0:08 all right Engineers what we're going to
0:09 do in this video is we're going to talk
0:12 about growth hormone so growth hormone
0:15 we discussed a little bit about um we
0:16 haven't really got to the complete
0:17 detail of it yet but we know
0:20 specifically in the hypothalamus there's
0:22 some specific hormones that are being
0:23 made right so for example if we look
0:26 here in the hypothalamus here's the
0:28 hypothalamus and the hypothalamus has a
0:30 specific nucleus situated in there
0:32 that's actually releasing this really
0:34 really really potent and Powerful
0:36 hormone and this hormone is called
0:40 growth hormone releasing hormone and if
0:41 you remember what was the growth hormone
0:44 releasing hormone do uh doing it was
0:46 actually circulating through the hypoy
0:48 portal system which is this circulatory
0:51 vascular connection between the
0:53 hypothalamus and the anterior pituitary
0:56 or we can call it the Adeno hypothesis
0:57 right so it circulates down through the
1:00 primary capillary plexus through the
1:02 intermediate hypophysial portal vein and
1:03 then out through the secondary capillary
1:05 plexus and then what it'll stimulate
1:07 what what's this actual green cell right
1:10 here called what is this green cell here
1:13 called this green cell here is actually
1:16 called a
1:20 somatrope somatotrope a somatotrope when
1:22 it responds to the growth hormone
1:25 releasing hormone will secrete out into
1:27 the bloodstream this very very very
1:29 important hormone that we're going to
1:31 spend most of our time you're talking
1:35 about and that is growth hormone so this
1:39 is actually growth hormone now real
1:41 quick ghr because it's actually being
1:43 released what's some of the secondary
1:45 triggers that can cause ghr to be
1:47 released so what are some other things
1:49 here that are causing this actual
1:51 release so you know growth hormone it's
1:53 actually stimulated by a couple
1:54 different things let's actually note
1:56 them so let's say here let's actually
1:57 number them so let's say what's
1:59 stimulating it so let's say here in this
2:00 these actual black column we're going to
2:02 say the things that are stimulating it
2:04 so one of the stimuli is actually going
2:08 to be um we could actually say high
2:09 amino acid
2:14 levels in the blood in the blood that's
2:17 one and I'll explain why that's a strong
2:21 stimulus another stimulus here is
2:26 actually going to be low glucose levels
2:30 in the blood okay so we could say hypo
2:31 glycemia right that's another word for
2:35 this low glucose in the blood another
2:41 stimulus is low fatty acid levels in the
2:45 blood okay so low fatty acids in the
2:49 blood another very very potent stimulus
2:51 of the growth hormone is going to be
2:54 exercise that's a huge one exercise is a
2:57 very strong stimulus and even we can say
2:59 certain types of healthy stressors right
3:01 so certain types of healthy
3:05 stressors okay because not all stress is
3:08 a bad thing so certain types of healthy
3:11 stressors okay these things right here
3:14 could be the very driving force to start
3:16 causing this growth hormone releasing
3:19 hormone how they could be utilizing this
3:21 mechanism by what stimulating this
3:23 nucleus here which we haven't even said
3:25 what this nucleus is this nucleus is a
3:27 very very potent nucleus and it's
3:29 actually releasing other hormones
3:31 besides growth hormone releasing hormone
3:32 so that's why it's important to know
3:34 what are the primary
3:37 stimuli um and these triggers that can
3:39 actually cause growth hormone release
3:40 well the
3:44 actual nucleus here is actually called the
3:46 the arcu
3:49 arcu
3:51 nucleus it's called the arcu nucleus
3:53 okay so this nucleus right here is
3:54 called the arcuate nucleus and again
3:56 what's stimulating it high amino acid
3:58 levels in the blood hypoglycemia
4:00 hypolipidemia EX exercise and certain
4:03 types of healthy stressors and it's
4:05 causing ghrh release which is
4:07 stimulating the somatotropes to produce
4:12 GH Okay now what's the function of
4:14 GH well growth hormone is actually going
4:16 to have a specific organ a Target organ
4:19 that it's going to go to first okay so
4:20 some of it will actually come to this
