CZ1 SPINES

This eighth-grade science lesson is about the structure and function of the spinal column. It is the second lesson in a sequence of five lessons on the skeletal system. The lesson is 45 minutes in duration. There are 30 students in the class.

TimeCaption
00:00:11Please, sit down.
00:00:39Natasa (Mojzisova) came in today. Does someone want to be examined? Someone who's very brave?
00:00:54We'll pick someone who is knowledgeable. How about Adela (Vetrakova).
00:01:06Okay. Adelo, name some types of bone connections?
00:01:09Bone connections may be inflexible or flexible. The inflexible ones are ligaments, cartilage, or ossification.
00:01:16Yes. Please draw the flexible ones for us.
00:01:19So, here we have a joint. [ laughter ]
00:01:33Here we have //the so- called ball and socket. In order for it to be flexible, a liquid is in the socket. All this together is called the joint.
00:01:34//Very good.
00:01:47Yes, correct. Here is the skeleton. Please, show us some of the different types of bones according to their shape.
00:01:51Here we see the second bone.
00:01:53Correct.
00:01:54Then shoulder blades, which are flat bones.
00:01:57Correct.
00:01:58And short bones, that's for example (inaudible).
00:02:01Yes. Correct. Let's go back to mammals. Tell us something about the proboscidians.
00:02:09Well, the proboscidians belong to group of elephants. For example, there is the Indian elephant and the African elephant.
00:02:17What are the differences between them?
00:02:18Okay, the African elephant, has larger ears than Indian elephant.
00:02:23Yes.
00:02:24He is more intelligent and (inaudible)-
00:02:31Yes. He is more aggressive in captivity. Correct.
00:02:34It also has- the African elephant has a flat forehead, and the Indian elephant has bumps on his head.
00:02:42Then, the African one- both the male and female- have tusks. And, in the case of the Indian elephant, only the male has the tusks.
00:02:50Yes.
00:02:51The African elephant has two little extensions at the tip of his trunk, and the Indian elephant has only one.
00:02:59That should be enough. Can you name some perissodacts?
00:03:02Perissodacts, would be the Zebra, Horse and Donkey.
00:03:08Very good job. You get an A. Anyone else? Is someone else brave enough to come up here?
00:03:14From the boys... Jirko, why don't you come up here.
00:03:19Jirko? What does a bone cross-section look like?
00:03:22Okay. So-
00:03:24Why don't you grab the chalk again and draw a picture of it. [ laughter ]
00:03:34This is the bone //marrow and that can be found only in the larger bones.
00:03:36//Correct.
00:03:39Here we have a thin bone.
00:03:41Yes.
00:03:42Here- next to the bone marrow, we can see dense bone.
00:03:45Correct.
00:03:46That is the strongest bone. Here we have growth cartilage, thanks to which the bones grow to full length.
00:03:56Yes. Growth cartilage is always in the same place at both ends of the bone. Yes?
00:04:03And additionally-
00:04:07And what is on the surface of the bone?
00:04:10Some kind of cover or layer.
00:04:11A layer, which is called?
00:04:15We need help from the class! Tatiano?
00:04:16Periosteum.
00:04:17Periosteum. What are the functions of the periosteum?
00:04:20That's where the nerves and vessels are. That's also where blood corpuscles are produced.
00:04:29Wait a minute. No, not on the periosteum. Where are blood corpuscles produced?
00:04:32In the bone marrow.
00:04:33The bone marrow, yes. But we're talking about the periosteum.
00:04:35And it encourages the width of bone growth.
00:04:40Yes. Please tell us, Jirko, what an ungulate's stomach looks like.
00:04:48It has four stomachs, so it can easily digest the herbivores' food. So that's reticulum, abomasum, rumen, and psalterium.
00:04:58Which one is its main stomach and which one is the largest?
00:05:01The biggest one is the reticulum and the main stomach is rumen.
00:05:06The main stomach is? //Please be quiet!
00:05:08//Abomasum.
00:05:09Abomasum. Correct. Tell us something about camels.
00:05:14Camels have calluses so they can lie down on the hot sand.
00:05:23Where do they have calluses?
00:05:24They have them on their bellies and on their feet. They also have them in their mouths so that they can eat sharp branches and bushes.
00:05:32Yes.
00:05:33Then, they have humps with fat inside. It's a food reserve.
00:05:41Energy.
