Brief Summary
This video provides a detailed explanation of the histology of the lip, focusing on its three main regions: the outer surface (thin skin), the inner mucosal surface, and the transition zone (vermilion zone). It describes the types of epithelium found in each region, the presence of various glands and structures like hair follicles and muscles, and the importance of blood supply.
- The lip consists of three layers: outer skin, transition zone, and inner mucosal surface.
- The main bulk of the lip is the orbicularis oris muscle.
- Each layer has distinct histological features, including different types of epithelium and the presence of glands.
The video introduces a discussion on the histology of the lip, emphasizing its mobile nature due to a well-developed core of striated muscles. The lip is divided into three main regions: the outer surface, the inner mucosal surface, and the transition border.
The outer surface of the lip is composed of thin skin, characterized by stratified squamous keratinized epithelium. This layer includes hair follicles, arrector pili muscles, and sebaceous glands. The thickness of the hair follicles varies, with thicker follicles present near the mustache region of the upper lip and thinner follicles in the lower lip. The epithelium consists of basal columnar cells with vertically oval nuclei, polygonal cells with round nuclei, and flattened squamous cells with a thin layer of keratin.
The transition zone, also known as the Vermilion Zone, is covered by stratified squamous non-keratinized epithelium, although some sources suggest a very thin layer of keratin may be present. This zone is notable for its rich blood supply, which gives the lip its red color due to the presence of numerous capillaries and nerves. The basement membrane in this region is wavy, forming rete ridges that aid in the firm attachment of the epithelium to the underlying lamina propria.
The inner mucosal surface is lined by stratified squamous non-keratinized epithelium. The basement membrane is folded, creating rete ridges. Underlying this layer are numerous mucosal and serosal glands that keep the surface moist. Unlike the transition zone, which is kept moist by saliva in the oral cavity, the mucosal surface has its own glands for moisture.
The main bulk of the lip is composed of the orbicularis oris muscle, a skeletal muscle. Depending on the section, it can appear as a transverse or oblique section. The muscle is rich in capillaries, especially below the transition zone. Histologically, it consists of polygonal-shaped muscle fascicles with peripherally placed multiple nuclei, characteristic of skeletal muscle.
The video concludes by summarizing the histology of the lip, highlighting the outer thin skin, inner mucosal surface, transition zone, and the main bulk of skeletal muscle. It emphasizes the presence of mucous glands in the mucosal surface for moisture and the hair and its apparatus in the thin skin. The video encourages viewers to refer to the labeled diagram provided at the end for further clarification.
Summarize any YouTube video in seconds
Get summaries like this one for any video, in your language, with the free Summ app.
Transcript
Full transcript of “Histology of Lip. step by step drawing with description”. Click a timestamp to open the video at that moment. Need another video? Use the YouTube transcript generator.
0:00 hello everyone today we'll discuss the histology of the Lip lip contains a well-developed core of striated muscles which makes it highly mobile so it has an outer surface then the inner mucosal surface and the transition border so outer surface it is nothing but a thin skin so it is lined by stratified squamous aized epithelium it has a thin layer of keratin with the hair so you have to remember how you wrote the skin so you have to write the hair follicle the aror P muzzle the sebaceous glands hair
0:48 follicles can be thin and uh thick also near the mustach region the outer part upper lip it can be a thick one the lower lip is a very thin area so remember how you wrote it's a basil columnar [Music] epithelium then you have a polygonal cells can write very thin skin so two to three layers of polygonal cells then the topmost layer of flattened scam cells and the another scamer cells without a nuclei that's a cartin so you have to write a thin layer of keratin also so this are polygonal cells which I'm
1:34 drawing then the flat cells and the Keratin [Music] layer make sure don't write the epithelium too big it's mainly the central core of muzzle which forms the main bulk of the lip so all representative diagram you have to draw in a miniature form don't draw how you draw in the skin the same layers you have to write in a small miniature you have to size you have to reduce because the main core is the muzzle there so that's the outer surface which is lined by stratified squamous keratinized epithelium the hairs the sebaceous glands aror p muszle
2:22 and all so remember the columnal cells has a vertically oval nucleus the polygonal cells with the round nucleus and the topmost cells has a horizontally flat nucleus the scamer [Music] cells that's a can in that's the cut section of the hair follicle the central core of hair and
3:07 surrounded by the [Music] epithelium director P which is smooth muszle and also the sebaceous glands which contains the cells lightly stained cells round cells with the centrally Place [Music]
3:58 nucleus [Music] that's the outer surface it's nothing but a thin [Music] skin this is transition zone also called Vermilion Zone it is uh covered by stratified squamous non karatin most of the books says but some books says it's a transition so keratin will be present very thin layer of keratin because the mucosal surface which is nothing but the inner surface inside the lip is non- cartin ised epithelium so you have on the one
4:44 side you have a keratinized epithelium another side you have a non- karatin ised epithelium and the transition zone is the area where keratin is almost become non-keratinized and keratin is almost reduced in number so keratin can be present but it's very thin layer keratin in the transition zone and transition zone deep to that you have a rich blood supply lip is the area where you have a rich blood supply that's a transition zone is nothing but the area where the lipstick is applied so that is red in color rich in capillaries and the nerves on the mucosal surface the basement membrane is wavy they are called retail rges which helps in The Firm attachment of the epi iium to
5:30 underlying lamina propria deep to that you have many salivary glands the many mucosal and serosal glands which keeps the mucosal surface moist so the mucosal surface is stratified scous non cariz epithelium the basement membrane is folded that's called reres underlying that you have a lot of mucosal glands which keep this mucosal surface moist but is a transition zone kept to moist by the saliva in the oral cavity now we have written the covering now the main bulk is composed of orbicularis orus muzzle which is a skeletal muzzle skeletal muzzle depending on the section how we take the specimen it can
6:17 be a transverse section or the oblique section whatever we are showing it looks mostly the transverse section so just remember how you wrote the transverse section of the skeletal muszle you have to write in a similar way and as I told you lip is rich in capillaries make sure you write a lot of capillaries especially below the transition zone so skeletal muzzle the polygonal shape of uh the fecycle muzzle fecycle and sharpen your pencil and you have to keep the peripherally placed multiple nucleus so remember it's a skeletal muzzle TS even the obli section also you can write the bundle of fyle muzzle phcle the polygonal shape and
7:03 peripherally placed [Music] nucleus so this is the hystology of the lip the outer uh thin skin inner mucosal cell and a transition zone and the main bulk is the skeletal muscle that's orbicularis orus mucosal surface has mucous glands to keep it moist thin skin you have to show about the hair and its apparatus I hope you understood how to draw the lip if you like the video please give a thumbs up share the video with your [Music] friends I've shared the label diagram also in the end of the video you can
7:49 just see refer that label the diagram thank you for [Music] watching
