Summary
whole cell histology summary
- Course
- Institution
whole summary of cell histology
[Show more]
Seller
Follow
jill3
Reviews received
Content preview
Lecture 1 epitheliumMicroscope
types
Light microscope:
- resolution: 0.2 micrometer
Electron microscope:
- Transmission EM: 0.2 nanometer
slide preparation
1) Fixation: stabilization of structure
o Formalin
2) Imbedding in paraffin: to prevent breakdown by liquids or oxygen
3) Cutting of slices: 50 nm-7 μm
4) Cytological staining
o Overview staining
o Cytochemical: identify specifics in cell (e.g. proteins, DNA, sugars, etc)
Embryonic origin
- Cell types that are part of the same basic tissue type can look much different!
- What these cells share is the same embryonic origin.
o Embryology & germ layers
▪ Ectoderm: nervous tissue, skin
▪ Endoderm: digestive tissue, lung
▪ Mesoderm: muscle, connective tissue (from mesenchyme)
4 basic types of tissue
- There are ± 200 different cell types, these are organized in tissues.
- These tissues can be classified in 4 basic types of tissue:
1) Epithelial Tissue: first layer on top of organ
2) Connective Tissue: provides connection between layers
3) Muscle Tissue: produce movement
4) Nervous Tissue: activate muscle tissue
- These basic tissue types are functionally organized in organs (e.g. liver, heart)
Epithelial Tissue
- Epithelium: tissue existing of cells that are tightly connected to each other.
- There are two types:
o Covering epithelia (e.g. skin)
o Glands (invaginaton of epithelial layers)
,Classification epithelia
- epithelium is classified based on
o embryonic origin: ecto-, endo-, or mesodermal
o morphology: shape of the cells
o cell organization: number of cell layers (strata)
cell shapes
Transitional: changes between Squamous and Cuboidal done by stretching
Epithelia: cell layers
SIMPLE: one layer of cells STRATIFIED: multi-layered or looks multi-layered
Characteristics
- No blood circulation, not in between the cells, but going underneath
- Polarized (apical:top and baso:bottom-lateral:between cells)
- Surface specializations
- Presence of a basal membrane
Apical domain
- Microvilli:
o Small fingers: increase surface area
to increase absorption
o Cytoskeleton of actin
(microfilaments)
o Also called brush barrier
- Cilia:
o movement of liquid
▪ sensory function
o Cytoskeleton of microtubuli (tubulin):
vary in length
o Larger than microvilli
, intracellular connections
Tight junction
Adhesion
belt
Terminal
web
Button
desmosome
Hemidesmosome
(a)
Gap junctions
Tight Junctions (Zonula Occludens)
- Round the whole cell
- TJ proteins function like a zipper
- Functions:
o Prevent transport of small molecules between cells
o Membrane proteins of both cells are compartmentalized (apical and basolateral) to
keep them separated
Adhesion Belt (Zonula adhaerens)
- Round the whole cell
- Adhesion between cells
- made by transmembrane-linker proteins: cadherins
- Intercellular: widened
- Intracellular: connected with actin
Gap junctions (nexus)
- Pores in cells for information transfer
- Intercellular transport: 1.5 nm
- Transmembrane proteins: connexins:
- tubule: connection from one connexion to another connexon
- Transport of ions, amino acids, molecules < 1kDa, certain hormones
Button desmosome
- Not round the whole cell
- Makes the strongest connection between cells
- Intracellular: connected with intermediate filaments (keratin, vimentin,
desmin, etc)
- Thicker than actin: stronger
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 jill3. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $5.90. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
52510 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now