00:05:42Energy. Then, water is absorbed from their red blood cells.
00:05:47Excellent. The camel's water supply comes from red blood cells. Yes. What kind of camels do you know of?
00:05:57The Bactrian, Dromedary, and Deloul.
00:05:59Yes. Can you name an animal that is related to the giraffes?
00:06:02Okapi.
00:06:03What are the differences?
00:06:04It's smaller and it lives in the jungle.
00:06:09What does that imply? Okapi versus giraffes?
00:06:12If this animal were as tall as the giraffe, it wouldn't be able to run in the forest.
00:06:17Yes. From a common ancestry, through adaptation to environment, new ones evolve. Correct.
00:06:26Tell us the difference between a wild rabbit and the domesticated rabbit.
00:06:28The wild rabbits have longer legs and ears. They're faster- faster runners, more nimble.
00:06:39Yes.
00:06:40Now, rabbits- at birth, the young have both fur and vision.
00:06:46Yes, and why?
00:06:47Because it only has a simple nest out in the open.
00:06:51Correct.
00:06:52And the domesticated rabbit has a rabbit hole; so the young are born with no fur and they are blind.
00:07:02Yes. What kind of digestive systems do wild rabbits have?
00:07:06Kind of double- they digest it once, and then they digest it again.
00:07:13Correct. [ laughter ] Tell us, what category, do wild rabbits fall into?
00:07:20They fall into-
00:07:27It's not difficult at all.
00:07:29Mammals-
00:07:30The category, category. You're right about the mammals //but what category.
00:07:33//(inaudible) and the-
00:07:39Leave him alone; he'll figure it out.
00:07:40Leporidae family.
00:07:42The Lagomorpha order. Okay, I'll give you a weak A.
00:07:51Today, we're going to continue with the same topic.
00:07:54In our last lecture, we talked about the structure of bones; what they look like, what they are made of, and how they function.
00:08:00Once again, we'll emphasize the function of a skeleton. It doesn't serve only as a support for the muscles.
00:08:07What is the other function? It has been already mentioned, here in class. Alice?
00:08:10The production of blood corpuscles and the supply of blood cells.
00:08:12Very good. The production of blood corpuscles. Blood corpuscles are produced where? Zorko?
00:08:15In the bone marrow.
00:08:16The bone marrow. What is the most common matter in it? Marketo? In the bones?
00:08:24Calcium!
00:08:25Calcium and //what else?
00:08:26//Phosphate.
00:08:27Phosphate, correct. Today, we're going to talk about the human skeleton and, accordingly, all of its constituent bones. If you take a look at the entire skeleton,
00:08:41We can- [ laughter ] this is an example of what bone? Pavlo?
00:08:48Short bones.
00:08:49Short bones. Okay. We'll fix this skeleton after class. Let's take a look at the entire skeleton.
00:08:55We can distinguish several major sections of the skeleton. The most important aspect of the entire skeleton-
00:09:01The spine.
00:09:02Let's not shout out the answer, please- which classifies the human body. It's called? Dusane?
00:09:06The spine.
00:09:07The spine. Why does the human skeleton fall into a particular system, as a result of the spine? Tatano?
00:09:12Because it's composed of vertebrae.
00:09:14Yes. And a human is categorized as?
00:09:15Vertebrate.
00:09:16Vertebrate. As mammals and vertebrates. Correct. So the first, important load-bearing part of the skeleton is the spine, to which is attached the rib cage.
00:09:24The second part of the skeleton consists of the extremities and their plaits. Plaits hold the extremities to the body skeleton.
00:09:31There are upper extremities and lower extremities.
00:09:34What about the animals? They don't have upper and lower extremities, but- Martino?
00:09:38Front and rear.
00:09:39Front and rear. Correct. The last part is the skull, which protects the brain and provides the form for the face.
00:09:47Let's write today's theme: Human Skeleton.
00:10:01And we'll write down the segments of the skeleton. Who can remember the first and very important segment? Dusane?
00:10:07The spine.
00:10:08The spine. Plus the rib cage. Okay?
00:10:22The second segment or part of the skeleton is? //Can anyone remember?
00:10:26//The extremities.
00:10:27Correct. The extremities, plus the parts which hold it attached to the spine, which are the plaits.
00:10:37Okay? The extremities plus the plaits. And the last segment, Dusane?
00:10:44The skull.
