FHMP 019 + 020 extracellular matrix and connective tissue histology Flashcards
What are stem cells?
unspecialized cells from which differentiated cells develop
what are the 3 different types of stem cells?
- embryonic stem cells = pluripotent
- adult stem cells =e.g. bone marrow = multipotent
- IPS (induced pluripotent Stem cells = pluripotent
what are the different types of connective tissue?
- connective tissue proper = loose (areolar, adipose, reticular) dense ( regular, irregular, elastic)
- specialised tissue (blood)
- supporting connective tissue (cartilage, bone)
What is the extracellular matrix?
- nonliving material found between cells in connective tissue
- made of collagen, elastic fibres, fibroblasts, reticulum and proteoglycans
what are the 5 types of collagen?
- type 1 = most connective tissues
- type 2 = cartilage
- type 3 = reticular fibres
- type 4 = basement membrane / basal lamina
- type 5 = embryonic tissue
what does type 1 collagen look like?
- collagen type 1 is in long fibres and cross banded (striated)
- if looking from end, looks like dense circles
- often have fibroblasts amongst the fibres
what does type 2 collagen look like?
- dense mesh with chrondrocytes/chrondroblasts
- no blood vessels or nerves
what does type 3 collagen look like?
- use silver stain
- long black hair like fibres
What are elastic fibers?
Networks of long, thin, elastin fibers that allow for stretch and recoil
what is reticulum?
a support network of connective tissue fibers surrounding all organs produced from reticular fibres
What are proteoglycans?
- hyaluronic backbone + glycosaminoglycans (GAGs)
- hydrophilic = attracts water, used to bind water, also resists compression
What are fibroblasts?
cells that secrete fibrous proteins like elastin and collagen
what are the layers of the skin?
- epidermis = top = stratified squamous, keratinised epithelium
- dermis = middle = connective tissue
- hypodermis = bottom = connective tissue and adipocytes