4:22 target organ some of it will actually go
4:23 into the blood triom so let's show it
4:25 bifurcating so it's like I'm going to go
4:27 this way and then the other way can
4:30 actually go and it can actually bind
4:32 right into this receptor right here so
4:34 let's say it binds into this receptor
4:36 right here so let's say here's the
4:38 growth hormone we'll draw it as a actual
4:40 green circle here let's say it's this
4:43 green circle and it binds on to this
4:45 receptor and actually this is a h
4:49 specific type of receptor um it actually
4:50 is going to activate a like kind of like
4:53 a tyrosine kinas receptor it's kind of
4:56 like a tyrosine kyes receptor and what
4:58 it does is there's a specific part
5:00 whenever growth hormone binds onto this
5:03 receptor it activates this
5:05 phosphorilation of specific types of
5:10 amino acids on this inner part of this
5:12 receptor and what it does is there's
5:15 this this enzyme that's activated here
5:18 and it's called jonis kyes but we just
5:21 actually denote it as Jack so jonis kyes
5:23 is Jack and he's the one that's
5:25 undergoing this phosphorilation right
5:27 and when Jack causes this
5:29 phosphorilation another thing that he
5:31 can do is he can phosphorate this uh
5:34 specific type of U transcription factor
5:36 and that transcription factor is actually
5:37 actually
5:41 called stat so here we got Jack this
5:44 Jack is activated and what does Jack do
5:45 so let's say here we we Square we we
5:49 kind of saw this is stat Jack actually
5:50 come over comes over here as a jonis
5:54 kyes and he can add phosphates onto stat
5:57 what is stat stand for it stands for
6:00 Signal transducer activator of
6:02 transcription so what do you think he's
6:05 going to do he's going to come in here
6:09 and he's going to bind onto a specific
6:12 sequence of DNA a gene sequence of DNA
6:14 right and when he binds onto the
6:16 specific Gene sequence it's going to
6:19 undergo transcription and it's going to
6:22 produce what mRNA then after the MRNA
6:26 it'll actually go to a what a ribosome
6:27 and then that ribosome will do what with
6:29 the protein I me with the actual Mna
6:32 it'll translate the MRNA when it
6:34 translates the MRNA it actually gets
6:37 converted into a protein and then it can
6:38 go through multiple different types of
6:40 other processes so again what is this
6:42 right here this is our
6:44 protein and it'll undergo some
6:45 modifications in the rough VR and the
6:49 GOI but eventually it'll be pushed out
6:51 into the
6:53 circulation what is this protein that we
6:56 actually secreted this protein is
6:58 actually going to be
7:00 called insulin
7:04 like growth factor so we got insulin
7:07 like growth factor type
7:10 one okay so it's making insulin like
7:13 growth factor type one okay why am I
7:14 mentioning this because I showed you
7:16 here right growth hormones kind of
7:18 making a little detour here so let's say
7:20 you know he's he's he has this little
7:21 fork in the road here so what's this
7:23 fork in the road right so he has a
7:25 little Fork on the road and he's some of
7:27 him is actually going to go this way so
7:29 a certain percentage of him is actually
7:31 going going to go into the bloodstream
7:32 and go exert its effects on target
7:34 organs some percentage of them is
7:35 actually going to go over here on the
7:37 liver and activate what's called this
7:40 Jack stat Pathway to lead to the
7:42 production of insulin like growth
7:45 factors okay what's going to happen now
7:47 so let's say here we have our growth
7:49 hormone let's focus on the effects of
7:51 insulin light growth factor
7:53 first okay insulin light growth factor
7:55 can do a lot of different things okay
7:57 one of the big things he's going to do
8:00 is he's actually going to go and promote
8:03 a lot of protein synthesis how so you
8:05 see this muscle cell right here what
8:08 he's going to do is he's going to come
8:09 out here he's going to come out of the
8:11 bloodstream so let's say here he comes
8:12 out of the
8:14 bloodstream and he comes over here and
8:18 he binds on to this receptor right here
8:20 let's actually draw him as um let's draw
8:22 him as green again let's say he's the
8:23 green molecule right so let say here we
8:26 have insulin light growth factor one he