00:10:45The skull. Please tell me once again, from what type of bone is the skull made? Pavlo?
00:10:52Flat bones.
00:10:53Made out of flat bones. Correct.
00:10:58So, that's the complete structure of the human from this point- [ laughter ]
00:11:06I was waiting for the skeleton to turn around. We'll put it back on its vertebra.
00:11:11Today, we're going to talk about the characteristics of the vertebrae, which is the spine. We've already talked about the spine in our early discussions, when we talked about the correct postures of the body.
00:11:23So you should have some knowledge about- at least the basics. Is the spine bent or is it straight? Mirko?
00:11:34Bent.
00:11:35How is it bent?
00:11:36In the shape of a double letter S.
00:11:37Yes. It's in the S-shape. We'll remind ourselves of those curves. How about the neck area? I mean, whether it's curved inward- the face would be over here- or curved outward.
00:11:51It's curved inward.
00:11:52Inward. So it's curved inward. Formally, what is it called; does anybody remember? Lordosis. The rib cage area is-
00:12:00The spine is outward here.
00:12:01It's curved outward. Didn't we mention the formal word?
00:12:02No.
00:12:04We'll call it cyrtosis. We'll talk and take notes about it. The lower back lumbar section is curved //inward.
00:12:08//Inward.
00:12:09Inward, and that's called again lordosis. And the bottom part, the sacrum and the coccyx, is called cyrtosis.
00:12:17Let's draw a picture and describe it.
00:12:23Don't forget- be sure to draw the face in the correct direction, so we'll know in which direction the curves go.
00:12:30Let's draw a face schematically and we may start. Okay, one more time. The first curve in the upper spine is inward.
00:12:41Don't overextend the curve. Just draw small curves. It'll come out just fine. As you can see, it is too curved.
00:12:48Then the spine curves outward, back inward, and, once again, outward.
00:12:54And let's write down: Lordosis is around the neck area and around the lumbar area.
00:13:11Two Lordosis, one is around the neck and the other one is around the lumbar area.
00:13:32Then the spine curves outward twice, those are the cyrtosis.
00:13:40It's spelled cyrtosis, with the letter Y after C. First cyrtosis and second cyrtosis. Cyrtosis in the back rib area, and cyrtosis at the bottom part of the spine.
00:14:06The fact that our spine has so many curves is not a coincidence. It's important for humans.
00:14:11It is not immediately evident at birth. If you recall, babies have a straight spine. As they grow older and start to sit, walk, stand up, and move their heads, the spine gradually flexes.
00:14:26Just imagine this curve-shaped spine, such as a stick or a pole.
00:14:31Since it has these curves, it has vertical flexibility and softens any direct blows during jumping, which would be severe for the spine and the brain.
00:14:42So this flexibility assures better maneuvering; and it softens any direct blows. Softens hits.
00:15:09What are the parts of a spine? What are the names? I hope no pieces of bones will start falling.
00:15:16What are the parts or fragments of a spine? That's very simple. These individual pieces are known as? Libuse?
00:15:23Vertebrae.
00:15:24Vertebrae, good. But that's not the only thing there. The only thing we see here are the vertebrae because all we have in front of us is a skeleton.
00:15:30But under normal circumstances, between every vertebrae, we have?
00:15:34Ligaments.
00:15:35Ligaments are there as well. They actually hold the entire spine together. But between every vertebra, there's also-
00:15:40Good afternoon.
00:15:41Good afternoon.
00:15:42Excuse me! (inaudible)?
00:15:45In the third grade.
00:15:46In the third grade. Thank you.
00:15:49Between every vertebra, we'll find- //Kveto?
00:15:51//Spondylus.
00:15:52Yes. Spondylus. And since it's between the vertebrae, we call it the spondylus vertebrae. We'll write it on the board in a minute.
00:15:59Before we do that, we'll talk about the purpose of the spondylus vertebra. The spondylus vertebra is made out of a unique matter.
00:16:07It's a cartilage tissue, which has a special characteristic to be flexible, softens- and it helps to absorb the pressure of the individual vertebrae and the entire spine.
00:16:18When you jump, for example, it softens the force.
00:16:20Since the spondylus is very flexible; constantly being flattened and stretched during our movements.
00:16:29But because this constant flexing occurs throughout the day,
00:16:33what may happen is that, when you wake up, your height is, for example, 160 centimeters.
