01:09.61,Default,,0000,0000,0000,,we're going to talk about today
Dialogue: 0,0:01:09.61,0:01:11.74,Default,,0000,0000,0000,,is of course phlegm.
Dialogue: 0,0:01:11.74,0:01:14.60,Default,,0000,0000,0000,,So when things get into\Nyour throat or your lungs,
Dialogue: 0,0:01:14.60,0:01:16.99,Default,,0000,0000,0000,,the walls of the lungs secrete the mucous
Dialogue: 0,0:01:16.99,0:01:19.08,Default,,0000,0000,0000,,which forms a phlegm.
Dialogue: 0,0:01:19.08,0:01:20.84,Default,,0000,0000,0000,,Now the system in the lungs also
Dialogue: 0,0:01:20.84,0:01:22.70,Default,,0000,0000,0000,,triggers a cough reflex,
Dialogue: 0,0:01:22.70,0:01:25.07,Default,,0000,0000,0000,,which so the walls here
Dialogue: 0,0:01:25.07,0:01:27.99,Default,,0000,0000,0000,,if you can me drawing in red here.
Dialogue: 0,0:01:27.99,0:01:31.24,Default,,0000,0000,0000,,The walls here are lined\Nwith smooth muscle,
Dialogue: 0,0:01:31.24,0:01:34.51,Default,,0000,0000,0000,,and when the area is being irritated,
Dialogue: 0,0:01:34.51,0:01:35.78,Default,,0000,0000,0000,,the smooth muscle spasm
Dialogue: 0,0:01:35.78,0:01:37.48,Default,,0000,0000,0000,,and that's how we get the cough reflex
Dialogue: 0,0:01:37.48,0:01:38.98,Default,,0000,0000,0000,,to bring the phlegm out.
Dialogue: 0,0:01:39.05,0:01:41.22,Default,,0000,0000,0000,,Now keep in mind, I\Nsaid this is the body's
Dialogue: 0,0:01:41.22,0:01:42.47,Default,,0000,0000,0000,,first line of defense.
Dialogue: 0,0:01:42.47,0:01:44.73,Default,,0000,0000,0000,,So these are good things to have,
Dialogue: 0,0:01:44.73,0:01:47.04,Default,,0000,0000,0000,,you want the body to do this.
Dialogue: 0,0:01:47.04,0:01:48.100,Default,,0000,0000,0000,,So chronic bronchitis is basically
Dialogue: 0,0:01:48.100,0:01:50.80,Default,,0000,0000,0000,,too much of a good thing.
Dialogue: 0,0:01:50.80,0:01:54.06,Default,,0000,0000,0000,,So we have over production of mucous,
Dialogue: 0,0:01:54.06,0:01:56.69,Default,,0000,0000,0000,,such that the body cannot clear it
Dialogue: 0,0:01:56.69,0:01:58.98,Default,,0000,0000,0000,,too much of a good thing,
Dialogue: 0,0:01:58.98,0:02:01.58,Default,,0000,0000,0000,,that's when we have chronic bronchitis.
Dialogue: 0,0:02:01.58,0:02:05.07,Default,,0000,0000,0000,,And of course itis just\Nmeans it's being irritated,
Dialogue: 0,0:02:05.07,0:02:07.14,Default,,0000,0000,0000,,and bronch refers to the lungs.
Dialogue: 0,0:02:07.14,0:02:10.79,Default,,0000,0000,0000,,So chronic inflammation and\Nirritation of the lungs.
Dialogue: 0,0:02:10.79,0:02:13.09,Default,,0000,0000,0000,,Alrighty, let's draw some airway.
Dialogue: 0,0:02:13.09,0:02:15.04,Default,,0000,0000,0000,,So we have our trachea,
Dialogue: 0,0:02:15.04,0:02:20.04,Default,,0000,0000,0000,,the big stem bronchus branch\Noff into their branches.
Dialogue: 0,0:02:20.30,0:02:22.48,Default,,0000,0000,0000,,Here you go, just keep going.
