1. Explain why simple squamous epithelium is best suited to lining our blood capillaries?
2. Simple columnar epithelium is usually ciliated and can produce mucous. Why are columnar cells best suited to producing mucous secretions?
3. What are the advantages of having stratified squamous epithelium lining the oral cavity?
I don't want to seem like I'm answering all the questions, but no one has posted anything here so here goes.
ReplyDelete1. Simple squamous cells provide a very thin, permeable layer with a large surface area to volume ratio. In capillaries, there is only a single layer of squamous cells present. This is important because it allows for very quick, efficient diffusion of nutrients, oxygen and other products such as hormones etc into and out of the surrounding cells.
2. Columnar cells have a much larger volume to surface area ratio. Some modified columnar cells are able to produce mucous, such as Goblet cells. The reason they are suited to doing so is that with a larger volume, they are able to house more mucous producing organelles and contain quite large amounts of mucous filled vesicles. (I hope this is right)
3. The advantages of having stratified squamous epithelium as a lining are numerous.
- Provides a thick layer which protects delicate underlying tissues or areas subject to friction or abrasion. Because mastication is the mouths primary function, this is very important.
- Can be keratinized or non-keratinized. Keratinised epithelium is very tough and allows for wear and tear, protecting underlying cells.
- It has a very high turnover rate which allows for quick regeneration and repair.
Just out of interest:
ReplyDeleteIf you get a biopsy result of a soft tissue sample saying "squamous cell carcinoma" does that mean that the cancer has only affected the squamous layer of cells and has not spread to underlying structures?
That's exactly right Mirela. Squamous ell carcinomas are not as invasive as basal cell carcinomas. Have a look at the following link from a previous BOH online project. There is a lot of information that can clarify things for you:
ReplyDeletehttp://bohone09.wikispaces.com/Group+2
There is another wiki that also give syou a lot of information on epithelium.
http://bohone2010.wikispaces.com/Group+2
Sophie
Is anyone able to provide further clarification of question 2?
ReplyDeleteColumnar cells secret mucus and the cilia then move it to where it needs to go? Is that why columnar cells are best suited to producing mucus secretions, because they have cilia which can help transport it?
Am I correct in saying that columnar cells ability to produce mucus has something to do with them having large volume and therefor more organels for different cell activity?
ReplyDeleteThat's correct Mirela.
ReplyDeleteHi SophieH,
ReplyDeleteIn my opinion, there is one type of columnar epithelial called pseudostratified columnar epithelium which typically possess cilia, so epithelia of this type normally line most of the nasal cavity, the trachea, the bronchi( branches of the trachea leading to the lungs) and portions of the male reproductive tract, so it is clear that the cilia helps the mucus which possiblly engulf some pathogens get out of the body.