L2 - Cells Flashcards
What is tissue organisation?
How cells are arranged in supportive ECM
What are the three stages of wound healing?
Inflammatory - clear dead cells and remove injury causing agents. Mainly neutrophils and macrophages
Proliferative - new tissue formed, disorganised. Fibroblasts deposit CT
Remodelling - remodelling of new CT
What is the overall healing process?
Cut blood vessels bleed into wound
Clot forms and leuk clean wound
BV regrow and granulation tissue forms
Epithelium regen and scar forms
What is regeneration?
Mild, superficial injury - regrowth of original structure
Define repair
Deeper injury, can’t replace original tissue so scar is formed instead
What happens during fibrous encapsulation?
Tissue response to implanted biomaterials. Implant = damage - abundant deposition of ECM and isolation of biomaterials from local environment
What are some common sources of cells?
Autologous
Allogeneic
Xenogenic
Syn/isogenic
What different stem cells can be used for tissue engineering?
Adult SC - already functioning but limited proliferative capacity
ESC - difficult to source but multipotent
iPSCs - autologous, need to check for function
What is the role of ECM in native tissue?
Structural support, mechanical contributions, send bioactive cues, act as a reservoir of growth factors and potentiates their actions
Scaffolding for ordinary tissue renewal
What are the components of the ECM?
Fibrous structural proteins - collagens and elastins - form bundles
Water hydrated gels - proteoglycans and hyaluronan - form compressive gels
Adhesive glycoproteins - laminin and fibronectin - allow cells to adhere to the ECM
What molecule is mainly responsible for cell adherence?
Integrins
Have EC, TMD and IC domains
Most recognise several ECM pt - redundancy
What sort of activation do integrins undergo?
Confimational activation
Bent = inactive
Extended = active by intrinsic ligand
Clustered = active by extrinsic ligand
What do integrins activate?
Signalling pathways