Dialogue: 0,0:02:22.48,0:02:24.95,Default,,0000,0000,0000,,There are 20 or 30 branches to this,
Dialogue: 0,0:02:24.95,0:02:25.50,Default,,0000,0000,0000,,you get the idea,
Dialogue: 0,0:02:25.50,0:02:27.70,Default,,0000,0000,0000,,they keep getting smaller and smaller.
Dialogue: 0,0:02:27.70,0:02:29.61,Default,,0000,0000,0000,,It's how our lungs expand.
Dialogue: 0,0:02:29.61,0:02:33.34,Default,,0000,0000,0000,,And as you know oxygen goes into our lungs
Dialogue: 0,0:02:33.34,0:02:36.95,Default,,0000,0000,0000,,and carbon dioxide from the body gets out.
Dialogue: 0,0:02:36.95,0:02:39.05,Default,,0000,0000,0000,,So you have irritants in there
Dialogue: 0,0:02:39.05,0:02:42.04,Default,,0000,0000,0000,,flooding what is usually a clear path,
Dialogue: 0,0:02:42.04,0:02:43.51,Default,,0000,0000,0000,,then the lungs are not going to like that.
Dialogue: 0,0:02:43.51,0:02:46.64,Default,,0000,0000,0000,,One of the most common chronic irritants
Dialogue: 0,0:02:46.64,0:02:48.28,Default,,0000,0000,0000,,that we have in our lungs
Dialogue: 0,0:02:48.28,0:02:50.23,Default,,0000,0000,0000,,is of course cigarette smoking.
Dialogue: 0,0:02:50.23,0:02:53.25,Default,,0000,0000,0000,,So, here we go, we're going\Nto light this cigarette.
Dialogue: 0,0:02:53.25,0:02:58.21,Default,,0000,0000,0000,,And where you see a smoke\Nrising from the cigarette
Dialogue: 0,0:02:58.21,0:03:00.08,Default,,0000,0000,0000,,is actually billions and\Nbillions of particles
Dialogue: 0,0:03:00.08,0:03:02.67,Default,,0000,0000,0000,,that can enter and lodge into our lungs.
Dialogue: 0,0:03:02.67,0:03:06.82,Default,,0000,0000,0000,,As a response the glands\Nin the side of the walls,
Dialogue: 0,0:03:06.82,0:03:08.70,Default,,0000,0000,0000,,they start secreting the mucous.
Dialogue: 0,0:03:08.70,0:03:11.31,Default,,0000,0000,0000,,Remember it's part of our normal response
Dialogue: 0,0:03:11.31,0:03:12.75,Default,,0000,0000,0000,,to irritation.
Dialogue: 0,0:03:12.75,0:03:13.86,Default,,0000,0000,0000,,But of course chronics,
Dialogue: 0,0:03:13.86,0:03:16.33,Default,,0000,0000,0000,,we're talking about years\Nand years of constant.
Dialogue: 0,0:03:16.33,0:03:18.32,Default,,0000,0000,0000,,Everyday it's like this.
Dialogue: 0,0:03:18.32,0:03:20.71,Default,,0000,0000,0000,,Now eventually, what's\Nsuppose to be a clear pathway
Dialogue: 0,0:03:20.71,0:03:23.33,Default,,0000,0000,0000,,becomes convoluted with the mucous.
Dialogue: 0,0:03:23.33,0:03:26.96,Default,,0000,0000,0000,,It's like, if you're drinking\Nthrough a straw from a cup,
Dialogue: 0,0:03:26.96,0:03:29.69,Default,,0000,0000,0000,,instead of having a clear straw,
Dialogue: 0,0:03:29.69,0:03:32.13,Default,,0000,0000,0000,,you're sucking on a milkshake.
Dialogue: 0,0:03:32.13,0:03:36.08,Default,,0000,0000,0000,,So this milkshake is thick\Nand it's clogging the straw.
Dialogue: 0,0:03:36.08,0:03:37.20,Default,,0000,0000,0000,,So you'll have to suck harder
Dialogue: 0,0:03:37.20,0:03:39.24,Default,,0000,0000,0000,,and work harder to get through.