00:16:39But when you go to bed at night- if you were to measure yourself, you would notice that you're actually about one centimeter smaller. Okay?
00:16:46It's because these spondylus flatten and the person becomes shorter.
00:16:54When you wake up in the morning you're back to your 160 centimeters. And since you're growing now, you're actually becoming taller.
00:17:04But the elderly- they don't have to be that old. At around the age of 40, the process of degeneration of these cartilages begins.
00:17:12You may have noticed that grandmothers seem to be getting smaller and smaller. Well, in reality, they are getting smaller.
00:17:19It's because they're losing the flexibility in the spondylus vertebrae. So as a result, spondylus is pressed down.
00:17:26But it doesn't rebound back from that. So as humans get older, the spondylus shrinks and they become shorter.
00:17:32The shrinking can be substantial. It may vary around five, 10, and 15 centimeters. It also depends on how long they live.
00:17:40So really old people may lose up to 20 centimeters of their original height. Once again, it's because of the shrinkage in the spondylus vertebrae.
00:17:51Now, we'll write down all of the spine segments. It consists of, one more time. Vertebrae, vertebra plus?
00:18:04The spondylus vertebrae.
00:18:06Correct. The spondylus vertebrae.
00:18:14The spine consists of the vertebrae and the spondylus vertebrae. Let's take a look at the vertebrae in your book.
00:18:27Open your books to page 73. Page 73. There, you'll see two different vertebrae.
00:18:42Look at the one on the bottom, which is partially outlined.
00:18:46So, tell me, what is the most important part of the vertebrae. What are the segments of the vertebrae? Dito? It's outlined in there.
00:18:59The medullary nerves.
00:19:00No. You're looking at the wrong picture. If you see the individual vertebrae, it's below that.
00:19:06The pillar and the pin vertebra.
00:19:10Are you on page 73?
00:19:12Yes.
00:19:15The bottom vertebra? Are you looking at the bottom vertebra? There are two vertebrae next to each other. The one below that.
00:19:26Yes, okay.
00:19:27It's outlined.
00:19:28The body of vertebrae.
00:19:30Okay. We can see the large part, which is called the body of vertebra. The other parts are not marked, so we have to do it ourselves.
00:19:37The protuberances that you see are called exactly that; in anatomical terminology it stands for protuberances. That's the other part of a vertebra.
00:19:45You can also see that opening there. Okay? That's anatomical terminology. The opening inside the vertebra is called the vertebral opening.
00:19:52See how simple it is? You'll just write in the correct names and color it.
00:19:57Please, also take a look at the bottom picture, originally described by Dita. You can see the spine. Can everyone see it?
00:20:05Yes.
00:20:06Okay. What else do we have on that page? Josefe? Let's be certain that we're all looking at the same picture.
00:20:11Spinal cord and //the medullary nerve.
00:20:12//Yes.
00:20:13Yes. Now, we should concentrate on the spinal cord. Please, go back to the picture of vertebra. You can see a drawing of the vertebral opening.
00:20:22It goes through it.
00:20:23Please raise your hand if you have something to say. Okay, Pavlo?
00:20:28The spinal cord runs through it.
00:20:29Yes. If we were to put the vertebrae in order- I'll show it to you on this model. If we were to place the vertebrae in order- here is a vertebra.
00:20:36If we were to place one on top of another, then you can see that one is larger than the other. But if they were stacked then they will form a canal. The spinal cord runs through this canal.
00:20:47You can see a drawing of the spinal cord in your books. Okay? Now, I'm going to draw a vertebra on the board.
00:20:55As we've said, it consists of the main body, which is the largest segment of the vertebra.
00:21:01Than we have these protuberances.
00:21:05The last segment is the vertebral opening. Mark it- it's very simple. Here is the body, protuberances, and the opening.
00:21:23We need to remember the fact that the spinal cord goes through the opening.
00:21:53And now we know everything that we need to. We can discuss the sections of the spine.
00:22:00You are all aware of these sections. But now we'll go into more details of each segment.
00:22:08Let's headline this: Parts of the Spine. The parts of the spine.
00:22:29You are all aware of the first part up here. It's called, Anezko?
00:22:34The neck.
00:22:35The neck area. The neck area. Don't write anything yet. We'll do that later. It's the most flexible part of the spine.
00:22:41You are fully aware that we have the ability to move our necks. And with the help of our neck, we can also move our-
00:22:47Mirko? Josefe?