8:28 binds onto this receptor present on the
8:31 muscle cells skeletal muscle right what
8:35 does he do he activates specific
8:37 signaling Pathways so he'll activate
8:39 specific signaling Pathways and let's
8:41 say inside here the muscle cell here's
8:44 the actual nucleus it activates specific
8:46 genes and produces specific types of
8:48 proteins and what are these proteins
8:50 going to do these proteins are going to
8:53 come over here and maybe phosphorate or
8:56 do some specific type of mechanisms to
8:57 these channels right here these green
8:59 channels guess what these green channels
9:02 are for they're for amino
9:04 acids what do we say was really high in
9:06 the blood in order for the stimulus to
9:07 occur we said that there was elevated
9:09 levels of amino
9:10 amino
9:12 acids well what are we going to do with
9:15 these amino acids well growth hormone is
9:17 stimulating what he's stimulating these
9:19 channels to open and guess who these
9:21 channels are specific for amino acids
9:22 and guess what's going to happen with
9:23 these amino acids they're going to get
9:26 taken into this muscle cell another
9:28 thing that's going to do is this isn't
9:30 the only pathway it can stimulate it can
9:32 stimulate another pathway it's going to
9:34 stimulate another pathway here which is
9:37 it's going to take these amino acids and
9:39 it's going to convert these amino
9:43 acids and cause them to get linked up
9:44 and when it links up a lot of these amino
9:45 amino
9:48 acids it's going to link these amino
9:50 acids together and produce what's called
9:52 proteins so what are we going to get out
9:55 of this we're also going to get proteins
9:57 and what kind of proteins could be many
9:59 many different types of proteins it
10:00 might be proteins that are going to be
10:02 like myofibrils like actin and myosin
10:04 and other different types of
10:05 cytoskeletal proteins and what is that
10:07 going to do to the overall size of the
10:09 muscle it's going to increase the muscle
10:11 size right so what's the overall result
10:14 of this The increased amino acid uptake
10:15 and increased protein synthesis can lead to
10:16 to
10:21 increase muscle size right so might te
10:24 lead to hypertrophy of the muscles so
10:25 it's going to increase the overall
10:27 muscle size and muscle function that's
10:29 that's a beautiful thing there there
10:31 okay so it's going to stimulate amino
10:32 acid uptake and increase protein
10:34 synthesis which can increase the muscle
10:36 size and function that's one thing that
10:38 this guy can do what's another thing you
10:40 can do so let's say that I take a look
10:42 here at the bone so let's say insulite
10:44 growth factor comes over here also okay
10:47 so Insite growth factor also decides
10:49 okay I'm going to come through this way
10:51 also so I'm going to come through here
10:53 and I'm going to exert my effects on
10:55 some specific parts of the bone all
10:57 right so what was this insulite growth
10:59 factor doing it was coming over here
11:01 here and on the bone you know you have a
11:03 bunch of different cells within the bone
11:04 what are these cells that we're going to
11:05 focus on specifically in the bone
11:08 there's going to be what's called
11:10 called
11:20 class what this actual growth I'm sorry
11:21 this insulin light growth factor is
11:23 going to do is it's going to be able to
11:26 work to regulate the activity of these
11:28 two cells so what it's actually going to
11:29 do is it's going going to be weird it's
11:31 actually going to increase the activity
11:33 of both of these cells so it's going to
11:35 increase osteoblastic activity and it's
11:38 going to increase osteoclastic activity
11:39 so it's going to increase bone
11:42 deposition and Bone resorption and
11:43 what's the overall result it's going to
11:46 play a very very crucial role within
11:48 bone growth but it also we could
11:49 actually even be more specific within
11:51 the bone not only does it increase
11:52 osteoplastic activity and increase
11:55 osteoplastic activity is it plays a very
12:06 endochondral
12:08 oifc okay so it plays a very very
12:12 important role with Endo condr
12:14 acific so one of the things that you're
12:16 going to see out of this is that there's
