The fifth lecture in a series for the module Cells and Immunity. This lecture covers cellular adhesion steps, migration for non-adhering cells, chemotaxis and more. A great way to start your understanding of the module or to miss a lecture or two.
Lecture:
Connective tissues (bonded by matrix) vs epithelial (sheets of cells)
Functions that require cell migration
o Cancer metastasis, angiogenesis, wound repair, pregnancy and immunity
Main way of organizing cells in vert tissue
Non-adherent cells use swimming (flagella)
o Faster than adhesion unless in ECM
o Flagella in sperm and protozoa
Axoneme = causes flagella to move bc is bending core
Containing 9 doublet microtubules in a ring around 2 single
microtubules
Dynein binds doublet microtubules and covers circumference
Dynein provides flexibility for movement of flagella
Kartagener’s syndrome = Dynein defect → immobile sperm →
sterility and high chance of chest infections (immotile cilia)
Basal bodies root cilia and flagella into memb
9 fused triplet microtubules in a cartwheel shape
Cilia beat in whip like fashion and in a wave like pattern with other cilia
o Flagella in bacteria
Repeated flagellin subunits make the flagella
Rotate via rotary motor protein in cell wall
Frequently migrating cells
o Immunity cells (macrophages and neutrophils)
o Osteoclasts
o Fibroblasts (connective tissue)
o Cancer
6 steps of migration (driven by EGF)
o 1) Sense (chemokines = directional)
o 2) Extension/protrusion ll (leading edge of PM forward)
Polymerizing + end actin monomers in the cytoskeleton
Branched structure created by Arp2/3 complex at 70֯ angle
o Lower pressure = ↓∆ puncturing
o Capping filaments stop polymerization by stopping adding
actin monomers
Actin = 5-9nm microfilaments
o Mech stiffness and support
o + face direction of movement and – bind to other filaments
in ARP complexes = 2D
o Involved in cell junctions
Adhere junctions anchor actin to connect cells
o ATP bound
o 3 types of protruding actin structures:
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 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 robbieseal. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for £7.99. You're not tied to anything after your purchase.