00:22:50Our heads.
00:22:51With our heads, yes. If we move our neck, we obviously move our head.
00:22:56What's really unique in the neck are the first two vertebrae. The first vertebra looks like this.
00:23:04It differs from the others. As you can see, it doesn't have the same body that we've come to know.
00:23:09It has only two curves and angled extremities. It's called atlas. You can also see it on page 73. It's called atlas.
00:23:18In Czech we also call it a pillar. And we call it a pillar because it carries- what is it carrying?
00:23:24The skull.
00:23:25Yes. It carries the skull. Petra will raise her hand. The atlas falls into the skull and, as a result, we can move our head. Okay?
00:23:40This is called atlas, pillar in Czech, and it holds the skull. The second vertebra below is a little different from all the others.
00:23:48Jirko, I'll dictate this to you. It's a bit different as well. It has this shape up here. We call it a pin.
00:23:57That is why the entire vertebra is called? //Marketo?
00:24:00//The pin vertebra.
00:24:01The pin vertebra. Good. We place- later, we'll have additional pieces, which we'll try to put together in the lab.
00:24:09We'll place the atlas on top of the pin vertebra. Now, just imagine the skull on top of the atlas. Now we can turn the atlas, side to side.
00:24:18What is happening with the skull at this point? Jirko?
00:24:20It can move.
00:24:22How will it move? Nod or what else will it do?
00:24:23Side to side.
00:24:24It turns side to side. Okay. The ability to move your head is helped by these two vertebrae.
00:24:32This pin on the pin vertebra is probably familiar to you. When someone breaks their neck, for example.
00:24:38Having a broken neck basically means that- look, here you can see the vertebra opening in which runs through, what did we say?
00:24:44The spinal cord.
00:24:45The spinal cord. The spinal cord runs through it. If this pin breaks- here we have the nape, which is not here because it's a soft tissue.
00:24:53Here we have the soft tissue. It's a soft matter, which may break due some kind of rapid force.
00:24:59This pin can actually break and put pressure on the spinal cord. The spinal cord in this area controls breathing or heart activity, for example.
00:25:09As soon as the pin is forced onto the spinal cord and disrupts it, then a person- or any mammal, for instance- automatically dies. Okay?
00:25:19So, when this pin is broken, that's called a broken neck. When someone breaks their neck, it doesn't automatically mean that they die.
00:25:27You don't have to die if someone is fortunate enough- it happens. Some people assume that if you break your neck, that's an automatic death. That's not true - it doesn't have to be that way.
00:25:34This is when you break the pin but it doesn't shift. Okay? So it's possible to survive a serious neck injury.
00:25:41The spondylus, which is here, protects it a bit. So if you are under the impression that someone has a neck injury- or other parts of the spine injured-
00:25:54When it comes to the neck injury, the concern is not only paralysis but death- It's important not to move the patient.
00:26:01It only takes a small movement for the broken fragments to shift in this area, which may result in a tragedy. Okay?
00:26:06So if you ever suspect a spine injury, do not move the patient.
00:26:12Instead, you secure his or her neck to prevent any additional movement and call the ambulance.
00:26:17Let's write the first segment of the spine. First, the neck area. The first part of the spine is the neck area.
00:26:34We'll write the first two vertebrae in the neck. Who can remember?
00:26:40Atlas.
00:26:41Okay, atlas.
00:26:45What is the Czech terminology? Please raise your hand? Stelo?
00:26:48The pillar.
00:26:49The pillar.
00:26:56The second vertebra? Mirko?
00:26:58The pin vertebra.
00:26:59Yes. The pin vertebra. Just remember why it's called that. Why is it called the pin vertebra? Klaro?
00:27:08Because it has the pin on top.
00:27:09Yes. Because it has the pin, correct. And then we have other neck vertebrae. Can someone tell me how many neck vertebrae we have? Martino?
00:27:19Seven.
00:27:20Seven. Does that number, apply only to humans?
00:27:22No. All mammals have seven neck vertebrae.
00:27:24Correct. All mammals have seven neck vertebrae. Now we're getting into the second part of the spine.
00:27:30What do we call the second part of the spine? //Mirko?
00:27:35//The rib cage part of the spine.
