Tissues - answerGroups of cells that are similar in structure that can perform common
or relates function
Histology - answerstudy of tissues
epithelial tissue - answeris a sheet of cells that covers a body surface or lines a body
cavity
- covering and lining epithelia
- on external and internal surfaces (skin)
- Glandular Epithelia
- Secretory tissue in glands
main functions- protection, absorption, filtration, excretion, secretion and sensory
receptors
Distinguishing Characteristics epithelial tissue
(Conner rolled as Paul squealed) - answer1. polarity
2. specialized contacts
3. supported by connective tissues
4. avascular but innervated
5. Regeneration
Polarity
-apical surface
- basal surface - answer- cells have polarity
Apical Surface- upper free side, is exposed to surface or cavity (mircovilli)
Basal Surface- lower attached side, faces inward toward body
specialized contacts - answer- epithelial tissue need to fit closely together
- specialized contact points bind adjecents epithelial cells together
-tight junctions
-desmosomes
Cells are very close together
Supported by connective tissue - answerall epithelial sheets are supported by
connective tissue
- basement membrane
, - made up of basal and reticular lamina
-reinforces epithelial sheet
-resists to stretching and tearing
-defines epithelial boundary
- gives it strength
Avascular but innervated - answerNo blood vessels are found in epithelial tissue
Must be nourished by diffusion from underlying connective tissues
Epithelia are supplied by nerve fibres
-O2 and nutrients
-connective tissue is feeding epithelia
Regerneration - answer- epithelial cells have high regenerative capacities
- stimulates by loss of apical-basal polarity and broken lateral contacts
- some cells are exposed to friction, some to hostile substances, resulting in damage so
must be replaced
- our skin heals fast, fast cell cycle
Simple Epithelia - answerone layer of cells
involved in absorption, secretion or filtration processes
Stratified epithelia - answermultiple layers thick for protection
Squamous - answerflat scale like
Cuboidal - answerbox-like, cube
Columar - answertall, column-like
simple squamous epithelium - answer- function where rapid diffusion is a priority
-cells are flatted laterally, and cytoplasm is sparse
-endothelium: lining the lymphatic vessels, blood vessel and heart
- mesothelium: serous membranes in the ventral body cavity
simple cuboidal epithelium - answer-single layer of cells
-secretion and absorption (carry urine)
they look like potato
simple columnar epithelium - answer- Made up of a single layer of tall cells that fit
closely together
-Function: absorption, secretion of mucus, enzymes and other substances
-found in the digestive tract
Pseudosratified columnar epithelium - answer-single layer of cells with different heights
- secrete substances, particularly mucus
- they are all connects
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller DESTINYGRACE. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $15.99. You're not tied to anything after your purchase.