Full transcript
0:00[Zene]
0:00bone is a very rigid type of connective
0:03tissue so that basically means bones are
0:06dense bones are strong and bones are
0:09hard so they have the ability to resist
0:11b tensile as well as compressive forces
0:15the question is why what exactly is
0:18found inside the bone that gives bone
0:21these types of properties so basically
0:24it's the extracellular matrix that is
0:27found surrounding our cells and in
0:29between our cells that actually gives
0:32the bone these types of properties so
0:34before we discuss the different types of
0:37cells inside the bone and the structure
0:39of the bone let's discuss the
0:41extracellular matrix of the bone so the
0:45extracellular matrix consist of organic
0:48matter as well as inorganic matter the
0:51organic component consist predominantly
0:54of a type of protein known as collagen
0:57and it's the collagen that gives the
0:59bone
1:06otherg comp of the extracellular matrix
1:10of the bone gives our bone the ability
1:13to resist compressive strength
1:15compressive force and gives the bone
1:17compressive strength and that's because
1:20in our inorganic component of the
1:22extracellular matri have csts as
1:28hydxydx
1:33calumos as
1:37hydrox the collagen gives the bone
1:40tensile strength but the
1:43hydroxyetite of the extracellular matrix
1:46that gives the bone compressive strength
1:49so now let's discuss the different types
1:51of cells found inside our b so we have
1:55osteoblast we have osteoces and we also
1:58haveost
2:03theosteoast so the osteoast are basic
2:06those cells inside the bone that are
2:09responsible for building that bone for
2:12building and secreting the extracellular
2:15matrix so that means these osteoblast
2:18are capable of secreting collagen into
2:21our extracellular matrix and cells are
2:25capable taking up calcium
2:28asos
2:30blood into extraellular matri basically
2:35these are the cells that are responsible
2:38for building bones they secrete organic
2:41as well as inorganic matter such as
2:44collagen calcium as well as phosphates
2:46and are responsible for creating the
2:49extracellular matrix that we just
2:52discussed above now eventually when
2:55these cells completely surround
2:57themselves and enclose themselves with
3:00mat basic differentiate into a type of
3:05celln as ost now what exactly is an
3:10ostoc basically the ost is the most
3:13common type of cell found in the bone
3:16and the ost is responsible for providing
3:19the bone with nutrients that the bone
3:22actually needs to survive the osteoc is
3:26connected to the blood vessel
3:28thatry types of nutrients as see in just
3:32a moment so osteocyes are the most
3:35common types of cell found inside bone
3:38and they are responsible for obtaining
3:41nutrients from the blood as well as
3:43dumping any type of waste products into
3:46our blood so that those waste products
3:49are recycled so osteocyes contain
3:52extensions that are known as processes
3:56so these two purple regions are the
4:01ex
4:03processes these
4:05processesadiate out and eventually they
4:08connect with canals and these canals are
4:11known as canaliculi so these canaliculi
4:16basically are canals that connect one
4:19oste to a second ost and these canalici
4:24basically are responsible for exchanging
4:26different types of materials between our
4:30between our adjacent
4:32osteoces now the final type of cell that
4:35i'd like to mention is our
4:37ostast so if these osteoblast basically
4:41build bone and one way to remember
4:44osteoblast building bone is the fact
4:46that we have a b in osteoblast so the b
4:50stands for building so osteocides build
4:53bones but ostoc do the opposite of
4:58building they basically resb our bone
5:01they break down the extracellular matrix
5:04of the bone and they secrete that into
5:07the blood for example they can break
5:09down our
5:10hydroxytite and they can release the
5:13calcium the phosphate back into the
5:15blood so osteoclass are the cells
5:18responsible for resorbing bone and that
5:22basically means they break down bone and
5:25they break down the extracellular matrix
5:27and release the mineral such as
5:31into the blood now attimes that can
5:35helpful because our muscle cells require
5:39calcium to contract and if we need our