Dialogue: 0,0:03:39.24,0:03:40.83,Default,,0000,0000,0000,,Likewise, with the mucous,
Dialogue: 0,0:03:40.83,0:03:42.91,Default,,0000,0000,0000,,sometimes there's so much build up
Dialogue: 0,0:03:42.91,0:03:46.96,Default,,0000,0000,0000,,that it can clog off one\Nlittle branch of the lungs.
Dialogue: 0,0:03:46.96,0:03:49.29,Default,,0000,0000,0000,,So no more gas exchange\Ncan take place here
Dialogue: 0,0:03:49.29,0:03:52.11,Default,,0000,0000,0000,,and depending on the\Nseverity of the disease
Dialogue: 0,0:03:52.11,0:03:54.57,Default,,0000,0000,0000,,you can have different areas of the lungs
Dialogue: 0,0:03:54.57,0:03:56.78,Default,,0000,0000,0000,,being out of commission\Nbecause of the mucous.
Dialogue: 0,0:03:56.78,0:03:58.85,Default,,0000,0000,0000,,Now of course we always\Ntalk about smoking,
Dialogue: 0,0:03:58.85,0:04:00.34,Default,,0000,0000,0000,,but there are other things
Dialogue: 0,0:04:00.34,0:04:02.01,Default,,0000,0000,0000,,that can lead to chronic bronchitis.
Dialogue: 0,0:04:02.01,0:04:04.44,Default,,0000,0000,0000,,One important thing is pollution.
Dialogue: 0,0:04:04.44,0:04:06.87,Default,,0000,0000,0000,,Again pollutants are also billions
Dialogue: 0,0:04:06.87,0:04:09.57,Default,,0000,0000,0000,,of particles in the air all the time.
Dialogue: 0,0:04:09.57,0:04:12.12,Default,,0000,0000,0000,,In some countries that's\Nespecially a big problem
Dialogue: 0,0:04:12.12,0:04:14.64,Default,,0000,0000,0000,,and chronic bronchitis\Nis very common there.
Dialogue: 0,0:04:14.64,0:04:16.15,Default,,0000,0000,0000,,Or we can have coal dust,
Dialogue: 0,0:04:16.15,0:04:18.06,Default,,0000,0000,0000,,for people who work in coal mines,
Dialogue: 0,0:04:18.06,0:04:21.04,Default,,0000,0000,0000,,or people who work with asbestos.
Dialogue: 0,0:04:21.04,0:04:22.96,Default,,0000,0000,0000,,Shipyard workers.
Dialogue: 0,0:04:22.96,0:04:25.62,Default,,0000,0000,0000,,The common theme here is
Dialogue: 0,0:04:25.62,0:04:27.72,Default,,0000,0000,0000,,it happens when we can inhale irritant
Dialogue: 0,0:04:27.72,0:04:29.64,Default,,0000,0000,0000,,and it happens everyday.
Dialogue: 0,0:04:29.64,0:04:31.24,Default,,0000,0000,0000,,Now if I just smoke for a few days
Dialogue: 0,0:04:31.24,0:04:32.26,Default,,0000,0000,0000,,and I have a lot of mucous,
Dialogue: 0,0:04:32.26,0:04:35.41,Default,,0000,0000,0000,,that doesn't qualify me for\Nhaving chronic bronchitis.
Dialogue: 0,0:04:35.41,0:04:38.39,Default,,0000,0000,0000,,The pathophysiology here talks about
Dialogue: 0,0:04:38.39,0:04:40.69,Default,,0000,0000,0000,,the overgrowth of the glands.
Dialogue: 0,0:04:40.69,0:04:42.98,Default,,0000,0000,0000,,So we actually look for tissue change.
Dialogue: 0,0:04:42.98,0:04:45.95,Default,,0000,0000,0000,,Now in a patient, to\Ndiagnose chronic bronchitis
Dialogue: 0,0:04:45.95,0:04:47.91,Default,,0000,0000,0000,,is usually a clinical diagnosis,
Dialogue: 0,0:04:47.91,0:04:49.25,Default,,0000,0000,0000,,which means there are no test,
Dialogue: 0,0:04:49.25,0:04:51.66,Default,,0000,0000,0000,,it's just from the story.