00:27:36The rib cage part of the spine. Correct. Please take a look at the skeleton here and try to figure out-
00:27:43We've said that the neck vertebrae is very flexible, and we can easily move our head. Here, we see these attached ribs on the rib cage.
00:27:51Do you think this part of the spine is flexible? What do you think? Klaro?
00:27:56No. Not flexible.
00:27:57Yes. It is the least flexible section of the spine, not including the sacral, which is a joint bone. Okay?
00:28:03Let's write: The rib cage. Does anybody know how many pairs of ribs we have?
00:28:13Twelve.
00:28:14Okay, Dusan?
00:28:15Twelve.
00:28:17Twelve pairs of ribs. We have the same number of ribs as we have rib cage vertebrae. So, Adelo? How many rib cage vertebrae //do we have?
00:28:25//Twelve.
00:28:26Twelve. Twelve rib cage vertebrae. What's unusual about the rib cage vertebrae is that the ribs are attached to the vertebrae. Please write in parenthesis ribs.
00:28:40The ribs are attached to the rib cage vertebrae.
00:28:49We'll name the rest of the spine segments and count how many vertebrae each section has. Numbers are easy to remember so I will tell them to you.
00:28:57Below the rib cage vertebrae, we have? Mirko?
00:29:04The lumbar area.
00:29:05The lower back part of the spine. So why don't you write it as number three, Lumbar. This section has five vertebrae.
00:29:23Try to compare- if you can see it through the skeleton. I'm going to turn it, facing you.
00:29:36The size of the vertebral bodies, which are the white bones. And between those, we have the cartilage discs.
00:29:45What is it- in what part of the spine can we find the largest vertebrae bones? You'll notice it. I need someone to tell me, why is it in this section?
00:29:54We know that the spine's function is to carry the entire body. So where are the largest and thickest vertebrae and why? Josefe?
00:30:03It's in the lumbar section because it's attached to the pelvis.
00:30:08Pelvis is attached to it, but that has nothing to do with carrying the entire body. So give it another try. Tibor?
00:30:14Because it carries the entire rib cage and the skull.
00:30:17Yes. The rib cage, skull, and practically the entire upper part of the body.
00:30:19Since it carries a larger mass- larger body weight, so the vertebrae here must be stronger.
00:30:25These neck vertebrae carry only the skull, so that's why the vertebrae up here are not as big. Okay?
00:30:34That was the lumbar part of the spine. The next section of the spine is? Please raise your hand. Anezko?
00:30:44Pyrosis?
00:30:45No, pyrosis doesn't exist. That's fine. Adelo?
00:30:48Sacrum.
00:30:49Sacrum, correct. The sacrum section of the spine. It's distinguished from the rest of the spine by being- try to see it here.
00:30:59Here we have the individual vertebrae. The last lumbar bone is down here, and then we have the sacrum. Those of you up front, can you see it? Jarko?
00:31:05It's joined together.
00:31:06Yes. It's joined. It's not individual vertebrae anymore but it's a sacrum bone, which is joined together.
00:31:15Joined together- sacrum. It is joined together with the same number of bones as the lumbar section, which is?
00:31:25It's five.
00:31:26It's five. Okay?
00:31:31And the last section is? I don't have any more room on the board, but you will write it in your notes. It's a small section all the way down here.
00:31:39You wouldn't even think of this as being an individual section. It is called?
00:31:42The tailbone (coccyx).
00:31:43Yes. The coccyx. The coccyx is already reduced, so much so that one can't see the very small vertebrae present.
00:31:51It doesn't have the continuous count of vertebrae. In fact, it has a lower amount of small vertebrae. The coccyx serves no known function for humans.
00:32:02But do you think there are other mammals that have this tailbone extended? Mirko?
00:32:10Felines, for example. Their tailbone extends all the way down to the tail.
00:32:12Yes. And it's, in fact, the tail end of the spine- which humans obviously don't have- and it's very much reduced.
00:32:20So number five on the board is the tailbone which has about four to five vertebrae. The coccyx includes four to five vertebrae.
00:32:38If we were to add them up, the vertebrae- can someone count quickly?
00:32:44Correct. We have approximately 33 to 34 vertebrae. Why did I say approximately 33 to 34?
00:32:50Why didn't I give you a single number? Kristyna?
00:32:52Because of the coccyx.
00:32:53Yes. Because of the coccyx, where there can be either four or five vertebrae.