12:17 going to be an increase in like the bone
12:18 mass right so the Bone's going to be a
12:21 little bit thicker it's going to be
12:23 bigger you're going to have this an
12:27 increased endochondral oifc process
12:28 another thing that it's going to do
12:30 what's other components of the bone it's
12:31 also going to stimulate protein
12:33 synthesis what is it going to stimulate
12:35 the protein synthesis of what's the type
12:37 of collagen that's present inside of our
12:40 bone collagen type one okay so you can
12:42 actually have a lot of collagen type one
12:44 in here so let's say here we can
12:46 actually put here in red we're going to
12:48 have a lot of collagen production and
12:50 again what type of collagen is actually
12:53 being produced here collagen type one so
12:54 we're going to be producing a lot of
12:57 collagen type one so that's going to
12:59 increase okay so that's that part so
13:01 what's the process of bone uh working on
13:02 the bone it's going to increase the
13:04 collagen type one it's going to increase
13:06 osteoblastic activity it's going to
13:08 increase osteoclastic activity but
13:09 they're going to be highly regulated
13:11 which is going to enhance the endoc
13:13 condr oifc response what's another thing
13:14 that this is actually going to do
13:16 there's not just that proteins you know
13:17 there's other things there's what's
13:19 called proteoglycans so it's going to
13:21 increase the production of what's called
13:24 proteo glycans and these are also
13:28 extremely important in bone also okay so
13:29 let's just remember that overall in the
13:31 bone what's the overall effect in the
13:32 bone it's going to increase the overall
13:35 production of type 1 collagen increase
13:37 proteoglycans highly regulate and
13:39 increase the activity of both of your
13:41 osteoclast and osteoblast to where they
14:03 okay let's say here again we have the
14:06 bone and then what part of the bone are
14:08 we looking at specifically for this part
14:10 here we're looking at the what is this
14:13 part here this is called the epiphysial
14:15 plates right so this is your epiphysial
14:17 plates okay because you have your
14:19 diaphysis then you have your epiphyses
14:20 and this is the epiphysial plate here on
14:23 the ends what is this insulin like
14:25 growth factor doing here insulin like
14:29 growth factor one is also acting on on
14:32 this right here what is it doing here
14:33 you know what's actually going to be
14:35 some of the main cells inside of this is
14:36 actually cartilage here you're going to
14:38 have a lot of condra sites so you're
14:39 going to have a lot of condr sites guess
14:41 what this actual insulin like growth
14:42 factor is going to be doing to these
14:45 condra sites it's going to be increasing the
14:46 the
14:50 differentiation the size the hypertrophy
14:53 proliferation of all of these condra
14:55 sites so what is it doing it's
14:57 increasing the let's actually write this
14:58 down what is it doing it's increasing the
15:05 differentiation okay it's increasing the
15:08 size okay and it's in it's causing
15:09 increase in
15:11 proliferation why are we doing this
15:12 because you know what's called
15:14 interstitial growth you have what's called
15:15 called inter
15:17 inter
15:20 stitial growth of the bone right where
15:22 it's increasing in in length because you
15:23 have appositional which is increasing in
15:24 width and you have interal which is
15:26 increasing in length what growth hormone
15:29 is doing is it's causing these actual
15:31 condra sites or condra blasts really to
15:33 start proliferating right so they start
15:35 proliferating well actually they get
15:37 bigger in size they hypertrophy all
15:38 right so they get bigger in size they
15:41 start proliferating excessively and then
15:44 what happens is these layers let's say
15:45 here's this is this is the part of the
15:47 bone down here let's say down here is
15:49 the bone and up here is the part of the bone
15:50 bone
15:53 right what's going to happen is there's
15:54 actually going to be osteoblasts which
15:57 are going to be chasing this cartilage
15:58 right so as we continue to keep
15:59 proliferating these guys and getting
16:00 them bigger and bigger and
16:03 hypertrophying and stuff like that down
