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High school biology
Course: High school biology > Unit 8
Lesson 3: The musculoskeletal system- Skeletal structure and function
- Cartilage
- Ligaments, tendons, and joints
- Three types of muscle
- Anatomy of a skeletal muscle cell
- LeBron Asks: What muscles do we use when shooting a basket?
- The musculoskeletal system review
- The musculoskeletal system
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Cartilage
Cartilage, a connective tissue, is secreted by chondrocytes and composed of collagen and elastin, providing strength and flexibility. It lacks nerve cells and blood vessels, gaining nutrition from surrounding fluid. There are three types: hyaline cartilage, found in the larynx, trachea, and joints, reduces friction and absorbs shock; elastic cartilage, found in the outer ear and epiglottis, provides shape and support; fibrous cartilage, found in the spine and pelvic bones, offers rigidity and shock absorption. Created by Tracy Kim Kovach.
Want to join the conversation?
- So what kind of cartilage is your nose made of? Part of it is cartilage, isn't it?(15 votes)
- The nose is made up of Hyaline cartilage.(20 votes)
- This might be a silly question, but if cartilage isn't innervated, how come ear piercings hurt?(13 votes)
- Because the skin and the veins around the cartilage are.(21 votes)
- I have an idea that Hyaline, Elastic, and Fibrous cartilage are comprised by different ratios of the Collagen and Elastin proteins. Would it be alright to understand them as:
Hyaline - 50% Collagen 50% Elastin
Elastic - around 100% Elastin
Fibrous - around 100% Collagen
Or are these estimations nowhere even close to reality?(19 votes) - Is your hair made up of cartilage?(4 votes)
- Nope! Your hair is made of a protein called Keratin!(21 votes)
- Do cartilage have living cells?(5 votes)
- Cartilage has living cells that exist in small pockets of space called lacunae (singular lacuna).(8 votes)
- at, you tell that you want to 'touch on briefly...' and then you start talking about something related to elastin and elastic protein. unfortunately I really cannot understand what you say there exactly :S (i am sorry I am not a native speaker and just this tiny bit of information went too fast for me :( ) could you explain it again for me? 0:46(2 votes)
- She said she wanted to "touch on briefly what I had struggled with for a little while...," which is the difference between cartilage and collagen. She then explained that cartilage is the connective TISSUE that's made up of collagen (a PROTEIN) and elastin (another protein). I've definitely confused those before as well. Hope this helps!(9 votes)
- what is elastin(2 votes)
- Elastin is a protein that has ability to recoil after it has been stretched. This is why it is called elastin (elastic protein).(8 votes)
- Does cartilage have veins and artery's in them just like the rest of your body?(1 vote)
- Cartilage tissue is avascular, i.e. it doesn't have blood supply. It is not innervated either.(6 votes)
- I find it very interesting that the Joints in your wrist weren't even mentioned, or even classified as Hyaline Cartilage. Why so?(3 votes)
- What structure gives cartilage its flexibility?(1 vote)
- It was mentioned in the video, but I'll still tell you........(Paused for dramatic effect)... Elastin! Like elastic.(3 votes)
Video transcript
- [Instructor] Alrighty, so
we're talking about cartilage, and cartilage is, at the most basic level, a connective tissue that can be found throughout the entire human body. And so cartilage is an
extracellular tissue secreted by cells called chondrocytes, which are derived from the
same precursor cells as bone, the fibroblast. Now chondrocytes secrete fibrous materials such as collagen, which is
a strong fibrous protein, and elastin, which as it's
name sort of sounds like, is an elastic protein that provides a rubbery, elastic component to cartilage. And one thing that I just
wanted to touch on briefly is something that I personally
sort of struggled with for a little while before I realized, ah that's what it is. So cartilage basically is, as I said, a connective tissue, just like bone, just like fat and other connective tissues that you find in the body. Collagen, on the other hand, is one of the building
blocks of cartilage. So, I feel like sometimes
it was easy for me to confuse these two terms, but realize that cartilage
is actually referring to the type of tissue
and collagen is referring to the type of protein
that is found in cartilage. Now the key thing to remember
about collagen and elastin, that make up cartilage, is that it gives cartilage
strength and flexibility. And a couple of other
key points to remember about cartilage is that
it is not innervated, meaning it doesn't have nerve cells, and it is also avascular, meaning it doesn't have any vasculature that runs through it. In other words, it doesn't have arteries and veins and blood
vessels that run through. Instead, cartilage receives nutrition and immune protection from
the surrounding fluid. So, there are three
main types of cartilage found within the body. The first type is called
hyaline cartilage. So, you can find hyaline cartilage in the larynx and trachea in
the throat portion of the body, and then also in all of the joints where the surfaces of bones
are articulating each other. So this is called articular cartilage. And, the main purpose of hyaline cartilage is to reduce friction and absorb shock. The second type of cartilage that you will find in the human body is called elastic cartilage, which can be found in the
shape of the outer ear, and also the epiglottis
which is the structure that protects your airway
whenever you are swallowing food. And so the main purpose
of elastic cartilage is to provide shape and support. And then finally we
have fibrous cartilage. And you can find fibrous cartilage in the intervertebral discs in the spine and also in an area of the pelvis called the pubic symphysis which is where the two
halves of your pelvic bones come together to form a joint there. And the main purpose of fibrous cartilage is to provide rigidity
and to absorb the shock that is transmitted between these joints.