Dialogue: 0,0:04:51.66,0:04:53.45,Default,,0000,0000,0000,,But we know from examining lungs of people
Dialogue: 0,0:04:53.45,0:04:54.78,Default,,0000,0000,0000,,who have passed away,
Dialogue: 0,0:04:54.78,0:04:56.87,Default,,0000,0000,0000,,the tissue change actually happens.
Dialogue: 0,0:04:56.87,0:04:59.13,Default,,0000,0000,0000,,So I just blew up one\Nbranch of the airway here.
Dialogue: 0,0:04:59.13,0:05:01.10,Default,,0000,0000,0000,,We'll call this the lumen.
Dialogue: 0,0:05:01.10,0:05:02.88,Default,,0000,0000,0000,,The lumen just means\Nthe inside of the tube.
Dialogue: 0,0:05:02.88,0:05:04.73,Default,,0000,0000,0000,,So the lumen is here,
Dialogue: 0,0:05:04.73,0:05:06.57,Default,,0000,0000,0000,,where the air is getting through.
Dialogue: 0,0:05:06.57,0:05:09.00,Default,,0000,0000,0000,,So the black space on both sides
Dialogue: 0,0:05:09.00,0:05:11.87,Default,,0000,0000,0000,,are the walls of the bronchi.
Dialogue: 0,0:05:11.87,0:05:15.48,Default,,0000,0000,0000,,So basically if we take a\Ncross section of our airway,
Dialogue: 0,0:05:15.48,0:05:18.97,Default,,0000,0000,0000,,in the middle here is the lumen.
Dialogue: 0,0:05:18.97,0:05:20.56,Default,,0000,0000,0000,,And right now I'm going to talk about
Dialogue: 0,0:05:20.56,0:05:23.47,Default,,0000,0000,0000,,the wall space of the bronchi.
Dialogue: 0,0:05:23.47,0:05:26.53,Default,,0000,0000,0000,,Okay so we have some smooth muscle
Dialogue: 0,0:05:26.53,0:05:28.80,Default,,0000,0000,0000,,around the walls.
Dialogue: 0,0:05:28.80,0:05:30.81,Default,,0000,0000,0000,,Again this spasm in this
Dialogue: 0,0:05:30.81,0:05:32.80,Default,,0000,0000,0000,,is what gives us the cough reflex.
Dialogue: 0,0:05:32.80,0:05:35.59,Default,,0000,0000,0000,,And right near the\Nsurface close to the lumen
Dialogue: 0,0:05:35.59,0:05:39.34,Default,,0000,0000,0000,,we have these layers of glands.
Dialogue: 0,0:05:39.34,0:05:41.03,Default,,0000,0000,0000,,They're responsible for\Nthe mucous production
Dialogue: 0,0:05:41.03,0:05:42.29,Default,,0000,0000,0000,,we've been talking about.
Dialogue: 0,0:05:42.29,0:05:45.11,Default,,0000,0000,0000,,As you can see they are\Nright under the surface.
Dialogue: 0,0:05:45.11,0:05:49.04,Default,,0000,0000,0000,,The job is to secrete\Nthings into the lumen.
Dialogue: 0,0:05:49.04,0:05:50.12,Default,,0000,0000,0000,,Okay just for completeness
Dialogue: 0,0:05:50.12,0:05:53.09,Default,,0000,0000,0000,,let me draw some irritants in the lumen.
Dialogue: 0,0:05:53.09,0:05:54.31,Default,,0000,0000,0000,,Okay.
Dialogue: 0,0:05:54.31,0:05:58.15,Default,,0000,0000,0000,,So that's what a normal\Nwall usually looks like.
Dialogue: 0,0:05:58.87,0:06:01.33,Default,,0000,0000,0000,,There is a way for us\Nto put a number on this.