16:05 here is where they're differentiating so
16:05 this is actually going to get turned
16:08 into bone and Bone and to bone into bone
16:09 so what is it helping the actual bone to
16:13 do to increase in length so it enhances
16:15 the interstitial growth right at the
16:18 epiphysial plates so it's increasing the
16:21 actual condr blasts proliferation their
16:24 hypertrophy they're increasing in size
16:25 and also it's causing them to
16:28 differentiate into certain types of bone
16:30 tissue okay so what do we have here for
16:32 cartilage it's increasing interstitial
16:34 growth what is it doing for bone it's
16:36 increasing the osteoblastic activity
16:38 osteoclastic activity which is enhancing
16:42 the endochondral oifc response is making
16:44 more proteins like collagen type 1 more
16:46 proteoglycans which is being able to
16:48 increase the actual density of the bone
16:50 and helping to have more thick bones
16:52 right and then what else is it doing
16:55 here in the muscle it's increasing amino
16:57 acid uptake into the muscle cells and
16:59 it's activating genes to uh trigger the
17:03 protein synthesis process okay now that
17:05 we've done that we've looked at the
17:06 effects of insulin like growth factor
17:08 one it's causing a lot of effects
17:11 specifically on the bones the muscles
17:12 and the
17:15 cartilage now it also does have some
17:16 extraskeletal effects but let's look at
17:18 the growth hormone real quick you know
17:19 growth hormone he loves to act on the
17:21 liver so he also has other you know not
17:23 only does he actually work through this
17:24 Pathway to stimulate the production of
17:27 insulin like growth factor one but you
17:29 know he also can act let's actually show
17:32 it over here here this is also going to
17:34 act to be able to do some specific
17:36 process what is this process that he's
17:38 also going to stimulate here he can also
17:40 stimulate what's called gluco
17:42 gluco
17:47 neo genesis what's the overall effect of
17:51 glucon neogenesis it helps to be able to
17:54 increase the blood glucose levels how
17:55 are you making this glucose from
17:58 non-carbohydrate sources where's those
18:00 non-carbohydrate sources coming from
18:01 let's let's track this growth hormone
18:03 all the way over here to the adapost
18:04 tissue so this is our adapost tissue
18:06 right here
18:09 right this is the atopos what this
18:10 growth hormone is going to do is it's
18:12 going to bind on to these receptors here
18:15 right so here's a receptor here here's a
18:16 receptor here what's it going to do it's
18:18 going to trigger this intracellular
18:20 mechanism right activating an enzyme
18:22 called hormone sensitive lipase what's
18:24 that hormone sensitive lipase going to
18:27 do the hormone sensitive lipase is going
18:29 to act as that cutter we talked about
18:32 right it's going to start breaking down
18:34 what this actual triglycerides when it
18:37 starts breaking down these triglycerides
18:39 here it's going to break down the
18:41 triglycerides into two components what
18:43 are those two components one of the
18:49 glycerol what's the other component that
18:50 we're actually going to make out of it fatty
18:52 fatty
18:54 acids right so we're making two
18:56 components out of this what's that
18:59 glycerol actually going to be good for
19:01 it's actually going to be good for the
19:03 process of gluconeogenesis we actually
19:06 use that in order to make glucose so
19:07 that's one of the things that growth
19:09 hormone can do is it can come over here
19:11 act on adapost tissue and increase this
19:13 process right here which is called what
19:14 is this process called when you break
19:16 down triglycerides into glycerol fatty
19:18 acids it's
19:23 called lipolysis right then what happens
19:25 the breakdown products of lipolysis like
19:27 glycerol can actually be used in the
19:29 liver to make glucose that's called
19:32 gluconeogenesis right we said before
19:35 that odd chain fatty acids sometimes odd
19:37 chain fatty acids can some of them can
19:40 also get converted into glucose uh for
19:42 glucogenesis but we're like we're saying
19:44 here we're going to stick primarily with
19:46 talking about uh specifically just the
19:48 glycerol for this case but just if you