00:33:04So we have just described the spine. We'll review it once again by watching a video. Don't put your work away, just turn around.
00:33:39It's connected to the pectoral muscles.
00:33:44Can you all see it?
00:33:46Our bones are made out of one of the strongest materials nature has created. Bones are four times stronger than cement.
00:33:58Our bones are equal to aluminum in strength. The entire skeleton comprises only 14% of our entire body weight.
00:34:09A steel bar of the comparable size weighs four to five times more.
00:34:18Anatomists divide the skeleton into two major segments. The first segment of the body is the center part of the skeleton. The skull, spine, and the rib cage.
00:34:33The second segment of the body consists of the upper and lower extremities, including the shoulders and pelvic plait.
00:34:46Humans are the only mammals that walk on two feet. This contributes to their exceptional status among all mammals. But due to this exceptionality, there is a large amount of strain on the spine.
00:34:59The human spine, in fact, which is similar in shape to the letter S, performs the function as to straight the entire body.
00:35:09All 33 vertebrae assure strength, flexibility, and protect the spinal cord.
00:35:25There are seven neck vertebrae. Those vertebrae are the smallest in size, but allow the entire movement from side to side.
00:35:35Half way through the spine there are 12 larger rib cage vertebrae. They build the main part of the back. The lower section consists of five lumbar vertebrae.
00:35:47These vertebrae are the largest. These vertebrae also carry the most weight.
00:35:57Below that, there are five small vertebrae which grow together around the age of 25 and create the sacrum.
00:36:05It's a bone which is between the two hip bones and creates the back of the pelvis plait.
00:36:14Below the sacrum bone, we have the tailbone. It's a very small bone, which includes four small joint vertebrae.
00:36:24This bone has no function. It's probably just a reminder that our ancestors had a tail.
00:36:36Spondylus discs are between the vertebrae and give us flexibility. They also protect the spine from direct hits and violent shaking.
00:36:50Even the soldiers of the past //knew that the most important protection of his body is-
00:36:51//Now it's about the skull. We're going to view that in our next lesson.
00:37:18Please, pass this around from both sides, so it will go faster. Everyone will get one sheet.
00:37:33Jirka, go around.
00:37:44(inaudible) gets one?
00:37:45No, everyone receives their own. Take a look at the pictures. Try to orient yourselves. I will tell you what you're supposed to do.
00:38:04This is what's left? Everybody has one, correct? Let's take a look at the figures on the left. You can see the numbered figures.
00:38:14And below that, you have outlined diseases or deficiencies of the spine which are not in order. Your job is to match the correct number to the right letter.
00:38:28You'll write that below the heading. The next assignment is- look at the skeleton there on the right side.
00:38:38There, you'll use your colored pencils. You'll color each section of the spine using the different color.
00:38:44It means that you'll count down the vertebrae and, based on your calculations, you'll be able to tell what section it is and describe it.
00:38:52The last assignment- I'm curious to see how many of you will get it right. You ought to be able to do that.
00:39:02Okay? Which vertebra do you have there? Write the- the view from the top and side equals one vertebra.
00:39:10Okay? Give it a try.
00:39:30When you start matching the pictures, start with the ones that you know. Whatever remains will be easier to figure out.
00:39:47Just to make it simple for review, write a number one for example, dash and the letter. Okay?
00:39:54It's going to be very complicated to check your work if you were to start with letters. So use a number and a letter next to it.
00:40:03Numbers from one to five.
00:41:25The vertebrae- are we supposed to write what sections the vertebrae are from?
00:41:29Write what section it comes from, and give me the specific names of the first two vertebrae.
00:42:28Jano, describe each section as well, okay?
00:42:36You must color the spine, and also describe each section of the spine.
00:42:54(inaudible) vertebra?
00:43:00This one here. Just as you colored it. It doesn't go beyond that. After that, you have the coccyx.
00:43:15If you're not sure about the rib cage vertebrae, for example, you can count up from the last rib.
00:43:20That's where the rib cage vertebrae end and count up 12 vertebrae. Okay?
00:44:30Move on to the last part. You can color it later, so we can still check the work.
00:44:41Those of you who are not done, will finish it at home. We'll go over the work at the beginning of our next class. Okay?
00:44:51Dusan? Please take the skeleton away, okay? Jonasi?
00:44:54Yes.
00:45:07Patrik? Please help them out by carrying these fragments, including the skeleton. Okay?