Dialogue: 0,0:06:01.33,0:06:02.70,Default,,0000,0000,0000,,And we only do this,
Dialogue: 0,0:06:02.70,0:06:06.40,Default,,0000,0000,0000,,we've only seen this in\Npeople who have passed away
Dialogue: 0,0:06:06.40,0:06:08.14,Default,,0000,0000,0000,,and their lungs get caught up in the lab,
Dialogue: 0,0:06:08.14,0:06:09.54,Default,,0000,0000,0000,,and we can look under the microscope
Dialogue: 0,0:06:09.54,0:06:11.75,Default,,0000,0000,0000,,to see the Reid index.
Dialogue: 0,0:06:11.75,0:06:14.56,Default,,0000,0000,0000,,Which is a way to calculate\Nthe ratio of the glands,
Dialogue: 0,0:06:14.56,0:06:17.55,Default,,0000,0000,0000,,the thickness of the\Nglands to the whole wall.
Dialogue: 0,0:06:17.55,0:06:21.86,Default,,0000,0000,0000,,Now normal Reid index is less than 40%.
Dialogue: 0,0:06:21.86,0:06:23.95,Default,,0000,0000,0000,,So we can see the thickness here
Dialogue: 0,0:06:23.95,0:06:26.78,Default,,0000,0000,0000,,versus the thickness of this whole wall.
Dialogue: 0,0:06:26.78,0:06:29.57,Default,,0000,0000,0000,,It should be less than 40% in you or me.
Dialogue: 0,0:06:29.57,0:06:30.63,Default,,0000,0000,0000,,And of course in the middle here
Dialogue: 0,0:06:30.63,0:06:31.96,Default,,0000,0000,0000,,there are other things like cartilage
Dialogue: 0,0:06:31.96,0:06:33.74,Default,,0000,0000,0000,,or connective tissue.
Dialogue: 0,0:06:33.74,0:06:35.50,Default,,0000,0000,0000,,We're just going to\Nfill it in a little bit.
Dialogue: 0,0:06:36.59,0:06:38.88,Default,,0000,0000,0000,,Now what happens in chronic bronchitis is,
Dialogue: 0,0:06:38.88,0:06:43.44,Default,,0000,0000,0000,,the actual thickness of\Nthe gland layer grows.
Dialogue: 0,0:06:43.44,0:06:47.04,Default,,0000,0000,0000,,So the glands start proliferating,
Dialogue: 0,0:06:47.04,0:06:49.66,Default,,0000,0000,0000,,because we need so much mucous
Dialogue: 0,0:06:49.66,0:06:51.80,Default,,0000,0000,0000,,that the original number is not enough,
Dialogue: 0,0:06:51.80,0:06:54.22,Default,,0000,0000,0000,,so the body is recruited\Nto make more glands
Dialogue: 0,0:06:54.22,0:06:58.28,Default,,0000,0000,0000,,and they extend towards the smooth muscle.
Dialogue: 0,0:06:58.28,0:07:00.34,Default,,0000,0000,0000,,So in chronic bronchitis,
Dialogue: 0,0:07:00.34,0:07:03.76,Default,,0000,0000,0000,,the Reid index is usually over 50%.
Dialogue: 0,0:07:03.76,0:07:06.15,Default,,0000,0000,0000,,So definitely more than\Nhalf of the thickness
Dialogue: 0,0:07:06.15,0:07:08.91,Default,,0000,0000,0000,,of the whole wall is made of glands.
Dialogue: 0,0:07:08.91,0:07:11.21,Default,,0000,0000,0000,,Now remember we cannot\Ndo this in living people
Dialogue: 0,0:07:11.21,0:07:14.09,Default,,0000,0000,0000,,because we have to cut away their lungs.
Dialogue: 0,0:07:14.09,0:07:17.12,Default,,0000,0000,0000,,So just a way for us to put\Na number on this disease,
Dialogue: 0,0:07:17.12,0:07:19.08,Default,,0000,0000,0000,,but usually the patients are diagnosed
Dialogue: 0,0:07:19.08,0:07:21.54,Default,,0000,0000,0000,,and treated according to their symptoms.
Dialogue: 0,0:07:21.54,0:07:23.82,Default,,0000,0000,0000,,And the symptoms all come\Nfrom this tissue change
Dialogue: 0,0:07:23.82,0:07:26.81,Default,,0000,0000,0000,,and the over production of mucous.