19:50 want to know for your own personal
19:53 interest yes odd chain fatty acids can
19:55 be converted into
19:57 glucose but this is the mechanism that
19:59 we're going to talk about so again
20:01 glycerol to glucon glucose via
20:03 gluconeogenesis is one of the effects of
20:06 growth hormone lipolysis is a lipolysis
20:09 is an effect of growth hormone also okay
20:11 and growth hormone can also activate
20:14 amino acid uptake also so we could also
20:16 say here if we show with this blue
20:18 representing the growth hormone he could
20:20 also act on that receptor to increase
20:22 the amino acid uptake into the muscle
20:25 cells okay so now that we've done that
20:27 let's just go over really quickly here
20:29 on this board
20:31 what's the overall effects of growth
20:32 hormone and what's the overall effects
20:34 of insulin like growth factor insulin
20:36 like growth factor
20:38 one and then growth
20:40 hormone let's write down their effects
20:42 real quick so he was doing what he was
20:44 stimulating the muscles right so he was
20:47 acting on the muscles he was acting on the
20:48 the
20:52 bones he was acting on the
20:54 cartilage he can also do certain types
20:55 of metabolic functions as well but we're
20:57 going to stick to this what was he doing
20:58 in the muscles he was working working to
21:01 be able to do what
21:03 increase amino acid
21:05 acid
21:09 uptake and he also increased protein
21:11 synthesis right so he's helping with the
21:13 muscle growth right so the muscle
21:15 hypertrophy and the muscle growth what
21:17 is it doing for the bones doing a lot of
21:18 stuff right increasing Osteo I'm going
21:21 to put OB for osteoblastic activity it
21:24 was also increasing osteoclastic
21:27 activity it was increasing collagen type
21:30 one production
21:33 okay so collagen type one you know how
21:35 you can actually remember how collagen
21:37 type 1 is actually the main collagen in
21:40 the bone you know how you spell bone b o
21:43 n e look one okay so collagen type one
21:46 is the type of collagen in the bone okay
21:49 so collagen type one another thing is
21:51 actually going to be besides collagen
21:52 type one we also said it could be increased
21:53 increased
21:56 proteoglycans right so a lot of stuff
21:57 like that and then the increase in
21:59 osteoblastic and Osteo classtic activity
22:03 assisted in what's called Endo condal
22:08 oifc okay we're going to put growth
22:10 hormone obviously to the left
22:12 now all right
22:15 now we talk about cartilage what is it
22:16 going to do for cartilage we already
22:17 said for cartilage it was going to
22:19 increase the proliferation right so it's
22:21 going to increase the proliferation of
22:24 the uh condra blast of the condra
22:27 blast it was going to increase the size
22:33 blast we said that it was also going to
22:36 increase the
22:38 differentiation right so in other words
22:41 the condra blast would be converted into
22:43 specifically um it would actually be
22:44 converted the cartilage the tissue would
22:47 eventually be converted into bone tissue
22:48 so cartilage would eventually get
22:50 converted into bone tissue so
22:53 differentiation of ctil like we'll say
22:55 the condr sites or the condr blast right
22:56 so the
22:59 condro blast
23:00 So eventually this would actually lead
23:03 into bone tissue right and what's the
23:06 overall result of this an overall result
23:09 was an increase in the interstitial growth
23:16 interstitial growth which increases the
23:18 length of the bone so we could say with
23:23 this would increase the length of bone
23:25 all right what do we say was the effect
23:27 of growth
23:29 hormone what we said the effect of
23:30 growth hormone was on the
23:34 liver and it was on the atap
23:38 POS and it was also on the muscles what
23:40 is it doing it's working on the liver to
23:44 be able to increase what's called gluco neo
23:45 neo
23:48 genesis it's also working on the liver
23:50 to increase the insulin like growth
23:56 production it's also going to act on the
23:58 atopos tissue and when it works on the
23:59 atap post tissue it enhances what's called
24:02 called
24:04 lipolysis and it's also going to work on
24:06 the muscle tissue and in the muscle
24:07 tissue it's going to help to be able to