5:42calcium this is how our bone basically
5:45releases the calcium so that the muscles
5:48can actually contract and when we
5:51discuss the process offorming and
5:54remoding our bone the osteoc and the
5:57osteoblast basically
6:00cruci ro in that process the bone is a
6:03living tissue continually being reformed
6:07that means it's continually being broken
6:09down and reformed and that's exactly why
6:12these two cells are crucial now what
6:16about the structure of the bone so just
6:19like our muscle cells our skelet muscle
6:22cells and cardiac muscle cells cons
6:25individual units
6:28as cons
6:31indiv know
6:33asost now the ost cons of concentric
6:37rings concentric circles that are known
6:40as lamell and these lamell are basically
6:44our extra cellular matrix that we spoke
6:47of earlier so this is the top view of
6:50our osteon we have these concentric
6:53circles we called lamell so this is one
6:57lamell a second lamell d l these are
7:01regions in white and l is basically our
7:05extracellular matrix that consist of
7:08collagen and our hydroxy appetite now
7:12along our lamell we basically have these
7:16spaces these space regions known as our
7:20lacuni and these lacuni are basically
7:23shown in black so these are the spaces
7:26and within these spaces we basically
7:28have the
7:30osteoblast that secreted our
7:32extracellular matrix and eventually
7:35became our osteocdes so these purple
7:39dots are basically our osteocdes and
7:42these blue extensions are the processes
7:45as well as our canals known as our
7:49canalcly so we have these blue
7:51extensions we have our canals known as
7:54canaliculi and we also have this center
7:58region at the center
8:01as aion canal now thision canal is
8:05basically a central canal that consists
8:08of lymph vessels it consists of blood
8:11vessels and it also consists of neurons
8:15so nerve cells so in the center of the
8:18oston the building block of the bone we
8:21have a canal known as ourion canal or
8:24the central canal and this canal
8:26contains the blood vessels our lmph
8:28vessel
8:32es prodct blood ving different tyes of
8:36nutrients and we also have neurons that
8:39basicallyv our bone now bone contain
8:44many of these individual ost so if we
8:47actually take a small crossction of our
8:50bone we basically get the following
8:53diagram we have many ofost in case we
8:57have two f five si of these concentric
9:02cylindrical regions we call ostons and
9:05at the center of each ost we have our
9:08central canal known as the herversion
9:11canal and within this herversion canal
9:14we basically have the blood vessels lmph
9:16vessels and our nerve cells our nerve
9:19fibers now what about the connecting
9:22regions between these herversion canals
9:25so the herersion canal of
9:28one
9:34a can know as volk canal so the volk
9:39canal is basically our canal that
9:42bridges that connects adjacent herion
9:45canals as sh in the following
9:48crossctional diagram so once again the
9:52building building un of our is
9:58as
10:01mat exraell mat that isated
10:06ostoast once we create this matrix the
10:09osteoblast basically differentiate into
10:12our osteoces shown by these purple
10:15regions these osteoces basically have
10:18these extensions known as processes and
10:21these processes connect to one another
10:24canals as our
10:27can can bas connect and allj ostdes to
10:33exch important types of materials
10:36important types of nutrients now within
10:39our center region of the oston we have
10:42our harversion canal which contains our
10:45blood vessels lmph vessels as well as
10:48our nerve cells our neurons now these
10:52concentric regions of matrix is known as
10:55our lam and the spaces where we have the
10:58ost
10:59that is know
11:01asun now inside the matrix we have
11:04collagen as the main organic mat and we
11:07have the hydroxy appeetite as the main
11:10inorganic matter and inside bone we have
11:13three types of cells osteoblast that
11:16build the matrix and build the bone
11:19osteocyes that allow the exchange the
11:22exchange of nutrients between other
11:25osteoces as well as our blood and lmph
11:27vesss and we have the osteoclass that
11:31basically resorb our bone break down the
11:34bone and release the different types of
11:36materials minerals into our blood