Identifying Connective Tissue | Review and Practice

0:00after i tell you how to differentiate the six types of connective tissue proper

0:04i have 10 practice questions so when you're looking at connective tissue you want to think

0:12what fiber types am i seeing what directions are those fibers going in

0:19and it can also be helpful to look at the type of cells and the quantity of cells you're seeing

0:27so there's three possible fibers collagen elastic and reticular collagen is the thickest

0:34elastic is medium and reticular is the finest now i did put colors

0:41but the color is going to depend on what type of stain was used to stain the slide collagen

0:50and elastic are visible with the most common type of stain that they use as being pink and purple

1:00but the reticular usually you can't see it because that requires a special type of stain

1:15so looking at the first one that's the easiest that everyone learns very quickly that is adipose

1:27you don't have to worry about the fiber types it's just a bunch of fat cells

1:31so each one of these bubbles is a singular fat cell and the inside is filled with a drop of fat

1:38the biggest problem people have with adipose

1:46is that people will see simple squamous and think that it's adipose

1:50i'm gonna make a short video about that issue and pin it in the comments once i make it

1:58so the tissue next door in the background you're seeing kind of out of focus

2:06thicker pink fibers and in the foreground these black looking fibers

2:17so this is areolar connective tissue

2:25and the defining characteristic of it is that you have these pink collagen fibers and the

2:32black to purple elastic fibers randomly arranged in many directions and there's a lot of open space

2:41because a reeler is a loose connective tissue as opposed to a dense connective and there's also

2:51usually lots of these little black dots which are cells called fibroblasts

3:01over here so

3:05if you compare these black thready fibers to the fibers that you're seeing in areolar you'll notice

3:13that they look more like a net and more like a mesh whereas the areolar ones are very straight

3:22now those are the reticular fibers so this is reticular connective tissue

3:28and this is the one where you need a special stain to see it

3:35now when you're first learning usually the example

3:38they show you is a lymph node and in a lymph node you have lots of these circular cells

3:46so those circular cells you're seeing are also a hint that this is reticular

3:59so all these ones on the top are loose connective tissues

4:05because they're not packed as densely they don't have as much collagen

4:13if we go down to the bottom now this is a dense connective tissue so

4:21if you see the fibers they're kind of stained a light pink

4:28this is why you can't rely on color too much because many people would not see that as being

4:32pink but you see that the fibers are all going in one direction and these cells are kind of smushed

4:43in between the different fiber bundles this is dense regular connective tissue

4:51so it's called regular because the fibers are running in one direction next door we have fibers

5:03running in many directions so you have some fibers running this way and then this was a bundle of

5:09fibers that was kind of coming straight at us and then it got cut so we're seeing like the stumps

5:16that have been cut so because these collagen fibers are running in many different directions

5:27this is dense irregular

5:32and over here now this type of tissue is not very common and all the examples i have ever seen do

5:42tend to look pretty much like this you're seeing wavy elastic in the foreground and

5:48in the background it's kind of over a bed of pink collagen fibers this is elastic connective tissue

5:59not to be confused with elastic cartilage which is an entirely different tissue if you want to

6:06learn about cartilage i will pin a link in the comments i have a special video just for cartilage

6:20okay so i'm going to show you 10 practice questions

6:25and i'm going to give you 10 seconds to think about each question

6:30before i explain what the correct answer is and how you should have been able to know what it was

6:48okay so you should see that we have fibers going in one direction we only see one fiber

6:54type which appears to be collagen because it is pink and sandwiched in between we see fibroblasts

7:05and that's how you should know it's dense regular connective tissue

7:17i'm not even giving you 10 seconds because i know that you know

7:21when you see all these little bubbles all these very thin little bubbles

7:30you're looking at adipose

7:45okay so you're seeing black fibers that are making a net

7:54which lets you know you're looking at reticular connective tissue

8:13all right so this very much looks like hamburger meat

8:16what you're seeing is fibers going in all different directions that have been cut

8:24that's how you know that you're looking at dense irregular connective tissue

8:41so you have these black fibers going in all different directions in the foreground

8:49and there's kind of a haze of pink in the back that haze of pink is collagen fibers

8:54which are out of focus and you're seeing many of these little black circles which are fibroblasts

9:01and all of those things should tell you that this is areolar connective tissue

9:23okay so i cheated this is not connective tissue this is simple squamous um and this is how people

9:30are going to confuse it with adipose because they see lots of open space and circles and they're

9:35like oh adipose but what you need to pay attention to is all those little black specks are nuclei

9:43um that tells you that this is multiple cells it's not just one fat cell we have

9:49multiple nuclei multiple cells so this is many little squamous cells making a circle

9:58also you'll notice if you compare side by side squamous simple squamous um this

10:05isn't a lung it's not perfect little circles they're kind of irregular

10:10circles and if you need more help like i said i'm gonna make a video specifically just about this

10:28okay so you're seeing purple little waves those are bundles of elastic

10:38and it's over a background of collagen which is kind of out of focus

10:42and that tells you that this is elastic connective tissue

10:59so this is further away than you've seen it before but even though you can't see the individual

11:07fibers you can kind of see the wavy pattern in the background and you've got a bunch of cells

11:14here which are smooshed so what you're seeing is fibroblasts smushed in between collagen fibers

11:25so this is your dense regular connective tissue people sometimes will see certain types of smooth

11:35muscle and confuse it with this i'm going to make up a whole other video about that as well

11:51so once again black purple elastic over pink it's elastic connective tissue

12:16and lastly are fibers going in all different directions two different fiber types are visible

12:25little black specks which are fibroblasts has to be areolar connective tissue

12:37Alright, i hope that was helpful have a great day and have fun learning